Silent Spring, meet Silent Stream
Waterways across the Great Lakes Basin and New York State host environmental contaminants.
In “Silent Spring,” Rachel Carson addressed the widespread use of the chemical compound DDT as an insecticide. Calling out the chemical for its environmental and multispecies impacts, notably its ability to bioaccumulate and thin bird eggshells, Carson wrote, “On the mornings that had once throbbed with the dawn of chorus of robins, catbirds, doves, jays, wrens, and scores of other bird voices there was now no sound; only silence lay over the fields and woods and thrush.”
Carson no doubt would have continued writing about modern contaminants of emerging concern if alive today. Pain killers and other pharmaceuticals, veterinary medicines, hormones, soaps, fragrances, cosmetics, pesticides, flame retardants and plasticizers are some products containing chemicals that may be released into the environment and are collectively known as contaminants of emerging concern (CECs).
CECs are used or discarded by consumers every day and enter waterways through municipal waste streams and agricultural runoff. CECs, not typically removed in wastewater treatment facilities, have been detected in waterways, wildlife and agricultural soils applied with sewage sludge or manure from industrial animal farming.
“We all should be paying more attention to contaminants of emerging concern,” said Dan Gefell, a biologist at the U.S. Fish and Wildlife Service New York Field Office.
The U.S. Fish and Wildlife Service has investigated the distribution and impacts of CECs in the Great Lakes since 2010 with funding from the Great Lakes Restoration Initiative (GLRI). One of the largest sources of freshwater in the world, the Great Lakes provide about 5,500 cubic miles of open water and 5,400 miles of shoreline with embedded coastal wetland habitats. Waterways of the Great Lakes Basin are home to about 160 species of fish, many of which are susceptible to CECs.
“We are just beginning to understand the array of unintended consequences the release of CECs into the environment may cause,” said New York Field Office biologist Amy Roe. With thousands of CECs consumed in commercial products nationwide, the amount of CECs in waterways and upland environments is reaching levels hazardous to many species.
Some chemicals of emerging concern such as DEET, an active ingredient in many insect repellents, are well known. Less known is the potential for DEET to wash off when people are recreating or showering and then remain in waterways. DEET has been detected in almost all waterways sampled in the Great Lakes Basin.
CECs also include chemicals some consumers may have never heard of like neonicotinoids (“neonics”), a class of neuro-active insecticides widely used in agriculture that are chemically similar to nicotine. When runoff from farm fields reaches waterways, it carries chemicals that were applied to soils and crops. A preliminary survey by the Service in upstate New York found neonics in five out of eleven streams, one out of five crayfish, and one out of ten mussels. Other wildlife that may be exposed to neonics include salt marsh sparrows, piping plovers, Indiana bats, and many pollinators such as monarch butterflies and rusty patch bumblebees.
A CEC known to produce toxigenic effects in monitored fish species is ibuprofen, a common pain reliever and anti-inflammatory drug. When pills are incorrectly flushed down the toilet or when trace levels of the drug are not absorbed by the body and are instead excreted in urine or feces, ibuprofen enters the waterway.
What harm can a pain reliever cause? Throughout the Great Lakes basin, ibuprofen is hazardous to fish. Studies summarized by the Service illustrate that ibuprofen can impact fish circulatory systems, reproduction, early life development, physiological processes and gene expression. These combined effects can lead to mortality and population fluctuation in sensitive species.
Unpacking and understanding the effects one chemical may have on the environment is a difficult challenge. Since CECs can come from both point source and non-point sources, their arrival into waterways is often hard to trace. Point sources are easy to identify, sources where CECs enter the waterway from a single place such as wastewater treatment plants (WWTPs) and combined sewage overflow (CSO) discharge sites. Non-point sources are harder to address, depositing CECs from many places at once in the form of rainwater run-off from agricultural and developed areas as well as aerial deposition.
There is evidence of long-term decline in aquatic species diversity in the wild. Among many environmental stressors, CECs may negatively impact diversity. Unfortunately it is difficult to identify the biological effects that could be attributed to CECs. Lab studies involving impacts of individual CECs on fish do not necessarily translate perfectly to the field as many CECs interact together in unanticipated ways. In addition, original parent compounds can break down into different chemicals once in the environment and have various biological impacts. As CECs are currently unregulated as environmental pollutants, curbing initial discharge is an essential first step.
The Service has identified concentrations for 14 CECs that mark the threshold for negative impacts to fish. These concentrations, known as screening values, have been determined for CECs including N-diethyl-meta-toluamide (DEET), ibuprofen, and estrone among others (full list here). Many regions of New York State have been sampled for CECs including the rivers on the north slope of the Adirondacks, the Susquehanna River Basin and sections of the Great Lakes Basin.
Screening values provide a tool to assist in evaluating whether CECs are driving observed ecological declines and for prioritizing among natural resource management projects. Areas with lower CEC concentrations and lower hazards to fish are prioritized by the Service for management actions such as fish passage restoration and recreational improvements.
The thought of attempting to address the negative impacts of CECs with current consumer culture and the growing global population seems overwhelming. Yet, individual actions can help. Some solutions include:
- Not flushing medicine and personal care products down the toilet. Instead of flushing products, use prescription take-back programs. Inquire about local take-back programs by contacting law enforcement officials.
- Avoid the purchase of products containing microbead plastics, antibacterial soaps with triclosan or triclocarbon, and sunscreen with nanoparticles, oxbenzone or octinoxate.
- View safe product alternatives at https://www.epa.gov/saferchoice
- Swap home cleaning chemicals for non-toxic, biodegradable products.
- Reduce use of pesticides and fertilizers by planting native plants that require less maintenance.
The solution begins with small steps taken by individuals.
The presence of pain-killers, pesticides and endocrine (hormone) disrupting compounds among other CECs have the potential to not only impact fish and wildlife, but humans as well. Although biologists are still studying what degree these chemicals are present in waterways and how they may affect human health, the presence of CECs has been documented across drinking water sources globally.
In summary, while products containing CECs were designed to benefit people, the release of these products into the environment can come with hidden costs. As Rachel Carson wrote in Silent Spring, “The earth’s vegetation is part of a web of life in which there are intimate and essential relations between plants and the earth, between plants and other plants, between plants and animals. Sometimes we have no choice but to disturb these relationships, but we should do so thoughtfully, with awareness that what we do may have consequences remote in time and place.”
The Service’s Environmental Quality Program remains dedicated to addressing this issue by providing contaminants expertise to outside organizations and the greater public.
Further Reading: Contaminants of Emerging Concern, USFWS
https://www.fws.gov/midwest/es/ec/cec/index.html
