Slipping Past Filters: Microplastics Are Infiltrating Drinking Water Worldwide

A new study from UT Arlington reveals that wastewater treatment plants continue to fall short in eliminating hazardous microplastics.

Despite improvements in wastewater treatment technologies, microplastics, tiny plastic particles less than five millimeters in size, are still escaping into the environment, according to recent research from The University of Texas at Arlington. These persistent pollutants raise serious concerns for both human health and ecosystems.

Plastic’s popularity stems from its low cost, durability, and versatility, making it a staple in products ranging from food packaging and clothing to personal care items. However, once discarded, plastic doesn’t biodegrade. Instead, it gradually fragments into microplastics that infiltrate soil and water systems, persisting in the environment for decades or longer.

“What our systematic literature review found is that while most wastewater treatment facilities significantly reduce microplastics loads, complete removal remains unattainable with current technologies,” said Un-Jung Kim, assistant professor of earth and environmental sciences at UT Arlington and senior author of the study published in Science of the Total Environment.

“As a result, many microplastics are being reintroduced into the environment, likely transporting other residual harmful pollutants in wastewater, such the chemicals Bisphenols, PFAS and antibiotics,” Dr. Kim added. “These microplastics and organic pollutants would exist in trace level, but we can get exposure through simple actions like drinking water, doing laundry or watering plants, leading to potential long-term serious human health impacts such as cardiovascular disease and cancer.”

Challenges in Detection and Standardization

According to the study, one of the main challenges in detecting and mitigating microplastics is the lack of standardized testing methods. The researchers also call for a unified approach to define what size particle qualifies as a microplastic.

“We found that the effectiveness of treatments varies depending on the technology communities use and how microplastics are measured to calculate the removal rates,” said the study’s lead author, Jenny Kim Nguyen. “One way to better address the growing microplastics issue is to develop standardized testing methods that provide a clearer understanding of the issue.”

Nguyen began this research as an undergraduate student in Kim’s Environmental Chemistry Lab. She is now pursuing a master’s degree in earth and environmental sciences at UTA, where she is working to develop standardized experimental protocols for studying microplastics in air and water.

Toward Solutions and Public Awareness

“This work helps us understand the current microplastics problem, so we can address its long-term health impacts and establish better mitigation efforts,” said Karthikraj Rajendiran, a co-author of the study and assistant professor of research from UTA’s Bone Muscle Research Center within the College of Nursing and Health Innovations.

The team also emphasizes the need for greater public awareness of microplastics to help consumers make more eco-friendly choices.

“While communities must take steps to improve microplastic detection and screening at the wastewater and water quality monitoring, consumers can already make a difference by choosing to buy clothing and textiles with less plastics whenever feasible, knowing that microfibers are the most common microplastic continually released through wastewater,” Kim added.

Reference: “A review on microplastic fibers and beads in wastewater: The current knowledge on their occurrence, analysis, treatment, and insights on human exposure impact” by Jenny Kim Nguyen, Rajendiran Karthikraj, Jean Baptiste Habyarimana and Un-Jung Kim, 18 February 2025, Science of The Total Environment.
DOI: 10.1016/j.scitotenv.2025.178818

Funding for the project was provided by UTA’s Research Enhancement Program, which supports multidisciplinary researchers in launching new projects.

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