Sylvia Lee, PhD, is a scientist at the Cary Institute of Ecosystem Studies in Milbrook, New York. She has access to an unusual-yet essential-set of laboratory equipment: a whole greenhouse filled with white fiberglass bathtubs. There's no mistaking these vessels with those you'd find in the average bathroom, however. While these bathtubs are about the same length, they're shallower, narrower, and have a raised racetrack-like interior that water circulates around. And none of the lab members spend time inside them.
Instead, researchers fill them with rocks and organisms obtained from local streams in upstate New York. And in place of bubble bath, they add to the water D-amphetamine, the same active substance found in several ADHD and narcolepsy medications. The water in the tubs is mixed with enough amphetamines to make the organisms think they're sitting downstream from one of Baltimore's water treatment plants. The goal of this lab is to find out what the US' heavily medicated population might be doing to its surroundings.
The United States of America is a highly medicated country: almost seven in 10 Americans take prescription drugs. That translates to 4.4 billion prescriptions and nearly $310 billion spent on medication in 2015. Painkillers, cholesterol-lowering medications, and antidepressants top the list of drugs most commonly prescribed by doctors.
Needless to say, the work of biologists like Lee may prove to be crucial.
Where drugs go after we're done with them
Americans aren't just putting these drugs into their bodies; they're also putting more drugs into the environment. A growing body of research suggests all types of drugs, from illegal drugs to antibiotics to hormones, enter the environment through sewage and cesspool systems across the country. And while pharmaceutical drugs-when used as prescribed-are capable of curing disease and alleviating symptoms in people, they can wreak havoc on nature.
There, they persist for long periods without breaking down. Hormones in medications like birth control cause changes such as intersex development in fish and amphibians. Antidepressants have been found in the brain tissue of fish downstream from wastewater treatment plants. Research on the presence of illegal drugs in water bodies has revealed some interesting trends: drug concentrations are highest on weekends and skyrocket after social events, such as music festivals, where large quantities of drugs are often consumed.
Amphetamines, a class of both legal and illegal stimulant drugs, also appear to have an effect on aquatic ecosystems, according to new research. For people with Attention Deficit Hyperactivity Disorder (ADHD), amphetamines can mean the difference between extreme distraction and intense focus. For people seeking an illicit high, amphetamines like meth and amphetamine-related drugs like ecstasy result in an overwhelmingly euphoric-often dangerous-high.
In 2012, 16 million people were prescribed legal amphetamines in the United States, and about 1.2 million people took illicit methamphetamine. Hundreds of thousands took prescription amphetamines illegally or in an addictive manner.
In June 2013 and June 2014, Lee (whose research focuses on how human activities affect urban streams) led an international group of scientists in collecting water samples at six stream sites in Baltimore, Maryland. They found 14 different drugs, including amphetamines and methamphetamines, in varying concentrations at all six test sites.
According to Lee, "We detected higher amphetamine concentrations than those found previously [by researchers in Spain] in surface waters," which had previously held the record for the highest concentration of amphetamines in surface waters ever recorded. "We expected the concentration of amphetamine in Baltimore streams to be higher because there is untreated sewage entering these streams. However, it is notable that even low concentrations of amphetamine and other pollutants may change stream ecosystems."
Artificial streams
To quantify ecosystem change, the scientists outfitted eight of the Cary Institute's artificial streams with rocks, stream microorganisms, bacteria, algae, and aquatic insects collected from an untainted stream in upstate New York. At the start of the experiment, they added D-amphetamine to four tubs until they had a similar concentration to the Baltimore streams. The other four were not treated.
After just a week, life in the amphetamine-treated streams began changing. The aquatic insects they contained developed and reproduced like they were on speed-much more quickly. The amount of algae was down by nearly 50 percent compared to untreated streams; the algae that was present produced much less oxygen. After three weeks, DNA tests revealed that the diversity and number of bacteria and diatoms (a simple type of algae) present in the treated streams was markedly different from those in the untreated streams.
"Stream bacterial and diatom communities play important roles in stream ecosystems as transformers of chemical compounds, the production of food for aquatic organisms, and the decomposition of organic materials," says Lee. "A healthy stream ecosystem should perform these chemical and biological cycles efficiently, while a stream affected by pollution may act more as a pipe allowing pollution to ultimately flow out into the oceans."
Lee points out that these changes could affect the diets of the organisms that rely on them as a food source, such as aquatic insects and fish. It's not well understood how amphetamines act as they move up the food chain from basic stream organisms to much larger animals in water and on land, perhaps even humans.
Lee's coauthor, Emma Rosi, PhD, also of the Cary Institute, says that her group's experimental design is a good way to understand the effects of one pollutant on a controlled ecosystem, since all streams are virtually identical in design and experience the same environmental conditions, save for the added pollutant. However, she notes, it's a closed-loop system, unlike real streams that receive a continuous supply of new microbes from upstream. That limits the duration the experiment can run, because the microbes that have been collected die over time.
While previous studies have looked at whether drugs are present in bodies of water like streams and ponds, this is one of the first that systematically examines the biological implications of their presence. Because much about the effects of amphetamines on nonhuman life are unknown, Lee recommends we do more "scientific research to further investigate the ecological consequences of these and other emerging contaminants to better understand [their] environmental effects."
