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Sunday, August 2, 2026

Gender disparities in health

From Wikipedia, the free encyclopedia

The World Health Organization (WHO) has defined health as "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity." Identified by the 2012 World Development Report as one of two key human capital endowments, health can influence an individual's ability to reach his or her full potential in society. Yet while gender equality has made the most progress in areas such as education and labor force participation, health inequality between men and women continues to harm many societies to this day.

While both males and females face health disparities, women have historically experienced a disproportionate amount of health inequity. This stems from the fact that many cultural ideologies and practices have created a structured patriarchal society where women's experiences are discredited. Additionally, women are typically restricted from receiving certain opportunities such as education and paid labor that can help improve their accessibility to better health care resources. Females are also frequently underrepresented or excluded from mixed-sex clinical trials and therefore subjected to physician bias in diagnosis and treatment.

Definition of health disparity

Health disparity has been defined by WHO as the differences in health care received by different groups of people that are not only unnecessary and avoidable, but also unjust and prejudiced. The existence of health disparity implies that health equity does not exist in many parts of the world. Equity in health refers to the situation whereby every individual has a fair opportunity to attain their full health potential. Overall, the term "health disparities", or "health inequalities", is widely understood as the differences in health between people who are situated in different positions in a socioeconomic hierarchy.

Gender as an axis of difference

Bias against females

The social structures of many countries perpetuate the marginalization and oppression of women in the form of cultural norms and legal codes. As a result of this unequal social order, women are usually relegated to positions where they have less access to and control over healthcare resources, making women more vulnerable to suffering from health problems than men. For example, women living in lower-income areas have acutely restricted protection of their health because they are less likely to have access to tertiary education and employment. As a result, female life expectancy at birth, nutritional well-being, and immunity against communicable and non-communicable diseases, are often lower than those of men.

Bias against males

There are situations in which men tend to fare poorer. One example is lower life expectancy for men in most countries. Another such instance is armed conflicts, where men are often the immediate victims. A study of conflicts in 13 countries from 1955 to 2002 found that 81% of all violent war deaths were male. Apart from armed conflicts, areas with high incidence of violence, such as regions controlled by drug cartels, also see men experiencing higher mortality rates. This stems from social beliefs that associate ideals of masculinity with aggressive, confrontational behavior. Lastly, sudden and drastic changes in economic environments and the loss of social safety nets, in particular social subsidies and food stamps, have also been linked to higher levels of alcohol consumption and psychological stress among men, leading to a spike in male mortality rates. This is because such situations often make it harder for men to provide for their families, a task that has been long regarded as the "essence of masculinity." A retrospective analyses of people infected with the common cold found that doctors underrate the symptoms of men, and are more willing to attribute symptoms and illness to women than men. Women live longer than men in all countries, and across all age groups, for which reliable records exist. In The United States, men are less healthy than women across all social classes. Non-white men are especially unhealthy. Men are over-represented in dangerous occupations and represent a majority of on-the-job deaths. Further, medical doctors provide men with less service, and less advice, and spend less time with men than they do with women per medical encounter.

Bias against intersex people

Another axis of health disparity is within the intersex community. Intersex people are people born with sex characteristics, such as chromosomes, gonads, or genitalia, that do not fit typical binary notions of male and female bodies.

Healthcare of intersex persons is centered around what may be considered "cultural understandings of gender" or the binary system commonly used as gender. Surgeries and other interventions are often used for intersex persons to attempt to physically change their body to conform with one sex. It has been debated whether or not this practice is ethical. Much of this pressure to choose one sex to conform to is socially implemented. Data suggest that children who do not have one gender to conform to may face embarrassment from peers. Parents may also pressure their children to having cosmetic surgery to avoid being embarrassed themselves. Particular ethical concerns come into play when decisions are made on behalf of the child before they are old enough to consent.

Intersex people can face discrimination when seeking healthcare. Laetitia Zeeman of University of Brighton, UK writes, "LGBTI people are more likely to experience health inequalities due to heteronormativity or heterosexism, minority stress, experiences of victimization and discrimination, compounded by stigma. Inequalities of LGBTI health(care) vary depending on gender, age, income, and disability as well as between LGBTI groupings." James Sherer of Rutgers University Medical School also found, "Many well-meaning and otherwise supportive healthcare providers feel uncomfortable when meeting an LGBT patient for the first time due to a general lack of knowledge about the community and the terminology used to discuss and describe its members. Common mistakes, such as incorrect language usage or neglecting to ask about sexual orientation and gender at all, may inadvertently alienate patients and compromise their care."

Types of gender disparities

Male-female sex ratio

Map indicating the human sex ratio by country.
  Countries with more females than males.
  Countries with approximately the same number of males and females.
  Countries with more males than females.
  No data

At birth, boys outnumber girls with the ratio of 105 or 106 male to 100 female children. However, after conception, biology favors women. This is because women, on the whole, are more resistant to diseases and less prone to debilitating genetic conditions. However, the ratio of women to men in developing regions such as South Asia, West Asia, and China can be as low as 0.94, or even lower. This deviation from the natural male-to-female sex ratio has been described by Indian philosopher and economist Amartya Sen as the "missing women" phenomenon. According to the 2012 World Development Report, the number of missing women is estimated to be about 1.5 million women per year, with a majority of the women missing in India and China.

Female mortality

In many developing regions, women experience high levels of mortality. Many of these deaths result from maternal mortality and HIV/AIDS infection. Although only 1,900 maternal deaths were recorded in high-income nations in 2008, India and Sub-Saharan Africa experienced a combined total of 266,000 deaths from pregnancy-related causes. In Somalia and Chad, one in every 14 women dies from causes related to childbirth. However, some countries, such as Kenya, have made great strides in eliminating maternal and neonatal tetanus.

In addition, the HIV/AIDS epidemic also contributes significantly to female mortality. The case is especially true for Sub-Saharan Africa, where women account for 60% of all adult HIV infections.

Health outcome

Women tend to have poorer health outcomes than men for several reasons, ranging from sustaining greater risk to diseases to experiencing higher mortality rates. In the Population Studies Center Research Report by Rachel Snow that compares the disability-adjusted life years (DALY) of both males and females, the global DALYs lost to females for sexually transmitted diseases such as gonorrhea and chlamydia are more than ten times greater than those of the males. Moreover, the female DALYs to male DALYs ratio for malnutrition-related diseases such as Iron-Deficiency Anemia are often close to 1.5, suggesting that poor nutrition impacts women at a much higher level than men. Additionally, in terms of mental illnesses, women are also two to three times more likely than men to be diagnosed with depression.

In developed countries with more social and legal gender equality, overall health outcomes can disfavor men. For example, in the United States, as of 2001, men's life expectancy is 5 years lower than women's (down from 1 year in 1920), and men die at higher rates from all top 10 causes of death, especially heart disease and stroke. Men die from suicide more frequently, though women more frequently have suicidal thoughts and the suicide attempt rate is the same for men and women (see Gender differences in suicide). Men may suffer from undiagnosed depression more frequently, due to gender differences in the expression of emotion. American men are more likely to consume alcohol, smoke, engage in risky behaviors, and defer medical care.

Incidence of melanoma has strong gender-related differences which vary by age.

Women outlive men in 176 countries. Data from 38 countries shows women having higher life expediencies than men for all years both at birth and at age 50. Men are more likely to die from 13 of the 15 major causes of death in the U.S. However, women are more likely to suffer from disease than men and miss work due to illness throughout life. This is called the mortality-morbidity paradox, or Health Survival paradox This is explained by an excess of psychological, rather than physical, distress among women, as well as higher smoking rates among men. Androgens also contribute to the male deficit in longevity.

Access to healthcare

Women tend to have poorer access to healthcare resources than men. In certain regions of Africa, many women often lack access to malaria treatment as well as access to resources that could protect them against Anopheles mosquitoes during pregnancy. As a result of this, pregnant women who are residing in areas with low levels of malaria transmission are still placed at two to three times higher risk than men in terms of contracting a severe malaria infection. These disparities in access to healthcare are often compounded by cultural norms and expectations imposed on women. For example, certain societies forbid women from leaving their homes unaccompanied by a male relative, making it harder for women to receive healthcare services and resources when they need them most.

Gender factors, such as women's status and empowerment (i.e., in education, employment, intimate partner relationships, and reproductive health), are linked with women's capacity to access and use maternal health services, a critical component of maternal health. Still, family planning is typically viewed as the responsibility of women, with programs targeting women and overlooking the role of men—even though men's dominance in decision making, including contraceptive use, has significant implications for family planning and access to reproductive health services.

To promote equity in access to reproductive health care, health programs, and services should conduct analyses to identify gender inequalities and barriers to health, and determine the programmatic implications. The analyses will help inform decisions about how to design, implement, and scale up health programs that meet the differential needs of women and men.

Access to sexual and reproductive healthcare for men is important. Engaging men in sexual and reproductive health helps to decrease their risk-taking behaviors and increase gender equity. However, a scoping review in the Nordic countries has shown that men are facing healthcare difficulties related to sexual and reproductive health.

Causes

Cultural norms and practices

Cultural norms and practices are two of the main reasons why gender disparities in health exist and continue to persist. These cultural norms and practices often influence the roles and behaviors that men and women adopt in society. It is these gender differences between men and women, which are regarded and valued differently, that give rise to gender inequalities as they work to systematically empower one group and oppress the other. Both gender differences and gender inequalities can lead to disparities in health outcomes and access to health care. Some of the examples provided by the World Health Organization of how cultural norms can result in gender disparities in health include a woman's inability to travel alone, which can prevent them from receiving the necessary health care that they need. Another societal standard is a woman's inability to insist on condom use by her spouse or sex partners, leading to a higher risk of contracting HIV.

Son preference

One of the better-documented cultural norms that augment gender disparities in health is the preference for sons. In India, for instance, the 2001 census recorded only 93 girls per 100 boys. This is a sharp decline from 1961, when the number of girls per 100 boys was nearly 98. In certain parts of India, such as Kangra and Rohtak the number of girls for every 100 boys can be as low as in the 70s. Additionally, low female to male numbers have also been recorded in other Asian countries – most notably in China where, according to a survey in 2005, only 84 girls were born for every 100 boys. Although this was a slight increase from 81 during 2001–2004, it is still much lower than the 93 girls per 100 boys in the late 1980s. The increasing number of unborn girls in the late 20th century has been attributed to technological advances that made pre-birth sex determination, also known as prenatal sex discernment, such as the ultrasound test more affordable and accessible to a wider population. This allowed parents who prefer a son to determine the sex of their unborn child during the early stages of pregnancy. By having early identification of their unborn child's sex, parents could practice sex-selective abortion, where they would abort the fetus if it was not the preferred sex, which in most cases is that of the female.

Additionally, the culture of son preference also extends beyond birth in the form of preferential treatment of boys. Economic benefits of having a son in countries like India also explain the preferential treatment of boys over girls. For example, in Indian culture it is the sons who provide care and economic stability to their parents as they age, so having a boy helps to ensure the futures of many Indian families. This preferential care can be manifested in many ways, such as through differential provision of food resources, attention, and medical care. Data from household surveys over the past 20 years has indicated that the female disadvantage has persisted in India and may have even worsened in some other countries such as Nepal and Pakistan.

Female genital mutilation

map
FGM in Africa and Asia, as of 2024 (map of Africa).

Harmful cultural practices such as female genital mutilation (FGM) also cause girls and women to face health risks. Millions of females are estimated to have undergone FGM, which involves partial or total removal of the external female genitalia for non-medical reasons. It is estimated that 92.5 million females over 10 years of age in Africa are living with the consequences of FGM. Of these, 12.5 million are girls between 10 and 14 years of age. Each year, about three million girls in Africa are subjected to FGM.

Often performed by traditional practitioners using unsterile techniques and devices, FGM can have both immediate and late complications. These include excessive bleeding, urinary tract infections, wound infection, and in the case of unsterile and reused instruments, hepatitis and HIV. In the long run, scars and keloids can form, which can obstruct and damage the urinary and genital tracts. According to a 2005 UNICEF report on FGM, it is unknown how many girls and women die from the procedure because of poor record keeping and a failure to report fatalities. FGM may also complicate pregnancy and place women at a higher risk for obstetrical problems, such as prolonged labor. According to a 2006 study by the WHO involving 28,393 women, neonatal mortality increases when women have experienced FGM; an additional ten to twenty babies were estimated to die per 1,000 deliveries.

Psychological complications are related to cultural context. Women who undergo FGM might be emotionally affected when they move outside their traditional circles and are confronted with the view that mutilation is not the norm.

Violence and abuse

National Institute of Health: Among more than 1,400 adult females, childhood sexual abuse was associated with increased likelihood of drug dependence, alcohol dependence, and psychiatric disorders

Violence against women is a widespread global occurrence with serious public health implications. This is a result of social and gender bias. Many societies in developing nations function on a patriarchal framework, where women are often viewed as a form of property and as socially inferior to men. This unequal standing in the social hierarchy has led women to be physically, emotionally, and sexually abused by men, both as children and adults. These abuses usually constitute some form of violence. Although children of both sexes do suffer from physical maltreatment, sexual abuse, and other forms of exploitation and violence, studies have indicated that young girls are far more likely than boys to experience sexual abuse. In a 2004 study on child abuse, 25.3% of all girls surveyed experienced some form of sexual abuse, a percentage that is three times higher than that of boys (8.7%).

Such violence against women, especially sexual abuse, is increasingly being documented in areas experiencing armed conflicts. Presently, women and girls bear the brunt of social turmoil worldwide, making up an estimated 65% of the millions who are displaced and affected. Some of these places which are facing such problems include Rwanda, Kosovo, and the Democratic Republic of the Congo. This comes as a result of both the general instability around the region, as well as a tactic of warfare to intimidate enemies. Often being placed in emergency and refugee settings, girls and women alike are highly vulnerable to abuse and exploitation by military combatants, security forces, and members of rival communities.

The sexual violence and abuse of both young and adult women have both short and long-term consequences, contributing significantly to a myriad of health issues into adulthood. These range from debilitating physical injuries, reproductive health issues, substance abuse, and psychological trauma. Examples of the above categories include depression and post-traumatic stress disorder, alcohol and drug use and dependence, sexually transmitted diseases, lower frequency of certain types of health screenings (such as cervical cancer), and suicide attempts.

Abused women often have higher rates of unplanned and problematic pregnancies, abortions, neonatal and infant health issues, sexually transmitted infections (including HIV), and mental disorders (such as depression, anxiety disorders, sleep disorders and eating disorders) as compared to their non-abused peers. During peacetime, most violence against women is perpetrated by either male individuals whom they know or intimate male partners. An eleven-country study conducted by WHO between 2000 and 2003 found that depending on the country, between 15% and 71% of women have experienced physical or sexual violence by a husband or partner in their lifetime, and 4% to 54% within the previous year. Partner violence may also be fatal. Studies from Australia, Canada, Israel, South Africa and the United States show that between 40% and 70% of female murders were carried out by intimate partners.

Other forms of violence against women include sexual harassment and abuse by authority figures (such as teachers, police officers or employers), trafficking for forced labour or sex, and traditional practices such as forced child marriages and dowry-related violence. At its most extreme, violence against women can result in female infanticide and violent death. Despite the size of the problem, many women do not report their experience of abuse and do not seek help. As a result, violence against women remains a hidden problem with great human and health care costs. Worldwide men account for 79% of all victims of homicide. Homicide statistics by gender

Poverty

Poverty is another factor that facilitates the continual existence of gender disparities in health. Poverty is often directly linked with poor health. However, indirectly it affects factors such as lack of education, resources, and transportation that have the potential to contribute to poor health. In addition to economic constraints, there are also cultural constraints that affect people's ability or likelihood to enter a medical setting. While gender disparities continue prevalent in health, the extent to which it occurs within poor communities often depends on factors like the socioeconomic state of their location, cultural differences, and even age.

Children living in poverty have limited access to basic health needs overall, however, gender inequalities become more apparent as children age. Research done on children under the age of five suggests that in low to middle-income countries, approximately 50% of children living in poverty had access to basic health care. There was also no significant difference between boys and girls in access to healthcare services, such as immunizations and treatment for prevalent diseases such as malaria for both. Research focused on a wider age range, from infancy to adolescence, showed different results. It was found that in developing countries girls had more limited access to care, and if accessed they were likely to receive inferior care to that of boys. Girls in developing countries were also found to be more likely to suffer emotional and physical abuse inflicted by their family and community.

Gender inequalities in health for those living in poverty continue into adulthood. In research that excluded women's health disadvantages (childbirth, pregnancy, susceptibility to HIV, etc.) it was found that there was not a significant gender difference in the diagnosis and treatment of chronic conditions.  In fact, women were diagnosed more, which was attributed to the fact that women had more access to healthcare due to reproductive needs, or from taking their children in for checkups. By contrast, research that was inclusive of women's health disadvantages revealed that maternal health widened the gap between men's and women's health. Poor women in underdeveloped countries were said to be at greater risk of disability and death. The lack of resources and proper nourishment is often a cause of death and contributes to issues of preterm birth and infant mortality, as well as a contributor to maternal mortality. It is estimated that about 800 women die daily from maternal mortality, and most cases are preventable. However, 99% of the cases occur in poverty-ridden regions that lack the resources to access prompt, as well as preventive medical care.

The gendered health differences were slightly different for people living in poverty in wealthier countries. Women were reported to be more low-income than men, and more likely to forgo medical treatment due to financial circumstances. In the United States the Patient Protection and Affordable Care Act (PPACA) made it more possible for more people living in poverty to have access to healthcare, especially for women, however it is argued that the Act also promotes gender inequality because of differences in coverage. Gender-specific cancer screenings, such as for prostate cancer are not covered for men, while similar screenings for women are. At the same time, screenings such as counseling and other services for intimate partner violence are covered for women and not for men. In European countries the results were different than those of people in the United States. While in the United States, poor men had less quality healthcare than women, in European countries men had less access to healthcare. The studies revealed that people, age 50 and over, who struggled to make ends meet (subjective poverty) were 38% more likely to decline in health than those who were considered low income or had low overall wealth. However, men with subjective poverty of the same age group were 65% more likely to die than women, within a 3 to 6-year period.

Healthcare system

Not being listened to is a common experience of women in healthcare

The World Health Organization defines health systems as "all the activities whose primary purpose is to promote, restore, or maintain health". However, factors outside of healthcare systems can influence the impact healthcare systems have on the health of different demographics within a population. This is because healthcare systems are known to be influenced by social, cultural, and economic frameworks. As a result, health systems are regarded as not only "producers of health and health care", but also as "purveyors of a wider set of societal norms and values," many of which are biased against women.

In the Women and Gender Equity Knowledge Network's Final Report to the WHO Commission on Social Determinants of Health in 2007, health systems in many countries were noted to have been unable to deliver adequately on gender equity in health. One explanation for this issue is that many healthcare systems tend to neglect the fact that men's and women's health needs can be very different. In the report, studies have found evidence that the healthcare system can promote gender disparities in health through the lack of gender equity in terms of the way women are regarded – as both consumers (users) and producers (carers) of health care services. For instance, healthcare systems tend to regard women as objects rather than subjects, where services are often provided to women as a means of something else rather on the well-being of women. In the case of reproductive health services, these services are often provided as a form of fertility control rather than as care for women's well-being. Additionally, although the majority of the workforce in health care systems are female, many of the working conditions remain discriminatory towards women. Many studies have shown that women are often expected to conform to male work models that ignore their special needs, such as childcare or protection from violence. This significantly reduces the ability and efficiency of female caregivers providing care to patients, particularly female ones.

Structural gender oppression

Structural gender inequalities in the allocation of resources, such as income, education, health care, nutrition and political voice, are strongly associated with poor health and reduced well-being. Very often, such structural gender discrimination of women in many other areas has an indirect impact on women's health. For example, because women in many developing nations are less likely to be part of the formal labor market, they often lack access to job security and the benefits of social protection, including access to health care. Additionally, within the formal workforce, women often face challenges related to their lower status, where they suffer workplace discrimination and sexual harassment. Studies have shown that this expectation of having to balance the demands of paid work and work at home often gives rise to work-related fatigue, infections, mental ill-health, and other problems, which results in women faring poorer health.

Women's health is also put at a higher level of risk as a result of being confined to certain traditional responsibilities, such as cooking and water collection. Being confined to unpaid domestic labor not only reduces women's opportunities for education and formal job employment (both of which can indirectly contribute to better health in the long run) but also potentially exposes women to a higher risk of health issues. For instance, in developing regions where solid fuels are used for cooking, women are exposed to a higher level of indoor air pollution due to extended periods of cooking and preparing meals for the family. Breathing air tainted by the burning of solid fuels is estimated to be responsible for 641,000 of the 1.3 million deaths of women worldwide each year due to chronic obstructive pulmonary disorder (COPD).

In some settings, structural gender inequity is associated with particular forms of violence, marginalization, and oppression against females. This includes violent assault by men, child sexual abuse, strict regulation of women's behavior and movement, female genital mutilation, and exploitative, forced labor. Women and girls are also vulnerable to less well-documented forms of abuse or exploitation, such as human trafficking or "honor killings" for perceived behavioral transgressions and deviation of their social roles. These acts are associated with a wide range of health problems in women such as physical injuries, unwanted pregnancies, abortions, mental disorders such as depression, and anxiety, substance abuse, and sexually transmitted infections, all of which can potentially lead to premature death.

The ability of women to utilize health care is also heavily influenced by other forms of structural gender inequalities. These include unequal restriction on one's mobility and behavior, as well as unequal control over financial resources. Many of these social gender inequalities can impact the way women's health is regarded, which can in turn determine the level of access women have to healthcare services and the extent by which households and the larger community are willing to invest in women's health issues.

Other axes of oppression

Uninsured Children by Poverty Status, Household Income, Age, Race and Hispanic Origin and Nativity in the United States in 2009

Apart from gender discrimination, other axes of oppression also exist in society to further marginalize certain groups of women, especially those who are living in poverty or of minority status in which they live.

Race and ethnicity

Race is a well-known axis of oppression, where people of color tend to suffer more from structural violence. For people of color, race can serve as a factor, in addition to gender, that can further influence one's health negatively. Studies have shown that in both high-income and low-income countries, levels of maternal mortality may be up to three times higher among women of disadvantaged ethnic groups than among white women. In a study on race and mother death within the US, the maternal mortality rate for African Americans is close to four times higher than that of white women. Similarly in South Africa, the maternal mortality rate for black/African women and women of color is approximately 10 and 5 times greater respectively than that of white/European women.

Socioeconomic status

Although women around the world share many similarities in terms of health-impacting challenges, there are also many distinct differences that arise from their varying states of socioeconomic conditions. The type of living conditions in which women live is largely associated with not only their own socioeconomic status but also that of their nation.

At every single age category, women in high-income countries tend to live longer and are less likely to suffer from ill health and premature mortality than those in low-income countries. Death rates in high-income countries are also very low among children and younger women, where most deaths occur after the age of 60 years. In low-income countries, however, the death rates at young ages are much higher, with most deaths occurring among girls, adolescents, and younger adult women. Data from 66 developing countries show that child mortality rates among the poorest 20% of the population are almost double those in the top 20%. The most striking health outcome difference between rich and poor countries is maternal mortality. Presently, an overwhelming proportion of maternal mortality is concentrated within the nations that are suffering from poverty or some other form of humanitarian crises, where 99% of the more than half a million maternal deaths every year occur. This comes from the fact that institutional structures that could protect women's health and well-being are either lacking or poorly developed in these places.

The situation is similar within countries as well, where the health of both girls and women is critically affected by social and economic factors. Those who are living in poverty or of lower socioeconomic status tend to perform poorly in terms of health outcomes. In almost all countries, girls and women living in wealthier households experience lower levels of mortality and higher usage of healthcare services than those living in poorer households. Such socioeconomic status-related health disparities are present in every nation globally, including developed regions.

Environmental Injustice

Environmental injustice at its core is the presence of distributional injustice including both the distribution of decision-making power as well as the distribution of environmental burden. Environmental burdens, which include water pollution, toxic chemicals, etc., can disproportionately impact the health of women. Women are often left out of policy-making and decisions. These injustices occur because women are generally affected by the intersectionality of oppression which leads to lower incomes and less social status. The Root cause of these injustices is the fundamental presence of gender inequality, particularly in marginalized communities (Indigenous women, women from low-income communities, women from the Global South, etc.) that will become amplified by climate change. These women are often reliant on natural resources for their livelihoods and, therefore, are one of the first groups of people to be severely impacted by global climate change and environmental injustice. In addition, women all around the world are held responsible for providing food, water, and care to their families. This has sparked a movement to make the literature, research, and teaching more gender aware in the sphere of feminism.

However, women continue to face oppression in the sphere of media. CNN and Media Matters have reported that only 15% of those interviewed in the media on climate change have been women. Comparatively, women make up 90% of environmental justice groups across the United States. UN climate chief Christiana Figueres has publicly recognized gender disparity in environmental injustice and has pledged to put gender at the center of the Paris talks on climate change. "Women are disproportionately affected by climate change. It is increasingly evident that involving women and men in all decision-making on climate action is a significant factor in meeting the climate challenge". Studies have shown that women's involvement and participation in policy leadership and decision-making has led to a greater increase in conservation and climate change mitigation efforts.

When we analyze root causes, it is clear that women experience climate change with disproportionate severity precisely because their basic rights continue to be denied in varying forms and intensities across the world. Enforced gender inequality reduces women's physical and economic mobility, voice, and opportunity in many places, making them more vulnerable to mounting environmental stresses. Indigenous pregnant women and their unborn children are more vulnerable to climate change and health impacts by way of environmental injustice. Indigenous women, women from low-income communities, and women from the Global South bear an even heavier burden from the impacts of climate change because of the historic and continuing impacts of colonialism, racism and inequality; and in many cases, because they are more reliant upon natural resources for their survival and/or live in areas that have poor infrastructure. Drought, flooding, and unpredictable and extreme weather patterns present life-or-death challenges for many women, who are most often the ones responsible for providing food, water, and energy for their families.

Gender bias in clinical trials

Gender bias is prevalent in medical research and diagnosis. Historically, women were excluded from clinical trials, which affects research and diagnosis. Throughout clinical trials, Caucasian males were the normal test subjects and findings were then generalized to other populations. Women were considered more expensive and complicated clinical trial subjects because of variable hormone levels that differ significantly from men's. Specifically, pregnant women were considered an at-risk population and thus barred from participation in any clinical trials.

In 1993, the U.S. Food and Drug Administration (FDA) published "Guidelines for the Study and Evaluation of Gender Differences in the Clinical Evaluation of Drugs", overwriting the 1977 decision to bar all pregnant women from clinical trials. Through this, they recommended that women be included in clinical trials to explore differences in the sexes, specifying that the population included in clinical trials should be indicative of the population to whom the drug would be prescribed. This mandated the inclusion of female participants in clinical trials sponsored by the National Institutes of Health (NIH). The FDA's 1998 "Presentation of Safety and Effectiveness Data for Certain Subgroups of the Population in Investigational New Drug Application Reports and New Drug Applications" regulations mandated that drug trials prove safety and efficacy in both sexes to gain FDA approval and led to drugs being taken off the market due to adverse effects on women that had not been appropriately studied during clinical trials. Several more recent studies determined in hindsight that many federally funded studies from 2009 included a higher percentage of female participants but did not include findings specified between males and females.

In 1994, the FDA established an Office of Women's Health, which promotes that sex as a biological variable should be explicitly considered in research studies. The FDA and NIH have several ongoing formal efforts to improve the study of sex differences in clinical trials, including the Critical Path Initiative, which uses biomarkers, advanced technologies, and new trial designs to better analyze subgroups. Another initiative, Drug Trial Snapshots, offers transparency to subgroup analysis via a consumer-focused website. However, despite such work, women are less likely to be aware of or to participate in clinical trials.

Although the inclusion of women in clinical trials is now mandated, there is no such mandate for the use of female animal models in non-human research. Typically, male models are used in non-human research and results are generalized to females. This can complicate diagnosis. A 2011 review article examined sex bias in biomedical research and found that while sex bias has decreased in human clinical trials, particularly since the US National Institute of Health Revitalization Act of 1993, sex bias has increased in non-human studies. Additionally, studies often fail to analyze results by sex specifically. Another example of this is the thalidomide epidemic. In the late 1950s thalidomide was prescribed to pregnant women to treat morning sickness. Its use unexpectedly resulted in severe birth defects in over 10,000 children. However, proper studies were not conducted to determine adverse effects in women, specifically those who are pregnant and it was determined that mice, the animal model used to test thalidomide, were less sensitive to it than humans.

Gender bias in diagnosis

A 2018 literature review of 77 medical articles found gender bias in the patient-provider encounter as it related to pain. Their findings confirmed a pattern of expectations and treatment differences between men and women, "not embedded in biological differences but gendered norms." For example, women with pain were viewed as "hysterical, emotional, complaining, not wanting to get better, malingerers, and fabricating the pain, as if it is all in her head." Women suffering from chronic pain are often erroneously attributed psychological rather than somatic causes for their pain by physicians. And in searching for the effect on pain medication given to men and women, studies determined that women received less effective pain relief, less opioid pain medication, more antidepressants, and more psychiatric referrals.

Chronic pain disproportionately affects women, with 70% of chronic pain sufferers being female. While women are more likely to experience chronic pain, 80% of pain studies are conducted on male subjects. One study on gender differences in pain found that women tend to experience pain more intensely and more frequently than men. Even so, men are given more aggressive treatments and higher doses or stronger painkillers than women.

Management

The Fourth World Conference on Women asserts that men and women share the same right to the enjoyment of the highest attainable standard of physical and mental health. However, women are disadvantaged due to social, cultural, political and economic factors that directly influence their health and impede their access to health-related information and care. In the 2008 World Health Report, the World Health Organization stressed that strategies to improve women's health must take full account of the underlying determinants of health, particularly gender inequality. Additionally, specific socioeconomic and cultural barriers that hamper women in protecting and improving their health must also be addressed.

Gender mainstreaming

Training rural women in Oral Health Promotion activities in Nepal

Gender mainstreaming was established as a major global strategy for the promotion of gender equality in the Beijing Platform for Action from the Fourth United Nations World Conference on Women in Beijing in 1995. Gender mainstreaming is defined by the United Nations Economic and Social Council in 1997 as follows:

"Mainstreaming a gender perspective is the process of assessing the implications for women and men of any planned action, including legislation, policies or programmes, in all areas and at all levels. It is a strategy for making women's as well as men's concerns and experiences an integral dimension of the design, implementation, monitoring, and evaluation of policies and programmes in all political, economic, and societal spheres so that women and men benefit equally and inequality is not perpetuated. The ultimate aim is to achieve gender equality".

Over the past few years, "gender mainstreaming" has become a preferred approach for achieving greater health parity between men and women. It stems from the recognition that while technical strategies are necessary, they are not sufficient in alleviating gender disparities in health unless the gender discrimination, bias and inequality that in organizational structures of governments and organizations – including health systems – are being challenged and addressed. The gender mainstreaming approach is a response to the realisation that gender concerns must be dealt with in every aspect of policy development and programming, through systematic gender analyses and the implementation of actions that address the balance of power and the distribution of resources between women and men. In order to address gender health disparities, gender mainstreaming in health employs a dual focus. First, it seeks to identify and address gender-based differences and inequalities in all health initiatives; and second, it works to implement initiatives that address women's specific health needs that are a result either of biological differences between women and men (e.g. maternal health) or of gender-based discrimination in society (e.g. gender-based violence; poor access to health services).

Sweden's new public health policy, which came into force in 2003, has been identified as a key example of mainstreaming gender in health policies. According to the World Health Organization, Sweden's public health policy is designed to address not only the broader social determinants of health but also the way in which gender is woven into the public health strategy. The policy specifically highlights its commitment to address and reduce gender-based inequalities in health.

Female Empowerment

The United Nations has identified the enhancement of women's involvement as a way to achieve gender equality in the realm of education, work, and health. This is because women play critical roles as caregivers, formally and informally, in both the household and the larger community. Within the United States, an estimated 66% of all caregivers are female, with one-third of all female caregivers taking care of two or more people. According to the World Health Organization, it is important that approaches and frameworks that are being implemented to address gender disparities in health acknowledge the fact that majority of the care work is provided by women. A meta-analysis of 40 different women's empowerment projects found that increased female participation have led to a broad range of quality of life improvements. These improvements include increases in women's advocacy demands and organization strengths, women-centered policy and governmental changes, and improved economic conditions for lower class women.

In Nepal, a community-based participatory intervention to identify local birthing problems and formulate strategies is effective in reducing both neonatal and maternal mortality in a rural population. Community-based programs in Malaysia and Sri Lanka that used well-trained midwives as front-line health workers also produced rapid declines in maternal mortality.

International states of gender disparities in health

South-East Asia region

Women in South-East Asia often find themselves in subordinate positions of power and dependency on their male counterparts regarding cultural, economic, and societal relations. Because there is a limited level of control and access granted to women in this region, the capability of daughters to counteract generational biases regarding gender-specific roles is highly limited. In contrast to many other industrialised countries, life expectancy is equal or shorter for women in this region, with the probability of surviving the first five years of life for women equal to or smaller than that of males.

A potential explanation as to why there are disparate differences in health status and access between genders is due to an unbalanced sex ratio-for example, the Indian subcontinent has a ratio of 770 women per 1000 men. Neglect of female children, limited or poor access to health care, sex-selective abortions, and reproductive mortality are all additional reasons why there is a severe inequity between genders. Education and increased socioeconomical independency is projected to assist in the leveling of healthcare access between the genders, but there are sociocultural circumstances and attitudes concerning the prioritization of males over females that stagnate progress. Sri Lanka has repeatedly been identified as a role model of sorts for other nations within this region, as there are minimal differences in health, educational, and employment levels between genders.

European Region

According to the World Health Organization (WHO) gender discrimination in relation to lack of access, and provision of health in this region is supported by concrete survey data. In the European Region, 1 in 5 women have been domestic violence victims, while honour killings, female genital mutilation, and bride kidnapping still occur. Additional studies done by the WHO have found that immigrant women face a 43% higher risk of having an underweight child, a 61% greater risk of having a child with congenital malformations, and a 50% higher chance of perinatal mortality. In European countries, women make up the majority of those unemployed, earning an average of 15% less than men while 58% were observed to be unemployed. Differences in wages are even greater in the Eastern part of the region, as represented in the comparison of wages between women (4954 US dollars) in Albania versus men (9143 US dollars.)

Eastern Mediterranean Region

Access to education and employment are key elements in achieving gender equality in health. Female literacy rates in the Eastern Mediterranean were found by the WHO to fall sharply behind their male counterparts, as evident in the cases of Yemen (66:100) and Djibouti (62:100.) Further barriers other than the prioritization of providing opportunities for males, include the inability for females in this region to pursue anything more than a tertiary education because of economic constraints. Contraceptive usage and knowledge of reproductive options were found to be more present amongst women who had received higher levels of education in Egypt, the rate of contraceptive usage being 93% among those who were university-educated versus illiterate.

In regards to the influence of employment upon a woman's capability to know of and fight for equity in health care, in this region, women were found by the WHO to participate less in the labor market than in other regions (at an average of 28%.) The lowest number of women in paid employment within this region was found in Saudi Arabia and other countries of the Gulf Cooperation Council (GCC), while the highest number of women with paid employment were in Morocco, Lebanon, and Yemen.

The lack of availability of health care services in this region particularly complicates matters as certain countries are already strained by ongoing conflict and war. According to WHO, the ratio of physicians per population is drastically lower in the countries Sudan, Somalia, Yemen, and Djibouti, while health infrastructures are nearly nonexistent in Afghanistan. With additional complications of distance to and from medical services, the access to health care services is even more complex for women in this region as the majority are unable to afford the transportation costs or time.

Western Pacific Region

Gender-based division of labor in this region has been observed by the WHO as reason for the differences in health risks that the two genders are exposed to in contrast to one another. Most commonly, women of this region are engaged in insecure and informal forms of labor, therefore being unable to gain related benefits such as insurance or pension. In regards to education, the gap between males and females is relatively small in primary and secondary schools, however, there is undeniably an uneven distribution of literacy rates between the various countries within this region. According to the WHO substantial differences in literacy rates between men and women exist particularly in Papua New Guinea (55.6% for women and 63.6% for men) and Lao People's Democratic Republic (63.2% for women and 82.5% for men.)

Brain health and pollution

From Wikipedia, the free encyclopedia

The effects of pollution on the brain are felt throughout the lifespan. Prenatal exposure to pollution is associated with an increased risk of negative fetal outcomes, including central nervous system damage and developmental delays. Exposure to pollution can lead to neurodevelopmental disorders involving brain development, cognitive function, intellectual development, and emotional and behavioral regulation, often becoming apparent during childhood or adolescence (e.g. ADHD, autism). Pollution is also linked to mental health outcomes that are commonly diagnosed in adolescence or adulthood such as schizophrenia, neuroticism, depression, anxiety, and suicide. Pollution is associated with neurological conditions such as migraines and stroke and neurodegenerative disorders such as multiple sclerosisAlzheimer's diseaseParkinson's disease, and dementia.

Pollutants can be inhaled, eaten, drunk, or absorbed through skin. The criteria air pollutants sulfur dioxide, nitrogen dioxide, particulate matter, carbon monoxide, ozone, and lead have been identified as harmful to human health by the World Health Organization and the U.S. Environmental Protection Agency (EPA). Many of them are linked to the burning of fossil fuels, through vehicle use, heating and cooking. Substances in air pollution that have negative effects on the central nervous system (CNS) include particulate matter, dioxins, and heavy metalsIndoor and outdoor air pollution can also contain endocrine-disrupting chemicals and microplastics that have negative effects on the central nervous system. Neurotoxicity is mediated by processes such as oxidative stress, mitochondrial dysfunction, and neuroinflammationPollutants such as ozone and microplastics can affect the neurophysiology of individuals after the structure of the CNS has become mostly stabilized, an example of neuroplasticity.

Environmental pollution is a potentially preventable contributor to disease burden. Steps can be taken to minimize exposures to pollutants such as avoiding smoking, minimizing dust, using glass instead of plastics, carefully selecting cleaning products and cosmetics, and exercising away from heavy traffic routes. Control strategies can also be implemented to improve industrial safety and public health.

Pollutants

Air pollution is a complex mixture that includes solids, liquids and gases. Particulate matter is made up of tiny particles of solid or liquid matter suspended in air. Air pollution can result both from natural causes such as sea spray or desert dust and from human activities such as smoke from fires, first and second-hand tobacco and cannabis smoke, and automobile exhaust fumes from fossil fuel combustion.

Particulate matter

Airborne particulate matter is a Group 1 carcinogen. Particulates are the most harmful form (other than ultra-fines) of air pollution as they can penetrate deep into the lungs and brain from blood streams, causing health problems such as heart disease, lung disease, and premature death. There is no safe level of particulates. Ultrafine particles are both manufactured and naturally occurring. Hot volcanic lava, ocean spray, and smoke are common natural UFPs sources. UFPs can be intentionally fabricated as fine particles to serve a vast range of applications in both medicine and technology. Other UFPs are byproducts, like emissions, from specific processes, combustion reactions, or equipment such as printer toner and automobile exhaust. Anthropogenic sources of UFPs include combustion of gas, coal or hydrocarbons, biomass burning (i.e. agricultural burning, forest fires and waste disposal), vehicular traffic and industrial emissions, tire wear and tear from car brakes, air traffic, seaport, maritime transportation, construction, demolition, restoration and concrete processing, domestic wood stoves, outdoor burning, kitchen, and cigarette smoke.

While hand-held power tools are very helpful (e.g., in renovation and construction), they also produce large amounts of vibrations and particulates (particulate matter), including ultrafine particles, from both fuel combustion and the mechanical tasks. Not only power tools, hand tools also generate UFPs.

Many construction tasks create dust. High dust levels are caused by one of more the following:

  • equipment – using high energy tools, such as cut-off saws, grinders, wall chasers and grit blasters produce a lot of dust in a very short time
  • work method – dry sweeping can make a lot of dust when compared to vacuuming or wet brushing
  • work area – the more enclosed a space, the more the dust will build up
  • time – the longer one works the more dust there will be

Examples of high dust level tasks include:

  • using power tools to cut, grind, drill or prepare a surface
  • sanding taped plaster board joints
  • dry sweeping

Currently there seems to be no or little regulations on the size and amount of dust emitted by power tools. Some industry standards do exist, though it appears that they are not widely known or used globally. Knowing that dust is generated throughout the construction process and can cause serious health hazards, manufacturers are now marketing power tools that are equipped with dust collection system (e.g. HEPA vacuum cleaner) or integrated water delivery system which extract the dust after emission. However, the use of such products is still not common in most places. As Q1 2024 petrol powered tools are banned in California.

Dioxins

Organohalogen compounds, such as dioxins, are commonly found in pesticides or created as by-products of pesticide manufacture or degradation. These compounds can have a significant impact on the neurobiology of exposed organisms. Some observed effects of exposure to dioxins are altered astroglial intracellular calcium ion (Ca2+), decreased glutathione levels, modified neurotransmitter function in the CNS, and loss of pH maintenance. A study of 350 chemical plant employees exposed to a dioxin precursor for herbicide synthesis between 1965 and 1968 showed that 80 of the employees displayed signs of dioxin poisoning. The study suggested that the effects of dioxins were not limited to initial toxicity. Dioxins, through neuroplastic effects, may cause long-term damage that may not manifest itself for years or even decades.

Heavy metals

Heavy metal exposure can result in an increased risk of various neurological diseases. Among the most neurotoxic heavy metals are mercury, lead, and cadmium. Mercury and lead are particularly neurotoxic for many reasons: they easily cross cell membranes, have oxidative effects on cells, react with sulfur in the body (leading to disturbances in the many functions that rely upon sulfhydryl groups), and reduce glutathione levels inside cells. Methylmercury, in particular, has an extremely high affinity for sulfhydryl groups. Organomercury is a particularly damaging form of mercury because of its high absorbability Lead also mimics calcium, a very important mineral in the CNS, and this mimicry leads to many adverse effects. Mercury's neuroplastic mechanisms work by affecting protein production. Elevated mercury levels increase glutathione levels by affecting gene expression, and this in turn affects two proteins (MT1 and MT2) that are contained in astrocytes and neurons.

Lead's ability to imitate calcium allows it to cross the blood–brain barrier. Lead also upregulates glutathione. Blood lead concentrations ≥ 5·0 μg/dL could result in children scoring 3–5 points lower in intelligence tests than those with the concentrations < 5·0 μg/dL . Higher blood lead concentrations are also associated with serious cognitive function losses. "Lead-related IQ losses are associated with increased rates of school failure, behavioural disorders, diminished economic productivity, and global economic losses of almost $1 trillion annually."

Effects across the lifespan

Potential particle pathways as of 2018.

Prenatal effects

Research has consistently shown that exposure to pollutants can affect fertility, fetal development, health of offspring in later life, and the genetics of future generations. Potential mechanisms of action by toxic environmental chemicals include oxidative stress, inflammation, changes in placental function, endocrine disruption and genetic alterations. Components of air pollution such as polycyclic aromatic hydrocarbons (PAHs) can negatively affect fetal brain development, with impacts on cognition and behavior.

Autism

Heavy metal exposure, when combined with certain genetic predispositions, can place individuals at increased risk for developing autism. Many examples of CNS pathophysiology, such as oxidative stress, neuroinflammation, and mitochondrial dysfunction, could be by-products of environmental stressors such as pollution, as found in a 2010 study.

Early-life exposure to air pollution may be a risk factor for autism. Children of mothers living near a freeway, and traffic-related pollution, during the third trimester of pregnancy were twice as likely to develop ASD. A distance of 1,014 feet, or a little less than 3.5 football fields, was considered near a freeway. Children with a mutation in a gene called MET, combined with high levels of exposure to air pollution, may have increased risk.

Prenatal and early childhood exposure to heavy metals, like mercury, lead, or arsenic; altered levels of essential metals like zinc or manganese; pesticides; and other contaminants cause concern. A study of twins used baby teeth to determine and compare levels of lead, manganese, and zinc in children with autism to their twin without the condition. Autistic children were low on manganese and zinc, metals essential to life, but had higher levels of lead, a harmful metal during specific developmental time periods studied. Altered zinc-copper cycles, which regulate metal metabolism in the body, are disrupted in ASD cases.

Maternal exposure to insecticides during early pregnancy was associated with higher risk of autism in their children. Contaminants such as Bisphenol A, phthalates, flame retardants, and polychlorinated biphenyls are also being studied.

Effects in adolescents

A 2008 study compared children and dogs raised in Mexico City (a location known for high pollution levels) with children and dogs raised in Polotitlán, Mexico (a city whose pollution levels meet the current US National Ambient Air Quality Standards). Children raised in areas of higher pollution were found to score lower in intelligence (i.e., on IQ tests), and showed signs of lesions in MRI scanning of the brain. In contrast, children from the low pollution area scored as expected on IQ tests and showed no significant sign of the risk of brain lesions.

Effects in adults

Schizophrenia

Exposure to air pollution may be associated with elevated risk of schizophrenia.

Epilepsy

Multiple air pollutants are probably associated with the risk of epilepsy, e.g., carbon monoxide, ozone, sulfur dioxide, nitrogen dioxide, large particulate matter, and fine particulate matter. It was hypothesized that air pollutants increase epilepsy risk by increasing inflammatory mediators, and by providing a source of oxidative stress, eventually altering the blood–brain barrier's function and cause brain inflammation. Brain inflammation is known to be a risk factor for epilepsy; thus, the sequence of events provides a plausible mechanism by which pollution may increase epilepsy risk in individuals who are genetically vulnerable to the disease.

Neurodegenerative disorders

Accelerated neural aging

Neuroinflammation is associated with increased rates of neurodegeneration. Inflammation tends to increase naturally with age. By facilitating inflammation, pollutants such as air particulates and heavy metals cause the CNS to age more quickly. Many late-onset diseases are caused by neurodegeneration. Multiple sclerosis, Parkinson's disease, amyotrophic lateral sclerosis (ALS), and Alzheimer's disease are all believed to be exacerbated by inflammatory processes, resulting in individuals displaying signs of these diseases at an earlier age than is typically expected.

Multiple sclerosis occurs when chronic inflammation leads to the compromise of oligodendrocytes, which in turn leads to the destruction of the myelin sheath. Then axons begin exhibiting signs of damage, which in turn leads to neuron death. Multiple sclerosis has been correlated to living in areas with high particulate matter levels in the air.

According to Lancet (2021), exposure to "environmental pollution with toxins, such as pesticides (eg, paraquat) or chemicals (eg, trichloroethylene), known to be harmful to Parkinson's disease-related neurons and brain circuits," is associated with Parkinson's disease. Multi-decade studies have identified an increased likelihood of Parkinson's in association with agricultural work, pesticide exposure, and rural habitation. Chlorinated solvents, used in commercial and industrial application like dry cleaning and degreasing, are associated with increased PD risk, particularly trichloroethylene. Other chemical risk factors include manganese, suspended particles from traffic fumes, and exposure to other heavy metals such as mercury and lead.

In the case of Alzheimer's disease, inflammatory processes lead to neuron death by inhibiting growth at axons and activating astrocytes that produce proteoglycans. This product can only be deposited in the hippocampus and cortex, indicating that this may be the reason these two areas show the highest levels of degeneration in Alzheimer's disease. Tiny particles (e.g., engineered nanoparticles and combustion nanoparticle emissions, also called nanomaterials, including those containing manganese) can bypass the blood-brain barrier (the body's filtering system) and enter the brain as they are breathed in.

Cognitive decline and dementia

Exposure to air pollution was positively associated with an increased risk of stroke hospital admission (PM2.5, PM10, SO2, NO2, CO, and O3), incidence (PM2.5, SO2, and NO2), and mortality (PM2.5, PM10, SO2, and NO2). There is a "well-recognized link between PM2.5 and vascular injury and the role of vascular injury in dementia". Air pollution in the cerebrovascular system may result in "stroke, vascular dementia, or other types of dementia". The risk of dementia, including Alzheimer's disease and vascular dementia, may be increased by long-term exposure to PM2.5.

Interest in the possible effects of air pollutants on the brain began in about 2002 when Calderon-Garciduenas and colleagues reported that dogs exposed to air pollution in Mexico City showed neuropathological changes of the type associated with Alzheimer's disease. This work was an extension of studies undertaken in the 1990s on the effects of Mexico City air pollution on the olfactory epithelium of humans and dogs. Later, interest in possible effects on the brain has been strengthened by epidemiological studies, which suggest that exposure to air pollutants is associated with a decline of cognitive function and the development of dementia.

Magnetite nanoparticles have been found in the brain with a morphology that suggests an exogenous origin. Similar ferrous nanoparticles were found in air collected at traffic roadsides in the UK. These nanoparticles may be able to reach the brain via the olfactory nerves and olfactory bulb, or via the circumventricular organs where the blood-brain barrier is more permeable. In addition, the blood-brain barrier could be made less impermeable by systemic inflammation for which exposure to air pollutants is a known risk factor. The blood-brain barrier is also more permeable in the very young and old, making these two life stages opportunities for the entry of nanoparticles into the brain, and potential elicitation of neurological damage.

In addition to the possible direct effects from nanoparticles reaching the brain, there are indirect mechanisms by which pollutants could potentially lead to brain injury. These include damage to the vasculature, leading to cerebral ischaemia or extravasation of neurotoxic proteins such as fibrinogen. Brain injury could also be secondary to systemic inflammatory responses to air pollution.

Calderon-Garciduenas et al. reviewed their work in children and youngsters in Mexico City and reported neuropathological changes in children and young adults similar to those in Alzheimer's disease. There was increased neuro-inflammation and vascular damage: upregulated mRNA cyclooxygenase-2, interleukin-1β and CD14, and clusters of mononuclear cells around blood vessels and activated microglia in the frontal and temporal cortex, subiculum and brain stem. They also found deposits of amyloid-β42, α-synuclein, hyperphosphorylated tau, and evidence of oxidative stress, neuronal damage and death. Children in Mexico City (with high levels of air pollution) also had low serum BDNF concentrations.

Studies of white matter volume found associations between exposure to air pollution and reduced white matter volume. Evidence suggests that long-term exposure to air pollutants is associated with cognitive decline and with the risk of development of dementia. There is epidemiological evidence suggestive of a causal association between exposure to a range of air pollutants and a number of effects on the nervous system including the acceleration of cognitive decline and the induction of dementia.

Dementia is an umbrella term for a range of conditions that affect how the brain works, reducing the ability to remember, think and reason. It mainly affects older people and gets worse over time. Health and lifestyle factors such as high blood pressure and smoking are known to increase the risk of developing dementia.

The Committee on the Medical Effects of Air Pollutants (COMEAP) in UK have reviewed nearly 70 studies in human populations (epidemiological studies) and think it is likely that air pollution can contribute to a decline in mental ability and dementia in older people. It is known that air pollution, particularly small particle pollution, can affect the heart and the circulatory system, including circulation to the brain. These effects are linked to vascular dementia (a form of dementia), which is caused by damage to the blood vessels in the brain. Therefore, it is likely that air pollution contributes to mental decline and dementia caused by effects on the blood vessels. Air pollution might also stimulate the immune cells in the brain, which can then damage nerve cells.

In 2022, COMEAP has concluded that the evidence is suggestive of an association between ambient air pollutants and an acceleration of the decline in cognitive function often associated with ageing, and with the risk of developing dementia. There are a number of plausible biological mechanisms by which air pollutants could cause effects on the brain leading to accelerated cognitive decline and dementia. Some of these have been demonstrated in experimental studies. There is a strong case for the effects of air pollutants on the cardiovascular system having a secondary effect on the brain. COMEAP has already concluded that long-term exposure to air pollutants damages the cardiovascular system (COMEAP 2006, 2018). It is likely that such effects have an effect on the blood supply to the brain. That such an effect might well lead to damage to the brain seems likely. Therefore it is regarded that the association between exposure to air pollutants and effects on cognitive decline and dementia as likely to be causal with respect to this mechanism.

A number of mechanisms have been suggested by which air pollutants could have direct effects on the brain. These include the translocation of small particles from the lung to the blood stream and thence to the brain. The evidence suggests that a small proportion of very small particles that are inhaled can enter the brain, both from the blood and via the olfactory nerves leading from the nasal passages to the olfactory bulbs. What is much less clear is whether exposure to ambient concentrations of particulate material results in sufficient translocation to produce damage to the brain. Study of the literature has suggested that particles which enter the brain are cleared from the brain only slowly, if at all. This is clearly a point in favour of the suggestion that particulate material which does enter the brain might produce detrimental effects. Animal and in vitro studies of ultrafine particulate material, diesel engine exhaust or ozone have all shown effects on the brain or brain cells. The mechanisms involved include the generation and release of free radicals within the brain and the induction of an inflammatory response; these 2 mechanisms seem likely to be linked. A number of common pollutants may affect brain function.

COMEAP concluded that:

  • The epidemiological evidence is suggestive of an association between exposure to ambient air pollutants and both the risk of developing dementia and acceleration of cognitive decline. The epidemiological literature is inconsistent as to which pollutant is most associated with these effects.
  • There is evidence that air pollution, particularly particulate air pollution, increases the risk of cardiovascular, including cerebrovascular, disease. These diseases are known to have adverse effects on cognitive function. There is likely to be a causal association between particulate air pollution and effects on cognitive function in older people.
  • As of 2022, direct quantification of cognitive decline or dementia associated with air pollution would be subject to unknown uncertainty.
  • It may be possible to develop an indirect method of quantification of cognitive effects secondary to the effects of particulate pollution on cardiovascular disease.

Economics

Dementia

Dementia is a pressing public health challenge. Its prevalence is strongly age-related: doubling every 5–6 years over the age of 65 years. The number of people living with dementia worldwide is estimated at 50 million and expected to reach 152 million by 2050. Its current economic cost worldwide is US$818 billion/year (as of 2015) and it will rise in proportion to the numbers affected (WHO, 2019).

Mitigations

Environmental pollution is a potentially preventable contributor to disease burden. On an individual level, steps can be taken to minimize exposures to pollutants such as avoiding smoking, minimizing dust, using glass instead of plastics, carefully selecting cleaning products and cosmetics, and avoiding idling vehicles and heavy traffic routes. Exposure to air pollutants may be lessened by staying away from places that have high levels of pollution, avoiding cross-contamination or secondary contamination (between persons and their personal belongings/environment), better personal hygiene, use of face masks and air purifiers, etc.

Control strategies can be implemented to improve industrial safety and public health. Urban planning can keep sources of pollutants away from residents and improve conditions. For point-source pollution: Do not produce the pollutants. If produced, remove at source as soon as possible. If not removed at source, use barriers. If barriers do not work well or not installed properly (i.e., pollutants escaped), neighbors need filtration, sealing, or proper ventilation / pollutant dilution, etc. for their premises. Large scale air cleaning system may also help as a passive measure. Clean-up programmes may be needed to prevent further secondary contamination or pollution.

At local, state and national governmental levels, policies can be established and regulatory and cleanup activities can be taken to minimize population exposures to pollution. Governments can participate in international agreements to reduce air pollution, increase use of renewable energy and clean fuels, and support the use of low- or no-pollution vehicles such as electric cars. The most frequently used policy initiatives are directed at the transportation sector. In countries where air pollution control measures have been enacted, most cases have resulted in positive outcomes.

Personal activities

Air-purifiers with air flow generated by bladeless fan.

Recommendations for personal strategies to minimise the effects of air pollution have been developed based on scientific research. To minimize personal exposure to indoor pollution:

  • Reduce sources of household air pollution including both first- and second-hand smoke. Avoid tobacco, marijuana, and vaping.
  • Use clean fuels for heating and cooking rather than solid fuels, ventilate well, and use nonpolluting cooking stoves if possible.
  • Use portable air cleaners to improve ventilation (e.g. Portable air cleaners fitted with HEPA filters).
  • Eat a healthy, balanced diet high in fruits and vegetables and low in fats.
  • Remove and minimize dust: remove shoes when entering a house and use damp mops rather than dry sweeping when cleaning.
  • Use glass instead of plastics and avoid plastic packaging.
  • Carefully select cleaning products and cosmetics to avoid harmful ingredients.

To minimize personal exposure to outdoor (ambient) pollution:

  • Be aware of local air pollution levels using information from local air quality forecasts and maps.
  • Wear close-fitting facemasks (e.g. N95 or KN95) when ambient air pollution levels are high.
  • Exercise regularly but mimimise outdoor activity when ambient air pollution levels are high.
  • When possible, cycle or walk rather than using motorised fossil-fuel driven vehicles, to obtain the benefit of exercise and to minimize contributions to pollution.
  • Choose low-traffic routes and routes with open spaces to minimise near-road air pollution exposure. Minimise travel at peak times, and avoid waiting in areas of high air pollution.
  • Share rides and use public transportation.
  • Optimise driving style and vehicle settings: drive with windows closed when in traffic, use car air filtration systems, and avoid engine idling.

Healthy life styles

Healthy lifestyle factors include avoiding smoking (tobacco, marijuana and vaping), not drinking alcohol, engaging in regular physical activity, and eating a healthy diet. These factors promote brain health by reducing inflammation, increasing neuroplasticity, and improving cardiovascular functioning. While air pollution can negatively affect cognitive and executive function, a healthy lifestyle can have beneficial effects and may help to counter the harmful effects of pollutants like particulate matter (PM2.5). For example, one study suggests that an extra 13.6 minutes of moderate-to-vigorous physical activity (MVPA) can help to offset the negative cognitive effects of an increase of 10 μg/m3 of PM2.5.

While exercising is beneficial, care should be taken to avoid exercising in polluted environments. Increased respiratory rates during aerobic exercise may increase the inhalation of harmful particulate matter into the lungs. When particulate matter levels are reported to be high outside, consider exercising inside. Avoid exercising near high-pollution areas such as heavily-trafficked roads.

Exercise such as walking and cycling usually stimulates the production of brain-derived neurotrophic factor (BDNF), a protein that helps the growth of new brain cells. Pollutants from heavy traffic or smog interferer with the production of BDNF.

Diet

Vitamins

NIEHS-funded studies have found taking prenatal vitamins may help lower autism risk. Taking vitamins and supplements might provide protective effects for those exposed to certain environmental contaminants during pregnancy. Women were less likely to have a child with autism if they took a daily prenatal vitamin during the three months before and first month of pregnancy, compared to women not taking vitamins. This finding was more evident in women and children with genetic variants that made them more susceptible to developing autism.

Folic acid is a source of the protective effects of prenatal vitamins. Women who took the daily recommended dosage during the first month of pregnancy had a reduced risk of having a child with autism. Folic acid intake during early pregnancy may reduce the risk of having a child with autism for those women with high exposure to air pollution, and pesticides.

Pregnant mothers who used multivitamins, with or without additional iron or folic acid, were less likely to have a child with autism and intellectual disability. Maternal prenatal vitamin intake during the first month of pregnancy may also reduce ASD recurrence in siblings of children with ASD in high-risk families.

Professional activities

Urban planners can make the creation of green spaces, parks, and recreational areas away from roads and traffic a priority. Infrastructure that supports urban physical activity can be an important step towards brain health. Best practices should include situating large sources of pollutants such as major roadways, ports, and rail yards away from residential areas, schools, day care centers, playgrounds, and hospitals. Planning efforts in areas such as Camden, New Jersey, and Los Angeles and Long Beach, California, have resulted in emissions reductions.

Medical organizations such as the UK's Royal College of Physicians and the European Respiratory Society recommend that healthcare professionals be able to advise patients about the effects of air pollution and steps that can be taken to avoid negative effects. This is particularly important for higher-at-risk populations such as pregnant women, children, and older people.

In 2022, academics and other stakeholders in the United Kingdom outlined a policy agenda for brain health, identifying priorities for the policy domains of research and funding, education and awareness, and policy evaluation. Education and awareness recommendations included (1) informing people about the importance of air quality as a public health issue (2) developing educational materials (3) providing publicly available monitoring, assessment and screening tools and (4) connecting air pollution and brain health to existing public health initiatives.

Government policies

Policies enacted by governments tend to be either incentive policies (e.g. free public transportation to minimize use of private cars), supportive policies (e.g. subsidies for use of specific household fuels), or punitive policies (e.g. tolls for cars). In most cases where air pollution control measures have been enacted, outcomes have been positive.

In the United States, ambient air quality management is a joint responsibility of the federal and state governments as outlined in the US Clean Air Act and its amendments. Following these initiatives, concentrations of particulate matter (PM2.5) in the United States fell by about 40% between 2000 and 2016. Since then, the U.S.'s overall air quality has worsened.

As of 2019, scientists identified a group of combustion-related air pollutants including particulate matter (PM2.5), nitrogen dioxide, polycyclic aromatic hydrocarbons (PAHs), and black carbon as critical targets for US air pollution policy. Project TENDR (Targeting Environmental Neurodevelopmental Risks) recommended (1) that the US Environmental Protection Agency (EPA) consider the effects of air pollutants on neurodevelopment when setting standards and making cost-benefit assessments of health outcomes (2) strengthen and enforce federal fuel efficiency standards (3) advance clean energy policies to reduce reliance on fossil fuels (4) focus on reducing emissions of combustion-related pollutants from large sources near residential areas, such as major roadways, ports, and rail yards (5) restrict permitting of new sources of combustion-related air pollutants near residential areas (6) increase air monitoring near locations where children spend time such as schools and playgrounds (7) increase research into mitigation and (8) increase research into health effects of ultrafine particles.

Gender disparities in health

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Gender_disparities_in_health   ...