Emerging Contaminants in the Bay

From antibacterial soaps to sunscreen, chemicals are found in every facet of our daily life. Chemicals that make up our personal care products, pharmaceuticals, cleaning supplies, and cookware are often thought of as beneficial, especially to our quality of life. The downside, however, is that these chemicals can often make their way into the Chesapeake Bay and become contaminants.

Chemical contaminants negatively affecting human health and the environment in the Chesapeake Bay isn’t something new. Contaminants of known concern, like polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and mercury, have been monitored for decades and inform fish consumption advisories and fish health throughout the watershed. The Chesapeake Bay Program’s Science and Technical Advisory Committee (STAC) released a report last year detailing what we currently know about the wide range of contaminants harming the Bay, the challenges they pose, what opportunities exist to help with reduction.

However, the effects of another group of chemical contaminants are just now surfacing and these chemicals are known as contaminants of emerging concern, or CECs. While called contaminants of emerging concern, the contaminants themselves are not just emerging – they’ve likely been present in water as long as humans have been around, but have only recently been raised to a level of concern due to more widespread testing and monitoring.

The September CRC Roundtable, Moving Beyond Concern: Emerging Management for Contaminants also focused on CECs and featured a discussion between Kelly Smalling, research hydrologist with the U.S. Geological Survey, and Greg Allen, chair of the Toxic Contaminants Workgroup at the Chesapeake Bay Program, about contaminants of emerging concern and what we can do to manage them.

What is a contaminant of emerging concern?

Lee Blaney, Associate Professor at University of Maryland, Baltimore County, describes CECs as “chemicals that we haven’t looked for as extensively in the environment in the past, things like pharmaceuticals or personal care products. We haven’t really thought about them as pollutants, but we think about them as things that benefit our lives.”

This includes per– and polyfluoroalkyl substances (PFAS), a group of thousands of chemicals that have been used for decades in a wide variety of everyday products, such as nonstick cookware, pizza boxes, stain repellents, and in fire-fighting foams; pharmaceuticals; UV-filters from sunscreen; and more. These items like medicine or sunscreen were designed for a specific purpose, but when they get into the environment, they might have unexpected consequences that weren’t considered during the initial design of the compounds. “Contaminants of emerging concern encompasses that whole thing. A contaminant that we’re starting to look for more now in the environment and has some potential for toxicity outcomes, even if they haven’t been fully vetted yet,” explains Blaney.

What’s at risk?

The pharmaceuticals we put into our own bodies or personal care products that we wash off our bodies can make their way into the ecosystem and have unintended consequences on aquatic creatures. Improper disposal is one way these medications can enter our waterways, but they can also come directly from the human body. When we ingest pharmaceuticals, our systems don’t typically utilize the entire dose. Trace amounts are excreted in our waste, and our wastewater treatment plants are not designed to treat the thousands of specialty chemicals in pharmaceuticals and personal care products. Many of the active and inactive ingredients present in these products ultimately end up in rivers, streams, or oceans.

Estrogen is considered an endocrine disrupting chemical (EDC) that interferes with the body’s natural endocrine or hormone system. Estrogenic compounds are produced both synthetically and naturally and can have adverse effects on the reproductive health and metabolism of aquatic animals. They are used widely in birth control pharmaceuticals and hormone replacement therapy.

Vicki Blazer, a researcher with the U.S. Geological Survey, found that synthetic hormones and estrogenic endocrine disrupters, promote intersex characteristics in fish, which is the presence of both male and female characteristics in an animal that should exhibit the characteristics of just one sex in its lifetime. “The sources of estrogenic chemicals are most likely complex mixtures from both agricultural sources, such as animal wastes, pesticides and herbicides, and human sources from wastewater treatment plant effluent and other sewage discharges,” says Blazer.

Kelly Smalling, a research hydrologist with the U.S. Geological Survey, focuses on the presence of CECs and the environment, and works with biologists and toxicologists to determine the effects of these contaminants. “We know that CECs degrade water quality and negatively affect fish and wildlife and up to humans. Not addressing this is going to have ramifications for fish and wildlife in the Chesapeake Bay, particularly from a fish health standpoint,” emphasized Smalling. “From a fisheries biologist standpoint, addressing this and attempting to reduce these CECs, along with nutrients and sediment, is obviously going to improve water habitat quality, and hopefully fish health, and improving fish health improves human health. So really, it’s a win-win for everyone.”

Testing for contaminants

At Penn State University, Heather Preisendanz and her team have sampled 13 monitoring wells bimonthly since in October 2019 for PFAS and are increasing their sampling frequency to monthly, due to funding from a new EPA grant. The water from these wells is part of Penn State’s “The Living Filter” project, where the university’s wastewater effluent is used to spray irrigate on to agricultural fields.

The sampling data so far shows that while those two compounds are present in 11 of the 13 monitoring wells at the site, depending on the direction that groundwater is moving, the levels are below the EPA recommended levels of 70 nanograms per liter. Preisendanz and her team are also expanding future data collection to include crop tissue, because there is potential for crop uptake at the site. The crops, primarily corn silage and fescue for hay, are then fed to animals on campus and the team is curious to see if there are any effects of the wastewater irrigation that shows up in the crops.

Other states throughout the Bay region have also begun testing groundwater and surface water for CECs, with some starting the movements to regulate these chemicals. A recent Bay Journal article outlined the results from PFAS testing completed in Maryland and Pennsylvania drinking water systems, which found two water systems in each state with levels higher than the EPA’s health advisory threshold. Virginia’s Department of Health has also been tasked with sampling drinking water from up to 50 waterworks and/or water sources. The results have not yet been released; however the department is required to report the results by Dec. 1.

Best management practices (BMPs) are currently used throughout the watershed to help reduce nutrient and sediment pollution and restore the environment. Several states that are implementing BMPs to hit total maximum daily (TMDL) goals are doing studies to kind of understand whether there are co-benefits are happening.

The STAC report looked at contaminants from both agricultural and urban sectors and found several BMPs that may also help reduce contaminants while improving nutrient and sediment pollution runoff. However, more study is needed—particularly on how the various contaminants interact with one another, how the consequences of these interactions can change based on concentrations or environmental factors, and what that means for future fish health.