Last Monday, The Medium attended a seminar presented by BIO434 students Lauren Ead, Matthew Chan, and Rashoun Maynard. The project, titled “Microplastics: Micro in Size, Macro in Threat?,” shed light on what microplastics are and what their effect may be on human health and the marine biota.
Microplastics are around 0.1-5 millimeters in size. They appear in the environment through primary and secondary sources. Primary sources are manufactured, such as the microbeads present in cosmetics, while secondary sources arise from the decomposition of larger plastic products. These can include tire dust from the abrasion of rubber tires against roads and synthetic microfibers from clothing in washing machines. According to research done by Dr. Richard Thompson, the director of the Marine Institute at the University of Plymouth, up to seven hundred thousand microfibers can be released into a washing machine per each load of laundry.
Microplastics can contaminate the soil and water through natural and man-made pathways. Road runoff, wastewater treatment systems, wind, sewage, and littering all contribute to the presence of microplastics in the environment. According to a study published in Environmental Science & Technology in 2015, eight trillion microbeads enter the aquatic environments in the United States every day.
The abundance of microplastics is concerning since microplastics can take up to hundreds of years to degrade. Microplastics are also excellent absorbents and carriers for pollutants and contaminants. Harmful pesticides and toxic microorganisms stored in microplastics can accumulate in species at lower trophic levels. The effect is magnified as these species are consumed by other organisms at higher trophic levels.
There are numerous ways through which humans are exposed to microplastics on a daily basis. These microplastics are around the same size as dust particles and therefore, can be inhaled or ingested through food. The average person consumes 272 microplastics in a day, which adds up to over 99 000 in a year. Chronic inhalation can result in symptoms which align with various lung diseases. Other sources of microplastics include sea salt and bottled water. In fact, according to a study conducted by Dr. Kim Seung-Kyu, an associate professor at Incheon National University and Greenpeace East Asia, 90 per cent of sea salt samples from around the world were found to contain microplastics.
While not much research has been done to determine the effects of microplastics on humans, microplastics have been shown to have adverse effects on marine life. Microplastics affect the animals’ physical structure, their behavior, and their reproductive success.
Experts recommend covering exposed food to prevent microplastic contamination from the air, reducing sea salt intake, and drinking tap water instead of bottled water. Another thing to focus on long term is to be more cautious about the items we purchase. Purchasing clothing with natural fibers instead of synthetic fibers can vastly reduce the amount of plastic that ends up in the oceans. Using reusable water bottles as an alternative to plastic water bottles is another easy way to reduce your carbon footprint. Whether it is to protect aquatic life or to protect oneself, there are several actions which can be undertaken to minimize exposure to microplastics and reduce their presence in the environment.