The amazing New York Time series on Toxic Waters continues, this time with an article by Charles Duhigg on drinking water pollution in the U.S.A.
Basically, you have an outdated drinking water law from a few decades back that regulates less than 100 substances, while 60,000 chemical compounds from human sources are currently used in America. The effects of these substances on human health are mosly or totally unknown and good health research cannot keep pace with technological development:
«Many contaminants are hazardous only if consumed for years. And some researchers argue that even toxic chemicals, when consumed at extremly low doses over long periods, pose few risks. Other argue that the cost of removing minute concentrations of chemicals from drinking water does not equal the benefits.
Moreover, many of the thousands of chemicals that have not been analysed may be harmless. And researchers caution that such science is complicated, often based on extrapolation from animal studies, and sometimes hard to apply nationwide, particluarly given that more than 57,400 water systems in this contry each deliver, essentially, a different glass of water every day.»
This appears to be a clear case where the conjoined application of the principles of precaution and prevention could lead to a salutary ban on the introduction of new chemical substances unless positively proven harmless through comprehensive and exhaustive scientific studies. The European Union has recently taken steps in this direction with the new regulation on chemicals REACH.