For years, scientists around the globe have been expressing concerns about the potential dangers of microplastics. These minuscule particles, less than 5 millimeters long, are products of plastic pollution and are virtually omnipresent.
They permeate deep-sea trenches, remote corners of Antarctica, and even the seafood that graces our dining tables. But what’s the real impact of microplastics on our ecosystems and health?
In an international collaboration, researchers, including those from McGill University, have unearthed disturbing evidence regarding the impact of microplastics on our environment. They found that these tiny plastic particles, when ingested by seabirds, bring about significant changes in their gut microbiome.
The effects? An increase in the presence of harmful pathogens and antibiotic-resistant microbes, paired with a decrease in beneficial gut bacteria.
The scientists caution that their findings aren’t merely applicable to wildlife. “Our findings reflect the circumstances of animals in the wild. Since humans also uptake microplastics from the environment and through food, this study should act as a warning for us.”
Julia Baak, a co-author of the study and a PhD Candidate in the Department of Natural Resource Sciences at McGill University, helped explain why these changes are so concerning. “The gut microbiome encompasses all the microbes in the gastrointestinal tract, which help control the digestion of food, immune system, central nervous system, and other bodily processes. It’s a key indicator of health and well-being.”
To delve deeper into the microplastic problem, the scientists studied the gut microbiome of two seabird species, the northern fulmar (Fulmarus glacialis) and the Cory’s shearwater (Calonectris borealis). These seabirds dwell mainly in the open ocean, where they feed on marine mollusks, crustaceans, and fish, putting them at risk of chronic microplastic ingestion.
Gloria Fackelmann, who led this study as part of her doctoral thesis at the Institute of Evolutionary Ecology and Conservation Genomics at Ulm University in Germany, noted the research’s novelty. “Until now there was little research on whether the amounts of microplastics present in the natural environment have a negative impact on the gut microbial health of affected species,” she said.
The research team found that ingestion of microplastics altered the microbial communities throughout the gastrointestinal tract of both seabird species.
Fackelmann warned, “The more microplastics found in the gut, the fewer commensal bacteria could be detected. Commensal bacteria supply their host with essential nutrients and help defend the host against opportunistic pathogens. Disturbances can impair many health-related processes and may lead to diseases in the host.”
Most microplastic studies have been conducted in labs, where scientists often use high concentrations of microplastics. However, this study provides a more realistic picture.
“By studying animals in the wild, our research shows that changes in the microbiome can occur at lower concentrations that are already present in the natural environment,” Fackelmann stated, reminding us of the real-life implications of their findings.
The research is published in the journal Nature Ecology & Evolution.
Microplastics are tiny pieces of plastic that are less than 5 millimeters long. They originate from various sources and come in various shapes, including fragments, films, foams, pellets/beads, and fibers.
These are plastics that were initially manufactured to be small in size. They include plastic pellets or “nurdles” (used as raw material in the production of plastic products), microbeads (found in personal care products like facial scrubs, toothpastes), and fibers from synthetic textiles.
These are formed from the breakdown of larger plastic items due to environmental factors like sun exposure, wind, and wave action. They can also result from abrasion, such as when tires are used or when clothes are washed.
Microplastics have become a significant environmental concern due to their persistence in the environment, potential for widespread dispersal, and ability to absorb and desorb harmful pollutants. They’ve been found in a wide range of environments, including oceans, rivers, air, soil, and even Arctic sea ice.
Marine creatures can mistake microplastics for food, leading to physical harm (like blockage of digestive tract) and exposure to the harmful pollutants carried by the microplastics. The impact on human health is still unclear but could occur through the consumption of seafood or drinking water contaminated with microplastics, or inhalation of airborne microplastics.
Research is ongoing to understand the full environmental and health implications of microplastics. Nevertheless, the presence of microplastics in the environment is a clear sign of the widespread and long-lasting impact of plastic pollution. Therefore, efforts to reduce plastic waste, improve waste management, and develop biodegradable alternatives to conventional plastics are crucial.
Scientists are also working on methods to remove microplastics from the environment. Some proposed solutions include the use of bacteria that can degrade plastics, and technologies that can capture microplastics in wastewater before they’re released into the environment. However, these methods are still in the early stages of research and development.