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Introduction

1.1 Background

Health and environmental impacts of worldwide pollution and related environmental changes are increasing to a pandemic level for human health. The World Health Organization (WHO) estimated that 12.6 million people died in 2012 as a result of living or working in unhealthy environments (WHO 2016). This number was nearly a quarter (1 in 4) of all global deaths. It is also likely that this number is an underestimate because the health impacts of exposures to many pollutants and environmental factors are poorly known. Environmental risk factors, such as air, water, and soil pollution, toxic chemical exposures, global warming and climate change, and ultraviolet radiation contribute to over 100 diseases and injuries. Deaths related to unhealthy environments were attributed mainly to diseases such as stroke, heart disease, cancers, and chronic respiratory diseases. Indoor and outdoor air pollution was estimated to result in 7 million people dying prematurely every year (Climate & Clean Air Coalition 2018).

At the same time, global biodiversity and ecosystems are under persistent to increasing pressures from habitat loss, degradation, overexploitation and unsustainable use, invasive species, climate change from emissions of greenhouse gases, and excessive nutrient loads and other sources of pollution (Secretariat of the Convention on Biological Diversity 2010, pp. 9-13) (also known as the Global Biodiversity Outlook 3 [GBO-3]). Human-induced activities, including pollution loads and interactions, continue to cause global biodiversity to be significantly reduced for many major groups of plants and animal species. As well, many endangered species face a future of accelerating extinction.

A major problem for evaluating biodiversity is predicting ecological thresholds or tipping points that result in large ecological impacts on biodiversity. These are difficult to model, control, and reverse their impacts (see Chapter 3 of this book). In the case of climate change, tipping point analyses of global warming projections indicate major biodiversity changes at temperatures near or below 2?°C for a wide range of global ecosystems and regions, such as degradation of coral reefs, shifts in Arctic phytoplankton communities, and widespread dieback of Amazon forests (Secretariat of the Convention on Biological Diversity 2010).

The great challenge is whether our planet can provide sustainable ecosystem services in the form of biologically productive land and water to satisfy our needs (e.g. food) and to absorb our wastes. The problem is that our ecological footprint, measured in terms of the area of biologically productive land and water needed to produce goods consumed and to assimilate the wastes generated, already exceeds the annual capacity of the Earth to regenerate itself by over 50% (equivalent to 1.7 Earths) (Global Footprint Network 2018).

This situation is due to factors such as population growth, mega-urbanization, excessive emissions and waste disposal, greenhouse gases and global warming, and major impacts on biodiversity, human health, and ecosystem services.

Despite international agreements, many national environmental regulations and pollution controls, there continues to be great scientific and societal demands to evaluate and reduce the effects of pollutants on the health of ecosystems and human populations using risk-based management solutions that meet the needs of sustainability principles and criteria.

To face the challenge due to pollution impacts on our planet, at strategic, policy, and practice levels, there are several things we can readily do, that continue to be an urgent priority. We can rapidly advance and disseminate our knowledge of the scientific principles that largely govern the effects of pollution on ecosystems and human health, improve and apply our ability to evaluate these effects and associated risks within this context, and enhance our capacity to achieve sustainable healthy environments, at all scales, and implement practical solutions.

In the Twenty-first Century, our future sustainable solutions and adaptation to environmental changes depend on environmental science, ecology, earth sciences, environmental engineering, environmental education, conservation, pollution control and regulation, risk communication, and sustainable environmental management. They are now major areas of scientific research, policy development, and practice in environmental management, greatly supported by the emergence and recent advances in pollution science, environmental chemistry, ecotoxicology, environmental health, and risk assessment.

1.2 Environmental Pollution

Pollution occurs when substances resulting from human activities are added to the environment, causing adverse alteration to its physical, chemical, biological, or aesthetic characteristics. All nonhuman organisms also produce wastes which are released to the environment, but these are generally considered part of the natural system, whether they have adverse effects or not. Pollution is usually considered to occur as a result of human actions such as from the discharge of poorly treated wastes. However, natural processes can result in situations in the natural environment where they can resemble those due to pollutants (Connell and Miller 1984, p. 1). Fish kills, for example, in water bodies can result from sudden loss of dissolved oxygen (deoxygenation) caused by microbial respiration during biodegradation of abnormal inputs of organic matter (e.g. sugars or carbohydrates) following intense rainfall events from their catchments.

Chemicals released to the environment may affect it in different ways. In the air, they can act as air pollutants, greenhouse gases, ozone-depleting chemicals, or may contribute to acid rain formation. Chemicals can contaminate water resources through direct discharges to bodies of water, stormwater runoff, or via deposition of air contaminants to water. As water pollutants, they can have adverse effects on aquatic organisms, including fish, and on the availability of water resources for drinking, bathing, and other activities. It is common for soil pollution to be a direct result of atmospheric deposition, dumping of waste, spills from industrial or waste facilities, mining activities, contaminated water, or pesticide applications. Soil contamination impacts include loss of agricultural productivity, contamination of food crops grown on polluted soil, adverse effects on soil microorganisms, and human uptake of contaminants, either through food or direct exposure to contaminated soil or dust.

While objective measures can be made about indicators of pollution or actual pollutants and biological effects, there is an element of subjective judgment about pollution as to whether an adverse effect has occurred or not. For example, the release of plant nutrients into a freshwater body may stimulate the growth of aquatic plants in the system such as phytoplankton (algae) and fish numbers. From a fishing perspective, this is likely to be viewed as a beneficial outcome and not pollution. In contrast, a water authority using this water body to supply household drinking water may find a significant increase in algal numbers in the raw water supply, as a detrimental effect, that requires treatment to ensure suitable water quality (Connell and Miller 1984, pp. 1-2).

It is evident that perceptions of pollution or subjective decisions about pollution are critical factors in the evaluation and management of pollution impacts and also risks. In fact, how to resolve conflicts between scientific and public judgments of technical and perceived risks about pollution have emerged as a major challenge for decision-makers to achieve consensus-based agreements and equitable solutions on management actions. This type of problem is clearly shown by the issue of global climate change where scientific consensus exists on the highly probable role between emissions of greenhouse gases from human activities and observed global warming events and modeling of risk-based scenarios for the Twenty-first Century (see Chapter 14).

1.3 Drivers of Environmental Pollution

Human activities cause changes to our environment and health through pressures involving human driving forces. These forces are seen as related to the following components (Landon 2006, p. 27):

• Population growth and urbanization
• Poverty and inequality
• Technological and scientific development
• Political and economic systems
• Cultural values

During the late 1960s and early 1970s, economic and ecological argument arose about rapid human population growth and the impacts of overuse of limited natural resources such as famine and starvation. Growth in GDP had increased steadily over a long time period, and was thought to drive an increase in human impacts on the environment, through increased consumption as many human populations became more affluent. In the early 1970s, the ecologists, Paul Ehrlich, John Holdren, and Barry Commoner proposed and developed the impact Eq. (1.1) that expressed human impacts (I) on the environment, as the product of population's size (P), its affluence (A), and the damage caused by the technologies used to supply each unit of consumption (T) (EJOLT 2012).

Population growth is the fundamental driver. Since the early period of the Industrial Revolution, the human population on Earth is estimated...