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.
To be sure, the concentrations of these pharmaceuticals are tiny, measured in quantities of parts per billion or trillion, far below the levels of a medical dose. Also, utilities insist their water is safe.
But 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.
In the course of a five-month inquiry, the AP discovered that drugs have been detected in the drinking water supplies of 24 major metropolitan areas -- from Southern California to Northern New Jersey, from Detroit, Michigan, to Louisville, Kentucky.
Water providers rarely disclose results of pharmaceutical screenings, unless pressed, the AP found. For example, the head of a group representing major California suppliers said the public "doesn't know how to interpret the information" and might be unduly alarmed.
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.
... Even users of bottled water and home filtration systems don't necessarily avoid exposure. ...
"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. - cnn
How do you remove them?
"Increased retention time within treatment plants, chlorination, ozonation, and the natural reduction of a compound’s mass or concentration over time due to processes such as biodegradation all increase the removal of some drugs from wastewater; more advanced treatments such as adding activated carbon or reverse osmosis can remove even more. ... reverse osmosis ... removes pharmaceuticals down to parts per trillion. - ehponline
No comments:
Post a Comment