The potential health and environmental hazards from microplastics filtered into our drinking water is real. Microplastics are tiny solid plastic particles, less than 5 millimeters in size, that result from the breakdown of larger plastics or are directly found in some of the consumer products.
Our recently published research in the peer-reviewed journal Science of the Total Environment systematically reviewed over 120 research articles from the past 10 years on microplastics in wastewater treatment plants.
These articles were selected based on specific criteria, allowing for an in-depth analysis of the occurrence, removal rates and behaviors of microplastic fibers and beads in wastewater and water environments. Our study gives the latest information on where microplastics are found, what happens to them, how they affect health and current regulations. It also includes details about their size and shape, specifically microfibers and microbeads found in wastewater.
The study highlights that while most wastewater treatment facilities significantly reduce inflowing microplastics loads, complete removal remains impossible with current technologies.
Microfibers, primarily shed from synthetic textiles like polyester, dominate wastewater streams. Microbeads, even though there are fewer of them now because of bans, still cause pollution because they release harmful chemicals like plastic softeners and fire-resistant additives.
As a result, many microplastics are being reintroduced to the environment, likely transporting other residual harmful pollutants in wastewater, including chemicals, pesticides and antibiotics.
Right now, the release of microplastics from wastewater treatment facilities is inevitable. Therefore, it is necessary to evaluate the exposure risks to not only microplastics but the relevant organic chemical pollutants that can be released from or absorbed on the microplastics and transported along with the microplastics from wastewater treatment plants into receiving environmental water systems.
Many of the chemicals that stick to microplastics can mess with hormones and be harmful even in tiny amounts. If microplastics and these chemicals keep getting released into the environment, they could cause serious long-term health problems for people, like increasing the risk of heart disease and cancer.
Despite advancements in wastewater treatment technologies to keep harmful pollutants out of water sources, findings from our study urge us to address the growing microplastics issue in water and other environmental media by developing standardized testing methods to help understand the issue.
We hope our findings bring better understanding of microplastics and their dangers so we can improve our risk management and mitigation efforts.
Bringing attention to this complex pollutant that is continuously released in wastewater and other pathways demands more research. Microplastics can harm the environment and build up in our bodies through things like drinking water and the food we eat.
Un-Jung Kim is an assistant professor in the Earth and Environmental Sciences at the University of Texas at Arlington. Karthikraj Rajendiran is an assistant professor of research in the Kinesiology and Bone Muscle Research Center at UTA. Jenny Kim Nguyen is a graduate student in the Earth and Environmental Sciences at UTA. The opinions expressed in this column are the views of the authors, not of UTA.
