Friday, April 22, 2011

Our drinking water: a toxic brew?

Most countries don’t systematically follow drug residues in drinking water and there are also no maximum residue thresholds. In the USA, at least one contaminant was detected in seventy-five percent of the groundwater wells tested; in virtually all the streams and stream sediments tested; in about 80% of the estuarine sediments tested; in about 80% of the freshwater fish tested and in nearly all of the salt-water fish tested (H. John Heinz III Center 2008). 

N.J. water contains traces of daily life
Drink a glass of water in New Jersey and you'll likely get more than you expect: prescription drugs, preservatives, caffeine, even a by-product of nicotine. Hundreds of these compounds, the residue of our chemical-intensive society, have been found in tap water around the state. Meanwhile, epilepsy drugs, deodorants, and other compounds have been discovered in minute amounts in 30 of New Jersey's brooks and rivers. From the Peckman River in West Paterson to the Wallkill in Sussex, researchers found traces of antibiotics, flame retardants, artificial colours, and fuel additives. Carbamazepine, a painkiller; AHTN, a fragrance in consumer products; and prometon, a herbicide, were most common. Two of the sites - the Passaic and Ramapo rivers - supply water to more than 1 million customers in North Jersey. The medicines and other chemicals were discovered in such tiny concentrations that many scientists think they pose no risk. Still, researchers admit that no one knows for sure. Many of the compounds have been studied in high doses, but not at low concentrations ingested over months, years, or a lifetime. Even less understood are the chemical cocktails now forming as they mix in the environment. "The question is, 'Is this something the body deals with at low levels, metabolizes, and there's no problem? Or is this something that accumulates in the body?' We just don't know," said Brian Buckley, the Rutgers chemist who led the four-year drinking water study. "To be honest, we are just starting to deal with the question." (North Jersey News 2003).

 Of 62 big waterworks in the USA, only 28 had tested their water for drug residues by the mid 2000s. New York, Houston, Chicago and Miami had never tested their water. Those that do test find a disturbing reality. In Philadelphia 56 different drugs were found in the drinking water and 63 in the water source. In San Francisco’s drinking water there are sexual hormones, in Washington 6 different drugs (USA Today 2008). Purification of water to get rid of the drugs might cost in the range of 200 dollar per inhabitant and year (UNT 2008).

Among the human medications found in water in the USA are antidepressants, medications for high blood pressure and diabetes, anticonvulsants, steroid medications, oral contraceptives, hormone replacement therapy medications, codeine, non-prescription pain relievers, chemotherapy drugs, heart medications, and antibiotics (President’s Cancer Panel 2010)

Our drinking water doesn't only contain prescription drugs, but pesticides as well. In most countries there is no systematic follow up of pesticides in nature and in no country there is monitoring of all active substances; what is found is still frightening enough. Eighty percent of all rivers in the USA contain pesticide residues. Sixty percent of all wells have residues. The proportion contaminated wells was almost as high in urbanized areas, due to use in home gardens, gravel or stone paths, golf courses etc. In France, pesticides are found in all rivers and half of all water sources had at least traces of them. Of the fifty substances that are checked in the Netherlands, two thirds were found in ground water (OECD 2001). 20 pesticides were found in groundwater used by 3.5 million people in the Santa Ana River watershed. On the great plains in the USA researchers detected two insecticides and 27 herbicides in reservoir water. Water treatment removed from 14 to 86% of individual herbicides. Drinking water contained 3–15 herbicides (average, 6.4).

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