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"This is surprising," Daughton says, "especially since certain pharmaceuticals are designed to modulate endocrine and immune systems." Hence, they have "obvious potential as endocrine disruptors in the environment"? Even though it is now recognised that PPCPs have permeated sensi- tive ecosystems, very little research has ever been conducted on their potential effects. No municipal sewage treatment plants are engi- neered for PPCP removal. The risks posed to aquatic organisms (by continual life-long exposure) and to humans (by long-term consump- tion of minute quantities in drinking and bathing water) are essentially unknown. While the major concerns to date have been with the promotion of pathogen resistance to antibiotics and the disruption of endocrine sys- tems by natural and synthetic sex steroids, the consequences of many other PPCPs are unknown. According to Bent Halling-Sorensen, professor of analytical chemistry at the Royal Danish School for Pharmaceuticals: "Between 30 and 90 per cent of an administered dose of most antibiotics to humans and animals is excreted with the urine." The problem is particularly acute in the fish-farming industry, where 70 to 80 per cent of drugs administered end up in the environment; The PPCP problem gained prominence in the United States in 2002, when results from the US Geological Survey's (USGS) sampling of 139 streams showed detectable, although minute, quantities of PPCPs targeted by researchers, the most frequent being steroids and nonpre- scription drugs. Antibiotics, prescription medications, detergents, fire retardants, pesticides and natural and synthetic hormones were also present.° A BIRTH CONTROL PILL WITH YOUR COFFEE? Synthetic oestrogen hormones are taken by millions of women worldwide as oral contraceptive control or hormone replacement ther- apy. Oestrogens are also prescribed to men for prostate cancer treat- ment. Both natural and synthetic oestrogens enter sewage treatment plants in large quantities; so do oestrogen-mimicking chemicals origi- nating from the degradation of surfactants and plasticisers. Is it possi- ble that steroid hormones could interfere with vulnerable hormonal receptors in living creatures? The jury is in...and the answer is "Yes!" Results from a Canadian study provided concrete evidence of just what exposure to these chemicals portends. For three years, Canadian scientists added birth-control pills to a remote and pristine Ontario lake set aside for research to measure this impact. The result: all male fish in the lake—from tiny tadpoles to large trout—were "feminised", meaning they had egg proteins growing abnormally in their bodies.’ This was an unmistakable sign of hormone disruption. Feminised male fish have now been found in rivers and streams throughout the world. In river otters, frogs and other living aquatic populations, the effect is the same: the presence of female hormones is making the male species less male—much less male. For instance, in the US state of Washington, scientists have found that synthetic oestrogens are drasti- cally reducing the fertility of male rainbow trout. Another source of hormone contamination comes from the cattle industry. Hormones are leaking into streams and ground water from the 30 million hor- mone-implanted cattle in US feedlots. The endocrine-disrupting efflu- ent caused "significant alterations in the repro- ductive biology" of fish immediately down- stream from a large Nebraska feedlot. The male fish had about one-third less testosterone and testes about half as big as unexposed fis upstream. The female fish had about two per cent less oestrogen and four per cent more testosterone than females from the uncontami- nated section of the stream. In addition, lal tests confirmed that feedlot effluent contained a complex and potent mix of androgens (male sex hormones) and oestrogens (female hor- mones).* Theo Colborn, senior scientist at the World Wildlife Fund (WWF) and co-author of Our Stolen Future, is very worried about pharma- ceutical oestrogens mixing with chemicals already present in streams. "You can liken it to side effects of a prescription drug—you don't know how it's going to interact with the over-the-counter drugs you're taking. For example bisphenol A, a component of plastic, causes female mice to reach puberty earlier nes OF RECENT RESEARCH INTO THE PPCP PROBLEM Many government officials are uneasy discussing these dangers, and so are the water utilities. In the USA, this is a new, emerging, environmental problem. Little is being done to limit drugs entering the water supply, and scientists are baffled not only by the scope of the problem and lack of effective water testing and purification systems but also by the paucity of research. However, in Europe the response has been quite different. In the 1980s, the issue of PPCPs emerged as a serious area of investigation. A study in Germany, which has been at the forefront of this research, found PPCPs in treated and untreated sewage effluent, surface water, ground water and drinking water. Most commonly found were anti- inflammatory and pain-killing drugs, cholesterol-lowering drugs, anti- convulsants and hormones from oral contraceptives. Samples from 40 German rivers and streams turned up residues of 31 different PPCPs? A study by Thomas Heberer and Hans-Jurgen Stan of the Technical University in Berlin found significant amounts of antibiotics, ibupro- fen, cholesterol-lowering drugs, hormones (oestrogen) and chemother- apy agents in Berlin's water supply, while Swiss researcher Hans- Rudolf Buser of the Swiss Federal Research Station in Wadenswil found cholesterol-lowering drugs in Swiss lakes. British scientists have estimated that more than a tonne of aspirin and a tonne of mor- phine derivatives flow down just one small river in northeast London every year. AL FER FE peach thee ceutic, eae syringes’ a — “BET jit € Seeerlle 36 * NEXUS APRIL — MAY 2005 www.nexusmagazine.com