The Great Lakes are the largest freshwater system in the world, providing drinking water, recreation, transportation, and habitat for millions of people and wildlife.
A new study has revealed that these lakes are also contaminated by microplastics, tiny pieces of plastic that can harm the environment and health.
Measured microplastic levels in the Great Lakes water samples
Naja Bertolt Jensen/ via Unsplash
The study, published in the journal Science of The Total Environment, was conducted by a team of researchers from the University of Toronto.
They reviewed data from peer-reviewed studies that had collected and analyzed water samples from the Great Lakes over the last 10 years.
They focused on microplastics that are smaller than 5 millimeters, which can be ingested by aquatic organisms or accumulate in sediments.
The researchers calculated the microplastic concentrations and masses in each water sample, as well as the risk levels for wildlife based on existing guidelines.
They also compared the microplastic levels among different lakes, regions, and seasons.
Study's findings and their significance for both wildlife and human health
The study found that about 90% of the water samples from the Great Lakes had microplastic levels that exceeded the safe threshold for wildlife, according to the guidelines from the US Environmental Protection Agency.
About 20% of the samples had microplastic levels that were at the highest risk level, indicating potential adverse effects on aquatic life.
The study also found that microplastic levels varied among different lakes, regions, and seasons.
The highest median levels were found in Lake Michigan and Lake Ontario, followed by Lake Erie, Lake Huron, and Lake Superior.
Furthermore, the highest levels were also found in tributaries and urban areas, where microplastic sources such as wastewater treatment plants, stormwater runoff, and industrial activities are more prevalent.
Meanwhile, the lowest levels were found in offshore and rural areas, where microplastic inputs are less frequent. The study also observed seasonal variations, with higher levels in summer and autumn than in winter and spring.
There is a widespread and persistent presence of microplastics in the Great Lakes, which pose a serious threat to their ecosystem and human health, according to the study.
Microplastics can affect aquatic organisms by causing physical damage, chemical toxicity, reduced growth and reproduction, altered behavior, and increased susceptibility to diseases.
They can also transfer along the food chain, reaching humans who consume fish or drink water from the lakes, and can also carry harmful chemicals or pathogens that can affect human health.
Reduce microplastic pollution in the Great Lakes
Microplastics can harm the environment and health by absorbing and transporting toxic chemicals and pathogens, affecting aquatic organisms and food webs, and entering human water supplies and food resources.
Fortunately, there are some actions that can be taken to reduce microplastic pollution in the Great Lakes.
Opting for reusable or refillable alternatives, such as water bottles, cloth bags, metal straws, and cutlery, can reduce the rate of plastic consumption and footprint.
Supporting innovative technologies can capture and remove plastic from the environment. Technology is an important tool for tackling plastic pollution.
Advocating for policies and regulations could help to address microplastic pollution at different levels. The policy is a powerful instrument for addressing microplastic pollution at different levels.
By taking these actions, we can help reduce microplastic pollution in the Great Lakes and protect their ecosystem and human health.
