The Challenge of Identifying Microplastics

Microplastic pollution is a growing global concern, with these tiny plastic particles found in virtually every environment, from the deepest oceans to the air we breathe. Accurately quantifying microplastic levels is crucial for understanding the extent of the problem and developing effective mitigation strategies. However, the very nature of microplastics – their small size and diverse composition – makes them incredibly challenging to study.

“We may be overestimating microplastics, but there should be none,” explained Anne McNeil, a professor of chemistry, macromolecular science and engineering at U-M, and senior author of the study. “There’s still a lot out there, and that’s the problem.” The issue isn’t that microplastics aren’t present; it’s that current measurement techniques may be compromised by external contamination.

Stearates: A Chemical Mimic

Stearates are salt-based, soap-like substances. Their chemical structure closely mirrors that of certain polymers used in plastics, creating a significant analytical hurdle. Standard laboratory methods often struggle to differentiate between the two, leading to false positives. This is particularly problematic when analyzing complex environmental samples where microplastics are present in low concentrations.

“This field is very challenging to work in because there’s plastic everywhere,” McNeil added. “But that’s why we need chemists and people who understand chemical structure to be working in this field.”

Mitigating the Contamination Risk

The U-M research team, led by Madeline Clough and Anne McNeil, recommends a simple yet effective solution: switching to cleanroom gloves. These specialized gloves are designed to release significantly fewer particles, minimizing the risk of contamination. While more expensive than standard lab gloves, the cost is justified by the potential for more accurate and reliable research results.

“For microplastics researchers who have these impacted datasets, there’s still hope to recover them and find a true quantity of microplastics,” said Clough, a recent doctoral graduate. Researchers can re-analyze existing data, accounting for the potential stearate contamination, to obtain a more accurate assessment of microplastic levels.

What impact will this discovery have on existing microplastics datasets? And how can laboratories ensure the integrity of their future research in the face of ubiquitous plastic contamination?

Further research is needed to fully understand the extent of stearate contamination in existing microplastics data and to develop more sophisticated analytical techniques that can reliably distinguish between stearates and true microplastics. Resources like the EPA’s Trash-Free Waters program are dedicated to addressing plastic pollution and supporting research in this critical area.

The findings were published in the journal Analytical Methods.

Frequently Asked Questions About Lab Glove Contamination and Microplastics