Researchers are finding that their studies on microplastic pollution may be misleading due to contamination from their own lab gloves. A recent study from the University of Michigan highlights how residue from disposable gloves is affecting the accuracy of microplastic measurements.
• Prevalence of Microplastics: Microplastics are widespread, found in the environment, in air, and in human bodies, raising concerns about their impact.
• Contamination Issue: Researchers realized that the protective lab gloves they wear can shed particles that mimic microplastics. This is due to a soap-like residue used during glove manufacturing.
• Research Findings: A doctoral graduate, Madeline Clough, was measuring atmospheric plastics and found unexpectedly high levels that seemed implausible. After multiple investigations, her team traced the contamination to lab gloves.
• Mechanism of Contamination: Disposable latex and nitrile gloves are coated with stearate salts to help them separate from molds easily. When researchers handle lab equipment, these salts transfer to surfaces, leading to inaccurate microplastic readings.
• Detection Problems: The stearates have a similar structure to polyethylene, the most common plastic. This similarity causes confusion in automated detection systems that researchers use to identify types of plastics.
• Size of Contaminants: Most particles shed from gloves are smaller than five micrometers, which are crucial to monitor as they pose health risks by entering biological systems.
• Future Recommendations: Clough and her team suggest researchers switch to cleanroom gloves that do not have stearate coatings to minimize contamination. These alternatives significantly reduce the number of false-positive readings.
• Recovering Data: While the researchers discarded their initial findings, new analytical methods have been developed to distinguish genuine microplastics from glove residue, allowing scientists to salvage previous datasets.
The discovery of contamination from lab gloves emphasizes the need for improved practices in microplastic research. By using specialized cleanroom gloves, future research can produce more accurate pollution metrics. This adjustment aims to enhance the reliability of data on environmental microplastic levels and ensure effective responses to pollution challenges. Researchers plan to continue their investigations into microplastic contamination in the atmosphere without the use of potentially contaminating gloves.