In 2017, Orb Media, a non-profit media group, sparked public concern after they published research showing that microplastics were present in global drinking water. Since then, research efforts have increased to examine the effect of microplastics on species and find ways to make the removal process more efficient.
At a lecture at McGill on Sept. 20, Robert Andrews, a lead scientist at the Drinking Water Research Group (DWRG) at the University of Toronto, explained that scientists have not yet determined a universal definition for ‘microplastics.’ However, they are widely agreed to be small pieces of plastic with a diameter ranging from one nanometre to five millimetres. If produced on purpose, these small plastic particles are called primary microplastics. Common primary microplastics include plastic pellets used in large-scale plastic production and microbeads found in cosmetics. Secondary microplastics, which include plastic film from labels and microfibres from laundry, are pieces that have degraded from larger plastic products.
The Drinking Water Research Group (DWRG) is one of the most prominent expert organizations in this relatively new field of study. In 2017, Andrews and his colleague Chelsea Rochman tested water samples from Lake Ontario and found microplastics in them. Ever since, DWRG’s main objective has been to quantify the presence, size, and type of microplastics in the Great Lakes and evaluate and improve the efficiency of current water treatment.
Andrews explained that conventional water treatment processes often add microplastics to the water.
“If you go to a water treatment plant where everybody dresses in a blue uniform, guess what colour the primary fibres that we find [are]? Blue!” Andrews said.
The DWRC found that although microplastics ranging from 100 to 500 micrometres were effectively removed by treatment, the number of those ranging from 10 to 45 micrometres increased after filtration.
“Had [the smaller pieces] been broken down by filters [or] by oxygen?” Andrews asked. “We don’t know. But within the next year, we will find out.”
Among the samples collected from Lake Huron, Lake Erie, and Lake Ontario, they found that Lake Ontario had the highest count of microplastics per litre. One explanation is that since Lake Ontario is downstream from the other Great Lakes, plastic particles accumulate. This is concerning for Ontario residents, because Lake Ontario provides nearly half of the population’s water source.
Scientists are unsure whether microplastics cause harm to humans once ingested, which is particularly troubling given recent McGill research showing billions of microplastics in tea. Research shows that plastic pieces can act as contaminant vectors in transporting pollutants and pathogens. Furthermore, the tiny plastics can also be translocated to the circulatory system in mussels and fish, leading to questions of whether the toxic chemicals released from these microplastics will go on to poison the organisms through their bloodstream.
According to Andrews, medical researchers have also expressed concerns regarding plastic use during medical procedures, specifically the breakdown of these plastics causing DNA damage and genetic mutations. However, a recent report issued by the World Health Organization (WHO) assessed the risk associated with ingesting microplastics as low but acknowledged the insufficiency of available information and the need for further studies.
“Even though [microplastics] are small, there may not be a whole lot of them [in your body],” Andrews said in an interview with The McGill Tribune. “If you accumulate them over a lifetime, perhaps there is an issue.”
Since the DWRG quantifies microplastics but does not study their effects on organisms, Andrews admitted that their research runs on the basis of the precautionary principle.
“That’s what we do in drinking water research,” Andrews said. “[We] try and say ‘what’s there?’ and then somebody else can say, ‘is it dangerous?’”
In the future, the DWRG aims to automate analysis and standardize testing water sampling methods. It also plans to continue examining the process of microplastics removal.