Oil shale geology

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https://en.wikipedia.org/wiki/Oil_shale_geology

Outcrop of Ordovician kukersite oil shale, northern Estonia

Lower Jurassic oil shale near Holzmaden, Germany

Oil shale geology is a branch of geologic sciences which studies the formation and composition of oil shales–fine-grained sedimentary rocks containing significant amounts of kerogen, and belonging to the group of sapropel fuels. Oil shale formation takes place in a number of depositional settings and has considerable compositional variation. Oil shales can be classified by their composition (carbonate minerals such as calcite or detrital minerals such as quartz and clays) or by their depositional environment (large lakes, shallow marine, and lagoon/small lake settings). Much of the organic matter in oil shales is of algal origin, but may also include remains of vascular land plants. Three major type of organic matter (macerals) in oil shale are telalginite, lamalginite, and bituminite. Some oil shale deposits also contain metals which include vanadium, zinc, copper, and uranium.

Most oil shale deposits were formed during Middle Cambrian, Early and Middle Ordovician, Late Devonian, Late Jurassic, and Paleogene times through burial by sedimentary loading on top of the algal swamp deposits, resulting in conversion of the organic matter to kerogen by diagenetic processes. The largest deposits are found in the remains of large lakes such as the deposits of the Green River Formation of Wyoming and Utah, USA. Oil-shale deposits formed in the shallow seas of continental shelves generally are much thinner than large lake basin deposits.

Classification and varieties

Cannel coal from the Pennsylvanian of northeastern Ohio

Marinite from Jordan

Lamosite from the Mahogany Zone of the Green River Formation, Colorado

Oil shale belongs to the group of sapropel fuels. It does not have a definite geological definition nor a specific chemical formula, and its seams do not always have discrete boundaries. Oil shales vary considerably in their mineral content, chemical composition, age, type of kerogen, and depositional history and not all oil shales would necessarily be classified as shales in the strict sense. Their common feature is low solubility in low-boiling organic solvents and generation of liquid organic products on thermal decomposition.

There are varying classifications of oil shales depending on their mineral content, type of kerogen, age, depositional history, and organisms from which they are derived. The age of the known oil shale deposits ranges from Cambrian to Paleogene age. Lithologies comprise shales and marl and carbonate rocks, all of which form a mixture of tightly bound organic matter and inorganic components.

Oil shales have been divided into three categories based on mineral composition – carbonate-rich shale, siliceous shale and cannel shale. Carbonate-rich shales derive their name from the large amount of carbonate minerals such as calcite and dolomite. As many as twenty carbonate minerals have been found in oil shales, the majority of which are considered authigenic or diagenetic. Carbonate-rich oil shales, particularly that of lacustrine-sourced deposits, have usually the organic-rich layers sandwiched between carbonate-rich layers. These deposits are hard formations that are resistant to weathering and they are difficult to process using ex-situ methods. Siliceous oil shales are usually dark brown or black shales. They are not rich in carbonates but rather in siliceous minerals such as quartz, feldspar, clay, chert and opal. Siliceous shales are not as hard and weather-resistant as carbonate-rich shales, and may be better suited for extraction via ex-situ methods. Cannel shales are usually dark brown or black shales, which consist of organic matter that completely encloses other mineral grains. They are suitable for extraction via ex-situ methods.

Another classification according to the type of kerogen, is based on the hydrogen, carbon, and oxygen content of the original organic matter in the oil shale. This classification is using the Van Krevelen diagram. The most used classification of oil shales was developed between 1987 and 1991 by Adrian C. Hutton of the University of Wollongong, adapting petrographic terms from coal terminology. According to this classification, oil shales are designated as terrestrial, lacustrine (lake-bottom-deposited), or marine (ocean bottom-deposited), based on the environment where the initial biomass was deposited. Hutton's classification scheme has proven useful in estimating the yield and composition of the extracted oil.

Classification of oil shales by environment of deposition

Terrestrial	Lacustrine	Marine
cannel coal	lamosite; torbanite	kukersite; tasmanite; marinite

Cannel coal (also called candle coal) is a type of terrestrial shale, which is hydrogen-rich brown to black coal, sometimes with shaly texture, composed of resins, spores, waxes, cutinaceous and corky materials derived from terrestrial vascular plants as well as varied amounts of vitrinite and inertinite. Lacustrine shales consist of lamosite and torbanite. Lamosite is a pale-brown and grayish-brown to dark-gray to black oil shale whose chief organic constituent is lamalginite derived from lacustrine planktonic algae. Torbanite, named after Torbane Hill in Scotland, is a black oil shale whose organic matter is telalginite derived from lipid-rich Botryococcus and related algal forms. Marine shales consist of three varieties, namely kukersite, tasmanite, and marinite. Kukersite, named after Kukruse in Estonia, is a light-brown marine oil shale whose principal organic component is telalginite derived from the green alga, Gloeocapsomorpha prisca. Tasmanite, named after Tasmania, is a brown to black oil shale whose organic matter consists of telalginite derived chiefly from unicellular tasmanitid algae of marine origin. Marinite is a gray to dark-gray to black oil shale of marine origin in which the chief organic components are lamalginite and bituminite derived from marine phytoplankton with varied admixtures of bitumen, telalginite, and vitrinite.

Composition

Fossils in Ordovician kukersite oil shale, northern Estonia

Photomicrograph showing detail of the varves in a rich Colorado oil shale specimen. The organic laminae are themselves finely laminated. The mineral laminae contain considerable organic matter, but they are readily distinguished by their coarser grain and greater thickness. Note sand grains (white). Enlarged 320 diameters.

Fossil in oil shale from Messel pit, south of Frankfurt am Main, Germany

As a sapropel fuel, oil shale differs from humus fuels in its lower content of organic matter. The organic matter has an atomic ratio of hydrogen to carbon of about 1.5 – approximately the same as that of crude oil and four to five times higher than coals. The organic matter in oil shales forms a complex macromolecular structure which is insoluble in common organic solvents. It is mixed with varied amounts of mineral matter. For commercial grades of oil shale, the ratio of organic matter to mineral matter is about 0.75:5 to 1.5:5.

The organic portion of oil shale consists largely of a pre-bitumen bituminous groundmass, such as remains of algae, spores, pollen, plant cuticles and corky fragments of herbaceous and woody plants, and cellular debris from other lacustrine, marine, and land plants. While terrestrial oil shales contain resins, spores, waxy cuticles, and corky tissues of roots and stems of vascular terrestrial plants, lacustrine oil shales include lipid-rich organic matter derived from algae. Marine oil shales are composed of marine algae, acritarchs, and marine dinoflagellates. Organic matter in oil shale also contains organic sulfur (about 1.8% on average) and a lower proportion of nitrogen.

Three major types of organic matter (macerals) in oil shale are telalginite, lamalginite, and bituminite. Telalginite is defined as structured organic matter composed of large colonial or thick-walled unicellular algae such as Botryococcus and Tasmanites. Lamalginite includes thin-walled colonial or unicellular algae that occur as distinct laminae, but display few or no recognizable biologic structures. Under the microscope, telalginite and lamalginite are easily recognized by their bright shades of yellow under ultraviolet/blue fluorescent light. Bituminite is largely amorphous, lacks recognizable biologic structures, and displays relatively low fluorescence under the microscope. Other organic constituents include vitrinite and inertinite, which are macerals derived from the humic matter of land plants. These macerals are usually found in relatively small amounts in most oil shales.

Mineral matter in oil shale contains fine-grained silicate and carbonate minerals such as calcite, dolomite, siderite, quartz, rutile, orthoclase, albite, anorthite, muscovite, amphipole, marcasite, limonite, gypsum, nahcolite, dawsonite and alum. Some oil-shale deposits also contain metals such as vanadium, zinc, copper, and uranium among others.

General composition of oil shales

Inorganic matrix	Bitumens	Kerogens
quartz; feldspars; clays (mainly illite and chlorite; carbonates (calcite and dolomite); pyrite and others	soluble in CS2	insoluble in CS2; containing uranium, iron, vanadium, nickel, molybdenum, etc.

Formation

Most oil shale deposits were formed during Middle Cambrian, Early and Middle Ordovician, Late Devonian, Late Jurassic and Paleogene times. These were formed by the deposition of organic matter in a variety of depositional environments including freshwater to highly saline lakes, epicontinental marine basins and subtidal shelves and were restricted to estuarine areas such as oxbow lakes, peat bogs, limnic and coastal swamps, and muskegs. When plants die in such an anaerobic aquatic environment, low oxygen levels prevent their complete bacterial decay.

For undecayed organic matter to be preserved and to form oil shale, the environment must remain uniform for prolonged periods of time in order to build up sufficiently thick sequences of algal matter. Eventually, the algal swamp or other restricted environment is disrupted and oil shale accumulation ceases. Burial by sedimentary loading on top of the algal swamp deposits converts the organic matter to kerogen by the following normal diagenetic processes:

• Compaction due to sediment loading on the coal, leading to compression of the organic matter.
• With ongoing heat and compaction, removal of moisture in the peat and from the intracellular structure of fossilized plants, and removal of molecular water.
• Methanogenesis—similar to treating wood in a pressure cooker— results in methane being produced, removing hydrogen, some carbon, and some further oxygen.
• Dehydration, which removes hydroxyl groups from the cellulose and other plant molecules, resulting in the production of hydrogen-reduced coals or oil shales.

Though similar in their formation process, oil shales differ from coals in several distinct ways. The precursors of the organic matter in oil shale and coal differ in a sense that oil shale is of algal origin, but may also include remains of vascular land plants that more commonly compose much of the organic matter in coal. The origin of some of the organic matter in oil shale is obscure because of the lack of recognizable biologic structures that would help identify the precursor organisms. Such materials may be of bacterial origin or the product of bacterial degradation of algae or other organic matter.

Lower temperature and pressure during the diagenesis process compared to other modes of hydrocarbon generation result in a lower maturation level of oil shale. Continuous burial and further heating and increased pressure over time could result in the conventional production of oil and gas from the oil shale source rock. The largest deposits are found in the remains of large lakes such as the deposits of the Green River Formation of Wyoming and Utah, USA. Large lake oil shale basins are typically found in areas of block faulting or crustal warping due to mountain building. Deposits such as the Green River may be as much as 2,000 feet (610 m) and yield up to 40 gallons of oil for each ton (166 L/t) of shale.

Oil shale deposits formed in the shallow seas of continental shelves generally are much thinner than large lake basin deposits. These are typically a few meters thick and are spread over very large areas, extending up to thousands of square kilometers. Of the three lithologic types of oil shales, siliceous oil shales are most commonly found in such environments. These oil shales are not as organically rich as lake-deposited oil shales, and generally do not contain more than 30 gallons of extractable oil per ton of oil shale. Oil shales deposited in lagoonal or small lake environments are rarely extensive and are often associated with coal-bearing rocks. These oil shales can have high yields– as much as 40 gallons per ton (166 L/t) of oil shale. However, due to their small areal extent, they are considered unlikely candidates for commercial exploitation.

Formations in the United States

The United States has two significant oil shale deposits which are suited for commercial development due to their size, grade and location. The Eocene Green River Formation covers parts of Colorado, Wyoming and Utah; the second significant deposit is Devonian oil shales in the eastern United States. In both places, there are sub-basins varying in volume and quality of the reserves. Oil shale in the Green River Formation is found in five sedimentary basins namely, Green River, Uinta, Piceance Creek, Sand Wash and Washakie. The first three have undergone some significant exploration and attempts to commercialize the oil shale reserves since the 1960s. The Green River Formation includes deposits from two large lakes which covered an estimated area of over 65,000 square kilometres (25,100 sq mi) during the Early to Middle Eocene. These lakes were separated by the Uinta uplift and the Axial Basin anticline. For significant periods during their 10 Ma life, the lakes became closed systems allowing many changes in size, salinity and sedimentation. The deposition of oil shales resulted from abundant blue-green algae that thrived in the lakes.

The oil shale that underlies almost 750,000 square kilometres (289,580 sq mi) in the eastern United States was formed in a marine depositional environment, very different from the Green River Basins. These deposits have also undergone commercialization attempts; they are also resources for natural gas and have been mined for low-grade oil shale. These oil shales were formed during the Late Devonian and Early Mississippian periods. During this time, much of the eastern United States was covered by a large shallow sea. The oil shale is thought to have been the result of slow deposition of planktonic algae, under anoxic conditions. In parts of the basin close to the shoreline, the organic mixture that helped form the oil shale contains organic-rich sediment from the rising Appalachian Mountains.

Formations in Brazil

Brazil has nine significant locations of oil shale deposits. The size, location and quality of oil shale deposits in the Paraíba Valley and the Irati Formation have attracted the most attention. These two contain an estimated 1.4 billion barrels of in-situ shale oil with total resources as much as more than three billion barrels. While the "Irati formation" deposit is the smaller of the two, containing an estimated 600 million barrels in-situ compared to 840 million in the Paraíba Valley formation, the former is more economically viable.

The Irati Formation consists of two oil shale beds separated by 12 metres (40 ft) of limestone and shale. The upper layer is thicker (9 metres (30 ft)) but the thinner lower bed (4 metres (10 ft)) is of greater value; the weight percent of shale oil yield is around 12% for the lower layer as compared to 7% for the upper one. The oil shale yield varies laterally, and may be as little as 7% for the lower layer and 4% for the upper layer. The formation is a very fine grained and laminated deposit ranging in color from dark gray to brown to black. While 60–70% of the shale consists of clay minerals, the balance is made up of organic matter.

No consensus has been reached on the exact depositional nature of the Irati oil shale. One theory suggests that the organic material in the Irati oil shale originated from algae deposited in a lacustrine environment with salinity varying from that of freshwater to brackish water. Other theory suggests that the organic sediment may have been deposited in a shallow, partially restricted marine environment. Hutton's classification describes it as a marine source oil shale.

Formation in Estonia

The kukersite oil shale of Ordovician age in Estonia is part of the Baltic oil shale basin and was deposited in shallow marine environments. The deposit is one of the world’s highest-grade deposits with more than 40% organic content and 66% conversion ratio into shale oil and gas. The oil shale is located in a single calcareous layer 2.5 to 3 metres (8.2 to 9.8 ft) in thickness and is buried at depths from 7 to 100 metres (23 to 328 ft). The total area of the basin is about 3,000 square kilometres (1,200 sq mi). Oil yield from Kukersite is 30 to 47%. Most of the organic matter is derived from the fossil green alga, Gloeocapsomorpha prisca, which has affinities to the modern cyanobacterium, Entophysalis major, an extant species that forms algal mats in inter-tidal to very shallow subtidal waters. Matrix minerals include low-magnesium calcite, dolomite, and siliciclastic minerals. It is not enriched in heavy metals.

Reserves

Main article: Oil shale reserves

As source rocks for most conventional oil reservoirs, oil shale deposits are found in all world oil provinces, although most of them are too deep to be exploited economically. As with all oil and gas resources, analysts distinguish between oil shale resources and oil shale reserves. "Resources" refers to all oil shale deposits, while "reserves", represents those deposits from which producers can extract oil shale economically using existing technology. Since extraction technologies develop continuously, planners can only estimate the amount of recoverable kerogen. Although resources of oil shale occur in many countries, only 33 countries possess known deposits of possible economic value. Well-explored deposits, potentially classifiable as reserves, include the Green River deposits in the western United States, the Tertiary deposits in Queensland, Australia, deposits in Sweden and Estonia, the El-Lajjun deposit in Jordan, and deposits in France, Germany, Brazil, China, southern Mongolia and Russia. These deposits have given rise to expectations of yielding at least 40 liters of shale oil per tonne of oil shale, using the Fischer Assay.

A 2008 estimate set the total world resources of oil shale at 689 gigatons — equivalent to yield of 4.8 trillion barrels (760 billion cubic metres) of shale oil, with the largest reserves in the United States, which is thought to have 3.7 trillion barrels (590 billion cubic metres), though only a part of it is recoverable. According to the 2010 World Energy Outlook by the International Energy Agency, the world oil shale resources may be equivalent of more than 5 trillion barrels (790 billion cubic metres) of oil in place of which more than 1 trillion barrels (160 billion cubic metres) may be technically recoverable. For comparison, the world's proven conventional oil reserves were estimated at 1.317 trillion barrels (209.4×10⁹ m³), as of 1 January 2007. The largest known commercial deposits in the world occur in the United States in the Green River Formation, which covers portions of Colorado, Utah, and Wyoming; about 70% of this resource lies on land owned or managed by the United States federal government. Deposits in the United States constitute 62% of world resources; together, the United States, Russia and Brazil account for 86% of the world's resources in terms of shale-oil content. These figures remain tentative, with exploration or analysis of several deposits still outstanding. Professor Alan R. Carroll of University of Wisconsin–Madison regards the Upper Permian lacustrine oil-shale deposits of northwest China, absent from previous global oil shale assessments, as comparable in size to the Green River Formation.

Environmental impact of the oil shale industry

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Kiviõli Oil Shale Processing & Chemicals Plant in Ida-Virumaa, Estonia

Environmental impact of the oil shale industry includes the consideration of issues such as land use, waste management, and water and air pollution caused by the extraction and processing of oil shale. Surface mining of oil shale deposits causes the usual environmental impacts of open-pit mining. In addition, the combustion and thermal processing generate waste material, which must be disposed of, and harmful atmospheric emissions, including carbon dioxide, a major greenhouse gas. Experimental in-situ conversion processes and carbon capture and storage technologies may reduce some of these concerns in future, but may raise others, such as the pollution of groundwater.

Surface mining and retorting

Land use and waste management

Surface mining and in-situ processing requires extensive land use. Mining, processing, and waste disposal require land to be withdrawn from traditional uses, and therefore should avoid high density population areas. Oil shale mining reduces the original ecosystem diversity with habitats supporting a variety of plants and animals. After mining the land has to be reclaimed, process takes time and cannot necessarily re-establish the original biodiversity. The impact of sub-surface mining on the surroundings will be less than for open pit mines. However, sub-surface mining may also cause subsidence of the surface due to the collapse of mined-out area and abandoned stone drifts.

Disposal of mining wastes, spent oil shale (including semi-coke) and combustion ashes needs additional land use. According to the study of the European Academies Science Advisory Council, after processing, the waste material occupies a greater volume than the material extracted, and therefore cannot be wholly disposed underground. According to this, production of a barrel of shale oil can generate up to 1.5 tonnes of semi-coke, which may occupy up to 25% greater volume than the original shale. This is not confirmed by the results of Estonia's oil shale industry. The mining and processing of about one billion tonnes of oil shale in Estonia has created about 360-370 million tonnes of solid waste, of which 90 million tonnes is a mining waste, 70–80 million tonnes is a semi-coke, and 200 million tonnes are combustion ashes.

The waste material may consist of several pollutants including sulfates, heavy metals, and polycylic aromatic hydrocarbons (PAHs), some of which are toxic and carcinogenic. To avoid contamination of the groundwater, the solid waste from the thermal treatment process is disposed in an open dump (landfill or "heaps"), not underground where it could potentially reach clean ground water. As semi-coke consists of, in addition to minerals, up to 10% organics that may pose hazard to the environment owing to leaching of toxic compounds as well as to the possibility of self-ignition.

Water management

Mining influences the water runoff pattern of the area affected. In some cases it requires the lowering of groundwater levels below the level of the oil shale strata, which may have harmful effects on the surrounding arable land and forest. In Estonia, for each cubic meter of oil shale mined, 25 cubic meters of water must be pumped from the mine area. At the same time, the thermal processing of oil shale needs water for quenching hot products and the control of dust. Water concerns are a particularly sensitive issue in arid regions, such as the western part of the United States and Israel's Negev Desert, where there are plans to expand the oil shale industry. Depending on technology, above-ground retorting uses between one and five barrels of water per barrel of produced shale oil.  In situ processing, according to one estimate, uses about one-tenth as much water.

Water is the main transmitter of oil shale industry pollutants. One environmental issue is to prevent noxious materials leaching from spent shale into the water supply. The oil shale processing is accompanied by the formation of process waters and waste waters containing phenols, tar and several other products, heavily separable and toxic to the environment. A 2008 programmatic environmental impact statement issued by the United States Bureau of Land Management stated that surface mining and retort operations produce 2 to 10 U.S. gallons (7.6 to 37.9 L; 1.7 to 8.3 imp gal) of waste water per 1 short ton (0.91 t) of processed oil shale.

Air pollution management

Main air pollution is caused by the oil shale-fired power plants. These factory plants provide the atmospheric emissions of gaseous products like nitrogen oxides, sulfur dioxide and hydrogen chloride, and the airborne particulate matter (fly ash). It includes particles of different types (carbonaceous, inorganic ones) and different sizes. The concentration of air pollutants in flue gas depends primarily on the combustion technology and burning regime, while the emissions of solid particles are determined by the efficiency of fly ash-capturing devices.

Open deposition of semi-coke causes distribution of pollutants in addition to aqueous vectors also via air (dust).

There are possible links from being in an oil shale area to a higher risk of asthma and lung cancer than other areas.

Greenhouse gas emissions

Carbon dioxide emissions from the production of shale oil and shale gas are higher than conventional oil production and a report for the European Union warns that increasing public concern about the adverse consequences of global warming may lead to opposition to oil shale development.

Emissions arise from several sources. These include CO₂ released by the decomposition of the kerogen and carbonate minerals in the extraction process, the generation of the energy needed to heat the shale and in the other oil and gas processing operations, and fuel used in the mining of the rock and the disposal of waste. As the varying mineral composition and calorific value of oil shale deposits varies widely, the actual values vary considerably. At best, the direct combustion of oil shales produces carbon emissions similar to those from the lowest form of coal, lignite, at 2.15 moles CO₂/MJ, an energy source which is also politically contentious due to its high emission levels. For both power generation and oil extraction, the CO₂ emissions can be reduced by better utilization of waste heat from the product streams.

In-situ processing

Currently, the in-situ process is the most attractive proposition due to the reduction in standard surface environmental problems. However, in-situ processes do involve possible significant environmental costs to aquifers, especially since in-situ methods may require ice-capping or some other form of barrier to restrict the flow of the newly gained oil into the groundwater aquifers. However, after the removal of the freeze wall these methods can still cause groundwater contamination as the hydraulic conductivity of the remaining shale increases allowing groundwater to flow through and leach salts from the newly toxic aquifer.

 

Environmental impact of fracking

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Fracking
Shale gas drilling rig near Alvarado, Texas The environmental impact of fracking is related to land use and water consumption, air emissions, including methane emissions, brine and fracturing fluid leakage, water contamination, noise pollution, and health. Water and air pollution are the biggest risks to human health from fracking. Research has determined that fracking negatively affects human health and drives climate change. Fracking fluids include proppants and other substances, which include chemicals known to be toxic, as well as unknown chemicals that may be toxic. In the United States, such additives may be treated as trade secrets by companies who use them. Lack of knowledge about specific chemicals has complicated efforts to develop risk management policies and to study health effects. In other jurisdictions, such as the United Kingdom, these chemicals must be made public and their applications are required to be nonhazardous.

Water usage by fracking can be a problem in areas that experience water shortage. Surface water may be contaminated through spillage and improperly built and maintained waste pits, in jurisdictions where these are permitted. Further, ground water can be contaminated if fracturing fluids and formation fluids are able to escape during fracking. However, the possibility of groundwater contamination from the fracturing fluid upward migration is negligible, even in a long-term period. Produced water, the water that returns to the surface after fracking, is managed by underground injection, municipal and commercial wastewater treatment, and reuse in future wells. There is potential for methane to leak into ground water and the air, though escape of methane is a bigger problem in older wells than in those built under more recent legislation.

Fracking causes induced seismicity called microseismic events or microearthquakes. The magnitude of these events is too small to be detected at the surface, being of magnitude M-3 to M-1 usually. However, fluid disposal wells (which are often used in the USA to dispose of polluted waste from several industries) have been responsible for earthquakes up to 5.6M in Oklahoma and other states.

Governments worldwide are developing regulatory frameworks to assess and manage environmental and associated health risks, working under pressure from industry on the one hand, and from anti-fracking groups on the other. In some countries like France a precautionary approach has been favored and fracking has been banned. The United Kingdom's regulatory framework is based on the conclusion that the risks associated with fracking are manageable if carried out under effective regulation and if operational best practices are implemented. It has been suggested by the authors of meta-studies that in order to avoid further negative impacts, greater adherence to regulation and safety procedures are necessary.

Air emissions

A report for the European Union on the potential risks was produced in 2012. Potential risks are "methane emissions from the wells, diesel fumes and other hazardous pollutants, ozone precursors or odours from hydraulic fracturing equipment, such as compressors, pumps, and valves". Also gases and hydraulic fracturing fluids dissolved in flowback water pose air emissions risks. One study measured various air pollutants weekly for a year surrounding the development of a newly fractured gas well and detected nonmethane hydrocarbons, methylene chloride (a toxic solvent), and polycyclic aromatic hydrocarbons. These pollutants have been shown to affect fetal outcomes.

The relationship between hydraulic fracturing and air quality can influence acute and chronic respiratory illnesses, including exacerbation of asthma (induced by airborne particulates, ozone and exhaust from equipment used for drilling and transport) and COPD. For example, communities overlying the Marcellus shale have higher frequencies of asthma. Children, active young adults who spend time outdoors, and the elderly are particularly vulnerable. OSHA has also raised concerns about the long-term respiratory effects of occupational exposure to airborne silica at hydraulic fracturing sites. Silicosis can be associated with systemic autoimmune processes.

"In the UK, all oil and gas operators must minimise the release of gases as a condition of their licence from the Department of Energy and Climate Change (DECC). Natural gas may only be vented for safety reasons."

Also transportation of necessary water volume for hydraulic fracturing, if done by trucks, can cause emissions. Piped water supplies can reduce the number of truck movements necessary.

A report from the Pennsylvania Department of Environmental Protection indicated that there is little potential for radiation exposure from oil and gas operations.

Air pollution is of particular concern to workers at hydraulic fracturing well sites as the chemical emissions from storage tanks and open flowback pits combine with the geographically compounded air concentrations from surrounding wells. Thirty seven percent of the chemicals used in hydraulic fracturing operations are volatile and can become airborne.

Researchers Chen and Carter from the Department of Civil and Environmental Engineering, University of Tennessee, Knoxville used atmospheric dispersion models (AERMOD) to estimate the potential exposure concentration of emissions for calculated radial distances of 5 m to 180m from emission sources. The team examined emissions from 60,644 hydraulic fracturing wells and found “results showed the percentage of wells and their potential acute non-cancer, chronic non-cancer, acute cancer, and chronic cancer risks for exposure to workers were 12.41%, 0.11%, 7.53%, and 5.80%, respectively. Acute and chronic cancer risks were dominated by emissions from the chemical storage tanks within a 20 m radius.

Climate change

Hydraulic fracturing is a driver of climate change. However, whether natural gas produced by hydraulic fracturing causes higher well-to-burner emissions than gas produced from conventional wells is a matter of contention. Some studies have found that hydraulic fracturing has higher emissions due to methane released during completing wells as some gas returns to the surface, together with the fracturing fluids. Depending on their treatment, the well-to-burner emissions are 3.5%–12% higher than for conventional gas.

A debate has arisen particularly around a study by professor Robert W. Howarth finding shale gas significantly worse for global warming than oil or coal. Other researchers have criticized Howarth's analysis, including Cathles et al., whose estimates were substantially lower." A 2012 industry funded report co-authored by researchers at the United States Department of Energy's National Renewable Energy Laboratory found emissions from shale gas, when burned for electricity, were "very similar" to those from so-called "conventional well" natural gas, and less than half the emissions of coal.

Studies which have estimated lifecycle methane leakage from natural gas development and production have found a wide range of leakage rates. According to the Environmental Protection Agency's Greenhouse Gas Inventory, the methane leakage rate is about 1.4%. A 16-part assessment of methane leakage from natural gas production initiated by the Environmental Defense Fund found that fugitive emissions in key stages of the natural gas production process are significantly higher than estimates in the EPA's national emission inventory, with a leakage rate of 2.3 percent of overall natural gas output.

Water consumption

Massive hydraulic fracturing typical of shale wells uses between 1.2 and 3.5 million US gallons (4,500 and 13,200 m³) of water per well, with large projects using up to 5 million US gallons (19,000 m³). Additional water is used when wells are refractured. An average well requires 3 to 8 million US gallons (11,000 to 30,000 m³) of water over its lifetime. According to the Oxford Institute for Energy Studies, greater volumes of fracturing fluids are required in Europe, where the shale depths average 1.5 times greater than in the U.S. Whilst the published amounts may seem large, they are small in comparison with the overall water usage in most areas. A study in Texas, which is a water shortage area, indicates "Water use for shale gas is <1% of statewide water withdrawals; however, local impacts vary with water availability and competing demands."

A report by the Royal Society and the Royal Academy of Engineering shows the usage expected for hydraulic fracturing a well is approximately the amount needed to run a 1,000 MW coal-fired power plant for 12 hours. A 2011 report from the Tyndall Centre estimates that to support a 9 billion cubic metres per annum (320×10⁹ cu ft/a) gas production industry, between 1.25 to 1.65 million cubic metres (44×10⁶ to 58×10⁶ cu ft) would be needed annually,^[47] which amounts to 0.01% of the total water abstraction nationally.

Concern has been raised over the increasing quantities of water for hydraulic fracturing in areas that experience water stress. Use of water for hydraulic fracturing can divert water from stream flow, water supplies for municipalities and industries such as power generation, as well as recreation and aquatic life. The large volumes of water required for most common hydraulic fracturing methods have raised concerns for arid regions, such as the Karoo in South Africa, and in drought-prone Texas, in North America. It may also require water overland piping from distant sources.

A 2014 life cycle analysis of natural gas electricity by the National Renewable Energy Laboratory concluded that electricity generated by natural gas from massive hydraulically fractured wells consumed between 249 gallons per megawatt-hour (gal/MWhr) (Marcellus trend) and 272 gal/MWhr (Barnett Shale). The water consumption for the gas from massive hydraulic fractured wells was from 52 to 75 gal/MWhr greater (26 percent to 38 percent greater) than the 197 gal/MWhr consumed for electricity from conventional onshore natural gas.

Some producers have developed hydraulic fracturing techniques that could reduce the need for water. Using carbon dioxide, liquid propane or other gases instead of water have been proposed to reduce water consumption. After it is used, the propane returns to its gaseous state and can be collected and reused. In addition to water savings, gas fracturing reportedly produces less damage to rock formations that can impede production. Recycled flowback water can be reused in hydraulic fracturing.^[30] It lowers the total amount of water used and reduces the need to dispose of wastewater after use. The technique is relatively expensive, however, since the water must be treated before each reuse and it can shorten the life of some types of equipment.

Water contamination

Injected fluid

In the United States, hydraulic fracturing fluids include proppants, radionuclide tracers, and other chemicals, many of which are toxic. The type of chemicals used in hydraulic fracturing and their properties vary. While most of them are common and generally harmless, some chemicals are carcinogenic. Out of 2,500 products used as hydraulic fracturing additives in the United States, 652 contained one or more of 29 chemical compounds which are either known or possible human carcinogens, regulated under the Safe Drinking Water Act for their risks to human health, or listed as hazardous air pollutants under the Clean Air Act. Another 2011 study identified 632 chemicals used in United States natural gas operations, of which only 353 are well-described in the scientific literature. A study that assessed health effects of chemicals used in fracturing found that 73% of the products had between 6 and 14 different adverse health effects including skin, eye, and sensory organ damage; respiratory distress including asthma; gastrointestinal and liver disease; brain and nervous system harms; cancers; and negative reproductive effects.

An expansive study conducted by the Yale School of Public Health in 2016 found numerous chemicals involved in or released by hydraulic fracturing are carcinogenic. Of the 119 compounds identified in this study with sufficient data, “44% of the water pollutants...were either confirmed or possible carcinogens.” However, the majority of chemicals lacked sufficient data on carcinogenic potential, highlighting the knowledge gap in this area. Further research is needed to identify both carcinogenic potential of chemicals used in hydraulic fracturing and their cancer risk.

The European Union regulatory regime requires full disclosure of all additives. According to the EU groundwater directive of 2006, "in order to protect the environment as a whole, and human health in particular, detrimental concentrations of harmful pollutants in groundwater must be avoided, prevented or reduced." In the United Kingdom, only chemicals that are "non hazardous in their application" are licensed by the Environment Agency.

Flowback

Less than half of injected water is recovered as flowback or later production brine, and in many cases recovery is <30%. As the fracturing fluid flows back through the well, it consists of spent fluids and may contain dissolved constituents such as minerals and brine waters. In some cases, depending on the geology of the formation, it may contain uranium, radium, radon and thorium. Estimates of the amount of injected fluid returning to the surface range from 15-20% to 30–70%.

Approaches to managing these fluids, commonly known as produced water, include underground injection, municipal and commercial wastewater treatment and discharge, self-contained systems at well sites or fields, and recycling to fracture future wells. The vacuum multi-effect membrane distillation system as a more effective treatment system has been proposed for treatment of flowback. However, the quantity of waste water needing treatment and the improper configuration of sewage plants have become an issue in some regions of the United States. Part of the wastewater from hydraulic fracturing operations is processed there by public sewage treatment plants, which are not equipped to remove radioactive material and are not required to test for it.

Produced water spills and subsequent contamination of groundwater also presents a risk for exposure to carcinogens. Research that modeled the solute transport of BTEX (benzene, toluene, ethylbenzene, and xylene) and naphthalene for a range of spill sizes on contrasting soils overlying groundwater at different depths found that benzene and toluene were expected to reach human health relevant concentration in groundwater because of their high concentrations in produced water, relatively low solid/liquid partition coefficient and low EPA drinking water limits for these contaminants. Benzene is a known carcinogen which affects the central nervous system in the short term and can affect the bone marrow, blood production, immune system, and urogenital systems with long term exposure.

Surface spills

Surface spills related to the hydraulic fracturing occur mainly because of equipment failure or engineering misjudgments.

Volatile chemicals held in waste water evaporation ponds can evaporate into the atmosphere, or overflow. The runoff can also end up in groundwater systems. Groundwater may become contaminated by trucks carrying hydraulic fracturing chemicals and wastewater if they are involved in accidents on the way to hydraulic fracturing sites or disposal destinations.

In the evolving European Union legislation, it is required that "Member States should ensure that the installation is constructed in a way that prevents possible surface leaks and spills to soil, water or air." Evaporation and open ponds are not permitted. Regulations call for all pollution pathways to be identified and mitigated. The use of chemical proof drilling pads to contain chemical spills is required. In the UK, total gas security is required, and venting of methane is only permitted in an emergency.

Methane

In September 2014, a study from the US Proceedings of the National Academy of Sciences released a report that indicated that methane contamination can be correlated to distance from a well in wells that were known to leak. This however was not caused by the hydraulic fracturing process, but by poor cementation of casings.

Groundwater methane contamination has adverse effect on water quality and in extreme cases may lead to potential explosion. A scientific study conducted by researchers of Duke University found high correlations of gas well drilling activities, including hydraulic fracturing, and methane pollution of the drinking water. According to the 2011 study of the MIT Energy Initiative, "there is evidence of natural gas (methane) migration into freshwater zones in some areas, most likely as a result of substandard well completion practices i.e. poor quality cementing job or bad casing, by a few operators." A 2013 Duke study suggested that either faulty construction (defective cement seals in the upper part of wells, and faulty steel linings within deeper layers) combined with a peculiarity of local geology may be allowing methane to seep into waters; the latter cause may also release injected fluids to the aquifer. Abandoned gas and oil wells also provide conduits to the surface in areas like Pennsylvania, where these are common.

A study by Cabot Oil and Gas examined the Duke study using a larger sample size, found that methane concentrations were related to topography, with the highest readings found in low-lying areas, rather than related to distance from gas production areas. Using a more precise isotopic analysis, they showed that the methane found in the water wells came from both the formations where hydraulic fracturing occurred, and from the shallower formations. The Colorado Oil & Gas Conservation Commission investigates complaints from water well owners, and has found some wells to contain biogenic methane unrelated to oil and gas wells, but others that have thermogenic methane due to oil and gas wells with leaking well casing. A review published in February 2012 found no direct evidence that hydraulic fracturing actual injection phase resulted in contamination of ground water, and suggests that reported problems occur due to leaks in its fluid or waste storage apparatus; the review says that methane in water wells in some areas probably comes from natural resources.

Another 2013 review found that hydraulic fracturing technologies are not free from risk of contaminating groundwater, and described the controversy over whether the methane that has been detected in private groundwater wells near hydraulic fracturing sites has been caused by drilling or by natural processes.

Radionuclides

Main article: Naturally occurring radioactive material

There are naturally occurring radioactive materials (NORM), for example radium, radon, uranium, and thorium, in shale deposits. Brine co-produced and brought to the surface along with the oil and gas sometimes contains naturally occurring radioactive materials; brine from many shale gas wells, contains these radioactive materials. The U.S. Environmental Protection Agency and regulators in North Dakota consider radioactive material in flowback a potential hazard to workers at hydraulic fracturing drilling and waste disposal sites and those living or working nearby if the correct procedures are not followed. A report from the Pennsylvania Department of Environmental Protection indicated that there is little potential for radiation exposure from oil and gas operations.

Land use

In the UK, the likely well spacing visualised by the December 2013 DECC Strategic Environmental Assessment report indicated that well pad spacings of 5 km were likely in crowded areas, with up to 3 hectares (7.4 acres) per well pad. Each pad could have 24 separate wells. This amounts to 0.16% of land area. A study published in 2015 on the Fayetteville Shale found that a mature gas field impacted about 2% of the land area and substantially increased edge habitat creation. Average land impact per well was 3 hectares (about 7 acres)  In another case study for a watershed in Ohio, lands disturbed over 20 years amount to 9.7% of the watershed area, with only 0.24% attributed to fracking wellpad construction. Research indicates that effects on ecosystem services costs (i.e. those processes that the natural world provides to humanity) has reached over $250 million per year in the U.S.

Seismicity

Hydraulic fracturing causes induced seismicity called microseismic events or microearthquakes. These microseismic events are often used to map the horizontal and vertical extent of the fracturing. The magnitude of these events is usually too small to be detected at the surface, although the biggest micro-earthquakes may have the magnitude of about -1.5 (M_w).

Induced seismicity from hydraulic fracturing

As of August 2016, there were at least nine known cases of fault reactivation by hydraulic fracturing that caused induced seismicity strong enough to be felt by humans at the surface: In Canada, there have been three in Alberta (M 4.8 and M 4.4 and M 4.4) and three in British Columbia (M 4.6, M 4.4 and M 3.8); In the United States there has been: one in Oklahoma (M 2.8) and one in Ohio (M 3.0), and; In the United Kingdom, there have been two in Lancashire (M 2.3 and M 1.5).

Induced seismicity from water disposal wells

According to the USGS only a small fraction of roughly 30,000 waste fluid disposal wells for oil and gas operations in the United States have induced earthquakes that are large enough to be of concern to the public. Although the magnitudes of these quakes has been small, the USGS says that there is no guarantee that larger quakes will not occur. In addition, the frequency of the quakes has been increasing. In 2009, there were 50 earthquakes greater than magnitude 3.0 in the area spanning Alabama and Montana, and there were 87 quakes in 2010. In 2011 there were 134 earthquakes in the same area, a sixfold increase over 20th century levels. There are also concerns that quakes may damage underground gas, oil, and water lines and wells that were not designed to withstand earthquakes.

A 2012 US Geological Survey study reported that a "remarkable" increase in the rate of M ≥ 3 earthquakes in the US midcontinent "is currently in progress", having started in 2001 and culminating in a 6-fold increase over 20th century levels in 2011. The overall increase was tied to earthquake increases in a few specific areas: the Raton Basin of southern Colorado (site of coalbed methane activity), and gas-producing areas in central and southern Oklahoma, and central Arkansas. While analysis suggested that the increase is "almost certainly man-made", the USGS noted: "USGS's studies suggest that the actual hydraulic fracturing process is only very rarely the direct cause of felt earthquakes." The increased earthquakes were said to be most likely caused by increased injection of gas-well wastewater into disposal wells. The injection of waste water from oil and gas operations, including from hydraulic fracturing, into saltwater disposal wells may cause bigger low-magnitude tremors, being registered up to 3.3 (M_w).

Noise

Each well pad (in average 10 wells per pad) needs during preparatory and hydraulic fracturing process about 800 to 2,500 days of activity, which may affect residents. In addition, noise is created by transport related to the hydraulic fracturing activities. Noise pollution from hydraulic fracturing operations (e.g., traffic, flares/burn-offs) is often cited as a source of psychological distress, as well as poor academic performance in children. For example, the low-frequency noise that comes from well pumps contributes to irritation, unease, and fatigue.

The UK Onshore Oil and Gas (UKOOG) is the industry representative body, and it has published a charter that shows how noise concerns will be mitigated, using sound insulation, and heavily silenced rigs where this is needed.

Safety issues

In July 2013, the United States Federal Railroad Administration listed oil contamination by hydraulic fracturing chemicals as "a possible cause" of corrosion in oil tank cars.

Community impacts

Impacted communities are often already vulnerable, including poor, rural, or indigenous persons, who may continue to experience the deleterious effects of hydraulic fracturing for generations. Facility siting in fracking projects disproportionately tilts towards lower income communities, a persisting issue partially due to these disadvantaged residents not having the resources to evade environmental hazards. A spatial analysis of the demographics of residents around fracking sites found that median incomes around wells in Pennsylvania were substantially lower. Competition for resources between farmers and oil companies contributes to stress for agricultural workers and their families, as well as to a community-level “us versus them” mentality that creates community distress. Rural communities that host hydraulic fracturing operations often experience a “boom/bust cycle,” whereby their population surges, consequently exerting stress on community infrastructure and service provision capabilities (e.g., medical care, law enforcement). A study of rural communities around fracking sites in Pennsylvania found that while there was some local support of fracking as a source of jobs and a boost to small businesses, there was more skepticism of if these jobs would stay within the community at all, and if there would be a significant 'bust' to the economy after the natural gas dried up.

Indigenous and agricultural communities may be particularly impacted by hydraulic fracturing, given their historical attachment to, and dependency on, the land they live on, which is often damaged as a result of the hydraulic fracturing process. Native Americans are especially vulnerable to the negative environmental impacts of fracking operations, in part due to existing legislature surrounding fracking wastewater and environmental pollutants on indigenous lands. The Resource Conservation and Recovery Act (RCRA) has a special exemption preventing indigenous groups from protecting their water sources with quality standards. Native Americans, particularly those living on rural reservations, may be particularly vulnerable to the effects of fracturing; that is, on the one hand, tribes may be tempted to engage with the oil companies to secure a source of income but, on the other hand, must often engage in legal battles to protect their sovereign rights and the natural resources of their land.

While hydraulic fracturing is primarily recognized for its impacts on the natural environment, it also can provide stressors on a community's mental state. Research suggests that the activity surrounding fracking operations leads to a degree of degradation in 'socio-psychological functioning' of surrounding community members. In an attempt to support findings from the existing literature, one study performed a series of interviews with residents of Denton, Texas to get a community's personalized testimony. These discussions found that residents experienced heightened stress, anxiety, and hopelessness, as well as feeling a 'lack of control' over their community. Researchers also uncovered polarizing attitudes, a communal rift forming between those with pro and anti fracking beliefs.

Policy and science

Main article: Regulation of hydraulic fracturing

There are two main approaches to regulation that derive from policy debates about how to manage risk and a corresponding debate about how to assess risk.

The two main schools of regulation are science-based assessment of risk and the taking of measures to prevent harm from those risks through an approach like hazard analysis, and the precautionary principle, where action is taken before risks are well-identified. The relevance and reliability of risk assessments in communities where hydraulic fracturing occurs has also been debated amongst environmental groups, health scientists, and industry leaders. The risks, to some, are overplayed and the current research is insufficient in showing the link between hydraulic fracturing and adverse health effects, while to others the risks are obvious and risk assessment is underfunded.

Different regulatory approaches have thus emerged. In France and Vermont for instance, a precautionary approach has been favored and hydraulic fracturing has been banned based on two principles: the precautionary principle and the prevention principle. Nevertheless, some States such as the U.S. have adopted a risk assessment approach, which had led to many regulatory debates over the issue of hydraulic fracturing and its risks.

In the UK, the regulatory framework is largely being shaped by a report commissioned by the UK Government in 2012, whose purpose was to identify the problems around hydraulic fracturing and to advise the country's regulatory agencies. Jointly published by the Royal Society and the Royal Academy of Engineering, under the chairmanship of Professor Robert Mair, the report features ten recommendations covering issues such as groundwater contamination, well integrity, seismic risk, gas leakages, water management, environmental risks, best practice for risk management, and also includes advice for regulators and research councils. The report was notable for stating that the risks associated with hydraulic fracturing are manageable if carried out under effective regulation and if operational best practices are implemented.

A 2013 review concluded that, in the US, confidentiality requirements dictated by legal investigations have impeded peer-reviewed research into environmental impacts.

When looking at the regulations of fracking from the perspective of land rights, historic and continuing injustices against Native Americans are one angle to consider. Some legislature, such as the National Environmental Policy Act (NEPA), is written in a way that it only protects indigenous 'cultural resources' on specifically allocated tribal lands. This allows historically marginalizing policies of land allocation by the United States government to continue to determine harmful land use practices in Native American communities. For example, the Greater Chaco Canyon region, which spans across Arizona, Colorado, New Mexico, and Utah, is home to ancient Puebloan architecture, extremely significant grounds to descendant indigenous groups. Most of these lands, however, are controlled by the United States Forest Service (USFS) and the Bureau of Land Management (BLM), leaving them vulnerable to development from the oil sector. These organizations, particularly the BLM, have a recent history of allowing oil companies to exploit the resources beneath federal lands.

One significant roadblock to meaningful fracking legislation lies in the industry being relegated as a state-level decision. Without federal oversight, the Safe Drinking Water Act (SDWA), the Resource Conservation and Recovery Act (RCRA), the Clean Water Act (CWA), and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) omit fracking activity from their respective languages.

There are numerous scientific limitations to the study of the environmental impact of hydraulic fracturing. The main limitation is the difficulty in developing effective monitoring procedures and protocols, for which there are several main reasons:

• Variability among fracturing sites in terms of ecosystems, operation sizes, pad densities, and quality-control measures makes it difficult to develop a standard protocol for monitoring.
• As more fracturing sites develop, the chance for interaction between sites increases, greatly compounding the effects and making monitoring of one site difficult to control. These cumulative effects can be difficult to measure, as many of the impacts develop very slowly.
• Due to the vast number of chemicals involved in hydraulic fracturing, developing baseline data is challenging. In addition, there is a lack of research on the interaction of the chemicals used in hydraulic fracturing fluid and the fate of the individual components.

Prenatal and perinatal psychology

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Prenatal_and_perinatal_psychology

Prenatal and perinatal psychology explores the psychological and psychophysiological effects and implications of the earliest experiences of the individual, before birth, prenatal, as well as during and immediately after childbirth, perinatal. Prenatal and perinatal psychology can be seen as a part of developmental psychology, although historically it was developed in the heterogenous field of psychoanalysis. Prenatal and perinatal psychology are often discussed together to group the period during pregnancy, childbirth, and through the early stages of infancy. The role of prenatal and perinatal psychology is to explain the experience and behavior of the individual before birth, postnatal consequences, and the lasting effects on development that occur during this time period.

Although there are various perspectives on the topic, a common thread is the importance of prenatal and perinatal experiences in the shaping the future psychological development. There is a debate among scientists regarding the extent to which newborn infants are capable of forming memories, the effects of any such memories on their personality, and the possibility of recovering them from an unconscious mind, which itself is the subject of argument in the field. A widespread assumption concerning the prenatal phase was that the fetus is almost completely shielded from outside stimuli. Thus, perception and consciousness would develop after birth. Meanwhile, there is a great number of scientific studies which show clearly that behaviour, perception and learning is already developed before birth. This also holds for nonhuman species, as for rat fetuses acoustic conditioning can be demonstrated.

Psycho-physiological aspects of the prenatal and perinatal phases

Fetus, connected with the mother by umbilical cord and placenta

The physiological development while in the prenatal phase – especially that of the brain – is of particular importance for prenatal psychology. In the first eight weeks after insemination, the developing child is called an embryo. After the inner organs have developed (from the ninth week on) it is called a fetus. There are three stages of fetal development. The first stage is the germinal stage begins at conception and is the shortest stage. The second stage is the embryonic stage which begins around the third week of pregnancy and ends at the eighth week. The final stage is the fetal stage which begins at the ninth week of pregnancy and lasts until birth. Another way to measure pregnancy is by trimesters. The first trimester is from conception to 12 weeks of pregnancy, the second trimester is from 13 to 28 weeks of pregnancy, and the third trimester is from 29 weeks until birth. During the prenatal phase, the fetus is developing the structures to carry out cognitive functions, such as brain cells, brain waves, and forming the lobes and other structures of the brain. 

Prenatal development

The basis of perception, experience, and behaviour is the brain. This is dependent on the presence of the structures in the brain that must be formed during gestation. While in gestation, a giant neuronal net is developing, delivering the condition for any mental process. About half of the developing neurons become destroyed again during the development of the brain because of the "programmed cell death" (apoptosis). At birth the infantile brain contains 100 billion neurons – as many as in the brain of an adult. In order to have this many neurons at birth, the fetus's brain must produce neurons at the rate of 250,000 per minute. At birth, every cortical neuron is connected with about 2500 neurons; after a year, with about 15 000. Synapses develop, and are destroyed, over the whole life span – a process called neuroplasticity.

In the first trimester, the 3 to 4 weeks following conception, the neural groove closes into the neural tube that the human brain develops from to create the hindbrain, midbrain, and the forebrain. These three structures are vital for human development. The hindbrain regulates unconscious automatic functions, the midbrain is a relay center for sensory and motor nerve impulses, and the forebrain is essential for processing incoming information. The spinal cord will also develop from this neural tube in the first trimester. If this neural tube does not close completely, the fetus may have a birth disorder called spina bifida. In the case of spina bifida myelomeningocele, the fetus may experience changes to their brain structure among other developmental problems.  The second trimester is also essential for perinatal brain development. By week 20 of pregnancy, the area of the brain that is responsible for the awareness of the fetus's five sense begins to develop. In the fifth month of pregnancy, the fetal senses can be stimulated which results in the growth of synapses. The fetus, while not able to make sense of and process what they are hearing, has the ability to hear, feel pressure and different temperatures. The third trimester has many perinatal brain development milestones. In the 30th week, the fetus can control its own body heat. In the 31st week, the fetus is able to process more stimuli and information. While the other structures and organs of the fetus are mostly formed by this point, the brain continues to develop and only weighs two-thirds of what it should at birth. 

Maternal care during pregnancy has a lot of impact throughout prenatal development. One factor of improper maternal care is the use of substances throughout pregnancy which has several different effects on the fetus. Those who are pregnant and use substances during pregnancy have an association with also delaying or not seeking prenatal care, and those who delay prenatal care typically do not participate in follow up services. This is most likely to occur in younger pregnancy situations with alcohol abuse. This not only causes the fetus to be vulnerable to negative physiological and psychological effects as a result of no prenatal care, but it also creates insecure attachment of the mother towards the fetus during the prenatal stage which can then translate to insecure attachment in the perinatal stage. 

Perinatal Development

The development that occurs during the perinatal period is extremely impactful and predictive of the ability to emotionally regulate later in life. Secure attachment is essential to healthy development in the early infancy and perinatal stages. Improper attachment during these early stages can result in negative psychiatric manifestations including reactive attachment disorder (RAD), post traumatic stress disorder (PTSD), personality disorders, or disinhibited social engagement disorder. John Bowlby and Mary Ainsworth developed the attachment theory that describes the differences in avoidant-insecure attachment, disorganized-insecure attachment, secure attachment, and ambivalant-insecure attachment as well as the formation of attachment. The process of forming attachment begins at birth in the pre-attachment stage which lasts from birth to six weeks. In this stage, there is indiscriminate attachment where the infant will seek comfort in any caregiver. The next stage is attachment in the making occurring from the first six weeks to six months of the infants life. This stage is when the infant is more aware of a distinct caregiver and will seek comfort and trust in them. Following this stage is the clear-cut attachment stage which begins at six months old in the infant and lasts until they are about two years old. This is the stage in which the attachment style is most clear and will reflect the formation of reciprocal relationships stage from two years old and onwards. 

There are several factors that could influence parental and child attachment types such as the status of the parental relationship. Parents and guardians who are in stable relationships have greater capability to respond to infants needs and provide more secure attachments in turn. Another factor of insecure attachment in the perinatal stage is the environment. Regardless of the parent or guardians ability to provide emotional support, if an infant is in an unsafe environment this often leads to attachment issues as a result of feeling unsafe, in pain, or feelings of distress. Maternal depression has the ability to result in attachment issues between mother and infant as depression causes the parent to be unable to respond to the infants cues. Parents and guardians who are depressed are less likely to make eye contact with their infant, show variety in facial expressions, or convey emotional activity. Lack of exposure to emotional variety especially conveying positive emotions towards an infant results in emotional disregulation and disorganized or anxious insecure attachment. 

Motor development

In the 1930s the physiologist Davenport Hooker examined reflexes or reactions, respectively of aborted fetuses extrauterine. Currently, the motor skills of embryo and fetus can be examined with ultrasound techniques quite easily. From the eighth week on the embryo moves the rump, shortly after that his extremities. With the means of sonography one could demonstrate that these were not simple reflexes, but also endogenously provoked movements. According to Alessandra Piontelli, the fetus shows all patterns of movement which later can be found in the newborn.

The first movements in the fetus occur around the seven to eighth week of pregnancy. During this time, slight bending of the head and lower extremities can be picked up on. As the pregnancy progresses, so does movement of the fetus. General movements occur around the ninth and tenth week followed by more concise and complex movements. At the twelve to thirteen week milestone, the fetus can bring their hands towards their face. The thirteen to fourteen week mark shows evidence of the ability to swallow. The fifteenth week the fetus has the ability to suck their fingers. Eye movements are shown to exist from the 18th week on, from the 23rd week on there are rapid-eye-movements (REM-phases). These are connected with sleeping patterns and dreaming. Breath movements can be seen from the 19th week on, with the fetus taking amniotic fluid into his lungs.  Fetuses drink amniotic fluid and urinate into it.

Fetal activity and motor development can be altered by a variety of maternal factors. There is higher fetal activity when the mother is laying down and a decrease in activity when the mother is active or during exercise. Use of substances while pregnant can also affect activity and development of the fetus. Use of opiates or alcohol while pregnant results in a decrease in amount and duration of movements of the fetus while nicotine can result in a decrease in movement of the fetus, especially breathing movements. 

Development of perception and prenatal learning

The sense modalities of the fetus develop prenatally and are functioning very well at birth. The examination of such abilities is connected with experimental examination of behaviour, provoked by stimuli. Ray examined vibro-acoustic conditioning of human fetuses. According to Hepper it rested uncertain, if such conditioning was successful. Hepper claims to have repeat such conditioning experiments successfully, with the earliest vibro-acoustic conditioning in the 32nd week of gestation.

Prenatal learning often is examined by using the habituation paradigm. The fetus gets exposed to a stimulus, e.g. an acoustic one. Afterwards the experimenter watches the extinction of the reaction while repeating the same stimulus again and again. This procedure becomes completed by the use of a new stimulus and the recording of the according reaction. When the new stimulus is identified by the fetus as different from the old one, it releases a new pattern of reaction, e.g. accelerated frequency of the heart. If this does not happen, the new stimulus cannot be distinguished from the old focal stimulus. In 1991 a study demonstrated the acoustic habituation by recording the heart frequency of foetuses in the 29th week of gestation. Such studies can be used for examining memory. Fetuses older than 34 weeks of gestation can reproduce learned content over a period of 4 weeks. The earliest vibro-acoustic conditioning is successful at 22-week-old fetuses. Maybe habituation to taste is possible even earlier. Such habituation was also demonstrated in fetal rats.

Babies remember musical patterns they once heard in the womb, as W. Ernest Freud – a grandson of Sigmund Freud – could demonstrate. The empirical proof used the registration of heart frequency and motorical activity.

Also the development of speech is based on prenatal learning, as the study of DeCasper and Fifer from 1980 seems to demonstrate. This study used operant conditioning as a paradigm. Several empirical studies demonstrated that prenatal learning exists.

Historical development of psychoanalytical and depth psychological theories concerning prenatal life

Otto Rank (standing, left corner) and other psychoanalysts in 1922

Most psychoanalytical theories assume that the development of objects, the self and even consciousness begins after birth. Nevertheless, some psychoanalysts explicitly write that pre- and perinatal aspects are responsible for certain symptom formations, among them Otto Rank, Nandor Fodor, Francis J. Mott, Donald Winnicott, Gustav Hans Graber and Ludwig Janus. They think that the structuring of the unconscious psyche starts in the prenatal phase. The fetus already has early, emotionally relevant experiences. They assume the existence of perception in several sense modaliaties, states of asphyxia, fears and stress, which are stored and can be remembered after birth under certain circumstances. In psychoanalysis pre- and perinatal topics usually are seen as fantasies. The manifest prenatal content of dreaming or fantasizing of swimming under water while breathing, being inside of a cave, fighting with underwater monsters – are interpreted as re-projections in time onto the early phase. Janus assumes that in many psychoanalytical approaches there can be found contentual and phenomenological aspects close to prenatal psychology – but without explicit references. Janus wrote of the "hidden attendance of the prenatal existence" in the works of psychoanalysts such as Sandor Ferenczi, Carl Gustav Jung, Melanie Klein, Bela Grunberger, Françoise Dolto and others.

In 1924 Otto Rank (1884–1939), one of Sigmund Freud's disciples, published his book The Trauma of Birth (German: Das Trauma der Geburt und seine Bedeutung für die Psychoanalyse). There he stated that the emotional shock of being born is an individual's first source of anxiety. Because of this book the friendship between Freud and Rank came to an end. Rank was of the opinion that birth is connected with an overwhelming experience of fear of the fetus. He also presumed that this trauma was the cause of later anxieties. He also claimed that aspects of the later prenatal phase can be remembered. So already Rank himself had developed the outlines of a true prenatal psychology. In the light of such assumptions he interpreted cultural aspects, e.g. he understood Christian fantasies of the hell as being based on aversive intrauterine situations. In his book, he treated the interpretation of symbols, art and myths by using pre- and perinatal assumptions. Rank believed that a "primal fixation" with the prenatal state is the root of all neuroses and character disorders and developed a process of psychoanalysis based on birth experiences.

Donald Winnicott (1896–1971) tried to understand very early forms of symbol formation. He described in several case studies the reenactment of perinatal experiences in psychotherapies, especially of children. A five-year-old boy climbed into Winnicott's jacket and then slit down the pants onto the ground. He repeated this again and again. Winnicott interpreted this game as a regression and a repeating of birth. He presumed that some babies developed a paranoid attitude by having problems at birth, e.g. in the case of asphyxia. Also psychosomatic symptoms (headaches, breast- and breathing problems and feelings of getting choked) were interpreted as possible consequences of birth experiences by Winnicott. Nevertheless, he rejected the assumption of a universal birth trauma.

In his book The Search for the Beloved: A Clinical Investigation of the Trauma of Birth and Prenatal Condition of 1949 the British-American psychoanalyst Nandor Fodor (1895–1964) traced certain forms of anxiety back to unprocessed and repressed birth experiences following Rank's assumptions, who had been his psychoanalyst. Fodor interpreted dreams, experiencing the lack of oxygen, claustrophobia and sexual disorders and their etiology, which he explained by assuming specific pre- and perinatal experiences.

Francis John Mott (1901–1980) was a disciple of Fodor and the first author who concentrated on the placenta as the first object of the fetus. He wrote, that the fetus fears his placenta as a "blood sucker" or experience it as a "feeder" or "life-giver". His work an prenatal aspects is connected with his speculative assumptions on a quasi-religious design of the universe.

Material emerging from sessions of psychedelic psychotherapy using LSD and other hallucinogenic drugs was the foundation for research into the enduring effects of pre- and perinatal experiences in adult life conducted by Frank Lake, Athanasios Kafkalides (1919–1989) and Stanislav Grof. Grof went on to formulate an extensive theoretical framework for the analysis of pre- and perinatal experiences, based on the four constructs he called Basic Perinatal Matrices. Lake and Grof independently developed breathing techniques, following Wilhelm Reich (1897–1957) as an alternative to the use of psychedelic drugs, which was subject to considerable legal difficulty from the mid-1960s onwards. A related technique called Rebirthing was developed by psychotherapist Leonard Orr in the 1970s, and Core Process psychotherapy trainees relive presumed birth trauma as part of their training.

The US-American social scientist Lloyd deMause (born 1931) compiled in his essay from 1981 the psychoanalytic approaches to prenatal mental life as well as the physiological findings of the human ontogenesis concerning fetal development. He took several assumptions from the works of Grof and Mott, but left away their metaphysical implications completely. In his own approach he assumes, that the placenta becomes the first object of the fetus, namely in two split versions: a positive and a negative one, he called the "nurturing" and the "poisonous placenta". DeMause presumed that in every gestation – especially at the end of this period – there are problems of supply with oxygen for the fetus. Because of physiological conditions the placenta would not be able anymore to supply the growing fetus with enough oxygen. This would give rise to states of pain and deprivation. Pre- and perinatal experiences lead to a mental script, a kind of pattern, to which later experiences would be connected with and internalized. He calls the experience of successive good and painful states the "fetal drama", long precursing the well known "oedipal drama" sensu Freud. Besides these theories about prenatal psychology deMause also developed approaches in the field of psychohistory – a system of cultural psychological assumptions, which explain historical processes and phenomenons by using psychological theories. Especially aspects of childhood history and prenatal psychology play an important role.

Fetus at 14 weeks (profile)

In 1992 the Italian child neuropsychiatrist Alessandra Piontelli (born 1945) published a study in her book From Fetus to Child: An Observational and Psychoanalytic Study (1992). Using sonography she examined the behaviour of 11 fetuses. The fetuses showed a very complex behavioural repertoire and were quite different concerning their forms of activities. They reacted to stimuli in complex ways. Piontelli's study suggested that certain prenatal experiences determined later mental life. Psychological traits, e.g. enhanced oral activity, were recognizable in the prenatal phase, and also after birth. Piontelli interpreted her observations in psychoanalytical terms. Piontelli saw a remarkable continuity between pre- and postnatal mental development. Her study is important, because it combines the assessment of empirical data with the observation of single case studies in the postnatal phase and also in infancy. Her study use equally the methods of academic psychology together with the hermeneutics of psychoanalysis, what makes it unique in the scientific landscape.