What are Microplastics? – By Rowshyra Castaneda, PhD
Freshwater is a necessity for life. It is incredibly scarce in many places on Earth, but abundant in others. Canada has a large abundance of freshwater, it accounts for 7% of all global renewable water. This renewable water runs in our rivers and pools in our lakes. We rely on our rivers and lakes for the water we drink and need. We depend on our rivers and lakes not only for direct consumption, but also for food, e.g., fishes, and entertainment, e.g., sailing. Given that we heavily use our water resources, we would want to take care of it and preserve it. Unfortunately, this is not the case. We have heavily polluted our precious water by increasing nutrient loads, e.g., via agricultural fertilizer run-off, causing massive algal blooms that in some cases release toxins and use up all the oxygen, killing many fishes, closing beaches, etc. Many of us still litter or don’t recycle and these pollutants frequently end up in our waterways. Although, we may not feel directly responsible for these types of pollutants, we recycle or don’t use fertilizers, it’s possible we are still polluting our waterways from home without even noticing it. We may not be noticing it because these plastics, known as microplastics, are so small that they often go unnoticed. Microplastics are small fragments of plastic, either purposely made such as the microbeads, passively made through degradation of larger pieces of plastic, or unintentionally made by the release of fibres from artificial clothing during a laundry cycle.
Many cosmetic and cleaning products contain microbeads for their exfoliating and scrubbing properties. These microbeads are incredibly small so when they get washed down the drain and transported to our wastewater treatment facilities, they can easily escape filtering and enter our rivers and lakes. Some studies have shown that in one bottle of facial cleanser there could be up to 2.8 million of these microbeads. It was previously believed that these microbeads and other plastics all end up in our oceans; in other words, they are flushed downstream. However, several studies, in the Great Lakes, have shown that the retention of these microbeads is higher than previously assumed, increasing chemical release from the microbeads to the water and increasing chances of consumption by organisms, such as open water fishes. These microbeads are also subject to biofouling which increases their density causing them to sink into the sediment where they can release their chemicals. Once in the sediment, organisms that live on the bottom of the lake or river could ingest them, potentially contaminating the organisms through absorption, which can transfer up the food chain. There are many other hazards of these microbeads which are currently being researched. Of course, these problems are not just for microbeads; these are issues for all plastics and microplastics. Having recognized these issues, the Canadian Government has classified microbeads as a ‘toxic substance,’ therefore, many cosmetic brands have announced that they will no longer have microbes products by 2018-2019. This is a great first step, however, microbeads from cosmetics are only a fraction of the problem as there are many other sources of microplastic pollution.
So, what can we, as citizens, do to decrease the amount of microplastics in our freshwaters and oceans? Reducing our consumption of single-use plastic is incredibly important. Single-use plastics include plastic cutlery, styrofoam, straws, water bottles, etc. All single-use plastics can be replaced by using actual silverware, reusable hard plastic containers, refillable water bottles, etc. We need to start reducing our waste in general! Reuse your fabric grocery bags, use a travel mug for your tea or coffee (it keeps it warm longer anyway!); just say no to unsustainable habits.