Drinking water Technology, Eawag, developed a method by which hazard maps could be produced for geogenic toxic substances in groundwater. This provides an efficient way of determining which wells should be tested. Parameters for drinking water quality typically fall within three categories: Physical and chemical parameters include heavy metals, trace organic compounds, total suspended solids (TSS), and turbidity. Microbiological parameters include Coliform bacteria, "E. coli", and specific pathogenic species of bacteria (such as cholera-causing "Vibrio cholerae"), viruses, and protozoan parasites. Chemical parameters tend to pose more of a chronic health risk through buildup of heavy metals although some components like nitrates/nitrites and
Multiple chemical sensitivity variety of cleaning agents, pesticides, perfumes, vehicle exhaust, the products used in barber shops and beauty salons, new carpeting, new furniture, chlorine and fluoride in drinking water, fresh ink, and less commonly wood smoke and secondhand tobacco smoke. Food items reported as triggers include tartrazine (a.k.a. FD&C Yellow #5 or E102), and other azo dyes (in the absence of an allergy), caffeine, and monosodium glutamate. One proposed hypothesis for the cause of multiple chemical sensitivity is immune system dysfunction after being sensitized by a chemical exposure. Several mechanisms for a psychological etiology have been proposed, including theories based on misdiagnoses