Together, North America’s Great Lakes make up the largest body of fresh water in the world. Over 30 million people rely on them for drinking water as well as agricultural, industrial and recreational uses. They also provide habitat for wildlife ranging from mussels to lynx. Now, thanks to the abundance of plastics in modern life combined with inadequate pollution-preventing measures, these precious waters are brimming with tiny polymer pieces.
The unwelcome microplastics come from a wide range of sources: they wash down drains in personal care products such as exfoliating creams, detach from polyester and nylon in the laundry, or break off from discarded bottles, to name a few examples. Sunlight and agitation break them into smaller and smaller fragments that readily absorb harmful substances, like persistent organic pollutants, and then get ingested by wildlife. In the Great Lakes, scientists have measured microplastic concentrations of up to 1.1 million particles per square kilometre.
The impacts of microplastics on aquatic life and even human health are poorly understood. So far they have been found inside birds, fish, mammals, turtles and invertebrates such as mussels. In a 2013 study, researchers found that 82% of Lake Superior’s Lake Herring had microplastics inside. Another study from this year led by Oona Lönnstedt revealed that perch larvae in the Baltic Sea even preferred eating plastics to zooplankton. This junk food diet makes the fish sluggish and increases mortality rate—a phenomenon that could be occurring elsewhere, including in the Great Lakes. Plastics can also harm wildlife by blocking digestive tracts or feeding appendages, or by moving into the circulatory system.
Not only are the plastics themselves a hazard, the compounds they absorb can threaten animal health when ingested. These substances include polychlorinated biphenyls (PCBs), which can cause cardiac, skeletal and neurological problems; polycyclic aromatic hydrocarbons (PAHs), which can damage DNA and lead to cancer; and endocrine disruptors that can alter hormone levels.
Are microplastics getting into the tissues of humans that eat aquatic animals or drink from polluted water sources? If so, what effects do the plastics have on human health? These are questions we don’t yet have answers to.
Fortunately governments in the US and Canada are taking steps to curb the flow of microplastics into the Great Lakes. In December 2015, the US government introduced a law to incrementally stop the manufacture and sale of personal care products and over-the-counter drugs containing microbeads; implementation is slated to begin July 2017 and be fully in place by July 2019. Following suit, Canada’s federal government recently added microbeads up to 5 mm in diameter to the Environmental Protection Act List of Toxic Substances: a necessary first step towards controlling or prohibiting their use. Proposed regulations would see a Canadian ban in place six months after its American counterpart.
For the most part, the producers of personal care products are not too riled about the impending bans since harmless alternatives to microbeads like oatmeal and ground apricot pits are available. In fact, five out of the 14 companies represented by the Cosmetic, Toiletry and Fragrance Association—comprising the majority of companies that use microbeads in products distributed in Canada—have already stopped using microbeads or intend to do so by 2018 or 2019.
However some industry stakeholders are opposed to the wording of Canadian legislation pertaining to microbeads, saying it is too broad and will lead to stigmatization of products that contain plastics in forms other than microbeads. One industry association even accused the government of unscientific decision-making; however the move to add microbeads to the List of Toxic Substances was backed up by the findings of UN research and a review of 130 related scientific publications.
Some scientists are happy to see governments taking action to reduce the flow of plastics into the Great Lakes, but believe that banning microbeads in cosmetics and drugs is far from enough to solve the plastic problem. Many other forms of microplastic are abundant in the lakes including resin pellets and paint flakes from industrial materials, microfibres from clothing, fragments of larger plastic objects and microbeads from electronics and medical supplies.
Microfibres, thousands of which may come off an article of clothing with a single washing, are of particular concern. They are thought to be more abundant than microbeads and have been discovered entangling the digestive tract of fish and fish-eating birds due to their thread-like structure. They are also more difficult to prevent from entering or remove from the water supply than are microbeads.
In a recent op-ed, Canadian biologist Anthony Ricciardi asserted that ‘A ban on microbeads from personal-care products is a sensible and necessary step forward, but is inadequate to protect wildlife from this broad spectrum of microplastic pollution.’ According to Ricciardi, a broad range of solutions is needed to fully address the problem, from increasing control over the use and disposal of industrial plastics to improving wastewater treatment, updating recycling processes and—perhaps most importantly—scaling back society’s ‘addiction to plastic.’
Mysteries of the Great Lakes—IMAX
Mysteries of the Great Lakes explores the health of the Great Lakes, highlights the importance of this fresh water resource to North America, and shows us the need for preservation and conservation all while showcasing the regions amazing geography, ecology, science, and history.
Want to watch Mysteries of the Great Lakes? Simply subscribe to the Love Nature streaming app and start your 30-day free trial of the best on-demand natural history documentaries out there. [/geoip-content]