The U.S. Environmental Protection Agency (EPA) defines “overburdened community” as “minority, low-income, tribal, or Indigenous populations or geographic locations in the United States that potentially experience disproportionate environmental harms and risks.” See EPA, EJ 2020 Glossary at the EPA Env’t Just. website. “Disproportionality” can result from “greater vulnerability to environmental hazards, lack of opportunity for public participation, or other factors.” Id. “Greater vulnerability” might be caused by “accumulation of negative or lack of positive environmental, health, economic, or social conditions within these populations or places.” Id. In any case, EPA considers multiple contributing environmental and socioeconomic factors that might cumulatively contribute to “persistent environmental health disparities.” Id.
Certainly, overburdened communities are already recognized as being exposed to higher levels of environmental pollutants than other communities, along with lower income and other factors, including limited mobility, that prevent residents from leaving the community. Microplastic (plastic particles five millimeters or less in size) is yet another insidious pollutant just as hard to escape that we are only now beginning to understand.
We have recognized the ubiquitous nature of plastic and microplastic pollution, and the role the United States plays in plastic pollution, with the National Academes of Sciences, Engineering and Medicine (NASEM). Reckoning with the US Role in Global Ocean Plastic Waste, NASEM (2021) (concluding that the United States generates more plastic waste, two to eight times more per person, than other countries). We have also recognized that plastic in the environment breaks down into microplastics and nanoplastics by “photodegradation, hydrolysis, abrasion and biodegradation,” where even “biodegradable” plastics do not degrade in the environment and fail to even meet biodegradation standards. Plastics not only smother coral reefs and entangle, starve, and drown animals, but they also cause “physiological and toxicological stress and starvation.” Human exposure can cause “neurodevelopmental disorders; endocrine disruption; respiratory, cardiovascular and metabolic disease; cancer; adverse reproductive and pregnancy outcomes; and decreased antibody responses to vaccines.” Microplastics also act as “risk amplifiers,” causing a cascade of pollution resulting from plastic sorption and leaching of chemicals and interaction with microorganisms. See UN Env’t Assembly of the UN Env’t Programme (UNEP), Draft Report on the Work of the AdHock Open-Ended Expert Group on Marine Litter and Microplastics at Its Fourth Meeting ¶¶ 22–24 (Nov. 10, 2020).
With this context, consider the range of plastic goods and potential resulting microplastic exposure experienced by overburdened communities from microplastic pollution, both indoors and outdoors. In the environment, communities close to trucking routes and living among dense urban traffic are exposed to the highest ambient concentrations of microplastic air pollution from tire shred while outdoors. See, e.g., Where Pollution Hits the Road: The Growing Environmental Hazard of Rubber Tires, Hackaday (July 28, 2022).
Low-income households probably purchase cheaper synthetic clothing, bed sheets, carpeting, and plastic articles simply because they are cheaper. And the cheapest, lightest, and warmest blankets and coats are made from fleece that sheds microplastic fibers at the highest rates of all. See, e.g., Bethany M. Carney Almroth et al., Quantifying Shedding of Synthetic Fibers from Textiles; a Source of Microplastics Released into the Environment, 25 Env’t Sci. & Pollution Rsch. 1191 (2018). It is inescapable: Our plastic items generate significant microplastic pollution. Christopher D. Zangmeister et al., Common Single-Use Consumer Plastic Products Release Trillions of Sub-100 nm Nanoparticles per Liter into Water During Normal Use, 56 Env’t Science & Tech. 5448 (2022); NIST Study Shows Everyday Plastic Products Release Trillions of Microscopic Particles into Water, Nat’l Inst. of Standards & Tech. (Apr. 20, 2022).
With all the microplastic being released inside our homes from consumer goods, it is no surprise that microplastic has been identified as a significant source of indoor air pollution. A recent study found that, in Australia, up to 39% of household dust is petroleum-based microplastic. The study also found that Australia’s estimated indoor microplastic exposure is at the lower end of the spectrum globally. See Neda Sharifi Soltani, Mark Patrick Taylor & Scott Paton Wilson, Quantification and Exposure Assessment of Microplastics in Australian Indoor House Dust, 283 Env’t Pollution 117064 (Aug. 15, 2021).
And what about microplastic contamination in our food and water? It is difficult to grow your own vegetables and domestic backyard farm animals if you have no backyard and work two to three jobs. Thus, while some of us might have an opportunity to urban farm, overburdened communities are much more likely to rely more on cheap, commercially available food. Cheaper food is produced where it is convenient to produce the food, rather than at the location of the customer. Thus, cheap food is likely produced far away at large commercial agricultural operations and shipped long distances, relying on plastic packaging for preservation during shipping. And fast or pre-prepared food and associated plastic packaging are even more convenient. As a result, it is not surprising that another study finds that we may be eating as much as a credit card’s worth (5 grams) of plastic a week. Dalberg Advisors, No Plastic in Nature: Assessing Plastic Ingestion from Nature to People 7 (2019).
While one may want to avoid exposure to microplastic outdoors by avoiding the polluted ambient air from heavy traffic, the same individuals who live close to heavy traffic may also face very high exposures to microplastic indoors, as well as ingesting a fairly predictable plastic component in their diet. Given the dismal health statistics characterizing overburdened communities resulting from the stress of economic, safety, employment, and other uncertainties, these communities are ill-equipped to withstand the additional biological stress from microplastic in their indoor and outdoor environments and their diet.
How do we address this issue? Well, we really cannot ignore it. Yet, while tire shred is such a significant contributor to our daily microplastic exposure, we probably will not find a replacement for tires in the near future. Education may help. There are some affordable choices to mitigate microplastic exposure in the home, such as choosing an old-school metal tea kettle rather than a plastic one, metal utensils, ceramic dishes and cups, toys that are not plastic, and cotton cloths rather than plastic-reinforced wet wipes. See, e.g., Louise Atkinson, Purge Your Home of Microplastic, Irish Daily Mail (Dec. 2, 2021).
In any case, microplastic exposure should at least be considered in evaluating the environmental stress faced by these communities in all aspects of environmental permitting and enforcement, as well as traffic engineering. Consumer goods should be labeled, providing information regarding plastic content and microplastic shedding rates, along with adoption of limits regarding microplastic shed rates for consumer goods. Incentives, along with education, should support transition to alternative materials, encouraging replacement of consumer goods that are the worst microplastic offenders. Microplastic contamination of food and water should be specifically and expressly considered by the Food and Drug Administration for prospective regulation.
Soon, with the global response to plastic pollution contemplated with the 2024 international plastic treaty, manufacturers may assist in the transition to fewer plastic goods, or plastic goods that are more recyclable and that shed less microplastic while in use. But in the interim, we need to recognize the scope and impact of human exposure to microplastic pollution, especially for already overburdened communities, in order to achieve environmental justice regarding microplastic exposure as well.