Harmful effects from airborne pollutant exposure is hard to quantify, and its effects of such slow progressive pathology that most persons illnesses are hard put to confirm poor air quality as the symptomatic cause. Next to oxygen water is the most important nutrient for life. Unfortunately because it is such a good carrier water also carries polutants. Our major sources of drinking water are surface water and ground water. Surface water serves about one half the population in the U.S. and comes from lakes, rivers, reservoirs and streams.
Ground water comes from underground aquifers and wells.
Surface water can become contaminated by pesticide and fertilizer runoff, storm drain runoff, industrial wastes, leaking sewage and acid rain. Ground water can become contaminated by seeping pesticides and ferilizers, leeching industrial wastes, leaking gasoline storage tanks, discarded household chemicals, leaking septic systems and improperly created leech fields. Increasingly Americans are avoiding drinking tap water. In many places there is good reason for this. Chlorination bi-products are quite toxic and in many places there is outright contamination from leaking pipes, cracked water lines and inadequate filtration and cleansing proceedures.