The nation's rivers and streams are awash in trace amounts of painkillers, antibiotics, caffeine, contraceptives, anti-depressants and other pharmaceuticals that have passed first through people and then through sewage plants, according to a pioneering study released Wednesday by the U.S. Geological Survey.
Chemicals in the murky Chicago Sanitary and Ship Canal tested at Romeoville include anti-diabetic drugs, antacids, cholesterol and hypertension medication. Two other urban waterways sampled, the Des Plaines River at Riverside and Salt Creek at Western Springs, contain antibiotics, caffeine, nicotine metabolites and triclosan, an ingredient in detergents, antibacterial soap, cosmetics and lotions.
The findings offer new evidence for an emerging science examining whether very small amounts of pollutants--especially pharmaceuticals--might have profound impacts on wildlife and people.
Although no one knows what effect the accumulation or mixture of chemicals in the water has on human health or drinking water, very low concentrations of synthetic hormones have been found to feminize male fish in European and Canadian studies. Anti-depressants such as Prozac have been shown to have effects on spawning and other behavior in shellfish.
The new research "helps people understand that on an individual level, the things they do every day affect the environment," said Herb Buxton, coordinator of the Geological Survey's toxic substances hydrology program.
In the study published in Friday's issue of Environmental Science and Technology, researchers looked for 95 organic wastewater compounds. Water samples from 30 states were taken from 139 streams that were all thought to be contaminated with human, industrial and agricultural waste.
They found steroidal compounds in 89 percent of the streams tested, followed by nonprescription drugs (81 percent), insect repellent (74 percent) and detergent metabolites (69 percent). Antibiotics were detected in about half the streams, and fragrances in 27 percent.
"The conventional pollutants [such as pesticides] represent a tiny fraction of the manmade chemicals that are actually in the environment," said Christian Daughton, chief of environmental chemistry with the U.S. Environmental Protection Agency in Las Vegas.
Unregulated, elusive chemicals
The substances detected in the study are largely unregulated and elude the high-tech filtering systems of municipal wastewater treatment plants after they are flushed, poured or rinsed down the drain. In the Cook County area alone, 1.4 billion gallons of effluent water are pumped out of the seven Chicago Metropolitan Water Reclamation District plants into the environment each day.
Overall, the concentrations detected were very low--typically much less than one part per billion--and rarely exceeded drinking-water guidelines, health advisories or aquatic-life safety criteria.
But the issue of low-dose effects "is a quandary that permeates all toxicology," Daughton said. He worries that the effects on aquatic organisms could be happening so slowly that major changes aren't detected until they reach the point of irreversible change.
In addition to the urban areas tested in Illinois, three areas with agricultural drainage were sampled: Sugar Creek near Milford, Nippersink Creek above Wonder Lake and the Des Plaines River at Russell.
Though some of the streams sampled might be used for drinking water sources downstream, the study was not designed to test tap water.
Theoretically, some of the chemicals could be present in drinking water, and whether they can be effectively removed depends on the compound, Buxton said. One of the next steps is "looking at specific sites to see whether the contaminants persist downstream or degrade and dilute," he said.
Researchers also will be looking at individual prescription and nonprescription drugs, which are streaming into the marketplace. In the last two years, pharmaceutical companies have added more than 100 new drugs, according to the Pharmaceutical Research and Manufacturers of America, an industry trade group. More than 1,000 medicines are in development.
The industry's own task force says "the amount of pharmaceutical residue detected in other water studies has been very small--the equivalent to a single cube of sugar dissolved in 2 1/2 million gallons of water, about the size of four swimming pools," Jeff Trewhitt, a spokesman for the trade group, said.
"We'll continue to work closely with federal regulators and independent experts to assess the impact of pharmaceuticals in the environment."
Potential concerns include reproductive impairment, cancer, the potential increased toxicity of chemical mixtures and the development of antibiotic-resistant bacteria. The findings showed that 14 antibiotics used in humans and animals end up in the waterways.
Only the beginning
Researchers, who call the study a critical first step, admit that it raises many more questions than it answers, including whether waterways need protection from these pollutants.
"We do drink this water, and fish and other aquatic ecosystems depend on the water quality," said Tom Curtis, deputy executive director of the American Water Works Association, which works for safe drinking water. "The study certainly suggests the quality has been compromised."
Source: Chicago Tribune
