For example, a farmer who accidentally spills a pesticide may shortly thereafter suffer nausea, dizziness and vomiting. In Idaho and the rest of the nation the most commonly detected drinking water problem is bacterial contamination caused by improper well construction and maintenance. Bacterial contamination is a common cause of acute toxicity, producing symptoms as mild as upset stomach and diseases as serious as dysentery, typhoid fever and hepatitis. Household cleaners and garden chemicals are other examples of contaminants that can produce acute effects. Chronic Effects Chronic effects appear after longer incubation periods, possibly even after a number of years.
Chronic effects result from exposure to a substance over weeks or years.
For example, a coal miner who breathes traces of coal dust for many years may later develop serious respiratory problems. Over time, some drinking water contaminants can damage the liver, kidneys, heart and other body organs. Such effects may include cancer or damage to the central nervous system. Secondary Standards Secondary standards cover contaminants that cause offensive taste, odor, color, corrosivity, foaming and staining. Secondary standards are not enforced.