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Issue link: http://wateronline.epubxp.com/i/164028
Feature Recent studies, as well as observations in the wild, can serve as the proverbial canary in the coal mine in warning us of a developing and disturbing worldwide trend. • • • • • The birthrate for boys has declined every year for the past 30 years in more than 20 heavily industrialized nations — amounting to 3 million fewer males born. The number of boys born with penis abnormalities such as cryptorchidism (undescended testicle) and hypospadias (abnormal location of the urethra) has risen 200 percent in the past 20 years. The average sperm count of North American college students has declined more than 50 percent over 50 years. Up to 85 percent of the sperm in a healthy male is DNA-damaged. There has been a 300 percent increase in testicular cancer, which is linked to damaged sperm, in the past half-century. in alligators and otters; and egg-yolk proteins in male fish, amphibians, and birds.2 There's also that extremely lopsided sex ratio of longnose dace in Canada to consider. "It brings a question to people's minds that if the fish were affected ... might there be a potential problem for humans?" said Vickie Wilson, an EPA research biologist interviewed by the AP. Strong evidence of the effect of EDCs on birth ratios comes from the Aamjiwnaang First Nation. This community of about 850 Chippewa (Ojibwe) aboriginal peoples lives in southwestern Ontario, Canada, just across the U.S. border from Port Huron, MI — and downstream from a number of chemical plants. Environmental Health Perspectives notes that while the normal birthrate percentages for boys and girls break roughly 50/50, the birth ratio between 1999 and 2003 for the Aamjiwnaang was dramatically altered to 33 percent boys and 67 percent girls.8 The Aamjiwnaang is the first community on record with more than two girls to every boy, a fact that undoubtedly points to the volume of EDCs to which they were exposed. But what about the more common scenario of low-dose exposure to PPCPs and EDCs? That is the question and the debate for scientists, and ultimately for water and wastewater treatment professionals. The Smoking PPCP If PPCPs are to blame for such trends, it is likely due to the endocrine disrupting compounds (EDCs) among them. Though the quantities (per compound) in drinking water are slight, the impact of endocrine disruptors is significant by their very definition: compounds that mimic hormones or disrupt hormone regulation.5 In some cases, as with birth control pills, hormone manipulation is precisely the point. More than 100 million women worldwide take the pill, which contains the female hormone estrogen. That's a logical place to start when considering female-skewing alterations of gene expression. Like other pharmaceuticals, the pill is not completely absorbed by the body and thus ends up in wastewater. But it is far from the only source of estrogen in the water supply; in fact, it contributes very little to the total amount of estrogen in drinking water. According to a 2010 Environmental Science & Technology report, animal waste is a far greater contributor of natural and pharmaceutical hormones. Livestock produce 13 times more solid waste than humans, and the excretions often enter the waterways without treatment.6 The agriculture industry also uses pesticides with EDCs that mimic estrogen, as many chemicals do. Phthalates, for instance — found in soap, shampoo, deodorants, fragrances, hair spray, and nail polish — are among the most potent and worrisome EDCs. The incidence of these raging hormone-disruptors is linked to "feminization" within the animal kingdom. In 2008, the Associated Press conducted an investigative report on pharmaceuticals acknowledging that "Pharmaceuticals in waterways are damaging wildlife across the nation and around the globe."7 Examples include hermaphroditic "male" cane toads and polar bears; abnormal testes in bears, panthers, turtles, sea lions, whales, and birds; genitalia deformities wateronline.com Low-Dose Impact A fundamental tenet of toxicology states that "the dose makes the poison" — in other words, as the dose increases, so does the effect. For many, this tenet translates that PPCPs in the parts-per-billion range have little to no effect. Disputing this is a 2012 paper, "Hormones and Endocrine-Disrupting Chemicals: Low-Dose Effects and Nonmonotonic Dose Responses," written by 12 scientists and based on a review of 800 scientific studies, concluding that it is "remarkably common" for extremely small amounts of hormone-disrupting compounds to have significant and adverse human-health effects.9 The U.S. EPA remains wary but unconvinced, at least not enough to enact regulations. Benjamin H. Grumbles, the agency's assistant administrator for water at the time of the report, told AP investigators, "We recognize it is a growing concern and we're taking it very seriously."7 Meanwhile, the EPA website currently states, "To date, scientists have found no evidence of adverse human health effects from PPCPs in the environment." That's not exactly true. After reviewing hundreds of scientific reports, analyzing federal drinking water databases, and interviewing more than 230 officials, academics, and scientists, the AP commented that "Emerging scientific studies indicate that over time, humans could be harmed by ingesting drinking water contaminated with tiny amounts of pharmaceuticals." ■ Water Online The Magazine 9