Traces of 51 drugs have been detected in the wastewater that Burlington, Vermont, residents flush or pour down their drains and that ends up in Lake Champlain. Researchers at the University of Vermont and the United States Geological Survey found that levels of caffeine and nicotine in the water drop as college students leave for summer break, followed by increases in the relative amounts of drugs used by older people, such as diabetes and heart medications.
Burlington is not unique. “Pharmaceuticals are found in about eighty percent of the surface waters tested in the United States,” says University of Vermont scientist Christine Vatovec.
Which drugs are they?
Antibiotics, antidepressants, and other prescription medications, as well as caffeine.
How do they get into drinking water? Drug residues that people excrete are flushed down toilets. The U.S. Environmental Protection Agency (EPA) recently tested wastewater effluent from 50 of the biggest water utilities. (That’s treated sewage, which is released into rivers and lakes that may be used as sources of drinking water.) Traces of at least one prescription drug turned up in every sample.
How can these drug residues harm you? They probably don’t, says the EPA’s Mitch Kostich. The amounts are so minuscule “that you would have to drink two quarts of wastewater every day for decades, usually for an entire lifetime, before you would be exposed to even one therapeutic dose,” he says.
How do you know if they’re in your water? You don’t. Water utilities aren’t required to include prescription drugs in the “Consumer Confidence Report” most big water utilities are required to make available to their customers.
What about arsenic, a toxic element that’s found naturally in rocks, soil, water, and air?
How does it get into drinking water? Naturally occurring arsenic in rocks and soil can leach into water sources. So can arsenic that’s used in pesticides and in manufacturing.
How do you know if it’s in your water? Arsenic levels are listed in the Consumer Confidence Report. Your water shouldn’t have more than 10 ppb (parts per billion). That’s a compromise between what’s safe and what’s practical.
What’s safe? There is no safe level of arsenic, says the Environmental Protection Agency. Yet according to a 2009 survey, the arsenic in 7 percent of the private wells in the United States exceeded 10 ppb.
How can it harm you? Arsenic can cause bladder cancer. Its presence in wells in New England may explain why that region has a 20 percent higher incidence of bladder cancer than the national average.
Arsenic may also affect your brain, say several studies that are troubling but can’t prove cause and effect.
Elementary school children in Maine who lived most of their lives in homes where the well water contained 5 ppb or more of arsenic scored about 5 points lower on IQ tests than children whose well water averaged less.
And in two rural Texas counties where the arsenic in groundwater averaged about 6 ppb, the more arsenic in their tap water, the lower adults scored on tests of language, executive function, and memory.
“If you get your water from a public utility, find out what’s in your town’s water,” says Jeffrey Griffiths of the Tufts University School of Medicine. Griffiths chaired the drinking water committee for the Environmental Protection Agency’s Science Advisory Board.
To see your report, which water utilities are required to issue every year, go to epa.gov/ccr or call the EPA’s Safe Drinking Water Hotline at 800-426-4791.
The report will flag any substance that exceeds its maximum contaminant level (MCL). That’s the highest concentration allowed in drinking water. It will also tell you what the utility is doing to fix any problems.
Sources: Environ. Pollut. 184: 354, 2014; J. Natl. Cancer Inst. 108: djw099, 2016; Environ. Health 13: 23, 2014; Int. J. Environ. Res. Public Health 8: 861, 2011.
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