Drugs make an excellent job of increasing the quality of life of people around the world, but medicines do not stay with us forever and finally get washed out in our waste water. Now, new research suggests that not only is the tedious range of pharmaceutical products that enter the environment and accumulate in animals but grow in the food chain.
The problem of pharmaceutical pollution is largely the result of wastewater treatment plants that are not able to purify the rapidly growing concentration and variety of drugs that flood into sewerage pipelines. Still very functional active ingredients come out of nature through drains or wastewaters. Scientists are just beginning to understand the extent of ecological contamination, and the study published today Nature of communication adds a spiky pixel to the image. More than 60 different pharmaceutical compounds were discovered in bodies of Australian water insects, which were then passed on to their spider predators.
A team of scientists based in the US, Australia and Sweden sampled nearly 200 insect water from six different streams near Melbourne, Australia, testing their tissues for the presence of 98 different compounds. These compounds include many of the usual pain medications such as aspirin and ibuprofen, antibiotics and antidepressants.
Their findings? These bugs were on drugs –many drugs. A total of 69 different drugs were found in water insects. When researchers compared the insects they collected between the streams, they found that those in heavily affected areas or downstream of waste water treatment in most cases had much higher drug concentrations – even 100 times. But even relatively intact areas such as streams that erupt in national parks have discovered drug insects.
Disturbing, the pollution did not stop at the streams. The team also sampled spiders building networks along the streams to see if the drug went through the feeding chain when mature water insects leave water and fly shortly before colliding with a silken silk trap for death.
Disturbing, that's exactly what they found. Researchers have detected 66 drug compounds in tissue spiders, often at concentrations ten times greater than in aquatic insects. Another pollution, in other words, concentrates the food chain in a process called "biomagnification".
To get an idea of how many other animals the animals can experience, the team looked at slaughterhouses and brown trout, two types that eat insects with drug infusions at the beginning of the study. Using the concentrations of insects and the estimated food intake of predators, the team estimates the dose the recipients received. Antidepressants are at far greater levels than others, and trout expects to receive nearly 30 percent of human daily dose, and platypuses exceed 50 percent.
So how is all this bad for creatures who have dropped out of drugs? Frankly, scientists do not really know what makes the ubiquity of drugs at such high concentrations. Medicines that affect the behavior and physiology of animals are already known. Antidepressant waste makes crap less cautious than predators, and scabies become more restless after feeding on insects filled with antidepressants. Amphetamines in the streams mess with the time of transition of water insects to a winged form for adults.
Ecological effects of drug effects are still not well understood. Some of the compounds can interact and interact with each other in complex ways, affect behavior in a way that alters reproduction or how predators grab their prey or prevent prey from getting an ax. And pharmaceutical contaminants may be even more widespread than this study. After all, although the team measured about 100 different compounds, thousands of different medicines are being marketed around the world.
There are a number of unpleasant gaps here, but one thing is certain: if people do not find a way to keep their scrap drugs out of the environment, the cumulative impact – no matter what – should be more extreme.
Jake Buehler is a science fiction writer living on the Olympic Peninsula in Washington with adoration on a weird, wild and irresponsible tree of life Twitter or on his blog.