Fish on a cocktail of drugs
Drug- laced wastewater ends up in waterways and eventually, in fish.
PUGET Sound salmon are on drugs – Prozac, Advil, Benadryl, Lipitor, even cocaine. Those drugs and dozens of others are showing up in the tissues of juvenile chinook, researchers have found, thanks to tainted wastewater discharge.
The estuary waters off Seattle, near the outfalls of sewage treatment plants, and effluent sampled at the plants, were cocktails of 81 drugs and personal- care products, with levels detected among the highest in the United States.
The medicine chest of common drugs also included Flonase Flonase, Aleve and Tylenol.Tyleno Paxil, Valium and Zoloft. Tagamet, OxyContin andd Darvon. Nicotine and ca affeine. Fungicides, antiseptics anda anticoagulants. And Cipr ro and other antibiotics galore e.
Why are the levels s o high? It could be becau use people here use more ofo the drugs detected, or it couldd be related to the processes ofo wastewater treatment pla ants, said Jim Meador, an envi ironmental toxicologist at th he National Oceanic and Atmospheric Administra ation’s Northwest Fisheries Scien nce Centre in Seattle and lead author on a paper published in the journal Environmental Pollution.
“The concentrations in effluent were higher than we expected,” Meador said. “We analysed samples for 150 compounds and we had 61% of them detected in effluent. So we know these are going into the estuaries.”
The chemicals turned up in both the water and the tissues of migratory juvenile chinook salmon and resident staghorn sculpin. If anything, the study probably under- reports the amount of drugs in the water closer to outfall pipes, or in deeper water, researchers found. Even fish tested in the Nisqually estuary, which receives no direct municipal treatment plant discharge, tested positive for an alphabet soup of chemicals in supposedly pristine waters.
Meador was surprised that levels in many cases were higher than in many of the 50 largest wastewater treatment plants around the nation. The findings are of concern because most of the chemicals detected are not monitored or regulated in wastewater, and there is little or no established science on the environmental toxicity for the vast majority of the compounds detected.
Meador said he doubted there would be effects from the chemicals on human health, because people don’t eat sculpin or juvenile chinook, and levels are probably too low in the water to be active in humans. But one of the reasons the wastewater pollutants studied as a class are called “chemicals of emerging concern” is because so little is known about them.
“You have to wonder what it is doing to the fish,” Meador said. His earlier work has shown that juvenile chinook salmon migrating through contaminated estuaries in Puget Sound die at twice the rate of fish elsewhere.
The drugs detected in the study could be part of the reason, as they have the potential to affect fish growth, behaviour, reproduction, immune function and antibiotic resistance. The drugs selected for testing were chosen on the basis of their widespread use by people, the likelihood of their continued use and the potential for higher levels of contamination in the future as the human population continues to grow.
The results represent only a snapshot, and levels could be higher or lower, seasonally, depending on people’s use of drugs and volumes of treatment plant discharge. For instance, levels of DEET ( an insect repellent) and antihistamines are probably even higher in summer.
The Puget Sound area contains 106 publicly owned wastewater treatment plants that discharge to local waters. The amount of drugs and chemicals from all plants into Puget Sound could be as much as 44,000kg every year, the study found. Unexplored were the presence and effect of drugs in predators that eat the fish, and in other contaminated organisms that the fish eat, such as algae or invertebrates.
Some treatment plants are effective in removing some drugs in wastewater, but many drugs are recalcitrant and remain. Seizure drugs, for instance, are very hard to remove, and ibuprofen levels are knocked down – but not out – during treatment, said Betsy Cooper, permit administrator for King County’s Wastewater Treatment Division.
“You have treatment doing its best to remove these, chemically and biologically, but it’s not just the treatment quality, it’s also the amount that we use day to day and our assumption that it just goes away,” Cooper said. “But not everything goes away.” – The Seattle Times/ Tribune News Service