15.3: Water Pollution - Biology

15.3: Water Pollution - Biology

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The global water crisis also involves water pollution. Globally, improving water safety, sanitation, and hygiene could prevent up to 9% of all disease and 6% of all deaths.

In addition to the global waterborne disease crisis, chemical pollution from agriculture, industry, cities, and mining threatens global water quality. Some chemical pollutants have serious and well-known health effects, whereas many others have poorly known long-term health effects. In the U.S. currently more than 40,000 water bodies fit the definition of “impaired” set by EPA, which means they could neither support a healthy ecosystem nor meet water quality standards. In Gallup public polls conducted over the past decade Americans consistently put water pollution and water supply as the top environmental concerns over issues such as air pollution, deforestation, species extinction, and global warming.

Any natural water contains dissolved chemicals, some of which are important human nutrients while others can be harmful to human health. The concentration of a water pollutant is commonly given in very small units such as parts per million (ppm) or even parts per billion (ppb). An arsenic concentration of 1 ppm means 1 part of arsenic per million parts of water. This is equivalent to one drop of arsenic in 50 liters of water. To give you a different perspective on appreciating small concentration units, converting 1 ppm to length units is 1 cm (0.4 in) in 10 km (6 miles) and converting 1 ppm to time units is 30 seconds in a year. Total dissolved solids (TDS) represent the total amount of dissolved material in water. Average TDS values for rainwater, river water, and seawater are about 4 ppm, 120 ppm, and 35,000 ppm, respectively.

Water Pollution Overview

Water pollution is the contamination of water by an excess amount of a substance that can cause harm to human beings and/or the ecosystem. The level of water pollution depends on the abundance of the pollutant, the ecological impact of the pollutant, and the use of the water. Pollutants are derived from biological, chemical, or physical processes. Although natural processes such as volcanic eruptions or evaporation sometimes can cause water pollution, most pollution is derived from human, land-based activities (Figure (PageIndex{2})). Water pollutants can move through different water reservoirs, as the water carrying them progresses through stages of the water cycle (Figure (PageIndex{3})). Water residence time (the average time that a water molecule spends in a water reservoir) is very important to pollution problems because it affects pollution potential. Water in rivers has a relatively short residence time, so pollution usually is there only briefly. Of course, pollution in rivers may simply move to another reservoir, such as the ocean, where it can cause further problems. Groundwater is typically characterized by slow flow and longer residence time, which can make groundwater pollution particularly problematic. Finally, pollution residence time can be much greater than the water residence time because a pollutant may be taken up for a long time within the ecosystem or absorbed onto sediment.

Pollutants enter water supplies from point sources, which are readily identifiable and relatively small locations, or nonpoint sources, which are large and more diffuse areas. Point sources of pollution include animal factory farms (Figure (PageIndex{4})) that raise a large number and high density of livestock such as cows, pigs, and chickens. Also, pipes included are pipes from a factories or sewage treatment plants. Combined sewer systems that have a single set of underground pipes to collect both sewage and storm water runoff from streets for wastewater treatment can be major point sources of pollutants. During heavy rain, storm water runoff may exceed sewer capacity, causing it to back up and spilling untreated sewage directly into surface waters (Figure (PageIndex{5})).

Nonpoint sources of pollution include agricultural fields, cities, and abandoned mines. Rainfall runs over the land and through the ground, picking up pollutants such as herbicides, pesticides, and fertilizer from agricultural fields and lawns; oil, antifreeze, animal waste, and road salt from urban areas; and acid and toxic elements from abandoned mines. Then, this pollution is carried into surface water bodies and groundwater. Nonpoint source pollution, which is the leading cause of water pollution in the U.S., is usually much more difficult and expensive to control than point source pollution because of its low concentration, multiple sources, and much greater volume of water.

Types of Water Pollutants

Oxygen-demanding waste is an extremely important pollutant to ecosystems. Most surface water in contact with the atmosphere has a small amount of dissolved oxygen, which is needed by aquatic organisms for cellular respiration. Bacteria decompose dead organic matter and remove dissolved oxygen (O2) according to the following reaction:

[ ext{organic matter} + O_{2} ightarrow CO_{2} + H_{2} O]

Too much decaying organic matter in water is a pollutant because it removes oxygen from water, which can kill fish, shellfish, and aquatic insects. The amount of oxygen used by aerobic (in the presence of oxygen) bacterial decomposition of organic matter is called biochemical oxygen demand (BOD). The major source of dead organic matter in many natural waters is sewage; grass and leaves are smaller sources. An unpolluted water body with respect to BOD is a turbulent river that flows through a natural forest. Turbulence continually brings water in contact with the atmosphere where the O2 content is restored. The dissolved oxygen content in such a river ranges from 10 to 14 ppm O2, BOD is low, and clean-water fish such as trout. A polluted water body with respect to oxygen is a stagnant deep lake in an urban setting with a combined sewer system. This system favors a high input of dead organic carbon from sewage overflows and limited chance for water circulation and contact with the atmosphere. In such a lake, the dissolved O2 content is ≤5 ppm O2, BOD is high, and low O2-tolerant fish, such as carp and catfish dominate.

Excessive plant nutrients, particularly nitrogen (N) and phosphorous (P), are pollutants closely related to oxygen-demanding waste. Aquatic plants require about 15 nutrients for growth, most of which are plentiful in water. N and P are called limiting nutrients, however, because they usually are present in water at low concentrations and therefore restrict the total amount of plant growth. This explains why N and P are major ingredients in most fertilizer. High concentrations of N and P from human sources (mostly agricultural and urban runoff including fertilizer, sewage, and phosphorus-based detergent) can cause cultural eutrophication, which leads to the rapid growth of aquatic producers, particularly algae. Thick mats of floating algae or rooted plants lead to a form of water pollution that damages the ecosystem by clogging fish gills and blocking sunlight. A small percentage of algal species produce toxins that can kill animals, including humans. Exponential growths of these algae are called harmful algal blooms. When the prolific algal layer dies, it becomes oxygen-demanding waste, which can create very low O2 concentrations in the water (< 2 ppm O2), a condition called hypoxia. This results in a dead zone because it causes death from asphyxiation to organisms that are unable to leave that environment. An estimated 50% of lakes in North America, Europe, and Asia are negatively impacted by cultural eutrophication. In addition, the size and number of marine hypoxic zones have grown dramatically over the past 50 years including a very large dead zone located offshore Louisiana in the Gulf of Mexico. Cultural eutrophication and hypoxia are difficult to combat, because they are caused primarily by nonpoint source pollution, which is difficult to regulate, and N and P, which are difficult to remove from wastewater.

Pathogens are disease-causing microorganisms, e.g., viruses, bacteria, parasitic worms, and protozoa, which cause a variety of intestinal diseases such as dysentery, typhoid fever, and cholera. Pathogens are the major cause of the water pollution crisis discussed at the beginning of this section. Unfortunately nearly a billion people around the world are exposed to waterborne pathogen pollution daily and around 1.5 million children mainly in underdeveloped countries die every year of waterborne diseases from pathogens. Pathogens enter water primarily from human and animal fecal waste due to inadequate sewage treatment. In many underdeveloped countries, sewage is discharged into local waters either untreated or after only rudimentary treatment. In developed countries untreated sewage discharge can occur from overflows of combined sewer systems, poorly managed livestock factory farms, and leaky or broken sewage collection systems. Water with pathogens can be remediated by adding chlorine or ozone, by boiling, or by treating the sewage in the first place.

Oil spills are another kind of organic pollution. Oil spills can result from supertanker accidents such as the Exxon Valdez in 1989, which spilled 10 million gallons of oil into the rich ecosystem of coastal Alaska and killed massive numbers of animals. The largest marine oil spill was the Deepwater Horizon disaster, which began with a natural gas explosion (Figure (PageIndex{6})) at an oil well 65 km offshore of Louisiana and flowed for 3 months in 2010, releasing an estimated 200 million gallons of oil. The worst oil spill ever occurred during the Persian Gulf war of 1991, when Iraq deliberately dumped approximately 200 million gallons of oil in offshore Kuwait and set more than 700 oil well fires that released enormous clouds of smoke and acid rain for over nine months.

During an oil spill on water, oil floats to the surface because it is less dense than water, and the lightest hydrocarbons evaporate, decreasing the size of the spill but polluting the air. Then, bacteria begin to decompose the remaining oil, in a process that can take many years. After several months only about 15% of the original volume may remain, but it is in thick asphalt lumps, a form that is particularly harmful to birds, fish, and shellfish. Cleanup operations can include skimmer ships that vacuum oil from the water surface (effective only for small spills), controlled burning (works only in early stages before the light, ignitable part evaporates but also pollutes the air), dispersants (detergents that break up oil to accelerate its decomposition, but some dispersants may be toxic to the ecosystem), and bioremediation (adding microorganisms that specialize in quickly decomposing oil, but this can disrupt the natural ecosystem).

Toxic chemicals involve many different kinds and sources, primarily from industry and mining. General kinds of toxic chemicals include hazardous chemicals and persistent organic pollutants that include DDT (pesticide), dioxin (herbicide by-product), and PCBs (polychlorinated biphenyls, which were used as a liquid insulator in electric transformers). Persistent organic pollutants (POPs) are long-lived in the environment, biomagnify through the food chain, and can be toxic. Another category of toxic chemicals includes radioactive materials such as cesium, iodine, uranium, and radon gas, which can result in long-term exposure to radioactivity if it gets into the body. A final group of toxic chemicals is heavy metals such as lead, mercury, arsenic, cadmium, and chromium, which can accumulate through the food chain. Heavy metals are commonly produced by industry and at metallic ore mines. Arsenic and mercury are discussed in more detail below.

Arsenic (As) has been famous as an agent of death for many centuries. Only recently have scientists recognized that health problems can be caused by drinking small arsenic concentrations in water over a long time. It enters the water supply naturally from weathering of arsenic-rich minerals and from human activities such as coal burning and smelting of metallic ores. The worst case of arsenic poisoning occurred in the densely populated impoverished country of Bangladesh, which had experienced 100,000s of deaths from diarrhea and cholera each year from drinking surface water contaminated with pathogens due to improper sewage treatment. In the 1970s the United Nations provided aid for millions of shallow water wells, which resulted in a dramatic drop in pathogenic diseases. Unfortunately, many of the wells produced water naturally rich in arsenic. Tragically, there are an estimated 77 million people (about half of the population) who inadvertently may have been exposed to toxic levels of arsenic in Bangladesh as a result. The World Health Organization has called it the largest mass poisoning of a population in history.

Mercury (Hg) is used in a variety of electrical products, such as dry cell batteries, fluorescent light bulbs, and switches, as well as in the manufacture of paint, paper, vinyl chloride, and fungicides. Mercury acts on the central nervous system and can cause loss of sight, feeling, and hearing as well as nervousness, shakiness, and death. Like arsenic, mercury enters the water supply naturally from weathering of mercury-rich minerals and from human activities such as coal burning and metal processing. A famous mercury poisoning case in Minamata, Japan involved methylmercury-rich industrial discharge that caused high Hg levels in fish. People in the local fishing villages ate fish up to three times per day for over 30 years, which resulted in over 2,000 deaths. During that time the responsible company and national government did little to mitigate, help alleviate, or even acknowledge the problem.

Hard water contains abundant calcium and magnesium, which reduces its ability to develop soapsuds and enhances scale (calcium and magnesium carbonate minerals) formation on hot water equipment. Water softeners remove calcium and magnesium, which allows the water to lather easily and resist scale formation. Hard water develops naturally from the dissolution of calcium and magnesium carbonate minerals in soil; it does not have negative health effects in people.

Groundwater pollution can occur from underground sources and all of the pollution sources that contaminate surface waters. Common sources of groundwater pollution are leaking underground storage tanks for fuel, septic tanks, agricultural activity, landfills, and fossil fuel extraction. Common groundwater pollutants include nitrate, pesticides, volatile organic compounds, and petroleum products. Another troublesome feature of groundwater pollution is that small amounts of certain pollutants, e.g., petroleum products and organic solvents, can contaminate large areas. In Denver, Colorado 80 liters of several organic solvents contaminated 4.5 trillion liters of groundwater and produced a 5 km long contaminant plume. A major threat to groundwater quality is from underground fuel storage tanks. Fuel tanks commonly are stored underground at gas stations to reduce explosion hazards. Before 1988 in the U.S. these storage tanks could be made of metal, which can corrode, leak, and quickly contaminate local groundwater. Now, leak detectors are required and the metal storage tanks are supposed to be protected from corrosion or replaced with fiberglass tanks. Currently there are around 600,000 underground fuel storage tanks in the U.S. and over 30% still do not comply with EPA regulations regarding either release prevention or leak detection.

15.3 The Environment

At first glance, the environment does not seem to be a sociological topic. The natural and physical environment is something that geologists, meteorologists, oceanographers, and other scientists should be studying, not sociologists. Yet we have just discussed how the environment is affected by population growth, and that certainly sounds like a sociological discussion. In fact, the environment is very much a sociological topic for several reasons.

First, our worst environmental problems are the result of human activity, and this activity, like many human behaviors, is a proper topic for sociological study. This textbook has discussed many behaviors: racist behavior, sexist behavior, criminal behavior, sexual behavior, and others. Just as these behaviors are worthy of sociological study, so are the behaviors that harm (or try to improve) the environment.

Second, environmental problems have a significant impact on people, as do the many other social problems that sociologists study. We see the clearest evidence of this impact when a major hurricane, an earthquake, or another natural disaster strikes. In January 2010, for example, a devastating earthquake struck Haiti and killed more than 250,000 people, or about 2.5 percent of that nation’s population. The effects of these natural disasters on the economy and society of Haiti will certainly also be felt for many years to come.

As is evident in this photo taken in the aftermath of the 2010 earthquake that devastated Haiti, changes in the natural environment can lead to profound changes in a society. Environmental changes are one of the many sources of social change.

United Nations Development Programme – Haiti Earthquake – CC BY-NC-ND 2.0.

Slower changes in the environment can also have a large social impact. As noted earlier, industrialization and population growth have increased the pollution of our air, water, and ground. Climate change, a larger environmental problem, has also been relatively slow in arriving but threatens the whole planet in ways that climate change researchers have documented and will no doubt be examining for the rest of our lifetimes and beyond. We return to these two environmental problems shortly.

A third reason the environment is a sociological topic is a bit more complex: Solutions to our environmental problems require changes in economic and environmental policies, and the potential implementation and impact of these changes depends heavily on social and political factors. In the United States, for example, the two major political parties, corporate lobbyists, and environmental organizations regularly battle over attempts to strengthen environmental regulations.

A fourth reason is that many environmental problems reflect and illustrate social inequality based on social class and on race and ethnicity: As with many problems in our society, the poor and people of color often fare worse when it comes to the environment. We return to this theme later in our discussion of environmental racism.

Fifth, efforts to improve the environment, often called the environmental movement, constitute a social movement and, as such, are again worthy of sociological study. Sociologists and other social scientists have conducted many studies of why people join the environmental movement and of the impact of this movement.

Professionals and students studying the environment, especially as it relates to pollution also government workers and conservationists/ecologists

Part 1 Processes Affecting Fate and Transport of Contaminants

Chapter 1 The Extent of Global Pollution

1.2 Global Perspective of the Environment

1.3 Pollution and Population Pressures

1.4 Overview of Environmental Characterization

1.5 Advances in Analytical Detection Technology

1.6 The Risk Based Approach to Pollution Science

1.7 Waste Management, Site Remediation, and Ecosystem Restoration

References and Additional Reading

Chapter 2 Physical-Chemical Characteristics of Soils and the Subsurface

2.1 Soil and Subsurface Environments

2.5 Basic Physical Properties

References and Additional Reading

Chapter 3 Physical-Chemical Characteristics of Waters

3.2 Unique Properties of Water

3.5 Oxidation-Reduction Reactions

3.6 Light in Aquatic Environments

3.8 Lakes and Reservoirs—The Lentic System

3.9 Streams and Rivers—The Lotic System

3.10 Groundwater—Water in the Subsurface

References and Additional Reading

Chapter 4 Physical-Chemical Characteristics of the Atmosphere

4.2 Physical Properties and Structure

References and Additional Reading

Chapter 5 Biotic Characteristics of the Environment

5.1 Major Groups of Organisms

5.2 Microorganisms in Surface Soils

5.3 Microorganisms in the Subsurface

5.4 Biological Generation of Energy

5.5 Soil as an Environment for Microbes

5.6 Activity and Physiological State of Microbes in Soil

5.7 Enumeration of Soil Bacteria via Dilution and Plating

5.9 Microorganisms in Surface Water

References and Additional Reading

Chapter 6 Physical Processes Affecting Contaminant Transport and Fate

6.1 Contaminant Transport and Fate in the Environment

6.2 Contaminant Properties

6.6 Transformation Reactions

6.7 Characterizing Spatial and Temporal Distributions of Contaminants

6.8 Estimating Phase Distributions of Contaminants

6.9 Quantifying Contaminant Transport and Fate

References and Additional Reading

Chapter 7 Chemical Processes Affecting Contaminant Transport and Fate

7.2 Basic Properties of Inorganic Contaminants

7.3 Basic Properties of Organic Contaminants

7.5 Abiotic Transformation Reactions

References and Additional Reading

Chapter 8 Biological Processes Affecting Contaminant Transport and Fate

8.1 Biological Effects on Pollutants

8.2 The Overall Process of Biodegradation

8.3 Microbial Activity and Biodegradation

8.4 Biodegradation Pathways

8.5 Transformation of Metal Pollutants

References and Additional Reading

Part 2 Monitoring, Assessment, and Regulation of Environmental Pollution

Chapter 9 Physical Contaminants

9.3 Particles in Air or Aerosols

References and Additional Reading

Chapter 10 Chemical Contaminants

10.2 Types of Contaminants

10.3 Sources: Agricultural Activities

10.4 Sources: Industrial and Manufacturing Activities

10.5 Sources: Municipal Waste

10.6 Sources: Service-Related Activities

10.7 Sources: Resource Extraction/Production

10.8 Sources: Radioactive Contaminants

10.9 Natural Sources of Contaminants

References and Additional Reading

Chapter 11 Microbial Contaminants

11.1 Water-Related Microbial Disease

11.2 Classes of Diseases and Types of Pathogens

11.3 Types of Pathogenic Organisms

11.4 Sources of Pathogens in the Environment

11.5 Fate and Transport of Pathogens in the Environment

11.6 Standards and Criteria for Indicators

References and Additional Reading

The Role of Environmental Monitoring in Pollution Science

12.2 Sampling and Monitoring Basics

12.3 Statistics and Geostatistics

12.4 Sampling and Monitoring Tools

12.5 Soil and Vadose Zone Sampling and Monitoring

12.6 Groundwater Sampling and Monitoring

12.7 Surface Water Sampling and Monitoring

12.8 Atmosphere Sampling and Monitoring

References and Additional Reading

Chapter 13 Environmental Toxicology

13.1 History of Modern Toxicity in the United States

13.2 Toxic Versus Nontoxic

13.4 Evaluation of Toxicity

13.5 Responses to Toxic Substances

13.9 Chemical Toxicity: General Considerations

13.10 Chemical Toxicity: Selected Substances

References and Additional Reading

Chapter 14 Risk Assessment

14.1 The Concept of Risk Assessment

14.2 The Process of Risk Assessment

14.3 Ecological Risk Assessment

14.4 Microbial Risk Assessment

References and Additional Reading

Chapter 15 Environmental Laws and Regulations

15.2 The Safe Drinking Water Act

15.4 Comprehensive Environmental Response, Compensation and Liability Act

15.5 Federal Insecticide and Rodenticide Act

15.7 Resource Conservation and Recovery Act (RCRA)

15.8 The Pollution Prevention Act

15.9 Other Regulatory Agencies and Accords

References and Additional Reading

Part 3 Land and Water Pollution Mitigation

Chapter 16 Soil and Land Pollution

16.6 Agricultural Activities

16.8 Industrial Wastes With High Salts and Organics

References and Additional Reading

Chapter 17 Subsurface Pollution

17.1 Groundwater as a Resource

17.2 Groundwater Pollution

17.3 Groundwater Pollution Risk Assessment

17.4 Point-Source Contamination

17.4.1 Hazardous Organic Chemicals

17.5 Diffuse-Source Contamination

17.6 Other Groundwater Contamination Problems

17.7 Sustainability of Groundwater Resources

References and Additional Reading

Chapter 18 Surface Water Pollution

18.1 Surface Freshwater Resources

18.2 Marine Water Resources

18.3 Sources of Surface Water Pollution

18.4 Sediments as Surface Water Contaminants

18.6 Nutrients and Eutrophication of Surface Waters

18.7 Organic Compounds in Water

18.8 Enteric Pathogens as Surface Water Contaminants

18.9 Total Maximum Daily Loads (TMDLs)

18.10 Quantification of Surface Water Pollution

18.12 Dilution of Effluents

18.13 Dye Tracing of Plumes

18.14 Spatial and Temporal Variation of Plume Concentrations

18.15 Compliance Monitoring

References and Additional Reading

Chapter 19 Soil and Groundwater Remediation

19.3 Site Characterization

19.4 Remediation Technologies

References and Additional Reading

Chapter 20 Ecosystem Restoration and Land Reclamation

20.2 Site Characterization

20.5 Approaches to Ecosystem Restoration

References and Additional Reading

Part 4 Atmospheric Pollution

Chapter 21 Sensory Pollutants, Electromagnetic Fields and Radiofrequency Radiation

21.5 Odor as a Sensory Pollutant

21.6 Electromagnetic Fields and Radiofrequency Radiation

References and Additional Reading

Chapter 22 Indoor Air Quality

22.1 Fundamentals of Indoor Air Quality

22.2 Sources of Indoor Air Pollutants

22.3 Factors Influencing Exposure to Indoor Air Pollution

References and Additional Reading

Chapter 23 Atmospheric Pollution

23.1 Air Pollution Concepts

23.2 Sources, Types, and Effects of Air Pollution

23.3 Weather and Pollutants

23.4 Pollution Trends in the United States

References and Additional Reading

24.2 Global Warming and the Greenhouse Effect

24.4 Solutions to the Problems of Global Environmental Change

References and Additional Reading

Part 5 Waste and Water Treatment and Management

Chapter 25 Industrial and Municipal Solid Waste Treatment and Disposal

25.2 Relevant Regulations for Industrial and Municipal Solid Wastes

25.3 Major Forms of Industrial Wastes

25.4 Treatment and Disposal of Industrial Wastes

25.5 Reuse of Industrial Wastes

25.6 Treatment and Disposal of Municipal Solid Waste

References and Additional Reading

Chapter 26 Municipal Wastewater Treatment

26.1 The Nature of Wastewater (Sewage)

26.2 Modern Wastewater Treatment

26.5 Land Application of Wastewater

26.6 Wetlands and Aquaculture Systems

References and Additional Reading

Chapter 27 Land Application of Biosolids and Animal Wastes

27.1 Biosolids and Animal Wastes: A Historical Perspective and Current Outlook

27.2 The Nature of Wastewater (Sewage)

27.3 Wastewater (Sewage) Treatment

27.4 Methods of Land Application of Biosolids

27.5 Benefits of Land Application of Biosolids

27.6 Hazards of Land Application of Biosolids

27.7 Sources of Animal Wastes

27.8 Nonpoint Versus Point Source Pollution

27.9 Benefits of Land Application of Animal Wastes

27.10 Hazards of Land Application of Animal Wastes

27.11 Public Perceptions of Land Application

References and Additional Reading

Chapter 28 Drinking Water Treatment and Water Security

28.1 Water Treatment Processes

28.3 Factors Affecting Disinfectants

28.5 Disinfection By-Products

28.6 Residential Water Treatment

28.8 Monitoring Community Water Quality

References and Additional Reading

Part 6 Emerging Issues in Pollution Science

Chapter 29 Genetically Engineered Crops and Microbes

29.1 Introduction to Nucleic Acids

29.2 Recombinant DNA Technology

29.3 Transfer of Nucleic Acid Sequences from One Organism to Another (Cloning)

29.4 Chemical Synthesis, Sequencing and Amplification of DNA

29.5 Heterologous Gene Expression in Pro- and Eukaryotes

29.6 Genetically Engineered Plants for Agriculture

29.7 Genetically Engineered Plants for Remediation

29.8 Microbial-Assisted Remediation

29.9 Potential Problems Due to Genetically Modified Organisms

References and Additional Reading

Chapter 30 Antibiotic-Resistant Bacteria and Gene Transfer

30.1 Why Are Antibiotics An Issue?

30.2 Classification and Function of Antibiotics

30.3 Development of Bacterial Antibiotic Resistance

30.4 Transfer of Genetic Material by Horizontal Gene Transfer

30.5 Prevalent Environments Favoring HGT

30.6 Isolation and Detection of Antibiotic-Resistant Bacteria

30.7 Incidence of Antibiotic-Resistant Bacteria in Various Environments

30.8 Gene Transfer Between Bacteria—How Prelevants It?

30.9 Summary and Conclusions

References and Additional Reading

Chapter 31 Pharmaceuticals and Endocrine Disruptors

31.1 Endocrine Disruptors and Hormones

31.2 Significance of EDCs in Water

31.3 Incidence of EDCs in Water

31.4 Fate and Transport of Estrogenic Compounds in Municipal Wastewater

31.5 Methods for Measuring Estrogenic Activity in Water

31.6 What are the Risk of EDCs?

References and Additional Reading

Chapter 32 Epilogue: Is the Future of Pollution History?

32.1 The Role of Government in Controlling Pollution

32.2 Research Priorities Necessary to Protect Human Health

32.3 Pollution Prevention of Earth, Air, and Water

32.4 Is the Future of Pollution History?

2. Methodology and data

We begin this section with a detailed discussion of our two policies of interest. Following a series of environmental disasters in the 1950s and 1960s, Japan has been at the forefront of environmental regulation. In the 1970s six new environmental laws were enacted and a further eight were tightened. The 1990s saw a further tightening of environmental legislation, and in 1993 Japan implemented what became known as the Basic Environment Law. In 1997 Japan hosted the UN Framework Convention on Climate Change, which resulted in the Kyoto Protocol and thrust international environmental issues to the forefront of Japan's industrial policy. In 2001 a Ministry of the Environment was established, incorporating the previous roles of the Environment Agency, taking environmental policy into the heart of government decision making. The culmination of these various policies is that Japan established one of the strongest frameworks for achieving a clean and healthy environment earlier than most OECD countries and demonstrated that a good environmental reputation is not only good for the environment but is also a valuable economic and cultural asset (Sumikura 1998). 8

Although the current environmental literature tends to concentrate on cap and trade, taxes, and command and control policies, a little-known method used in Japan in the early 1970s was the environmental interest rate differential. The aim of the environmental interest rate subsidy program was to encourage firms to invest in abatement technologies to reduce emissions. Abatement investment includes technology to reduce air pollution (such as desulphurization), water pollution, noise pollution, recycling, and industrial waste. A gap caused by arbitrarily setting lower interest rates for certain financial schemes than the current market rates can be considered as a subsidy for abatement investment. There were three main finance schemes for large firms in abatement investment. One scheme used finance programs by the Japan Development Bank (JDB), which is a government bank under the Ministry of Finance. The JDB had special lending programs in abatement investment, which offered lower interest rates than market rates. This program continued until 1999. The other scheme was conducted by the Japan Environmental Corporation (JEC) (Kougai Boushi Jiigyoudan) (1965–2003). JEC's lending programs for environmental projects ended in 1999. In contrast to the JDB scheme, the JEC money was targeted at not only large firms but also small- and medium-sized enterprises (SMEs). An example of this is the Japan Corporation for Small and Medium Enterprise (JASME) (Chusho Kigyo Kinyu Koko) (1953–2008), which was a government bank that specialized in helping SMEs. All three lending programs used the same strategy of lowering interest rates for investment in abatement technologies, although the level of discount against market rates differed by lending body (discussed further subsequently).

The policy initiative to use interest rates in this way required the Japanese government to establish a rate of interest on borrowing between the market rate and the zaito rate (the rate used for government public finance policy). Any funds borrowed at this cheap rate of interest were used to finance environmental projects with the aim of alleviating abatement costs and reducing pollution. The money could be borrowed by large firms from the JDB, the JEC, or local government bodies. Funding from the JDB ceased in 1999. Funding from the JEC also finished in 1999 (lending actually stopped in 1998). In part the policy was no longer possible because of Japan's zero interest rates from 1998 onward.

The subsidized environmental loan program started in 1960 when the JDB starting making loans for investment that would mitigate water pollution. In 1963 this was extended to loans to help reduce pollution of soot and smoke. Two years later the JEC also started a loan program for anti-pollution measures followed by the JDB in 1971. In that same year the Agency of Industrial Science and Technology set up a subsidy system. The main developments in what we could call environmental finance were as follows: In 1960 JDB started loans for investment against water pollution and then in 1963 it started a loan program for investment against soot and smoke. In 1965 JEC started its loan program for anti-pollution investment. In 1971 the JDB also implemented an anti-pollution investment loan program. This was matched in 1971 by the Agency of Industrial Science and Technology, which also set up a subsidy system for anti-pollution investment. Finally, in 1974 the Agency of Industrial Science and Technology directly subsidized environmental technology for NOx reductions.

We now turn to our PCA measure. Japan is a highly centralized country, the central government sets environmental standards and tends to have uniform regulations across the country. Environmental damages, however, are idiosyncratic across regions and some cities and villages need more stringent regulations. This led to a number of regional governments coming to voluntary agreements with local polluting firms, although the voluntary nature of any agreement means that they could not be legally enforced. The agreements tended to specify more stringent environmental regulations than the national laws and regulations and thus no legal penalty could be enforced as long as the national regulation levels were met. Thus, cities and environmental community groups were required to supervise the firm's behavior. One of the most famous examples is Yokohama city, which signed an agreement with Tokyo Denryoku (TEPCO) in 1965 and with Electric Power Development Co. Ltd. (Dengen Kaihatsu) in 1964. 9 Because firms want to give the impression of being “greener” and environmentally friendly, PCAs were popular with firms willing to accept these agreements in the 1970s and 1980s when public disquiet about the high levels of pollution were at their greatest and as a result so was the threat of even stricter government regulation.

In our data set the PCA variable is measured as the number of ratified pollution control municipal agreements signed during a given year (flow data) between a firm/plant and a local government body. We count the number of agreements in the manufacturing sector, the agricultural sector, and an overall total (including the energy sector). Figure 1 shows the number of agreements in the manufacturing sector. The contents of each agreement depend on the negotiating stance of each municipality and are taken from the Environmental White Paper by the Ministry of Environment Japan for each year from 1972 onwards and the Pollution White Paper for years before 1971. As Figure 1 clearly shows, the number of signed PCAs peaked around 1990 just before the 1993 Basic Law was enacted, and then fell away dramatically.

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Fragmentation of river ecosystems Edit

A dam acts as a barrier between the upstream and downstream movement of migratory river animals, such as salmon and trout. [3]

Some communities have also begun the practice of transporting migratory fish upstream to spawn via a barge. [3]

Reservoir sedimentation Edit

Rivers carry sediment down their riverbeds, allowing for the formation of depositional features such as river deltas, alluvial fans, braided rivers, oxbow lakes, levees and coastal shores. The construction of a dam blocks the flow of sediment downstream, leading to downstream erosion of these sedimentary depositional environments, and increased sediment build-up in the reservoir. While the rate of sedimentation varies for each dam and each river, eventually all reservoirs develop a reduced water-storage capacity due to the exchange of "live storage" space for sediment. [4] Diminished storage capacity results in decreased ability to produce hydroelectric power, reduced availability of water for irrigation, and if left unaddressed, may ultimately result in the expiration of the dam and river. [5]

The trapping of sediment in reservoirs reduce sediment delivery downstream, which negatively impacts channel morphology, aquatic habitats and land elevation maintenance of deltas. [6] Apart from dam removal, there are other strategies to mitigate reservoir sedimentation.

Flushing flow method Edit

The flushing flow method involves partially or completely emptying the reservoir behind a dam to erode the sediment stored on the bottom and transport it downstream. [7] [6] Flushing flows aim to restore natural water and sediment fluxes in the river downstream of the dam, however the flushing flow method is less costly compared to removing dams or constructing bypass tunnels.

Flushing flows have been implemented in the Ebro river twice a year in autumn and spring since 2003, except for two dry years in 2004 and 2005. [8] [9] The construction of multiple dams on the Ebro river disrupted the delivery of sediments downstream and as a result, the Ebro delta faces a sediment deficit. The river channel also narrowed and bank erosion increased. [7] During experiments, it was found that suspended sediment concentration during flushing flows is double that of natural floods, although the total water discharge is lower. This means that flushing flows have a relatively high sediment transport capacity, [8] which in turn suggests that flushing flows positively impact downstream river ecosystems, maximising sediment delivery to the lowest reaches of the river. [10] A total of 340,000 t/year of sediment could be delivered to the Ebro delta, which could result in a net accretion rate of 1 mm per year. [7]

Sediment bypasses Edit

Sediment bypass tunnels can partially restore sediment dynamics in rivers downstream of dams, and are primarily used in Japan and Switzerland. [11] Bypass tunnels divert part of the incoming water and sediments during floods into a tunnel around a reservoir and dam. The water and sediment thus never enter the reservoir but join the river again below the dam. [12] Bypass tunnels reduce riverbed erosion and increase morphological variability below the dam. [13]

River line and coastal erosion Edit

As all dams result in reduced sediment load downstream, a dammed river is greatly demanding for sediment as it will not have enough sediment. This is because the rate of deposition of sediment is greatly reduced since there is less to deposit but the rate of erosion remains nearly constant, the water flow erodes the river shores and riverbed, threatening shoreline ecosystems, deepening the riverbed, and narrowing the river over time. This leads to a compromised water table, reduced water levels, homogenization of the river flow and thus reduced ecosystem variability, reduced support for wildlife, and reduced amount of sediment reaching coastal plains and deltas. [5] This prompts coastal erosion, as beaches are unable to replenish what waves erode without the sediment deposition of supporting river systems. [14] Downstream channel erosion of dammed rivers is related to the morphology of the riverbed, which is different from directly studying the amounts of sedimentation because it is subject to specific long term conditions for each river system. For example, the eroded channel could create a lower water table level in the affected area, impacting bottomland crops such as alfalfa or corn, and resulting in a smaller supply. [15] In the case of the Three Gorges Dam in China the changes described above now appears to have arrived at a new balance of erosion and sedimentation over a 10-year period in the lower reaches of the river. The impacts on the tidal region have also been linked to the upstream effects of the dam. [16]

Nutrients sequestration Edit

Once a dam is put in place represents an obstacle to the flux of nutrients such as carbon (C), nitrogen (N), phosphorus (P), and silicon (Si) on downstream river, floodplains and delta. The increased residence time of these elements in the lentic system of a reservoir, compared to the lotic system of a river, promotes their sedimentation or elimination [17] which can be up to 40%, 50%, and 60% for nitrogen, phosphorus and silica respectively [18] and this ultimately changes nutrients stoichiometry in the aquatic ecosystem downstream a dam. The stochiometric imbalance of nitrogen, phosphorus, and silicon of the outflow can have repercussion on downstream ecosystems by shifting the phytoplankton community at the base of the food web with consequences to the whole aquatic population. [19] [20] [21] An example is the effect of the construction of the Aswan High dam in Egypt, where the drop in nutrient concentration to the Nile delta impeded the diatom blooms causing a substantial decrease the fish population of Sardinella aurita and Sardinella eba, while the reduced load of mud and silt affected the micro-benthic fauna leading to the decline of shrimp population. [22] The change in nutrients stoichiometry and silicon depletion at a river delta can also cause harmful algal and bacterial blooms to the detriment of diatoms' growth for whom silicon availability represents a milestone for shells' formation.

Since dammed rivers store nutrients during their lifespan, it can be expected that when a dam is removed, these legacy nutrients are remobilized causing downstream ecosystems' eutrophication and probable loss of biodiversity, thereby achieving the opposite effect desired by the river restoration action at dam dismissal.

Water temperature Edit

The water of a deep reservoir in temperate climates typically stratifies with a large volume of cold, oxygen poor water in the hypolimnion. Analysis of temperature profiles from 11 large dams in the Murray Darling Basin (Australia) indicated differences between surface water and bottom water temperatures up to 16.7 degrees Celsius. [23] If this water is released to maintain river flow, it can cause adverse impacts on the downstream ecosystem including fish populations. [24] Under worse case conditions (such as when the reservoir is full or near full), the stored water is strongly stratified and large volumes of water are being released to the downstream river channel via bottom level outlets, depressed temperatures can be detected 250 - 350 kilometres downstream. [23] The operators of Burrendong Dam on the Macquarie River (eastern Australia) are attempting to address thermal suppression by hanging a geotextile curtain around the existing outlet tower to force the selective release of surface water. [25]

Natural ecosystems destroyed by agriculture Edit

Many dams are built for irrigation and although there is an existing dry ecosystem downstream, it is deliberately destroyed in favor of irrigated farming. After the Aswan Dam was constructed in Egypt it protected Egypt from the droughts in 1972–73 and 1983–87 that devastated East and West Africa. The dam allowed Egypt to reclaim about 840,000 hectares in the Nile Delta and along the Nile Valley, increasing the country's irrigated area by a third. The increase was brought about both by irrigating what used to be desert and by bringing under cultivation 385,000 hectares that were natural flood retention basins. About half a million families were settled on these new lands.

Effects on flood-dependent ecology and agriculture Edit

In many [ quantify ] low lying developing countries [ example needed ] the savanna and forest ecology adjacent to floodplains and river deltas are irrigated by wet season annual floods. Farmers annually plant flood recession crops, where the land is cultivated after floods recede to take advantage of the moist soil. Dams generally discourage this cultivation and prevent annual flooding, creating a dryer downstream ecology while providing a constant water supply for irrigation.

  • The Lake Manatali reservoir formed by the Manantali dam in Mali, West Africa intersects the migration routes of nomadic pastoralists and withholds water from the downstream savanna. The absence of the seasonal flood cycle causes depletion of grazing land, and is also drying the forests on the floodplain downstream of the dam. [27]
  • After the construction of the Kainji Dam in Nigeria, 50 to 70 percent of the downstream area of flood-recession cropping stopped. [28]

Potential for disaster Edit

Dams occasionally break causing catastrophic damage to communities downstream. Dams break due to engineering errors, attack or natural disaster. The greatest dam break disaster to date happened in China in 1975 killing 200,000 Chinese citizens. Other major failures during the 20th century were at Morbi, India (5,000 fatalities), at Vajont, Italy (2000 dead), while three other dam failures have each caused at least 1000 fatalities.

Flood control Edit

The controversial Three Gorges Dam in China is able to store 22 cubic kilometres of floodwaters on the Yangtze River. The 1954 Yangtze River floods killed 33,000 people and displaced 18 million people from their homes. In 1998 a flood killed 4000 people and 180 million people were affected. The flooding of the reservoir caused over a million people to relocate, then a flood in August 2009 was completely captured by the new reservoir, protecting hundreds of millions of people downstream.

Mercury cycling and methylmercury production Edit

The creation of reservoirs can alter the natural biogeochemical cycle of mercury. Studies conducted on the formation of an experimental reservoir by the flooding of a boreal wetland showed a 39-fold increase in the production of toxic methylmercury (MeHg) following the flooding. [29] The increase in MeHg production only lasted about 2–3 years before returning to near normal levels. However, MeHg concentration in lower food chain organisms remained high and showed no signs of returning to pre-flood levels. The fate of MeHg during this time period is important when considering its potential to bioaccumulate in predatory fish. [30]

Effects on humans Edit

Whilst reservoirs are helpful to humans, they can also be harmful as well. One negative effect is that the reservoirs can become breeding grounds for disease vectors. This holds true especially in tropical areas where mosquitoes (which are vectors for malaria) and snails (which are vectors for Schistosomiasis) can take advantage of this slow flowing water. [31]

Dams and the creation of reservoirs also require relocation of potentially large human populations if they are constructed close to residential areas. The record for the largest population relocated belongs to the Three Gorges dam built in China. Its reservoir submerged a large area of land, forcing over a million people to relocate. "Dam related relocation affects society in three ways: an economic disaster, human trauma, and social catastrophe", states Dr. Michael Cernea of the World Bank and Dr. Thayer Scudder, a professor at the California Institute of Technology. [2] As well, as resettlement of communities, care must also be taken not to irreparably damage sites of historical or cultural value. The Aswan Dam forced the movement of the Temple at Aswan to prevent its destruction by the flooding of the reservoir.

Greenhouse gases Edit

Reservoirs may contribute to changes in the Earth's climate. Warm climate reservoirs generate methane, a greenhouse gas when the reservoirs are stratified, in which the bottom layers are anoxic (i.e. they lack oxygen), leading to degradation of biomass through anaerobic processes. [32] [ page needed ] At a dam in Brazil, where the flooded basin is wide and the biomass volume is high the methane produced results in a pollution potential 3.5 times more than an oil-fired power plant would be. [33] A theoretical study has indicated that globally hydroelectric reservoirs may emit 104 million metric tonnes of methane gas annually. [34] Methane gas is a significant contributor to global climate change. This isn't an isolated case, and it appears that especially hydroelectric dams constructed in lowland rainforest areas (where inundation of a part of the forest is necessary) produce large amounts of methane. Bruce Forsberg and Alexandre Kemenes have demonstrated that the Balbina Dam for instance emits 39000 tonnes of methane each year [35] and three other dams in the Amazon produce at least 3 to 4× as much CO
2 as an equivalent coal-fired power plant. Reasons for this being that lowland rainforests are extremely productive and thus stores far more carbon than other forests. Also, microbes that digest rotting material grow better in hot climates, thus producing more greenhouse gases. Despite of this, as of 2020, another 150 hydroelectric dams are planned to be constructed in the Amazon basin. [36] There is some indication that greenhouse gas emissions decline over the lifetime of the dam. "But even including methane emissions, total GHG [Green-House Gas] per KWh generated from hydropower is still at least half that from the least polluting thermal alternatives.Thus, from the perspective of global warming mitigation, dams are the most attractive alternative to fossil fuel based energy sources." [32]

Research conducted at the Experimental Lakes Area indicates that creating reservoirs through the flooding of boreal wetlands, which are sinks for CO
2 , converts the wetlands into sources of atmospheric carbon. [29] In these ecosystems, variation in organic carbon content has been found to have little effect on the rates of greenhouse gas emission. This means that other factors such as the lability of carbon compounds and temperature of the flooded soil are important to consider. [37]

The following table indicates reservoir emissions in milligrams per square meter per day for different bodies of water. [38]

Prodded by petition, EPA reconsiders ocean pH limits

Katherine Boyle, E&E reporter

Published: Wednesday, April 15, 2009

U.S. EPA is weighing a revision of standards aimed at preventing the acidification of marine waters.

The effort marks the first time EPA has invoked the Clean Water Act to address ocean acidification, and comes in response to a 2007 petition from the Center for Biological Diversity. The center noted that EPA has failed to update the pH standard since 1976 and has ignored research published since then.

Concerns about ocean acidification have risen lately, as research shows a link between it and rising atmospheric carbon dioxide levels. Studies show that oceans absorb about 22 million tons of CO2 per day from the atmosphere, resulting in increasing acidity that impairs marine animals' ability to build and maintain protective shells and skeletons and threatens coral reefs.

The agency moved toward stiffening marine pH standards in a Federal Register notice seeking information on possible changes in ocean acidity.

Miyoko Sakashita, an attorney with the Center for Biological Diversity's ocean program, described the notice as a step in the right direction.

"The federal government has finally acknowledged that ocean acidification is a threat," she said in a statement. "Now it must take the next step and fully implement the Clean Water Act to protect our nation's waters from 'the other CO2 problem.'"

The center says EPA's recommended pH criterion is an important benchmark for states and tribes. A stricter recommendation could potentially help promote the imposition of federal CO2 controls.

The center also asked EPA to publish a guidance providing recommendations to states on preventing ocean acidification.

"We must take immediate action to address ocean acidification, or the impacts will be catastrophic," Sakashita said. "Fortunately, we need not wait for new legislation addressing CO2 emissions, as the Clean Water Act already provides us with important tools to confront this problem."

Stakeholders will have 60 days to submit ocean acidification data to the agency. EPA plans to decide whether the pH standards should be revised within one year.

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Most of DEQ’s functions are set by Title 27A of the Oklahoma Statutes. Licensing requirements for water and wastewater system operators, as well as individual septic system installers, are found in Title 59. Administrative procedures for enforcement and rulemaking are found in Title 75. The text of all Oklahoma statutes can be found on the Oklahoma State Courts Network website.

Before being adopted, DEQ rules undergo an extensive public review process as set by statute and the Office of Administrative Rules within the Oklahoma Secretary of State’s office. Proposed rules are published twice per month in the Oklahoma Register. This office also maintains the official version of all final rules, known as the Oklahoma Administrative Code (OAC). Both the Oklahoma Register and the OAC are available online.

As a convenience, DEQ makes its rules and fee schedules available online however, please be aware that the rules and fee schedules downloaded from here are unofficial. While every effort is made to ensure accuracy, there may be mistakes. If there are any discrepancies between the rules and fee schedules downloaded from here and those outlined by statute or in the official OAC at the Office of Administrative Rules, the statutes or official rules will prevail.

A summary of rule changes passed by the Environmental Quality Board during state fiscal year 2020 can be found here.

Stencil a Storm Drain

Get outside, volunteer, and do your part to and help raise awareness about storm water pollution and water quality in Seattle neighborhoods. This spring and summer, individuals, families, and small groups practicing COVID19 safe distance practices are welcome sign up and get a free reusables kit to paint stencils next to storm drains in their neighborhood with the message:

Dump No Waste
Drains to Puget Sound/Ocean

How does a stencil help? Most storm drains direct water and pollutants to a nearby stream, lake, or the Puget Sound. A stenciled drain reminds the community that what goes into the drain will end up in local waterways directly effecting wildlife and people. When people make the storm drain connection, they are less likely to dump pollutants like soaps, paints, antifreeze, and used motor oil into storm drains.

Watch the video: Water Pollution. Explained. Environmental Biotechnology (September 2022).


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  2. Quentrell

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  5. Gall

    Sorry to interfere, but in my opinion there is another way of solving the issue.

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