Unknown Impacts of Emerging Pollutants
by Patrick McCullough | published Mar. 3rd, 2022
Human activity has introduced a number of chemicals and compounds into an environment that has not encountered them before.
Scientists have a decent understanding of beneficial chemicals like fluoride, which has been added to drinking water since 1945 to help prevent tooth decay, and heavy metals such as mercury, which can accumulate to toxic levels in fish through contaminated water.
There are other chemicals, compounds and contaminants whose impacts are less clear. These substances are often the result of legacy pollution — pollution produced by industry that lingers in the environment long after being introduced.
Many of these pollutants are currently under investigation to discover exactly how harmful they are or could become.
Perfluorochemicals (PFCs) and more specifically perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a group of artificial compounds that make everyday products more resistant to water and stains.
PFCs can be used to keep food from sticking to cookware, make stain-resistant fabrics and be used as waterproofing. Their presence isn't limited to the kitchen or closet though, as they have also made their way into water supplies across the country.
In 2015, the town of Hoosick Falls, NY was advised to avoid public drinking water after the Environmental Protection Agency discovered high levels of perfluorooctanoic acid in the town’s water supply.
In North Carolina, PFASs were detected in 20 public water systems that drew their water from the Cape Fear River watershed, a lingering impact of industrial discharge from DuPont’s Fayetteville Works plant.
Paige Lawrence is a professor and chair of the Department of Environmental Medicine at the University of Rochester, and the director of the University of Rochester’s Environmental Health Science Center.
Lawrence’s work involves research into how the environment, and the chemicals and compounds present there, can impact human health.
“The carbon-fluorine bond in perfluorinated chemicals doesn’t exist in nature, so it’s a very strong bond. They are very resilient chemicals and are very hard to break down,” Lawrence explained.
A number of these chemicals have been phased out of American production lines since the 1980s, but the resilience that makes them so useful means they tend to linger in the environment.
Charles Ruffing is the director of the New York State Pollution Prevention Institute, an organization that works with companies and communities around New York State to help them reduce their environmental impact.
"They're so-called 'forever chemicals' because they persist in the environment for a long time."
“They’re so-called ‘forever chemicals’ because they persist in the environment for a long time,” Ruffing explained. “There’s a variety of uses for these perfluorinated materials, and they’ve been turning up in wastewater and a lot of people’s bloodstreams.”
The CDC has been measuring the levels of PFASs in blood serum, which is obtained from participants ages 12 and older. These tests have detected the presence of four different PFAS in nearly all of the people tested.
The question of how harmful these chemicals are to humans is still under investigation. There is research that suggests that PFAS exposure may have an impact on children's immune systems.
“There have actually been studies ... looking at vaccinations in children,” Lawrence said. “Higher amounts of those perfluorinated chemicals is inversely associated with the antibody response to those routine childhood vaccinations.”
The consequences of PFAS exposure are still emerging, but their presence — in air, water and soil — is undeniable.
Microplastics are pieces of plastic debris less than five millimeters in size. These particles have been discovered in freshwater rivers, lakes and all of the world's oceans.
“We don’t know a lot about what [microplastics] are doing in terms of health,” Lawrence explained. “We all use plastics, and they break down and get tinier and tinier and tinier. Now we have micro, and even nano, plastic particles that have been found in the water, in sediment, in fish and in other organisms.”
New techniques have allowed researchers to detect the chemical traces of plastic in human organs, and the question of to what extent these contaminants are present in the human body is still under investigation.
Christy Tyler is an aquatic ecologist and the director of the Graduate Program in Environmental Science at RIT. She identifies two main types of microplastics: plastics that start small and enter the environment and microplastics that break off of a larger piece.
Plastics that start small include — but are not limited to — microbeads, which were once present in many health and beauty products before they were banned with the Microbead-Free Waters Act of 2015.
“Some [plastic] breaks down before it gets out into the environment. That’s things like fleece fabric microfibers that come off your fleece jacket every time you wash it,” Tyler explained.
Plastic waste like bags and bottles shed microplastics as they deteriorate under the sun, wave energy and changes in the temperature.
Studying microplastics is complicated by the fact that, as they break down, their properties can change.
"We call it plastic pollution, but really it’s hundreds and hundreds of different kinds of compounds."
“We call it plastic pollution, but really it’s hundreds and hundreds of different kinds of compounds,” Tyler explained.
Plastics like polyethylene can come in different densities, with different dyes, plasticizers, fire retardants and UV protectants. These additives can change the plastic's chemical properties, how it breaks down and how toxic it is in the environment.
A plastic’s properties can also be altered by its environment. Some become more toxic when exposed to certain conditions, and some become less toxic.
“If it’s in a water body where there’s already contamination, ... some types of plastic act like a little sponge to absorb those different contaminants from the water,” Tyler said.
Pollutants like PFC and microplastics are leftover from a previous time when environmental regulations weren’t as strict and the potential impact of these substances were not as understood.
Companies respond to market pressures, and as younger generations become more environmentally conscious, those markets begin to demand more environmentally responsible products and production methods.
“In the corporate realm, some went very willingly, some were dragged into it, but there's definitely a heightened awareness and a call to action,” Ruffing said. “Companies realize that if they don’t manage this issue they’re not going to be financially successful.”
If these companies want to win everyone's business, they will have to change with the times.