I hope these posts help us better appreciate the work that's being done to understand how man’s actions are impacting ecosystems—and what we can do to make things better.
Sam Kaplan: I've worked for the Rhode Island Department of Environmental Management as an engineer since 2004 and before that I was a homeland security consultant at the Rhode Island Department of Health. During graduate studies at Worcester Polytechnic Institute, I wrote a journal article manuscript entitled "Review: Pharmacological Pollution in Water." I had heard about pharamcological pollution for the first time when I was at the Department of Health. A coworker who was very forward thinking circulated a news story about fish that had visible mutations which were attributed to the presence of pharmaceuticals and personal care products ("PPCPs") in the water.
My article summarizes research highlights on all aspects of the topic from approximately 1999 (when research in this field took off due to improved laboratory methods) to 2010. Before I tell you more, I would like to thank the researchers whose work I cited. It is very challenging to do original research about PPCPs because they typically occur in the environmental at the nanogram per liter (ng/L) level. 28 ng/L is one drop of water in an Olympic sized swimming pool. Measuring these small doses requires very meticulous sampling and lab work.
The paper was published in March of 2013 in "Critical Review in Environmental Science and Technology.” I have not had anyone I did not previously know contact me about the article, but I did find out from Google Scholar that some researchers in China cited my work to provide context for their research, which measured PPCPs in riverbed sediments in China.
PPCPs get into surface water and ground water from via sewage, farms, landfills, and toilet flushing of unused medications. There are some better alternatives to toilet flushing. The best thing to do is to return unused medication to your pharmacy, if they accept it for proper disposal. But most pharmacies don't accept unused medications for liability reasons. Another alternative is to bring medications to collection locations on drug take-back days run by the US Drug Enforcement Agency with the help of law enforcement agencies. Another alternative is to put unused medication in a resealable bag with coffee grounds or kitty litter and place it in the trash. The resealable bag prevents drugs for leaching into groundwater at the landfill, and the coffee grounds or kitty litter makes the drugs less likely to fall into the wrong hands.
The big unanswered question is what, if any, impacts the presence of PPCPs in drinking water is having on human health. As of the time the article was published, there is little evidence to indicate human health impacts, so there should be no cause for alarm. At the same time, I would add that we really don't know what the human health impacts are because any exposure from drinking water would happen at very, very low levels over a lifetime, and conventional risk assessment models for other areas of toxicology focus on short-term acute exposure to high levels of one drug that measure visible effects in the patient. So risk assessment models will have to be developed that are just the opposite: lifetime exposure to many substances with effects that are subtle, hard to measure, and hard to separate out from other stressors.
Research into the human health effects of PPCPs is a subset of research into human health effects of endocrine-disrupting compound (EDCs), natural and synthetic substances which mimic human and animal hormones. About a month ago, I received a call for papers about human health impacts of EDCs and PPCPs, so that's where the focus is now.
In contrast with human heath effects, which, as I noted, are in the process of being researched, there is evidence to indicate a variety of sub-lethal effects on freshwater and marine aquatic life at different levels of the food chain. Let me give two examples which I cited in my article:
- Saaristo et al. (2010) found that just 41 ng/L of a hormone changed the courtship and parenting behavior of the sand goby fish. These are sublethal impacts, but impacts that could have a detrimental effect on offspring and population. Please keep in mind that 41 ng/L is one and a half drops of water in an Olympic-sized swimming pool, so some of these PPCPs are extremely potent to animals who are continuously exposed.
- Ericson et. al. (2010) performed lab studies on Baltic Sea blue mussels. They exposed these organisms to different levels of three common pharmaceutical PPCPs and evaluated the organisms' responses. They found that the animals physiology was affected in certain portions of the experiment with effects that included muscle weakness, and bioconcentration of these substances in the mussel's tissues at over 100 times ambient levels. Now this may sound like typical experiment, but one surprise finding was that one of the pharmaceutical PPCPs (propranolol, an anti-hypertensive) was found in the mussels gathered from the Baltic Sea for use in the experiment before the experiment even began.
What important facts should people know about how chemicals are impacting local ecologies and human health?
As I said, the human health impacts are unknown, however, there is a lot of evidence to indicate the presence of PPCPs in a wide range of saltwater and freshwater species at many different levels of the foodchain, with sublethal effects quantified is some of those cases. To give a few more examples, Wilson et. al. (2003) found significant differences between algea communities upstream and downstream of a wastewater treatment plant which may be attributable to the presence of PPCPs. Fair et. al. (2009) found one particular PPCP, triclosan, an antimicrobial disinfectant, in the blood plasma of 7 of 26 dolphins evaluated in a catch and release study in coastal regions of South Carolina and Florida. If you include all the species that are or could be affected, over the life cycle of each organisms, over many generations, the impacts could be quite significant, and yet it would be hard to tease out those effects from other environmental stressors, making a definitive evaluation even more difficult. This argument was the thesis of a landmark article by Daughon and Ternes in 1999, and the research I cited provided further evidence of the veracity of that thesis.
The bottom line is that we need to think about ways to reduce our discharge of PPCPs to the environment, but we also have to balance that against the beneficial effect that many of these PPCPs have on human health, and recognize that improving human health is also an important societal goal.
What's the good news, if any, that the research is showing us?
Research by Dr. Christian Daughton of the US Environmental Protection Agency (2003) indicated that there may be some innovative nonregulatory responses that drug companies can take to voluntarily to reduce the environmental impacts of PPCPs. This falls under the banner of "green chemistry" and includes the development of drugs that are better absorbed by the body, and the use doses of medication that are customized to a drug consumer's physiology, preventing the use of doses that are higher than necessary. In this work, Daughton also suggested things that drug companies and pharmacies could do to make it less likely that drugs would go unused only to be flushed down the toilet later. This includes allowing prescriptions to be filled in lower amounts, like getting 10 pills instead of 30, and developing more exact drug expiration dates. I reached out to Dr. Daughton several times when doing my research and he was very helpful, so I would like to thank him. He put me in touch with people at US EPA in Washington who provided me with information about regulatory developments (which, for the sake of brevity I won't get into) and one person at US EPA even reviewed the entire manuscript on behalf of US EPA.
I want to thank my advisor, Professor John Bergendahl of Worcester Polytechnic Institute. He was my instructor for the independant study in which I wrote the article manuscript. Studying this topic was my idea but writing the article was his idea. A good teacher encourages their students to aim high and then go for it, and then supports them in that goal, and that's what he did.
At the consumer level, proper drug disposal is part of the solution. It would be great if the drug companies would get on board and start to adopt some of Dr. Daugton's suggestions for green pharmacy on a wide scale, with high visibility. Green pharmacy would also be a great thing for scientists and chemistry and biology students to research and explore. It would change the world and I also think it would be a great business opportunity, and it would be a chance for corporations to be models for responsible environmental stewardship. This problem cannot be solved by regulation alone, and we need all sectors—corporations, health care, education, and government to contribute to a solution.
Lastly, I would like to thank you, Bill, for the opportunity to share my findings with your readers. Your enthusiasm for environmental protection is making Rhode Island a better place.