Clean Air Act (United States)

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Clean Air Act

Long title	An Act to improve, strengthen, and accelerate programs for the prevention and abatement of air pollution.
Acronyms (colloquial)	CAA
Nicknames	Clean Air Act of 1963
Enacted by	the 88th United States Congress
Effective	December 17, 1963
Citations
Public law	88-206
Statutes at Large	77 Stat. 392
Codification
Titles amended	42 U.S.C.: Public Health and Social Welfare
U.S.C. sections amended	42 U.S.C. ch. 85, subch. I § 7401 et seq.
Legislative history
Introduced in the House as H.R. 6518 by Kenneth A. Roberts (D–AL) on July 9, 1963 Committee consideration by House Energy and Commerce Passed the House on July 24, 1963 (275-104) Passed the Senate on November 19, 1963 (passed voice vote, in lieu of S. 432) Reported by the joint conference committee on December 5, 1963; agreed to by the House on December 10, 1963 (276-112) and by the Senate on December 10, 1963 (passed voice vote) Signed into law by President Lyndon B. Johnson on December 15 , 1963
Major amendments
Motor Vehicle Air Pollution Control Act of 1965 (79 Stat. 992, Pub.L. 89–272) Air Quality Act of 1967 (81 Stat. 485, Pub.L. 90–148) Clean Air Act Extension of 1970 (84 Stat. 1676, Pub.L. 91–604) Clean Air Act Amendments of 1977 (91 Stat. 685, Pub.L. 95–95) Clean Air Act Amendments of 1990 (104 Stat. 2468, Pub.L. 101–549)
United States Supreme Court cases
Union Elec. Co. v. EPA, 427 U.S. 246 (1976) Chevron USA v. Natural Resources Defense Council, 467 U.S. 837 (1984) Whitman v. American Trucking Ass'ns, Inc., 531 U.S. 457 (2001)

The Clean Air Act (42 U.S.C. § 7401) is a United States federal law designed to control air pollution on a national level. It is one of the United States' first and most influential modern environmental laws, and one of the most comprehensive air quality laws in the world. As with many other major U.S. federal environmental statutes, it is administered by the U.S. Environmental Protection Agency (EPA), in coordination with state, local, and tribal governments. Its implementing regulations are codified at 40 C.F.R. Sub-chapter C, Parts 50-97.

The 1955 Air Pollution Control Act was the first U.S. federal legislation that pertained to air pollution; it also provided funds for federal government research of air pollution. The first federal legislation to actually pertain to "controlling" air pollution was the Clean Air Act of 1963. The 1963 act accomplished this by establishing a federal program within the U.S. Public Health Service and authorizing research into techniques for monitoring and controlling air pollution.

It was first amended in 1965, by the Motor Vehicle Air Pollution Control Act, which authorized the federal government to set required standards for controlling the emission of pollutants from certain automobiles, beginning with the 1968 models. A second amendment, the Air Quality Act of 1967, enabled the federal government to increase its activities to investigate enforcing interstate air pollution transport, and, for the first time, to perform far-reaching ambient monitoring studies and stationary source inspections. The 1967 act also authorized expanded studies of air pollutant emission inventories, ambient monitoring techniques, and control techniques. While only six states had air pollution programs in 1960, all 50 states had air pollution programs by 1970 due to the federal funding and legislation of the 1960s. Amendments approved in 1970 greatly expanded the federal mandate, requiring comprehensive federal and state regulations for both stationary (industrial) pollution sources and mobile sources. It also significantly expanded federal enforcement. Also, EPA was established on December 2, 1970 for the purpose of consolidating pertinent federal research, monitoring, standard-setting and enforcement activities into one agency that ensures environmental protection.

Further amendments were made in 1990 to address the problems of acid rain, ozone depletion, and toxic air pollution, and to establish a national permit program for stationary sources, and increased enforcement authority. The amendments also established new auto gasoline reformulation requirements, set Reid vapor pressure (RVP) standards to control Evaporative emissions from gasoline, and mandated new gasoline formulations sold from May to September in many states. Reviewing his tenure as EPA Administrator under President George H. W. Bush, William K. Reilly characterized passage of the 1990 amendments to the Clean Air Act as his most notable accomplishment.

The Clean Air Act was the first major environmental law in the United States to include a provision for citizen suits. Numerous state and local governments have enacted similar legislation, either implementing federal programs or filling in locally important gaps in federal programs.

Summary

Counties in the United States with one or more National Ambient Air Quality Standards not met as of June 2017

Title I: Programs and Activities

Graph showing decreases in US air pollution concentrations during 1990 to 2015

Part A: Air Quality and Emissions Limitations

This section of the act declares that protecting and enhancing the nation's air quality promotes public health. The law encourages to prevent regional air pollution and control programs. It also provides technical and financial assistance for preventing air pollution at both state and local governments. Additional sub chapters cover cooperation, research, investigation, training, and other activities. Grants for air pollution planning and control programs, and interstate air quality agencies and program cost limitations are also included in this section.

The act mandates air quality control regions, designated as attainment vs non-attainment. Non-attainment areas do not meet national standards for primary or secondary ambient air quality. Attainment areas meet these standards, while unclassified areas cannot be classified based on the available information.

Air quality criteria, national primary and secondary ambient air quality standards, state implementation plans and performance standards for new stationary sources are covered in Part A as well. The list of hazardous air pollutants that the act establishes includes compounds of Acetaldehyde, benzene, chloroform, Phenol, and selenium. The list also includes mineral fiber emissions from manufacturing or processing glass, rock or slag fibers as well as radioactive atoms. The list can periodically be modified. The act lists unregulated radioactive pollutants such as cadmium, arsenic, and poly cyclic organic matter and it mandates listing them if they will cause or contribute to air pollution that endangers public health, under section 7408 or 7412.

The remaining sub-chapters cover smokestack heights, state plan adequacy, and estimating emissions of carbon monoxide, volatile organic compounds, and oxides of nitrogen from area and mobile sources. Measures to prevent unemployment or other economic disruption include using local coal or coal derivatives to comply with implementation requirements. The final sub chapter in this act focuses on land use authority.

Part B: Ozone Protection

Because of advances in the atmospheric chemistry, this section was replaced by Title VI when the law was amended in 1990.

This change in the law reflected significant changes in scientific understanding of ozone formation and depletion. Ozone absorbs UVC light and shorter wave UVB, and lets through UVA, which is largely harmless to people. Ozone exists naturally in the stratosphere, not the troposphere. It is laterally distributed because it is destroyed by strong sunlight, so there is more ozone at the poles. Ozone is created when O₂ comes in contact with photons from solar radiation. Therefore, a decrease in the intensity of solar radiation also results in a decrease in the formation of ozone in the stratosphere. This exchange is known as the Chapman mechanism:

O₂ + UV photon → 2 O (note that atmospheric oxygen as O is highly unstable)

O + O₂ + M → O₃ (O₃ is Ozone) + M

M represents a third molecule, needed to carry off the excess energy of the collision of O + O₂.

Atmospheric freon and chlorofluorocarbons (CFCs) contribute to ozone depletion (Chlorine is a catalytic agent in ozone destruction). Following discovery of the ozone hole in 1985, the 1987 Montreal Protocol successfully implemented a plan to replace CFCs and was viewed by some environmentalists as an example of what is possible for the future of environmental issues, if the political will is present.

Part C - Prevention of Significant Deterioration of Air Quality

The Clean Air Act requires permits to build or add to major stationary sources of air pollution. This permitting process, known as New Source Review (NSR), applies to sources in areas that meet air quality standards as well as areas that are unclassified. Permits in attainment or unclassified areas are referred to as Prevention of Significant Deterioration (PSD) permits, while permits for sources located in nonattainment areas are referred to as non attainment area (NAA) permits.

The fundamental goals of the PSD program are to

1. prevent new non-attainment areas by ensuring economic growth in harmony with existing clean air;
2. protect public health and welfare from any adverse effects;
3. preserve and enhance the air quality in national parks and other areas of special natural recreational, scenic, or historic value.

Part D: Plan Requirements for Non-attainment Areas

Under the Clean Air Act states are required to submit a plan for non-attainment areas to reach attainment status as soon as possible but in no more than five years, based on the severity of the air pollution and the difficulty posed by obtaining cleaner air. 

The plan must include

• an inventory of all pollutants
• permits
• control measures, means and techniques to reach standard qualifications
• contingency measures

The plan must be approved or revised if required for approval, and specify whether local governments or the state will implement and enforce the various changes. Achieving attainment status makes a request for reevaluation possible. It must include a plan for maintenance of air quality.

Title II: Emission Standards for Moving Sources

Graph showing decreases in US air pollution emissions from transportation sources during 1980-2015, while US population and economic activity increased.

Part A: Motor Vehicle Emission and Fuel Standards

Sub-chapters of Title II cover state standards and grants, prohibited acts and actions to restrain violations, as well as a study of emissions from non road vehicles (other than locomotives) to determine whether they cause or contribute to air pollution. Motorcycles are treated in the same way as automobiles under the emission standards for new motor vehicles or motor vehicle engines. The last few sub chapters deal with high altitude performance adjustments, motor vehicle compliance program fees, prohibition on production of engines requiring leaded gasoline and urban bus standards.

This part of the bill was extremely controversial the time it was passed. The automobile industry argued that it could not meet the new standards. Senators expressed concern about impact on the economy. However the stricter standards led to the creation of the catalytic converter, which was a revolutionary development. (Coincidentally, these converters didn't work well with leaded gas, which contributed to the swift removal of lead from gasoline that was also recognized for having adverse health effects.) Specific new emissions standards for moving sources passed years later.

Part B: Aircraft Emission Standards

Many volatile organic compounds (VOCs) are emitted over airports and affect the air quality in the region. VOCs include benzene, formaldehyde and butadienes which are known to cause health problems such as birth defects, cancer and skin irritation. Hundreds of tons of emissions from aircraft, ground support equipment, heating systems, and shuttles and passenger vehicles are released into the air, causing smog. Therefore, major cities such as Seattle, Denver, and San Francisco require a Climate Action Plan as well as a greenhouse gas inventory. Additionally, federal programs such as the Voluntary Airport Low Emissions Program (VALE) are working to offset costs for programs that reduce emissions.

Title II sets emission standards for airlines and aircraft engines and adopts standards set by the International Civil Aviation Organization (ICAO). However aircraft carbon dioxide emission standards have not been established by either ICAO nor the EPA. It is the responsibility of the Secretary of Transportation, after consultation with the Administrator, to prescribe regulations that comply with 42 U.S. Code § 7571 (Establishment of standards) and ensure the necessary inspections take place.

Part C: Clean Fuel Vehicles

Trucks and automobiles play a large role in deleterious air quality. Harmful chemicals such as nitrogen oxide, hydrocarbons, carbon monoxide and sulfur dioxide are released from motor vehicles. Some of these also react with sunlight to produce Photochemical. These harmful substances change the climate, alter ocean pH and include toxins that may cause cancer, birth defects or respiratory illness. Motor vehicles increased in the 1990s since approximately 58 percent of households owned two or more vehicles. The Clean Fuel Vehicle programs focused on alternative fuel use and petroleum fuels that met low emission vehicle (LEV) levels. Compressed natural gas, ethanol, methanol, liquefied petroleum gas and electricity are examples of cleaner alternative fuel. Programs such as the California Clean Fuels Program and pilot program are increasing demand that for new fuels to be developed to reduce harmful emissions.

The California pilot program incorporated under this section focuses on pollution control in ozone non-attainment areas. The provisions apply to light-duty trucks and light-duty vehicles in California. The state also requires that clean alternative fuels for sale at numerous locations with sufficient geographic distribution for convenience. Production of clean-fuel vehicles isn't mandated except as part of the California pilot program.

Title III: General Provisions

Under the law prior to 1990, EPA was required to construct a list of Hazardous Air Pollutants as well as health-based standards for each one. There were 187 air pollutants listed and the source from which they came. The EPA was given ten years to generate technology-based emission standards. Title III is considered a second phase, allowing the EPA to assess lingering risks after the enactment of the first phase of emission standards. Title III also enacts new standards with regard to the protection of public health.

A citizen may file a lawsuit to obtain compliance with an emission standard issued by the EPA or by a state, unless there is an ongoing enforcement action being pursued by EPA or the appropriate state agency.

Title IV: Noise Pollution

This title pre-dates the Clean Air Act. With the passage of the Clean Air Act, it became codified as Title IV. However, another Title IV was enacted in the 1990 amendments. The second Title IV was then appended to this Title IV as Title IV-A (see below). 

This title established the EPA Office of Noise Abatement and Control to reduce noise pollution in urban areas, to minimize noise-related impacts on psychological and physiological effects on humans, effects on wildlife and property (including values), and other noise-related issues. The agency was also assigned to run experiments to study the effects of noise.

Title IV-A: Acid Deposition Control

This title was added as part of the 1990 amendments. It addresses the issue of acid rain, which is caused by nitrogen oxides (NO
x ) and sulfur dioxide (SO₂) emissions from electric power plants powered by fossil fuels, and other industrial sources. The 1990 amendments gave industries more pollution control options including switching to low-sulfur coal and/or adding devices that controlled the harmful emissions. In some cases plants had to be closed down to prevent the dangerous chemicals from entering the atmosphere.

Title IV-A mandated a two-step process to reduce SO₂ emissions. The first stage required more than 100 electric generating facilities larger than 100 megawatts to meet a 3.5 million ton SO₂ emission reduction by January 1995. The second stage gave facilities larger than 75 megawatts a January 2000 deadline.

Title V: Permits

The 1990 amendments authorized a national operating permit program, covering thousands of large industrial and commercial sources. It required large businesses to address pollutants released into the air, measure their quantity, and have a plan to control and minimize them as well as to periodically report. This consolidated requirements for a facility into a single document.

In non-attainment areas, permits were required for sources that emit as little as 50, 25, or 10 tons per year of VOCs depending on the severity of the region’s non-attainment status.

Most permits are issued by state and local agencies. If the state does not adequately monitor requirements, the EPA may take control. The public may request to view the permits by contacting the EPA. The permit is limited to no more than five years and requires a renewal.

Title VI: Stratospheric Ozone Protection

Starting in 1990, Title VI mandated regulations regarding the use and production of chemicals that harm the Earth’s stratospheric ozone layer. This ozone layer protects against harmful ultraviolet B sunlight linked to several medical conditions including cataracts and skin cancer.

The ozone-destroying chemicals were classified into two groups, Class I and Class II. Class I consists of substances, including chlorofluorocarbons, that have an ozone depletion potential (ODP) (HL) of 0.2 or higher. Class II lists substances, including hydro chlorofluorocarbons, that are known to or may be detrimental to the stratosphere. Both groups have a timeline for phase-out:

• For Class I substances, no more than seven years after being added to the list and
• For Class II substances no more than ten years.

Title VI establishes methods for preventing harmful chemicals from entering the stratosphere in the first place, including recycling or proper disposal of chemicals and finding substitutes that cause less or no damage. The Significant New Alternatives Policy (SNAP) Program is EPA's program to evaluate and regulate substitutes for the ozone-depleting chemicals that are being phased out under the stratospheric ozone protection provisions of the Clean Air Act.

Over 190 countries signed the Montreal Protocol in 1987, agreeing to work to eliminate or limit the use of chemicals with ozone-destroying properties.

History

Legislation

Congress passed the first legislation to address air pollution with the 1955 Air Pollution Control Act that provided funds to the U.S. Public Health service, but did not formulate pollution regulation. However, the Clean Air Act in 1963 created a research and regulatory program in the U.S. Public Health Service. The Act authorized development of emission standards for stationary sources, but not mobile sources of air pollution. The 1967 Air Quality Act mandated enforcement of interstate air pollution standards and authorized ambient monitoring studies and stationary source inspections.

In the Clean Air Act Extension of 1970, Congress greatly expanded the federal mandate by requiring comprehensive federal and state regulations for both industrial and mobile sources. The law established four new regulatory programs:

• National Ambient Air Quality Standards (NAAQS). EPA was required to promulgate national standards for six criteria pollutants: carbon monoxide, nitrogen dioxide, sulfur dioxide, particulate matter, hydrocarbons and photochemical oxidants. (Some of the criteria pollutants were revised in subsequent legislation.)
• State Implementation Plans (SIPs)
• New Source Performance Standards (NSPS); and
• National Emissions Standards for Hazardous Air Pollutants (NESHAPs).

The 1970 law is sometimes called the "Muskie Act" because of the central role Maine Senator Edmund Muskie played in drafting the bill.

To implement the strict new Clean Air Act of 1970, during his first term as EPA Administrator William Ruckelshaus spent 60% of his time on the automobile industry, whose emissions were to be reduced 90% under the new law. Senators had been frustrated at the industry’s failure to cut emissions under previous, weaker air laws.

The Clean Air Act Amendments of 1977 required Prevention of Significant Deterioration (PSD) of air quality for areas attaining the NAAQS and added requirements for non-attainment areas.

The 1990 Clean Air Act added regulatory programs for control of acid deposition (acid rain) and stationary source operating permits. The provisions aimed at reducing sulfur dioxide emissions included a cap-and-trade program, which gave power companies more flexibility in meeting the law's goals compared to earlier iterations of the Clean Air Act. The amendments moved considerably beyond the original criteria pollutants, expanding the NESHAP program with a list of 189 hazardous air pollutants to be controlled within hundreds of source categories, according to a specific schedule. The NAAQS program was also expanded. Other new provisions covered stratospheric ozone protection, increased enforcement authority and expanded research programs.

History of the Clean Air Act

Introduction

President Lyndon B. Johnson signing the 1967 Air Quality Act in the East Room of the White House, November 21, 1967.

 

The legal authority for federal programs regarding air pollution control is based on the 1990 Clean Air Act Amendments (1990 CAAA). These are the latest in a series of amendments made to the Clean Air Act (CAA), often referred to as "the Act." This legislation modified and extended federal legal authority provided by the earlier Clean Air Acts of 1963 and 1970.

The 1955 Air Pollution Control Act was the first federal legislation involving air pollution; it authorized $3 million per year to the U.S. Public Health Service for five years to fund federal level air pollution research, air pollution control research, and technical and training assistance to the states. Subsequently, the act was extended for four years in 1959 with funding levels at $5 million per year. The act was then amended in 1960 and 1962. Although the 1955 act brought the air pollution issue to the federal level, no federal regulations were formulated. Control and prevention of air pollution was instead delegated to state and local agencies.

The Clean Air Act of 1963 was the first federal legislation regarding air pollution control. It established a federal program within the U.S. Public Health Service and authorized research into techniques for monitoring and controlling air pollution. In 1967, the Air Quality Act was enacted in order to expand federal government activities. In accordance with this law, enforcement proceedings were initiated in areas subject to interstate air pollution transport. As part of these proceedings, the federal government for the first time conducted extensive ambient monitoring studies and stationary source inspections. 

The Air Quality Act of 1967 also authorized expanded studies of air pollutant emission inventories, ambient monitoring techniques, and control techniques.

Clean Air Act of 1970

The Clean Air Act of 1970 (1970 CAA) authorized the development of comprehensive federal and state regulations to limit emissions from both stationary (industrial) sources and mobile sources. Four major regulatory programs affecting stationary sources were initiated:

• The National Ambient Air Quality Standards [NAAQS (pronounced "knacks")],
• State Implementation Plans (SIPs),
• New Source Performance Standards (NSPS),
• The National Emission Standards for Hazardous Air Pollutants (NESHAPs).

Enforcement authority was substantially expanded. This very important legislation was adopted at approximately the same time as the National Environmental Policy Act.

Clean Air Act Amendments of 1977

Major amendments were added to the Clean Air Act in 1977 (1977 CAAA). The 1977 Amendments primarily concerned provisions for the Prevention of Significant Deterioration (PSD) of air quality in areas attaining the NAAQS. The 1977 CAAA also contained requirements pertaining to sources in non-attainment areas for NAAQS. A non-attainment area is a geographic area that does not meet one or more of the federal air quality standards. Both of these 1977 CAAA established major permit review requirements to ensure attainment and maintenance of the NAAQS. These amendments also included the adoption of an offset trading policy originally applied to Los Angeles in 1974 that enables new sources to offset their emissions by purchasing extra reductions from existing sources.

Clean Air Act Amendments of 1990

Another set of major amendments to the Clean Air Act occurred in 1990 (1990 CAAA). The 1990 CAAA substantially increased the authority and responsibility of the federal government. New regulatory programs were authorized for control of acid deposition (acid rain) and for the issuance of stationary source operating permits. The NESHAPs were incorporated into a greatly expanded program for controlling toxic air pollutants. The provisions for attainment and maintenance of NAAQS were substantially modified and expanded. Other revisions included provisions regarding stratospheric ozone protection, increased enforcement authority, and expanded research programs.

Milestones

Some of the principal milestones in the evolution of the Clean Air Act are as follows.

The Air Pollution Control Act of 1955:

• First federal air pollution legislation
• Funded research on scope and sources of air pollution

Clean Air Act of 1963:

• Authorized a national program to address air pollution
• Authorized research into techniques to minimize air pollution

Air Quality Act of 1967:

• Authorized enforcement procedures involving interstate transport of pollutants
• Expanded research activities

Clean Air Act of 1970:

• Established National Ambient Air Quality Standards
• Established requirements for State Implementation Plans to achieve them
• Establishment of New Source Performance Standards for new and modified stationary sources
• Establishment of National Emission Standards for Hazardous Air Pollutants
• Increased enforcement authority
• Authorized control of motor vehicle emissions

1977 Amendments to the Clean Air Act of 1970:

• Authorized provisions related to prevention of significant deterioration
• Authorized provisions relating to non-attainment areas

1990 Amendments to the Clean Air Act of 1970:

• Authorized programs for acid deposition control
• Authorized controls for 189 toxic pollutants, including those previously regulated by the national emission standards for hazardous air pollutants
• Established permit program requirements
• Expanded and modified provisions concerning National Ambient Air Quality Standards
• Expanded and modified enforcement authority

Regulations

Since the initial establishment of six mandated criteria pollutants (ozone, particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide, and lead), advancements in testing and monitoring have led to the discovery of many other significant air pollutants.

However, with the act in place and its many improvements, the U.S. has seen many pollutant levels and associated cases of health complications drop. According to the EPA, the 1990 Clean Air Act Amendments has prevented or will prevent:

	Year 2010 (cases prevented)	Year 2020 (cases prevented)
Adult Mortality - particles	160,000	230,000
Infant Mortality - particles	230	280
Mortality - ozone	4,300	71,000
Chronic Bronchitis	54,000	75,000
Heart Disease - Acute Myocardial Infarction	130,000	200,000
Asthma Exacerbation	1,700,000	2,400,000
Emergency Room Visits	86,000	120,000
School Loss Days	3,200,000	5,400,000
Lost Work Days	13,000,000	17,000,000

This chart shows the health benefits of the Clean Air Act programs that reduce levels of fine particles and ozone.

In 1997 EPA tightened the NAAQS regarding permissible levels of the ground-level ozone that make up smog and the fine airborne particulate matter that makes up soot. The decision came after months of public review of the proposed new standards, as well as long and fierce internal discussion within the Clinton administration, leading to the most divisive environmental debate of that decade. The new regulations were challenged in the courts by industry groups as a violation of the U.S. Constitution's nondelegation principle and eventually landed in the Supreme Court of the United States, whose 2001 unanimous ruling in Whitman v. American Trucking Ass'ns, Inc. largely upheld EPA's actions.

The Clean Air Act (CAA or Act) directs EPA to establish national ambient air quality standards (NAAQS) for pollutants at levels that will protect public health. EPA and American Lung Association promoted the 2011 Cross State Air Pollution Rule (CSAPR) to control ozone and fine particles. Aim was to cut emissions half from 2005 to 2014. It was claimed to prevent each year 400,000 asthma cases and save ca 2m work and schooldays lost by respiratory illness. Some states (e.g. Texas), cities and power companies sued the case (EPA v EME Homer City Generation). The appeals-court judges decided by two to one that the rule is too strict. Based on appeals the power companies were allowed to continue thousands of persons respiratory illnesses prolonged time in the USA. According to the Economist (2013) the Supreme Court decision may affect how the EPA regulates other pollutants, including the greenhouse gases.

Roles of the federal government and states

The 1970 Clean Air Act required states to develop State Implementation Plans for how they would meet new national ambient air quality standards by 1977. Although the 1990 Clean Air Act is a federal law covering the entire country, the states do much of the work to carry out the Act. The EPA has allowed the individual states to elect responsibility for compliance with and regulation of the CAA within their own borders in exchange for funding. For example, a state air pollution agency holds a hearing on a permit application by a power or chemical plant or fines a company for violating air pollution limits. However, election is not mandatory and in some cases states have chosen to not accept responsibility for enforcement of the act and force the EPA to assume those duties.

In order to take over compliance with the CAA the states must write and submit a state implementation plan (SIP) to the EPA for approval. A state implementation plan is a collection of the regulations a state will use to clean up polluted areas. The states are obligated to notify the public of these plans, through hearings that offer opportunities to comment, in the development of each state implementation plan. The SIP becomes the state's legal guide for local enforcement of the CAA. For example, Rhode Island law requires compliance with the Federal CAA through the SIP. The SIP delegates permitting and enforcement responsibility to the state Department of Environmental Management (RI-DEM). 

The federal law recognizes that states should lead in carrying out the Clean Air Act, because pollution control problems often require special understanding of local industries, geography, housing patterns, etc. However, states are not allowed to have weaker pollution controls than the national minimum criteria set by EPA. EPA must approve each SIP, and if a SIP isn't acceptable, EPA can take over CAA enforcement in that state. For example, California was unable to meet the new standards set by the Clean Air Act of 1970, which led to a lawsuit and a federal state implementation plan for the state.

The United States government, through the EPA, assists the states by providing scientific research, expert studies, engineering designs, and money to support clean air programs.

Metropolitan planning organizations must approve all federally funded transportation projects in a given urban area. If the MPO's plans do not, Federal Highway Administration and the Federal Transit Administration have the authority to withhold funds if the plans do not conform with federal requirements, including air quality standards. In 2010, the EPA directly fined the San Joaquin Valley Air Pollution Control District $29 million for failure to meet ozone standards, resulting in fees for county drivers and businesses. This was the results of a federal appeals court case that required the EPA to continue enforce older, stronger standards, and spurred debate in Congress over amending the Act.

State Programs

Many states, or concerned citizens of the state, have established their own programs to help promote pollution clean-up strategies. 

For example,(in alphabetical order by state):

• California - California's Clean Air Project - designed to create a smoke-free gaming atmosphere in tribal casinos
• Georgia - The Clean Air Campaign
• Illinois - Illinois Citizens for Clean Air and Water - coalition of farmers and other citizens to reduce harmful effects of large-scale livestock production methods
• New York - Clean Air NY
• Oklahoma - "Breathe Easy" - Oklahoma Statutes on Smoking in Public Places and Indoor Workplaces (Effective November 1, 2010)
• Oregon - Indoor Clean Air Act - Statutes on Smoking in Indoor Workplaces and Within 10ft of an Entrance
• Texas - Drive Clean Across Texas
• Virginia - Virginia Clean Cities, Inc.

Interstate air pollution

Air pollution often travels from its source in one state to another state. In many metropolitan areas, people live in one state and work or shop in another; air pollution from cars and trucks may spread throughout the interstate area. The 1990 Clean Air Act provides for interstate commissions on air pollution control, which are to develop regional strategies for cleaning up air pollution. The 1990 amendments include other provisions to reduce interstate air pollution. 

The Acid Rain Program, created under Title IV of the Act, authorizes emissions trading to reduce the overall cost of controlling emissions of sulfur dioxide.

Leak detection and repair

The Act requires industrial facilities to implement a Leak Detection and Repair (LDAR) program to monitor and audit a facility's fugitive emissions of volatile organic compounds (VOC). The program is intended to identify and repair components such as valves, pumps, compressors, flanges, connectors and other components that may be leaking. These components are the main source of the fugitive VOC emissions. 

Testing is done manually using a portable vapor analyzer that read in parts per million (ppm). Monitoring frequency, and the leak threshold, is determined by various factors such as the type of component being tested and the chemical running through the line. Moving components such as pumps and agitators are monitored more frequently than non-moving components such as flanges and screwed connectors. The regulations require that when a leak is detected the component be repaired within a set number of days. Most facilities get 5 days for an initial repair attempt with no more than 15 days for a complete repair. Allowances for delaying the repairs beyond the allowed time are made for some components where repairing the component requires shutting process equipment down.

Application to greenhouse gas emissions

EPA began regulating greenhouse gases (GHGs) from mobile and stationary sources of air pollution under the Clean Air Act for the first time on January 2, 2011, after having established its first auto emissions standards in 2010. Standards for mobile sources have been established pursuant to Section 202 of the CAA, and GHGs from stationary sources are controlled under the authority of Part C of Title I of the Act. The EPA's auto emission standards for greenhouse gas emissions issued in 2010 and 2012 are intended to cut emissions from targeted vehicles by half, double fuel economy of passenger cars and light-duty trucks by 2025 and save over $4 billion barrels of oil and $1.7 trillion for consumers. The agency has also proposed a two-phase program to reduce greenhouse gas emissions for medium and heavy duty trucks and buses.

Below is a table for the sources of greenhouse gases, taken from data in 2008. Of all greenhouse gases, about 76 percent of the sources are manageable under the CAA, marked with an asterisk (*). All others are regulated independently, if at all.

Source	Percentage
Electric Generation*	34%
Industry*	15%
Large Non-Agricultural Methane Sources*	5%
Light-, Medium-, and Heavy-Duty Vehicles*	22%
Other Transport	7%
Commercial and Residential Heating	7%
Agriculture	7%
HFCs	2%
Other	1%

Clean Air Act and environmental justice

By promoting pollution reduction, the Clean Air Act can help reduce heightened exposure to air pollution among communities of color and low-income communities. Environmental researcher Dr. Marie Lynn Miranda notes that African American populations are “consistently over represented” in areas with the poorest air quality. Dense populations of low-income and minority communities inhabit the most polluted areas across the United States, which is considered to exacerbate health problems among these populations. High levels of exposure to air pollution is linked to several health conditions, including asthma, cancer, premature death, and infant mortality, each of which disproportionately impact communities of color and low-income communities. The pollution reduction achieved by the Clean Air Act is associated with a decline in each of these conditions and can promote environmental justice for communities that are disproportionately impacted by air pollution and diminished health status.

Clean Air Act violations

The EPA analyzes violators of the Clean Air Act and addresses the violators accordingly. For companies or parties that do not comply with the act monetary penalties can be cited. Per day the EPA could fine civil administrators $37,500 per day, with a maximum of about 8 days; unless otherwise mandated by the EPA. For a field citation which is against federal facilities which are not abiding by EPA standards can get fines up to $7,500 per day.

Major cases of Clean Air Act violations include:

• The Volkswagen emissions scandal (2015), etc.
• Caterpillar and five other manufacturers violated diesel engine emission standards (consent decree, July 1999)
• Alleged violations by Hyundai and Kia which resulted in a total $100 million in civil penalties paid to the United States and to the California Air Resources Board.

Effects

A 2017 study found that the Clean Air Act of 1970 led to an over 10 percent reduction in pollution ("ambient TSP levels") in counties that exceeded the pollution thresholds set by the Act in the three years after the regulation went into effect. The study found that this regulation-induced reduction in air pollution is caused affected workers to work more and earned one percent more in annual earnings. The authors estimate that cumulative lifetime income gain for each affected individual is approximately $4,300 in present value terms.

In addition, because air quality across the United States improved; it is estimated 205,000 premature deaths and millions of other respiratory complications were prevented which resulted in an economic savings of $50 trillion versus the $523 billion invested to meet the Clean Air Act standard.

Mobile sources including automobiles, trains, and boat engines have become 99% cleaner for pollutants like hydrocarbons, carbon monoxide, nitrogen oxides, and particle emissions since the 1970s. The allowable emissions of volatile organic chemicals, carbon monoxide, nitrogen oxides, and lead from individual cars have also been reduced by more than 90%, resulting in decreased national emissions of these pollutants despite a more than 400% increase in total miles driven yearly.

Since the 1980s, 1/4th of ground level ozone has been cut, mercury emissions have been cut by 80%, and since the change from leaded gas to unleaded gas 90% of atmospheric lead pollution has been reduced.

A 2018 study found that the Clean Air Act contributed to the 60% decline in pollution emissions by the manufacturing industry between 1990 and 2008.

Future challenges

Climate change poses a challenge to the management of conventional air pollutants in the United States due to warmer, dryer summer conditions that can lead to increased air stagnation episodes. Prolonged droughts that may contribute to wildfires would also result in regionally high levels of air particles.

As of 2017, some US cities still don’t meet all national ambient air quality standards. It is likely that tens of thousands of premature deaths are still being caused by fine-particle pollution and ground-level ozone pollution.

Air pollution is not bound to a nation. Often, air coming into the U.S. contains pollution from upwind countries, making it harder to meet air quality standards. In turn, air that travels downwind of the U.S. likely has pollutants in it already. Addressing this may require international negotiations of reductions of pollutants in the originating countries. This also relates to the challenge of climate change.

Criticism

Diane Katz, a research fellow for the Heritage Foundation, criticized the validity of the Clean Air Act by stating, "The largest proportion of economic benefit is based on the value of avoiding premature mortality. Yet the valuation of this benefit ranks among the most significant uncertainties in the study, according to the researchers. Alternative estimates they cite would lower the benefit calculation by up to 22 percent." The Clean Air Act is a constant battle between current economic benefits versus future cost benefits of both health of the nation, and economy.

Healthy building

From Wikipedia, the free encyclopedia

Healthy building refers to an emerging area of interest that supports the physical, psychological, and social health and well-being of people in buildings and the built environment. Buildings can be key promoters of health and well-being since most people spend a majority of their time indoors. According to the National Human Activity Pattern Survey, Americans spend “an average of 87% of their time in enclosed buildings and about 6% of their time in enclosed vehicles.”

Healthy building can be seen as the next generation of Green building that not only includes environmentally responsible and resource-efficient building concepts, but also integrates “health, wellness, and human experience in buildings.” These benefits can include “reducing absenteeism and presenteeism, lowering health care costs, and improving individual and organizational performance.” Healthy building encompasses a wide range of concepts and applications that promote human health which include but are not limited to: site selection and construction, occupant engagement, personal control, indoor environmental quality, daylighting, biophilic design, access to potable water, healthy dining options, exercise in the workplace, and smoking restrictions.

Integrated design

Healthy building involves many different concepts, fields of interest, and disciplines. As such, taking an integrative or integrated design approach is essential to successfully creating a healthy building. Forming a diverse and interdisciplinary team early in the process can generate integrated or complementary strategies for improved performance or health impact considerations. An integrated design team can consist of stakeholders and specialists such as facility managers, architects, building engineers, health and wellness experts, and public health partners. Conducting charrettes with an integrated design team can foster collaboration and help the team develop goals, plans, and solutions.

Buildings and health components

There are many different components that can support health and well-being in buildings.

Site selection

Site selection is an important factor in designing a building and ensuring positive health and environmental impacts. Creating a walkable environment that connects people to workplaces, green spaces, public transportation, fitness centers, and other basic needs and services can influence daily physical activity, “the distances people travel to work, the convenience of purchasing healthy foods, and the safety and attractiveness of neighborhoods for walking.” In particular, proximity to green spaces (e.g., parks, walking trails, gardens, and etc.) or therapeutic landscapes can reduce absenteeism and improve well-being.

Building design

There are many aspects of a building that can be designed to support positive health and well-being. For example, creating well-placed collaboration and social areas (e.g., break rooms, open collaboration areas, cafe spaces, courtyard gardens) can encourage social interaction and well-being. Quiet and wellness rooms can provide quiet zones or rooms that help improve well-being and mindfulness. Specifically, a designated lactation room can support nursing mothers by providing privacy and helping them return to work more easily. A lactation room is required for offices with more than 50 employees and recommended for all other offices. Another design aspect to consider is biophilic design, which focuses on reconnecting people to the natural environment. Biophilic design has been linked to health outcomes such as stress reduction, enhanced mood, improved cognitive performance, enhanced social engagement, enhanced sleep, and enhanced movement. Ergonomics can also minimize stress and strain on the body by providing ergonomically designed workstations.

Indoor environmental quality (IEQ)

According to the National Institute for Occupational Safety and Health (NIOSH), "Indoor environmental quality (IEQ) refers to the quality of a building’s environment in relation to the health and wellbeing of those who occupy space within it." IEQ is determined by many factors including indoor air quality (IAQ), temperature, lighting, and selection of building materials. The Environmental Protection Agency (EPA) recommends three strategies to improve indoor air quality: source control, improved ventilation, and air cleaners. Selecting low-emitting products and materials that reduce volatile organic compound (VOC) emissions is one way prevent indoor air pollution. Product characteristics to consider include durability, indoor air quality effects, material transparency, and health impact on building occupants. Other aspects of IEQ that can improve health and well-being include thermal comfort, acoustic comfort, and integrated pest management (IPM).

Daylighting

Daylighting refers to providing access to natural daylight, which can be aesthetically pleasing and can reduce energy use. Light has a direct effect on human health because of how it affects circadian rhythms. If daylighting is not available, supplemental electric lighting can help ensure occupants receive enough light for the entrainment of circadian rhythms.

Diet

Providing access to water and healthy, nutritional food is essential to promoting health and a quality environment. The design of a building should take into consideration proximity to water and nutritional foods via cafeterias, vending machines, local stores and restaurants or farmers’ markets.

Exercise

Site selection and building design can promote increased physical activity and exercise. Well-lit and accessible stairwells can provide building occupants the opportunity to increase regular physical activity. Fitness centers or an exercise room can encourage exercise during the work day, which can improve mood and performance, leading to improved focus and better work-based relationships. Exercise can also be promoted by encouraging alternative means of transportation (e.g., cycling, walking, running) to and from the building. Providing facilities such as bicycle storage and locker/changing rooms can increase the appeal of cycling, walking, or running. Active workstations, such as of sit/stand desks, treadmill desks, or cycle desks, can encourage increased movement and exercise as well.

Occupant engagement

While some components of healthy buildings are inherently designed into the built environment, other components rely on the behavioral change of occupants, users, or organizations residing within the building. “Behavioral measures” can be taken to “encourage better public health outcomes: e.g., reducing sedentary behaviors by increasing access to stairways, using more active transportation options, and working at sit-to-stand desks.” Other examples that can promote health and well-being include establishing workplace wellness programs, health promotion campaigns, and encouraging activity and collaboration.

Health and well-being in standards and rating systems

There are several international and governmental standards, guidelines, and building rating systems that incorporate health and well-being concepts:

• Fitwel
• WELL Building Standard
• Green Building Initiative (GBI) Green Globes
• Leadership in Energy and Environmental Design (LEED)
• ANSI/ASHRAE/USGBC/IES Standard 189.1-2014, Standard for the Design of High-Performance Green Buildings
• United States Department of Defense Unified Facilities Criteria Program
• General Services Administration Facilities Standards for the Public Buildings Service (P-100)

Sick building syndrome

From Wikipedia, the free encyclopedia

Sick building syndrome (SBS) is a medical condition where people in a building suffer from symptoms of illness or feel unwell for no apparent reason. The symptoms tend to increase in severity with the time people spend in the building, and improve over time or even disappear when people are away from the building. The main identifying observation is an increased incidence of complaints of symptoms such as headache, eye, nose, and throat irritation, fatigue, and dizziness and nausea. These symptoms appear to be linked to time spent in a building, though no specific illness or cause can be identified. SBS is also used interchangeably with "building-related symptoms", which orients the name of the condition around patients rather than a "sick" building. A 1984 World Health Organization (WHO) report suggested up to 30% of new and remodeled buildings worldwide may be subject of complaints related to poor indoor air quality.

Sick building causes are frequently pinned down to flaws in the heating, ventilation, and air conditioning (HVAC) systems. However, there have been inconsistent findings on whether air conditioning systems result in SBS or not. Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile organic compounds (VOC), molds (see mold health issues), improper exhaust ventilation of ozone (byproduct of some office machinery), light industrial chemicals used within, or lack of adequate fresh-air intake/air filtration.

Signs and symptoms

Human exposure to bioaerosols has been documented to give rise to a variety of adverse health effects. Building occupants complain of symptoms such as sensory irritation of the eyes, nose, or throat; neurotoxic or general health problems; skin irritation; nonspecific hypersensitivity reactions; infectious diseases; and odor and taste sensations. Exposure to poor lighting conditions has led to general malaise.

Extrinsic allergic alveolitis has been associated with the presence of fungi and bacteria in the moist air of residential houses and commercial offices. A very large 2017 Swedish study correlated several inflammatory diseases of the respiration tract with objective evidence of damp-caused damage in homes. 

The WHO has classified the reported symptoms into broad categories, including: mucous membrane irritation (eye, nose, and throat irritation), neurotoxic effects (headaches, fatigue, and irritability), asthma and asthma-like symptoms (chest tightness and wheezing), skin dryness and irritation, gastrointestinal complaints and more.

Several sick occupants may report individual symptoms which do not appear to be connected. The key to discovery is the increased incidence of illnesses in general with onset or exacerbation within a fairly close time frame—usually within a period of weeks. In most cases, SBS symptoms will be relieved soon after the occupants leave the particular room or zone. However, there can be lingering effects of various neurotoxins, which may not clear up when the occupant leaves the building. In some cases—particularly in sensitive individuals—there can be long-term health effects.

Causes

It has been suggested that sick building syndrome could be caused by inadequate ventilation, deteriorating fiberglass duct liners, chemical contaminants from indoor or outdoor sources, and biological contaminants, air recycled using fan coils, traffic noise, poor lighting, and buildings located in a polluted urban area. Many volatile organic compounds, which are considered chemical contaminants, can cause acute effects on the occupants of a building. "Bacteria, molds, pollen, and viruses are types of biological contaminants" and can all cause SBS. In addition, pollution from outdoors, such as motor vehicle exhaust, can contribute to SBS. Adult SBS symptoms were associated with a history of allergic rhinitis, eczema and asthma.

A 2015 study concerning the association of SBS and indoor air pollutants in office buildings in Iran found as carbon dioxide levels increase in a building, symptoms like nausea, headaches, nasal irritation, dyspnea, and throat dryness have also been shown to increase. Certain work conditions have been found to be correlated with specific symptoms. For example, higher light intensity was significantly related to skin dryness, eye pain, and malaise. Higher temperature has also been found to correlate with symptoms such as sneezing, skin redness, itchy eyes and headache, while higher relative humidity has been associated with sneezing, skin redness, and pain of the eyes.

ASHRAE has recognized that polluted urban air, designated within the United States Environmental Protection Agency (EPA)'s air quality ratings as unacceptable requires the installation of treatment such as filtration for which the HVAC practitioners generally apply carbon-impregnated filters and their like. 

In 1973, in response to the 1973 oil crisis and conservation concerns, ASHRAE Standards 62-73 and 62-81 reduced required ventilation from 10 cubic feet per minute (4.7 L/s) per person to 5 cubic feet per minute (2.4 L/s) per person, but this was found to be a contributing factor to sick building syndrome. As of the 2016 revision, ASHRAE ventilation standards call for 5 to 10 cubic feet per minute of ventilation per occupant (depending on the occupancy type) in addition to ventilation based on the zone floor area delivered to the breathing zone.

Psychological factors

One study looked at commercial buildings and their employees, comparing some environmental factors suspected of inducing SBS to a self-reported survey of the occupants, finding that the measured psycho-social circumstances appeared more influential than the tested environmental factors. The list of environmental factors in the study can be found here. Limitations of the study include that it only measured the indoor environment of commercial buildings, which have different building codes than residential buildings, and that the assessment of building environment was based on layman observation of a limited number of factors. 

Research has shown that SBS shares several symptoms common in other conditions thought to be at least partially caused by psychosomatic tendencies. The umbrella term "autoimmune/inflammatory syndrome induced by adjuvants" has been suggested. Other members of the suggested group include Silicosis, Macrophagic myofascitis, Gulf War syndrome, Post-vaccination phenomena.

Workplace

Greater effects were found with features of the psychosocial work environment including high job demands and low support. The report concluded that the physical environment of office buildings appears to be less important than features of the psychosocial work environment in explaining differences in the prevalence of symptoms. However, there is still a relationship between sick building syndrome and symptoms of workers regardless of workplace stress.

Excessive work stress or dissatisfaction, poor interpersonal relationships and poor communication are often seen to be associated with SBS, recent studies show that a combination of environmental sensitivity and stress can greatly contribute to sick building syndrome.

Specific work-related stressors are related with specific SBS symptoms. Workload and work conflict are significantly associated with general symptoms (headache, abnormal tiredness, sensation of cold or nausea). While crowded workspaces and low work satisfaction are associated with upper respiratory symptoms.

Specific careers are also associated with specific SBS symptoms. Transport, communication, healthcare, and social workers have highest prevalence of general symptoms. Skin symptoms such as eczema, itching, and rashes on hands and face are associated with technical work. Forestry, agriculture, and sales workers have the lowest rates of sick building syndrome symptoms.

Milton et al. determined the cost of sick leave specific for one business was an estimated $480 per employee, and about five days of sick leave per year could be attributed to low ventilation rates. When comparing low ventilation rate areas of the building to higher ventilation rate areas, the relative risk of short-term sick leave was 1.53 times greater in the low ventilation areas.

Work productivity has been associated with ventilation rates, a contributing factor to SBS, and there's a significant increase in production as ventilation rates increase, by 1.7% for every two-fold increase of ventilation rate.

Home

Sick building syndrome can also occur due to factors of the home. Laminated flooring can cause more exposure to chemicals and more resulting SBS symptoms compared to stone, tile, and cement flooring. Recent redecorating and new furnishings within the last year were also found to be associated with increased symptoms, along with dampness and related factors, having pets, and the presence of cockroaches. The presence of mosquitoes was also a factor related to more symptoms, though it is unclear whether it was due to the presence of mosquitoes or the use of repellents.

Diagnosis

While sick building syndrome (SBS) encompasses a multitude of non-specific symptoms, building-related illness (BRI) comprises specific, diagnosable symptoms caused by certain agents (chemicals, bacteria, fungi, etc.). These can typically be identified, measured, and quantified. There are usually 4 causal agents in BRI; 1.) Immunologic, 2.) Infectious, 3.) toxic, and 4.) irritant. For instance, Legionnaire's disease, usually caused by Legionella pneumophila, involves a specific organism which could be ascertained through clinical findings as the source of contamination within a building. SBS does not have any known cure; alleviation consists of removing the affected person from the building associated with non-specific symptoms. BRI, on the other hand, utilizes treatment appropriate for the contaminant identified within the building (e.g., antibiotics for Legionnaire's disease). In most cases, simply improving the indoor air quality (IAQ) of a particular building will attenuate, or even eliminate, the acute symptoms of SBS, while removal of the source contaminant would prove more effective for a specific illness, as in the case of BRI. Building-Related Illness is vital to the overall understanding of Sick Building Syndrome because BRI illustrates a causal path to infection, theoretically. Office BRI may more likely than not be explained by three events: “Wide range in the threshold of response in any population (susceptibility), a spectrum of response to any given agent, or variability in exposure within large office buildings." Isolating any one of the three aspects of office BRI can be a great challenge, which is why those who find themselves with BRI should take three steps, history, examinations, and interventions. History describes the action of continually monitoring and recording the health of workers experiencing BRI, as well as obtaining records of previous building alterations or related activity. Examinations go hand in hand with monitoring employee health. This step is done by physically examining the entire workspace and evaluating possible threats to health status among employees. Interventions follow accordingly based off the results of the Examination and History report.

Prevention

• Toxin-absorbing plants, such as sansevieria.
• Roof shingle non-pressure cleaning for removal of algae, mold, and Gloeocapsa magma.
• Using ozone to eliminate the many sources, such as VOC, molds, mildews, bacteria, viruses, and even odors. However, numerous studies identify High-ozone shock treatment as ineffective despite commercial popularity and popular belief.
• Replacement of water-stained ceiling tiles and carpeting.
• Only using paints, adhesives, solvents, and pesticides in well-ventilated areas or only using these pollutant sources during periods of non-occupancy.
• Increasing the number of air exchanges; the American Society of Heating, Refrigeration and Air-Conditioning Engineers recommend a minimum of 8.4 air exchanges per 24-hour period.
• Proper and frequent maintenance of HVAC systems.
• UV-C light in the HVAC plenum.
• Installation of HVAC Air Cleaning systems or devices to remove VOC's, bioeffluents (people odors) from HVAC systems conditioned air.
• Regular vacuuming with a HEPA filter vacuum cleaner to collect and retain 99.97% of particles down to and including 0.3 micrometers.
• Place bedding in sunshine, which is related to a study done in a high-humidity area where damp bedding was common and associated with SBS.
• Increased ventilation rates that are above the minimum guidelines.
• Lighting in the workplace should be designed to give individuals control, and be natural when possible.

Epidemiology

Some studies have shown a small difference between genders, with women having slightly higher reports of SBS symptoms compared to men. However, many other studies have shown an even higher difference in the report of sick building syndrome symptoms in women compared to men. It is not entirely clear, however, if this is due to biological, social, or occupational factors. 

A 2001 study published in the Journal Indoor Air 2001 gathered 1464 office-working participants to increase the scientific understanding of gender differences under the Sick Building Syndrome phenomenon. Using questionnaires, ergonomic investigations, building evaluations, as well as physical, biological, and chemical variables, the investigators obtained results that compare with past studies of SBS and gender. The study team found that across most test variables, prevalence rates were different in most areas, but there was also a deep stratification of working conditions between genders as well. For example, men’s workplace tend to be significantly larger and have all around better job characteristics.  Secondly, there was a noticeable difference in reporting rates, finding that women have higher rates of reporting roughly 20% higher than men. This information was similar to that found in previous studies, indicating a potential difference in willingness to report.

There might be a gender difference in reporting rates of sick building syndrome because women tend to report more symptoms than men do. Along with this, some studies have found that women have a more responsive immune system and are more prone to mucosal dryness and facial erythema. Also, women are alleged by some to be more exposed to indoor environmental factors because they have a greater tendency to have clerical jobs, wherein they are exposed to unique office equipment and materials (example: blueprint machines), whereas men often have jobs based outside of offices.

History

In the late 1970s, it was noted that nonspecific symptoms were reported by tenants in newly constructed homes, offices, and nurseries. In media it was called "office illness". The term "Sick Building Syndrome" was coined by the WHO in 1986, when they also estimated that 10-30% of newly built office buildings in the West had indoor air problems. Early Danish and British studies reported symptoms. 

Poor indoor environments attracted attention. The Swedish allergy study (SOU 1989:76) designated "sick building" as a cause of the allergy epidemic as was feared. In the 1990s, therefore, extensive research into "sick building" was carried out. Various physical and chemical factors in the buildings were examined on a broad front. 

The problem was highlighted increasingly in media and was described as a "ticking time bomb". Many studies were performed in individual buildings. 

In the 1990s "sick buildings" were contrasted against "healthy buildings". The chemical contents of building materials were highlighted. Many building material manufacturers were actively working to gain control of the chemical content and to replace criticized additives. The ventilation industry advocated above all more well-functioning ventilation. Others perceived ecological construction, natural materials, and simple techniques as a solution. 

At the end of the 1990s came an increased distrust of the concept of "sick building". A dissertation at the Karolinska Institutet in Stockholm 1999 questioned the methodology of previous research, and a Danish study from 2005 showed these flaws experimentally. It was suggested that sick building syndrome was not really a coherent syndrome and was not a disease to be individually diagnosed. In 2006 the Swedish National Board of Health and Welfare recommended in the medical journal Läkartidningen that "sick building syndrome" should not be used as a clinical diagnosis. Thereafter, it has become increasingly less common to use terms such as "sick buildings" and "sick building syndrome" in research. However, the concept remains alive in popular culture and is used to designate the set of symptoms related to poor home or work environment engineering. "Sick building" is therefore an expression used especially in the context of workplace health. 

Sick building syndrome made a rapid journey from media to courtroom where professional engineers and architects became named defendants and were represented by their respective professional practice insurers. Proceedings invariably relied on expert witnesses, medical and technical experts along with building managers, contractors and manufacturers of finishes and furnishings, testifying as to cause and effect. Most of these actions resulted in sealed settlement agreements, none of these being dramatic. The insurers needed a defense based upon Standards of Professional Practice to meet a court decision that declared—that in a modern, essentially sealed building, the HVAC systems must produce breathing air for suitable human consumption. ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers, currently with over 50,000 international members) undertook the task of codifying its IAQ (Indoor Air Quality) standard. 

ASHRAE empirical research determined that "acceptability" was a function of outdoor (fresh air) ventilation rate and used carbon dioxide as an accurate measurement of occupant presence and activity. Building odors and contaminants would be suitably controlled by this dilution methodology. ASHRAE codified a level of 1,000 ppm of carbon dioxide and specified the use of widely available sense-and-control equipment to assure compliance. The 1989 issue of ASHRAE 62.1-1989 published the whys and wherefores and overrode the 1981 requirements that were aimed at a ventilation level of 5,000 ppm of carbon dioxide, (the OAHA workplace limit), federally set to minimize HVAC system energy consumption. This apparently ended the SBS epidemic.

Over time, building materials changed with respect to emissions potential. Smoking vanished and dramatic improvements in ambient air quality, coupled with code compliant ventilation and maintenance, per ASHRAE standards have all contributed to the acceptability of the indoor air environment. Only time and the courts will tell how right, or wrong ASHRAE is.