Environmental Pollution This Page Intentionally Left Blank Environmental Pollution FOURTH E D I T I O N. J. Jeffrey Peirce Duke University Ruth E Weiner . Complex environmental problems are often reduced to an inappropriate level of simplicity. While this book does not seek to present a comprehensive scientific. ~l,~lter Research Vol. 9. pp, to Pergamon Press Printed in Great Britain. BOOK REVIEWS Environmental Pollution Control. Allan D. McKni.
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6 days ago PDF | This is a book about environmental engineering for nontechnical students. No attempt is made to cover air and water pollution, solid. Environmental Pollution and Control, Third Edition focuses on the aspects of environmental engineering science and technology, including water pollution. Download PDF. Free Access 1. The principle of environmental pollution control . Pages Regional environmental systems engineering and technology.
Pergamon Press Printed in Great Britain. Allan D. McKnight, Pauline K. Marstrand and T. Craig Sinclair.
No knowledge of microbiology is assumed, but nevertheless a wide variety of situations in which microorganisms play a leading role are considered at a level which is high enough to hold the interest of any intelligent reader, whether professionally involved in environmental affairs or not. The author's skill in the presentation of information combined with a lucid, unpretentious style only partly account for the pleasure the reviewer has had in reading his book.
The rest is derived from the logical arrangement of the various chapters and the excellent diagrams and tabular matter that seem to have been carefully selected to complement the text. These chapters introduce the reader to the growth and death of microorganisms, after introductory accounts of the principles of ecology and the culturing of organisms.
The public health significance of microorganisms is not overlooked--though the author might have given even greater emphasis to the important relationship between man's environmental and social conditions and the incidence of outbreaks of waterborne diseases.
The growing concern of organic compounds that resist attack by microorganisms and so remain in the environ- nitrate, in waters abstracted for public supply, as a potential cause of methaemoglobinaemia are not mentioned. By far the largest chapter deals with social and technical aspects of noise pollution.
The author presents a comprehensive survey of the relative importance of noise sources and the cost in terms of damage sustained by the human frame so exposed and also in terms of remedial costs such as sound proofing.
Minor sections cover control of land dereliction and final chapters review the proceedings of the Stockholm Conferences on the Human Environment. Each chapter of the book concludes with numerous references: in most cases these are numerically related to specific instances in the text: however in two chapters the value is largely lost by the presentation of a list of unnumbered references in alphabetical order.
It is perhaps ironic that after so much care was taken to produce so complete an introduction to, and summary of the major forms of pollution, this work should be followed so soon by the significant changes resulting from the implementation of the Water Act and the introduction of the Control of Pollution Act It is hoped however that a future edition will soon appear and correct this.
Without question, this book should form part of the recommended reading for students of the subject and should appeal to all those members of the general public having the will to preserve the environment for future generations.
W O O D ment for'long periods is well described in chapters on the decomposition of organic matter and on recalcitrant compounds. Another fascinating subject is the method of communication that exists between organisms by the use of chemicals that convey information.
These considerations lead logically to the relationships between the members of a microbial community that indicate some form of stress that is absent under natural conditions.
From such considerations and a knowledge of the abundance of varieties of species, in contrast to the number of individual species, there is something to be learnt about the identification of sources of pollution. Such pollution increases the growth of microorganisms, which is equivalent to the conversion of inorganic nutrients and organic matter into microbial protein.
Because ethics involves a social contract, the rationale for the environmental ethic in this case is that we do not want to hurt other people by polluting the environment. We realize that the destruction or despoliation of the environment would be taking something from othersmnot much different from stealing. A river, for example, has value to others as a place to fish, and contaminating it takes something from those people. Cutting down old growth forests prevents us and our progeny from enjoying such wilderness, and such actions are therefore unethical.
The concept that nature has value is a fairly modern one.
Until the midnineteenth century, nature was thought of as something to fight againstmto destroy or be destroyed by. The value in nature was first expressed by several farsighted writers, most notably Ralph Waldo Emerson. He argued that nature had instrumental value to people, in terms of material wealth, recreation potential, and aesthetic beauty. Instrumental value can usually be translated into economic terms, and the resulting environmental ethic from this argument requires us to respect that value and not to destroy what others may need or enjoy.
The concern of Theodore Roosevelt and Gifford Pinchot about the destruction of American forests is was not because they believed that somehow the 14Fallows, J. Pollution and Environmental Ethics 11 forests had a right to survive but because they felt that these resources should be conserved and managed for the benefit of all. Such an environmental ethic can be thought of as conservation environmental ethics because its main aim is to conserve the resources for our eventual long-term benefit.
A modified form of the conservation environmental ethic evolved during this time, championed by John Muir, the founder of The Sierra Club and an advocate for the preservation of wilderness.
This preservation environmental ethic held that some areas should be left alone and not developed or spoiled because of their beauty or significance to people. Muir often clashed with Pinchot and the other conservationists because Muir wanted to preserve wilderness while Pinchot wanted to use it wisely.
Often this distinction can be fuzzy. The ages have been at work on it and man can only mar it, ''16 he was being both a conservationist and a preservationist. The condition of our rivers and lakes has been one of the more visible aspects of environmental pollution. Not too many years ago, the great rivers in urbanized areas were in effect open sewers that emptied into the nearest watercourse, without any treatment. As a result, many lakes and rivers became grossly polluted and, as an Boston Board of Health report put it, "larger territories are at once, and frequently, enveloped in an atmosphere of stench so strong as to arouse the sleeping, terrify the weak and nauseate and exasperate everybody.
The River Cam, for example, like the Thames, was for many years grossly polluted. There is a tale of Queen Victoria visiting Trinity College at Cambridge and saying to the Master as she looked over the bridge abutment: "What are all those pieces of paper floating down the river?
We simply do not like to see our planet contaminated and spoiled. Nor do we want to see species or places destroyed without justification, and we argue for both conservation and preservation because we believe that nonhuman nature has value to us and its destruction makes the lives of our children poorer. Thus the environmental ethic of conservation and preservation places value on nature because we want it conserved so it can continue to provide us with resources and preserved so it can continue to be enjoyed by us.
Environmental pollution is bad either because such pollution can be a public health concern or because such pollution can be a public nuisance, cost us money, or prevent us from enjoying nature. In the first case we want our water, air, food, and our 16Leydet, F. In the second case we do not want to have pollution because it decreases the quality of our lives.
We also do not want to destroy species because, in the first instance, these species may be useful to us in what they can provide to keep us alive longer or because, in the second sense, we enjoy having these species as our co-inhibitors.
These two views represent what has become known as an anthropocentric environmental ethic, that is, people centered. We do not want to cause pollution or destroy things because of the value these may have to humans, in terms of either public health or quality of life.
There is, however, a second kind of environmental ethic, one that recognizes all of the above concerns but also places a value on the environment, including animals, plants, and places. That is an intrinsic value, a value of and by itself, independent of what value we might place on it.
Such an environmental ethic can be thought of as the ethics of simply caring for nonhuman nature. Why indeed do animals, trees, or rocks deserve moral consideration and moral protection? Why should we extend the environmental ethic to cover the nonhuman world? Based on the rationalization for ethics, there cannot be a very strong argument for such an extension of the moral community. Because there is no reciprocity so goes the argument , there can be no ethics.
Our caring for nonhuman nature, then, cannot ever be rationally argued and defended. This leads to the temptation to give up the search for a rational environmental ethic and recognize that the scholarly field of ethics cannot ever provide us with the answers we seek. Using ethics to try to understand our attitudes and to provide guidance for our actions toward the nonhuman world is simply asking too much of it. Ethics was never intended to be used in this way, and we should not be disappointed that it fails to perform.
And yet we clearly do care for the nonhuman world. We would condemn anyone who wantonly destroyed natural places or who tortured animals. Why is it that we feel this way? One possibility is that our attitudes toward other species and nonhuman nature in general is spiritual. Spiritual feelings toward nature are not new, of course, and we might have much to learn from the religions of our forebears.
Many ancient religions, including Native American, are animistic, recognizing the existence of spirits within nature. These spirits do not take human form, as in the Greek, Roman, or Judaic religions. They are simply within the tree, the 18Dubos, R. Pollution and Environmental Ethics 13 brook, or the sky. It is possible to commune with these spirits, to talk to them, to feel close to them.
In many animistic religions any natural entity, such as a tree, has its own spirit, and one has to take these spirits seriously. If a tree is to be cut down in order to build a house, this action has to be explained to the spirit before cutting begins.
If the tree is to be used for a beneficial purpose, the spirit has no objections and actually moves with the tree to the house which assumes its own spirit.
Each piece of furniture, each tool, has its own spirit, and as a result all of these objects deserve respect and consideration. Such a spiritual environmental ethic based on respect does not prevent us from using the resources of the world for legitimate benefit. All life has to kill other life to survive. Woodpeckers poke holes in trees, whales eat algae, and parasitic bacteria use their host for reproduction, just as people kill chickens, harvest corn, or drain wetlands.
Life as it has been designed requires us to kill other life in order to survive, and to use resources for our benefit. In doing so, however, we are required by the spiritual environmental ethic to be aware, grateful, and careful with what we kill, what we use, and what we damage.
A spiritual environmental ethic is a new paradigm for our environmental morality. We recognize that the approach provided by classical ethics does not provide the basis for explaining our attitudes toward nature. The sooner we realize this the sooner will we be able to formulate cogent, useful, and defensible arguments for doing the right thing for our environment. But what if the concerns include that of nature, in the form of the spiritual environmental ethic?
How can resolution of disagreements between people be achieved? Because the spiritual environmental ethic is not based on reciprocity, conflicts can occur when the rights of nonhuman nature come into conflict with humans. Such situations occur when preserving or protecting the environment results in financial loss to humans, often couched in terms of "environment vs.
Under the Endangered Species Act old growth forest habitat for the Northern spotted owl does indeed take precedence and has resulted in the removal of many acres from potential logging. The town of Hoquiam, Washington, for example, lost its only industry, a mill that employed workers, most of whom had lived all their lives in Hoquiam and were the grandchildren of the original mill workers. Environmental ethics come into real conflict with our moral responsibilities not to hurt other people.
Do we have a right to hold that the preservation of nonhuman nature is more important than the welfare of humans? Granted, one can make such a choice for oneself, but has one the right to make the choice for another? One can even try to make such a choice democratically in one country, but can one country choose for another? Confronting this dilemma is a step in the maturation of the environmental ethic. In the best of all worlds, we will confront it honestly and find a solution that is a compromise: The preservation may not be perfect or total, but complete destruction will not be tolerated.
Or as Aldo Leopold, famous for his seminal A Sand County Almanac, said, "The first rule of intelligent tinkering is to save all the pieces. Instead, it is an attempt to answer either of two questions: "How ought I to treat others?
That is, polluting a stream is morally wrong only if this action diminishes someone's enjoyment of the stream or its utility. The stream, or its inhabitants, has no value and no ethical standing. Today, however, we realize that we owe responsibility to nature for its own sake, and not just because it might have instrumental value. But how to do this? Scientists and engineers look at the world objectively with technical tools, and often these technical tools are inappropriate for solving value problems.
We are ill-equipped to make decisions where the value of nature or other species, or even future generations of humans, is concerned. In response to these difficult, value-laden questions, a new form of applied ethics, environmental ethics, has evolved and attempts to address issues on human interactions with nonhuman nature. Such an attitude helps us make decisions where value questions come into play.
In the book, we weave together aspects of environmental engineering and environmental ethics. We believe that a basic understanding of environmental sciences and engineering is impossible without such a broad perspective. However, we also caution the reader that it is impossible to introduce these topics in any depth in this introductory textbook, and that the student should seek out more advanced courses that address all of these components of environmental pollution and control.
Chapter 2 Environmental Risk Analysis Risk analysis allows us to estimate impacts on the environment and on human health when we have not measured or cannot measure or directly observe those impacts. It also lets us compare these impacts. In this chapter, we introduce the concept of risk analysis and risk management. The former is the measurement and comparison of various forms of risk; the latter involves the techniques used to reduce these risks.
RISK Most pollution control and environmental laws were enacted in the early s in order to protect public health and welfare. In recent years, increasing numbers of substances appear to pose such threats; the Clean Air Act listed seven hazardous substances between and , and now lists approximately !
The environmental engineer thus has an additional job: to help determine the comparative risks from various environmental pollutants and, further, to determine which risks are most important to decrease or eliminate. Adverse effects on human health are sometimes difficult to identify and to determine. Even when such an adverse effect has been identified, it is still difficult to recognize those components of the individual's environment that are associated with it.
Risk analysts refer to these components as risk factors. That is, the adverse effect is not usually observed in the absence of the risk factor. Identification of a risk factor for a particular adverse effect may be made with confidence only if the relationship is consonant with, and does not contradict, existing knowledge of the cellular and organismic mechanisms producing the adverse effect.
Identification of the risk factor is more difficult than identification of an adverse effect. For example, we are now certain that cigarette smoke is unhealthy, both to the smokermprimary smoke riskmand to those around the smokerm secondary smoke risk.
Specifically, lung cancer, chronic obstructive pulmonary disease, and heart disease occur much more frequently among habitual smokers than among nonsmokers or even in the whole population including smokers.
The increased frequency of occurrence of these diseases is statistically significant. Cigarette smoke is thus a risk factor for these diseases; smokers and people exposed to secondhand smoke are at increased risk for them. Notice, however, that we do not say that cigarette smoking c a u s e s lung cancer, chronic obstructive pulmonary disease, or heart disease, because we have not identified the actual causes, or etiology, of any of them.
How, then, has cigarette smoking been identified as a risk factor if it cannot be identified as the cause? This observation about cigarette smoke was not made, and indeed could not be made, until the middle of the twentieth century, when the lifespan in at least the developed countries of the world was long enough to observe the diseases that had been correlated with exposure to cigarette smoke.
In the first half of the twentieth century, infectious diseases were a primary cause of death. With the advent of antibiotics and the ability to treat such diseases, the lifespan in the developed nations of the world lengthened, and cancer and heart disease became the leading causes of death.
From the early s, when the average lifespan in the United States was about 70, lifelong habitual cigarette smokers were observed to die from lung cancer at ages between 55 and This observation, which associated early death with cigarette smoke, identified cigarette smoke as a risk factor. Identification of a substance a toxicant that may have adverse health effects Scenarios for exposure to the toxicant Characterization of health effects An estimate of the probability risk of occurrence of these health effects The decision that the concentration of a certain toxicant in air, water, or food is acceptable is based on a risk assessment.
Environmental Risk Analysis 17 Toxicants are usually identified when an associated adverse health effect is noticed. In most cases, the first intimation that a substance is toxic is its association with an unusual number of deaths. Mortality risk, or risk of death, is easier to determine for populations, especially in the developed countries, than morbidity risk risk of illness because all deaths and their apparent causes are reported on death certificates, while recording of disease incidence, which began in the relatively recent past, is done only for a very few diseases.
Death certificate data may be misleading: An individual who suffers from high blood pressure but is killed in an automobile accident becomes an accident statistic rather than a cardiovascular disease statistic. In addition, occupational mortality risks are well documented only for men; until the present generation, too few women worked outside the home all their lives to form a good statistical base.
These particular uncertainties may be overcome in assessing risk from a particular cause or exposure to a toxic substance by isolating the influence of that particular cause. Such isolation requires studying two populations whose environment is virtually identical except that the risk factor in question is present in the environment of one population but not in that of the other. Such a study is called a cohort study and may be used to determine morbidity as well as mortality risk.
One cohort study, for example, showed that residents of copper smelting communities, who were exposed to airborne arsenic, had a higher incidence of a certain type of lung cancer than residents of similar industrial communities where there was no airborne arsenic. Retrospective cohort studies are almost impossible to perform because of uncertainties on data, habits, other exposures, and the like.
Cohorts must be well matched in size, age distribution, life-style, and other environmental exposures, and they must be large enough for an effect to be distinguishable from the deaths or illnesses that occur anyway. The response of an organism to a pollutant always depends in some way on the amount or dose of pollutant to the organism. The magnitude of the dose, in turn, depends on the exposure pathway. The same substance may have a different effect depending on whether it is inhaled, ingested, or absorbed through the skin, or whether the exposure is external.
The exposure pathway determines the biochemistry of the pollutant in the organism. In general, the human body detoxifies an ingested pollutant more efficiently than it does an inhaled pollutant. The relationship between the dose of a pollutant and the organism's response can be expressed in a dose-response curve, as shown in Figure The figure shows four basic types of dose-response curve possible for a dose of a specific pollutant and the respective responses.
Some characteristic features of the dose-response relationship are: 1. The existence of a threshold in health effects of pollutants has been debated for many years. A threshold dose is the lowest dose at which there is an observable effect.
Curve A in Figure illustrates a threshold response: There is no observed effect until a particular concentration is reached. This concentration is designated as the threshold. Curve B shows a linear response with no threshold; that is, the intensity of the effect is directly proportional to the pollutant dose, and an effect is observed for any detectable concentration of the pollutant in question.
Curve C, sometimes called sublinear, is a sigmoidal dose-response curve, characteristic of many pollutant doseresponse relationships. Although Curve C has no clearly defined threshold, the lowest dose at which a response can be detected is called the threshold limit value TLV. Occupational exposure guidelines are frequently set at the TLV. Curve D displays a supralinear dose-response relationship, which is found when low doses of a pollutant appear to provoke a disproportionately large response.
Total body burden. An organism, or a person, can be exposed simultaneously to several different sources of a given pollutant. The concentration of lead in the body is thus the sum of what is inhaled and ingested and what remains in the body from prior exposure, less what has been eliminated from the body.
This sum is the total body burden of the pollutant. Physiological half-life. The physiological half-life of a pollutant in an organism is the time needed for the organism to eliminate half of the internal concentration of the pollutant, through metabolism or other normal physiological functions. Bioaccumulation and bioconcentration. Bioaccumulation occurs when a substance is concentrated in one organ or type of tissue of an organism.
Iodine, Environmental Risk Analysis 19 for example, bioaccumulates in the thyroid gland. The organ dose of a pollutant can thus be considerably greater than what the total body burden would predict. Bioconcentration occurs with movement up the food chain. Exposure time and time vs. Most pollutants need time to react; the exposure time is thus as important as the level of exposure.
An illustration of the interdependence of dose and exposure time is given for CO exposure in Chapter 18, in Figure Because of the time-response interaction, ambient air quality standards are set at maximum allowable concentrations for a given time, as discussed in Chapter Synergism occurs when two or more substances enhance each other's effects, and when the resulting effect of the combination on the organism is greater than the additive effects of the substances separately.
For example, black lung disease in miners occurs much more often in miners who smoke than in those who do not.