Study Finds Traces of Drugs in Drinking Water in 24 Major U.S. Regions
A vast array of pharmaceuticals — including antibiotics, anti-convulsants, mood stabilizers and sex hormones — have been found in the drinking water supplies of at least 41 million Americans, an Associated Press investigation shows.
Although the concentrations of these pharmaceuticals are tiny, measured in quantities of parts per billion, nonetheless the presence of so many prescription drugs and over-the-counter medicines like acetaminophen and ibuprofen in so much of our drinking water is heightening worries among scientists of long-term consequences to human health.
How do the drugs get into the water?
People take pills. Their bodies absorb some of the medication, but the rest of it passes through and is flushed down the toilet. The wastewater is treated before it is discharged into reservoirs, rivers or lakes. Then, some of the water is cleansed again at drinking water treatment plants and piped to consumers. But most treatments do not remove all drug residue.
And while researchers do not yet understand the exact risks from decades of persistent exposure to random combinations of low levels of pharmaceuticals, recent studies — which have gone virtually unnoticed by the general public — have found alarming effects on human cells and wildlife.
“We recognize it is a growing concern and we’re taking it very seriously,” said Benjamin H. Grumbles, assistant administrator for water at the U.S. Environmental Protection Agency.
Here are some of the key test results obtained by the AP: Officials in Philadelphia said testing there discovered 56 pharmaceuticals or byproducts in treated drinking water, including medicines for pain, infection, high cholesterol, asthma, epilepsy, mental illness and heart problems. Sixty-three pharmaceuticals or byproducts were found in the city’s watersheds.
Anti-epileptic and anti-anxiety medications were detected in a portion of the treated drinking water for 18.5 million people in Southern California.
Researchers at the U.S. Geological Survey analyzed a Passaic Valley Water Commission drinking water treatment plant, which serves 850,000 people in Northern New Jersey, and found a metabolized angina medicine and the mood-stabilizing carbamazepine in drinking water.
The federal government doesn’t require any testing and hasn’t set safety limits for drugs in water.
The AP’s investigation also indicates that watersheds, the natural sources of most of the nation’s water supply, also are contaminated. Tests were conducted in the watersheds of 35 of the 62 major providers surveyed by the AP, and pharmaceuticals were detected in 28.
Of the 28 major metropolitan areas where tests were performed on drinking water supplies, only Albuquerque; Austin, Texas; and Virginia Beach, Va.; said tests were negative.
Even users of bottled water and home filtration systems don’t necessarily avoid exposure. Bottlers, some of which simply repackage tap water, do not typically treat or test for pharmaceuticals, according to the industry’s main trade group. The same goes for the makers of home filtration systems.
The problem isn’t confined to surface waters. Pharmaceuticals also permeate aquifers deep underground, source of 40 percent of the nation’s water supply. Federal scientists who drew water in 24 states from aquifers near contaminant sources such as landfills and animal feed lots found minuscule levels of hormones, antibiotics and other drugs. Perhaps it’s because Americans have been taking drugs — and flushing them unmetabolized or unused — in growing amounts. Over the past five years, the number of U.S. prescriptions rose 12 percent to a record 3.7 billion, while nonprescription drug purchases held steady around 3.3 billion.
“People think that if they take a medication, their body absorbs it and it disappears, but of course that’s not the case,” said EPA scientist Christian Daughton, one of the first to draw attention to the issue of pharmaceuticals in water in the United States.
Some drugs, including widely used cholesterol fighters, tranquilizers and anti-epileptic medications, resist modern drinking water and wastewater treatment processes. Plus, the EPA says there are no sewage treatment systems specifically engineered to remove pharmaceuticals.
Another issue: There’s evidence that adding chlorine, a common process in conventional drinking water treatment plants, makes some pharmaceuticals more toxic.
But at a conference last summer, Mary Buzby — director of environmental technology for drug maker Merck & Co. Inc. — said: “There’s no doubt about it, pharmaceuticals are being detected in the environment and there is genuine concern that these compounds, in the small concentrations that they’re at, could be causing impacts to human health or to aquatic organisms.”
Recent laboratory research has found that small amounts of medication have affected human embryonic kidney cells, human blood cells and human breast cancer cells. The cancer cells proliferated too quickly; the kidney cells grew too slowly; and the blood cells showed biological activity associated with inflammation.
There’s growing concern in the scientific community, meanwhile, that certain drugs or combinations of drugs may harm humans over decades because water, unlike most specific foods, is consumed in sizable amounts every day.
Some experts say medications may pose a unique danger because, unlike most pollutants, they were crafted to act on the human body.
“These are chemicals that are designed to have very specific effects at very low concentrations. That’s what pharmaceuticals do. So when they get out to the environment, it should not be a shock to people that they have effects,” says zoologist John Sumpter at Brunel University in London, who has studied trace hormones, heart medicine and other drugs.
