- FROM BIOETHICS BRIEFINGS
Environment, Ethics, and Human Health
Framing the Issue
Many of the most challenging ethical questions of our time address interactions between human health and the environment. How should we regulate pesticides, industrial chemicals, and pollutants? Should we develop genetically modified organisms for use in agriculture, medicine, and energy production? How should we regulate them? Should we use genetically modified mosquitos to control mosquito-borne illnesses such as malaria and Zika virus? How should we ensure the safety of our food supply? What steps should we take to reduce antibiotic resistance? Where should a community place a new solid waste facility? Where should a nation locate its hazardous or radioactive waste? What steps should we take to protect people from workplace hazards? Should we implement special workplace protections for pregnant or fertile women? How should we balance safety and affordability when establishing housing standards? Should we prohibit people from building homes in flood-prone areas? What steps should we take to mitigate or adapt to climate change? Should richer nations bear more of the responsibility than poorer ones? How should we regulate energy production and use to protect the environment and human health? Should we take steps to encourage democratic participation in environmental health decision-making?
The issues that arise in environmental health ethics are often complex, interdisciplinary, dynamic, and global in scope. Finding satisfactory solutions to environmental health problems will become increasingly important as the environmental impacts of human activities continue to mount and we learn more about the relationship between human health and the environment.
The Science: Environmental Health and Hazards
All organisms depend on their environments for energy and materials needed to sustain life: clean air, potable water, nutritious food, and safe places to live. For most of human history, increases in longevity were due to improved access to these necessities. Advances in agriculture, sanitation, water treatment, and hygiene have had a far greater impact on human health than medical technology.
Although the environment sustains human life, it can also cause diseases. Lack of basic necessities is a significant cause of human mortality. Environmental hazards increase the risk of cancer, heart disease, asthma, and many other illnesses. These hazards can be physical, such as pollution, toxic chemicals, and food contaminants, or they can be social, such as dangerous work, poor housing conditions, urban sprawl, and poverty.
Unsafe drinking water and poor sanitation and hygiene are responsible for a variety of infectious diseases, such as schistosomiasis, diarrhea, cholera, meningitis, and gastritis. In 2015, approximately 350,000 children under age 5 (mostly in the developing world) died from diarrheal diseases related to unsafe drinking water, and approximately 1.8 billion people used drinking water contaminated with feces. More than 2 billion people lacked access to basic sanitation.
- Heart disease
- Chronic obstructive pulmonary disease
- Occupational injuries
- Parkinson’s disease
By contrast, activities that promote health and extend human life can have adverse environmental effects. For example, food production causes environmental damage from pesticides and fertilizers, soil salinization, waste produced by livestock, carbon emissions from food manufacturing and transportation, deforestation, and over-fishing. Health care facilities also have adverse environmental impacts. Hospitals use large quantities of electricity and fossil fuels and produce medical wastes. To prevent some diseases, it may be necessary to damage the environment. For example, malaria was eradicated in the United States and other developed nations in the 1940s and 50s as a result of draining wetlands and spraying DDT to kill mosquitoes. A reduction in mortality from starvation or disease can lead to overpopulation, which stresses the environment in many different ways–increasing use of fossil fuels, clearing of land, generating pollution and waste, and so on.
Bioethical, Social, and Legal Considerations
Relationships between human health and the environment raise many ethical, social, and legal dilemmas by forcing people to choose among competing values. These considerations can be grouped into the following categories.
Managing benefits and risks. Many of the issues at the intersection of health and the environment have to do with managing benefits and risks. For example, pesticides play an important role in increasing crop yields, but they can also pose hazards to human health and the environment. Alternatives to pesticide use create trade-offs in health. The extreme action of stopping all pesticide uses could significantly reduce agricultural productivity, leading to food shortages and increased food prices, which would, in turn, increase starvation in some parts of the world. Public health authorities have opted to regulate the use of pesticides to enhance food production while minimizing damage to the environment and human health. Energy production and use helps sustain human life, but it can also pose hazards to human health and the environment, such as air and water pollution, oil spills, and destruction of habitats.
No issue demands greater care in balancing benefits and risks than global warming. A significant percentage of global climate change is due to the human production of greenhouse gases. Climate change is likely to cause tremendous harm to the environment and human health, but taking steps to drastically reduce greenhouse gases could have adverse consequences for global, national, and local economies, which would result in a general decline in human health and health care. For example, greatly increasing taxes on fossil fuels would encourage greater fuel efficiency and lower carbon dioxide emissions, but it would also increase the price of transportation, which would lead to widespread inflation and reduced consumer spending power.
Environmental Risk Factors for Disease
- Microbes in air, water, or soil
- Contaminants in food
- Weather conditions (e.g. droughts, heat waves)
- Natural disasters (e.g. hurricanes, earthquakes, floods)
- Pesticides and other chemicals
- Pests and parasites
- Lack of access to health care
For many years some politicians and scholars argued that we should wait for more evidence of global warming before taking action, since the steps needed to prevent or minimize it could have disastrous economic consequences. Others have argued that society cannot afford to wait for complete evidence because the consequences of global climate change could be catastrophic and irreversible. This difference of opinion raises fundamental questions about the ethics of risk management: what is the role of scientific evidence in decision-making? Should we use risk/benefit or precautionary decision-making to develop environmental health policies?
Most regulatory agencies in the U.S make benefit/risk decisions based on information from scientific studies, such as chemical analysis, cell studies, animal experiments, and controlled clinical trials. Agencies often refrain from making regulatory decisions until they have complete scientific evidence. Many commentators and organizations have endorsed an alternative approach called the precautionary principle. The idea is that society should take reasonable steps to prevent or minimize irreversible and significant harm, even when scientific evidence is incomplete, and that regulatory decisions to avoid harm need not await the accumulation of complete scientific evidence. Although the precautionary principle has gained many adherents, especially in Europe and California, it remains controversial.
Social justice. Managing benefits and risks raises social justice concerns. In general, people with lower socioeconomic status have greater exposure to certain detrimental environmental conditions in their homes or at work, such as lead, mercury, pesticides, toxic chemicals, or air and water pollution. Communities and nations should minimize such injustices when making decisions such as choosing a site for a factory, a power plant, or waste dump, or regulating safety in the workplace. The decision-making process should be fair, open, and democratic, so that people who will be affected by environmental risks have a voice in these deliberations and can make their concerns known.
When drafting and implementing environmental health regulations, it is important to consider vulnerable subpopulations. A vulnerable subpopulation is a group with an increased susceptibility to the adverse effects of an environmental risk factor, due to their age, genetics, health status, or some other condition. For example, children are more susceptible to the effects of lead, mercury, and some pesticides than adults. Some people have a genetic mutation that increases their susceptibility to cancer caused by passive smoking.
If an environmental regulation is designed to protect average members of the population it may fail to adequately protect vulnerable subpopulations. Justice demands that we take care of people who are vulnerable. However, almost everyone in the population has an above-average susceptibility to at least one environmental risk factor. Since providing extra protections to everyone would be costly and impractical, protections must be meted out carefully and the populations who are vulnerable to a particular environmental risk factor must be defined clearly. For example, about 0.4% of the U.S. population has a severe allergic reaction to peanuts. Banning the sale of peanuts would be a costly and impractical way of protecting people with peanut allergies, but requiring that products containing peanuts be labeled clearly would be reasonable.
Social justice must be a factor in allocating resources for health care. Governments spend billions of dollars trying to improve the health of citizens and prevent diseases. These funds go to biomedical research, overseeing the safety of foods and drugs, enforcing environmental or occupational health regulations, and running programs for disaster preparedness, public health, health education, sanitation, water treatment, and so on. In the U.S., the lion’s share of health resources goes to providing medical diagnosis and treatment, but one might argue that it would be wiser to shift some resources to disease prevention programs, such as environmental protection, public health, and health education, since prevention is generally more cost-effective than treatment.
Human rights. Various public health strategies pit the rights of individuals against the good of society, such as mandatory treatment, vaccination, or diagnostic testing; isolation and quarantine; and disease surveillance. The main argument for these public health strategies is that individual human rights may have to be limited to prevent the transmission of infectious diseases, such as tuberculosis, SARS, HIV/AIDS, and pneumonia. But restrictions on rights should be well thought-out and safeguards put in place to prevent public health authorities from overstepping their bounds. Protecting the public’s health should not come at the expense of human rights. (See “Public Health Ethics and Law” chapter.)
Some health and environmental protections also limit property rights. The owner of a coal-burning power plant must deal with many laws concerning the operation of the plant, workplace safety, and carbon emissions. A developer who plans to build 150 new homes with land he has purchased may also have to deal with laws concerning storm drainage, water and sewage lines, gas lines, sidewalks, and so on. Restrictions on property rights are justified to protect human health and the environment. But opponents of these restrictions argue that they are often excessive or not adequately supported by scientific evidence.
Human rights issues also come up in research on environmental health that involves human subjects. For such research to be ethical, human subjects must give consent, and great care must be taken to ensure that they understand that they can opt out of the research project. Since the late 1990s, some pesticide companies have tested pesticides on human subjects to gather data to submit to the government for regulatory purposes. Some commentators charge that these experiments are unethical because they place people at unacceptably high risk without a clear benefit to society. Others have argued that the experiments, if properly designed and implemented, could produce important benefits to society by providing useful knowledge about the effects of pesticides, which could lead to stronger regulations.
There are many new developments in science, technology, and industry that are bound to pose benefits and risks to the environment and human health. These include nanotechnology, genetic modification of plants and animals, antibiotic resistance, threats to food safety, and the growing market for biofuels. Longstanding challenges persist, including the preservation of ecosystems and endangered species and questions about animal experimentation. Many more developments will emerge. To deal with them in a responsible way, we must continue to research the relationship between human health and the environment and hold fair and democratic public deliberations, such as community forums, academic conferences, and legislative debates, involving participants with diverse cultural, socioeconomic, philosophic, and scientific perspectives.
This research was supported by the intramural program of the National Institute of Environmental Health Sciences/National Institutes of Health. It does not represent the views of the NIEHS or NIH. We are grateful to Ken Olden, Richard Sharp, and William Schrader for helpful comments.
David B. Resnik, JD, PhD, is a bioethicist and IRB chair at the National Institute of Environmental Health Sciences, National Institutes of Health. Christopher J. Portier, PhD, is a senior collaborating scientist at the Environmental Defense Fund.