- Understand the major ways in which environmental pollutants such as industrial chemicals make their way into humans
- Learn appropriate methods of personal drinking water treatment and sanitation for traveling and living in the developing world
- Learn to recognize health problems caused by contaminated drinking water or inadequate wastewater treatment and the benefits enjoyed by populations with good drinking water and sanitation
- Gain a basic understanding of appropriate methods of treating community drinking water and wastewater in the developing world
- Understand the magnitude of, health effects associated with, air pollution
Environmental factors profoundly influence human health. A 2006 report by the World Health Organization (WHO) estimated that 24% of the world’s burden of disease, and about a third of the burden in children, is due to preventable environmental factors.1 By preventable, it is meant that these risks can be altered or mitigated. This burden of avoidable disease is disproportionately felt by the residents of poor countries, with attributable disease burdens often 10-fold higher or more than that seen in wealthier nations.2 Reasons for the disproportionate effects felt in developing countries include a lack of modern technology, weak protective environmental laws and regulations, a lack of awareness, and poverty.3 Nonetheless, residents of wealthy countries are also affected by air pollution, poorly designed urban environments, flooding, and lead poisoning, among other risks, and thus environmental health is truly of global concern.
Unclean water and poor sanitation remain the most potent environmental causes of illness worldwide. Industrial chemical contaminants affect health everywhere. Of the more than 30,000 chemicals commonly used today, fewer than 1% have been studied in detail as to their health effects and toxicity,4 and our understanding of the effects of simultaneous low-level exposure to hundreds or thousands of chemicals is rudimentary at best. Air pollution has been found to be a top-ranked problem in nearly every country undergoing economic transition. This chapter outlines a number of the global environmental challenges to health.
Environmental hazards include biologic, physical, and chemical ones, along with the human behaviors that promote or allow exposure. Some environmental contaminants are difficult to avoid (the breathing of polluted air, the drinking of chemically contaminated public drinking water, noise in open public spaces); in these circumstances, exposure is largely involuntary. Amelioration or elimination of these factors may require societal action, such as public awareness and public health measures. In many countries, the fact that some environmental hazards are difficult to avoid at the individual level is felt to be more morally egregious than those hazards that can be avoided. Having no choice but to drink water contaminated with very high levels of arsenic, as is the situation in Bangladesh, or being forced to passively inhale tobacco smoke in restaurants, outrages people more than the personal choice of whether an individual smokes tobacco. These factors are important when one considers how change (risk reduction) happens.
It should be noted that environmental ...