This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: The shape of microplastics can influence how deadly a viral infection can be for fish, according to new research from William & Mary's Virginia Institute of Marine Science (VIMS). The findings suggest that some forms of plastic pollution pose greater biological risks than others, offering scientists a potential path toward reducing the environmental impacts of microplastics.
Recently published in Environmental Toxicology and Chemistry, the experimental study found that rainbow trout exposed continuously to nylon microfibers had approximately twice the odds of dying from a viral infection compared with fish exposed to the virus alone. By contrast, exposure to small, rounded nylon particles did not significantly increase virus-related mortality. The research also demonstrated that the timing of exposure mattered, with the greatest effects observed when fish were first exposed to microplastic fibers 30 days before virus exposure.
The study brought together a trio of professors at VIMS and the Batten School of Coastal & Marine Sciences: Meredith Evans Seeley, Ph.D. '21; Robert Hale, Ph.D. '83; and Andrew Wargo. Alongside then-undergraduate student Anna Mehlhorn '22, the scientists combined their expertise in environmental toxicology, contaminant chemistry and disease ecology to investigate how plastic pollution interacts with infectious disease. They anticipate their findings will help advance our understanding of an emerging environmental threat while revealing potential avenues for the development of practical solutions.
"Not all plastics are created equal, and so that creates an opportunity to identify the worst forms of pollution and come up with solutions," said Wargo. Referred to as "microplastics," plastic particles measuring less than 5 millimeters (0.2 inches) are widespread in aquatic environments, originating from the breakdown of larger plastic products and the shedding of synthetic materials such as clothing, fishing nets and ropes. While their prevalence has raised concerns about environmental and human health, much of the research has focused on whether exposure directly harms or kills organisms.
However, scientists are increasingly recognizing that pollutants can also have indirect effects, potentially weakening organisms' ability to withstand other environmental stressors. "One of the things that was becoming clear to us is that microplastics have really significant impacts, but they're not always lethal," explained Seeley, the study's lead author. She and her colleagues were particularly interested in whether microplastic exposure could influence infectious disease, an important concern in both wild fisheries and aquaculture.
In an earlier study, the researchers demonstrated that exposure to certain microplastics increased mortality among rainbow trout infected with infectious hematopoietic necrosis virus (IHNV), one of the primary pathogens contributing to production losses in trout aquaculture both in North America and globally. Nylon microfibers produced a particularly pronounced effect, raising questions about what made them different from other plastics. "We saw the effect with the nylon fibers and had to ask, 'Is it the fact it's a fiber or is it the fact that it was nylon?'" recalled Hale.
Extract — continue reading at the source.
