This chapter speaks to humanity’s massive impacts on Earth’s environment while also addressing basic concepts of pollution and its impacts. Section 1.1 opens with a brief introduction to the period in which we now live, widely called the Anthropocene because of humanity’s great impact. Examples are given of how we could identify the beginning of this epoch thousands of years from now. Section 1.2 introduces pollution and presents examples of pollution, how it happens, how pollutants are transported in the environment, and how they are degraded. Section 1.3 provides an example of catastrophic pollution, but then considers whether even tiny amounts of pollution are a concern. Section 1.4 discusses nature’s services and our absolute dependence on those services, before Section 1.5 homes in on one critical natural service: that provided by Earth’s soil. In Section 1.6 we ask about root causes of pollution – population, consumption, and technology. Section 1.7 asks us to face ourselves, to see that our personal actions have consequences, and to accept that we need to be part of the solution. Section 1.8 addresses the critical concept of living within our planet’s boundaries, and within this section Table 1.3 summarizes nine life-support systems. Section 1.9 provides a brief overview of the large-scale burning of fossil fuels worldwide, which is a major factor keeping humanity too close to, or beyond, several of the planetary boundaries discussed in Section 1.8. Here, Table 1.4 provides a summary of pollutants produced by fossil fuels and the problems they contribute toward. Section 1.10 presents the conclusion to the chapter.

In Section 8.1 we examine the often gross pollution associated with our use of motor vehicles as well as their other major environmental impacts. Section 8.2 primarily addresses the question: Is clean coal possible? To answer, we look at coal’s lifecycle. Despite their weighty pollution problems, fossil fuels will be used for years to come; Section 8.3 examines societal efforts to greatly increase the efficiency with which fossil fuels are used, while Section 8.4 addresses specifically how industry can use them more efficiently. Section 8.5 delves into the subject of the major quantities of waste energy produced, and methods employed to recover this energy. Section 8.6 examines the renewable energy source photovoltaics (PVs), which directly generate electricity as well as how concentrated solar power works. The much simpler passive solar does not generate electricity, but directly uses the Sun’s energy for heating. We look into the lifecycle of PVs in Box 8.1 and see the great amount of energy needed in their manufacture and the hazardous chemicals necessary to make highly purified polysilicon. Section 8.7 moves to wind power, another major renewable energy source, and examines both land-based and offshore wind. We further see how the use of both solar power and wind power has rapidly increased. In Section 8.8 we see the increasing ability of electric grids to deal with renewable energy sources, and how increasingly sophisticated energy-storing batteries contribute to this success. Section 8.9 provides examples of renewable energy use around the world. In Section 8.10 the end-of-life management of solar cells, wind turbines, and batteries is examined. Section 8.11 provides briefs on other renewable energy sources: geothermal, biomass (especially wood), hydroelectric, and tidal. Box 8.2 briefly considers nuclear power. Section 8.12 concludes the chapter.

Most of us in developed countries take clean and plentiful water as a given – not just drinking water, but water for household, yard, and other uses. Yet the American Academy of Microbiology says that, “Microbiologically safe drinking water can no longer be assumed, even in developed countries, and the situation will worsen unless measures are taken quickly– the crisis is global.” Drinking water treated to kill pathogens is given much credit for increasing human life spans. In the Western world, the Centers for Disease Control (CDC) states that “Chlorine revolutionized water purification, reduced the incidence of waterborne diseases” and “chlorination and/or filtration of drinking water has been hailed as the major public health achievement of the 20th century.”1

The reality of outdoor air pollution is more than the words “ambient air pollution” can convey. It is the eye-stinging pollution surrounding us in a city crowded with motor vehicles, the odor of ozone on a hot hazy day, the choking of a heavy dust storm, the smoke from wood or coal fires on a winter day, the fumes from an uncontrolled industrial facility, the odor from uncontrolled sewage or an open dump. Many living in wealthy countries are spared the worst of these. Not so for many people living in less-developed countries, who suffer from heavy exposure. And more and more often, air pollution far from where we live is reaching us.1

Some years ago, the US Environmental Protection Agency (EPA), working with Harvard University, was studying the sources of various environmental pollutants. They made what was at the time a startling observation: Regardless of the community studied or its location, whether rural or urban, lightly or highly industrialized, and regardless of sex, age, smoking habits, and occupation, indoor air pollution was the major source of exposure to many air pollutants.1 This is perhaps not surprising: Most people spend 90 percent or more of their time indoors, and indoor sources emit many of the same pollutants as outdoor sources. Also, dilution with outdoor air happens slowly. In the years after this study indoor air pollution came to be ranked as a priority environmental health risk.

Whether animal, plant, or microbe, water is essential to life. Fish and other water-dwelling creatures are vulnerable to polluted water and there are waters in the world so polluted that life has disappeared. In other locales, fish and shellfish survive, but are not safe to eat because their flesh is contaminated. Humans enjoy being around water, but contamination with infectious organisms makes the water unsafe for swimming. Water with foul odors or scum, or clogged with algae blooms, are noxious. Clean water – and enough of it – is vital. Laws governing water quality existed in the USA before 1972, but no uniform national law existed. Water pollution was not well controlled, and some states, eager to keep or attract industry, were negligent. The Clean Water Act (CWA) of 19721 and the Safe Drinking Water Act (SDWA) of 1974 were laws mandating that water pollution be treated uniformly nationwide; they have been updated over the years.

Municipal solid waste (MSW) is the waste we know best. Better known as trash or garbage, MSW is but a small percentage of all solid wastes that humanity produces. Among our many other wastes are hazardous waste, ash, construction and demolition debris, various sludges, agricultural wastes, industrial process wastes, and more.1 In 2015, each American produced an average of 2 kg (~4.45 lb) of MSW per day.2 This MSW contains the residues or unwanted parts of everything that we use for as little as a moment for a throw-away cup, or years for a drinking glass. It cumulatively represents our lives

Pesticides include a multitude of agents. “A pesticide is something that prevents, destroys, or controls a harmful organism (a pest or disease), or that protects plants or plant products during production, storage and transport.”1 Pesticide use is both controversial and prevalent. Many or most individuals believe pesticides are necessary to destroy the enemies of human agriculture and of human health. Others believe we can use organic farming to accomplish these ends without synthetic pesticides. Another group follows the principles of integrated pest management, believing that pesticides are sometimes needed, but recognizing their limitations and risks, and minimizing their use. There is no simple answer, but we do need answers. Twenty years ago two “green” chemists, Dennis Hjeresen and Rangel Gonzales, issued a challenge: “Can green chemistry promote sustainable agriculture?”: “Human population is increasing. Demand for food is rising … Environmental impacts are worsening. Taken together, few issues reflect the difficulties of sustainable development more than the problem of controlling pests and increasing food production while protecting the environment and conserving natural resources.”2

Chapter 1 focused attention on the mammoth ways that humans have changed the world’s environment, and Chapter 2 spoke to the concept of risk and ways to reduce it. Chapter 3 examines toxicity as the major risk of chemicals. Section 3.1 overviews terminology and gives examples of chemicals that can be either toxic or beneficial, as well as examples of how they exert toxicity. Acute and chronic toxicity are compared. Section 3.2 examines the relationship between dose and toxic impact, and also dose per time. Examples of how several chemicals exert toxicity are provided. Section 3.3 looks at systemic and local effects of toxicants, and follows a chemical as it is absorbed into the body, distributed, metabolized, and excreted. Section 3.4 looks at factors affecting toxicity, such as species, gender, and nutrition. Toxic substances pose special concerns for the fetus and small child. Box 3.2 looks at biological, physical, and chemical factors affecting toxicity, and introduces bioaccumulation and biomagnification. Endocrine disrupters are discussed in Section 3.5, with special emphasis on environmental estrogens, where we explore whether these chemicals adversely impact humans. Section 3.6 looks at cancer; Box 3.4 examines carcinogenesis and Box 3.5 looks at factors that increase cancer risk. The latter notes the high incidence of cancer in China. Section 3.7 very briefly considers epigenetics and disease. Section 3.8 overviews the specific impacts toxicants have for different organs – the liver, kidneys, and others. In Box 3.6 we see the problem of liver cancer worldwide and how the poor are particularly at risk. Section 3.9 notes that 9.5 million people each year are adversely affected by heavy pollution in poor countries. Section 3.9 concludes the chapter.

Section 2.1 defines hazard, risk, and other terms, and briefly introduces chemical risk assessment. Section 2.2 introduces comparative risk assessment, which can be “used to systematically measure, compare, and rank environmental problems.” It has no scientific basis, but is a useful tool and we see the basics of doing a comparative risk assessment. Section 2.3 reminds us of how complex risk assessment can be, as we are reminded of the risks to nine planetary boundaries. Section 2.4 points out the major reductions in risk that environmental regulations have provided, while also highlighting their limitations. Section 2.5 describes the right-to-know law, and especially the Toxics Release Inventory. Letting people know of chemical and other industrial releases in their locales can lead to industry reducing emissions. In Section 2.6 we see how each step of the waste management hierarchy has an important role in reducing risk: pollution prevention (P2) at the apex is closely followed by reuse, and then recycling, treatment, and disposal. In Section 2.7, with the introduction of industrial symbiosis, we learn that it is possible to move beyond P2: in industrial symbiosis there is an association between a number of facilities in which the wastes of one can be a raw material for others; in later chapters we see that it is also possible to move beyond industrial symbiosis. Section 2.8 concludes the chapter.

Remember nature’s services, a major topic in Chapter 1: To sustain meaningful life on Earth, it is absolutely necessary to sustain Earth’s habitats and biodiversity, and its ability to continue to perform the services on which humanity and all life depends. Sustaining nature’s services necessitates producing a minimal amount of damaging wastes and emissions (“zero”). The Product Life Institute provides one of several worthwhile introductions to sustainability.1

Acid deposition, better known as acid rain,1 goes far beyond the deposition of acid pollutants. It is atmospheric deposition, a phenomenon in which airborne chemicals and particulates – whether acids, metals, organic chemicals, microbes, or pollens – deposit from air onto land and water. You became familiar with fine particulates, PM2.5, in Chapter 5 and know that many chemicals can be associated with particulate matter.