[Pharmwaste] Bugs are full of our drugs—and they could be getting other critters hooked, too
deborah.debiasi at deq.virginia.gov
Wed Nov 7 08:35:42 EST 2018
Nov 07, 2018
Bugs are full of our drugs—and they could be getting other critters hooked,
Wildlife that feed on bugs near streams are at a higher risk of being dosed
<https://ehn.org/community/brianbienkowski> Brian Bienkowski
Insects near streams are taking in loads of pharmaceutical drugs and can
pass the compounds on to predators higher in the food chain, such as frogs,
birds and bats, according to a new study.
"Predators that consume aquatic invertebrates in wastewater-influenced
streams may be exposed to about one quarter and up to one half of a human
dose of some pharmaceuticals," the authors wrote in the study, published
today in Nature Communications.
Pharmaceuticals are increasingly detected in waterways around the world as
prescription drug use increases. The drugs get into the water via people
excreting them or when they're flushed down the toilet. Wastewater
treatment plants were not designed to handle such contamination and
previous research shows only about half of drugs are removed by sewer
The new study is the first to show that the pervasive pharmaceutical
pollution in waters around the world can concentrate in bugs near streams
and travel up the food chain—potentially exposing top predators to
"therapeutically-relevant doses," Emma Rosi, an aquatic ecologist at Cary
Institute of Ecosystem Studies and a co-author on the paper, told EHN.
The study has global implications, she added.
"We've known for a while pharmaceuticals are found in streams in places
like the Great Lakes and across the U.S.," Rosi said. "If they're getting
into food webs in Australia, it shouldn't be any different here."
"Undoubtedly represents an underestimate"
Collecting aquatic invertebrates to test for pharmaceuticals in Brushy
Creek in Churnside Park, Victoria, Australia. (Credit: Keralee Browne)
Rosi and colleagues tested six Melbourne, Australia, streams for 98
pharmaceuticals—including antibiotics, antidepressants and
antihistamines—and found 69 of the drugs in aquatic insects and 66 in
"If you go to doctor and tell them you're taking one drug they want to know
if there are interactions within your body," Rosi said. "We found *69
different drugs* in aquatic invertebrates."
They found the highest levels in those tested downstream of wastewater
treatment plants or highly populated areas—concentrations at these areas
were 10 to 100 times higher than other sites.
"Insect tissues had drug concentrations that were orders of magnitude
higher than concentrations measured in surface waters," said co-author
Jerker Fick, a chemist at Umeå University in Sweden, in a statement. "We
also found a diverse suite of drugs in spiders, indicating that drugs are
passed from the water to prey to predator, thereby exposing other animals
in the food web to drugs."
Rosi pointed out the riparian spiders build their webs right over streams,
so the "only way they're getting drugs is when bugs emerge from streams as
adults and are eaten by the spiders."
The authors note that the screening "undoubtedly represents an
underestimate of the diversity of compounds present in food webs because in
the U.S. market, for example, there are [more than] 1,400 Food and Drug
Administration approved pharmaceuticals."
By looking at these concentrations, and knowing the feeding habits of
predators that eat stream insects, the researchers also estimated the drug
exposure of trout and platypus.
Rosi stressed it's not entirely clear if trout and platypus—and animals
further up the food chain like birds—would receive the full load of
pharmaceuticals from eating the bugs, simply because we don't yet fully
understand how much of the drugs are passed on when prey are consumed.
However, the loads could be significant, according to their estimates.
Platypus, for example, could be getting up to 50 percent of a human dose of
This intake is "likely to have biological effects," Rosi added.
"What does it mean to be a trout with more than 60 drugs in your tissues?"
It's hard to say what the effects of these exposures might be. Previous
studies have found that drugs in streams can disrupt the timing of insect
emergence, and spiders' ability to spin webs.
In fish, much depends on the drug, the mixture and the dose; however, mixes
of pharmaceuticals have previously been shown
to disrupt the endocrine system, feminized them, altered behavior and
reproduction, changed growth, and increased liver sizes.
There is less research for other wildlife such as birds, but a study
earlier this year found male European starlings sang less to females that
had been fed a diet of worms spiked with fluoxetine—known by the trade name
Prozac—at concentrations found at wastewater treatment facilities. Singing
is a crucial part of courtship and reproduction for birds and such changes
in behavior could cause population level impacts.
The researchers also note that pharmaceutical use is expected to continue
increasing, especially as the world population rises.
Though conducted in Australia, the study has implications for streams and
wildlife everywhere. Many of the insects in the study—and all of the
drugs—are found throughout the world.
"What does it mean to be a platypus or trout with more than 60 drugs in
your tissues? Are there synergistic effects?" Rosi said.
"We really don't know."
Deborah L. DeBiasi
*Email: Deborah.DeBiasi at deq.virginia.gov *WEB site address:
Virginia Department of Environmental Quality, Office of Water Permits
State Coordinator for Industrial Pretreatment/Whole Effluent Toxicity (WET)
PPCPs, EDCs, and Microconstituents
Mail: P.O. Box 1105, Richmond, VA 23218
Location: 1111 E. Main Street, Suite 1400 Richmond, VA 23219
PH: 804-698-4028 FAX: 804-698-4032
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