WC133 NovDec 2023 - Magazine - Page 24
FEATURE
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In the second study, the team explored
the risk of microplastics exposure to
species living in the Great Lakes using an
ecological risk assessment and management framework recently developed and
proposed by researchers in the field for
regulatory use in California. The analysis
showed that nearly 90 per cent of the water samples collected from the Great Lakes
basin contain microplastic concentrations
surpassing the lowest risk threshold,
signaling low-risk potential. About 20
per cent of those water samples contain
microplastic concentrations that exceed
the highest risk threshold. However, all
sediment samples collected contain microplastic concentrations below the proposed
risk thresholds.
And this matters for many reasons.
Implications and recommendations
It’s hard to overstate the importance of
fresh water to North America’s economy and peoples. The Great Lakes alone
account for 21 per cent of the global
freshwater supply, and no fewer than 35
million Americans and Canadians depend
on them for their drinking water.
But it’s certainly not all bad news.
While the study’s findings are disconcerting, the researchers aimed for pragmaTop to bottom: As winter descends on Lake Ontario, the icy surface belies the hidden accumulation of mitism, focusing on recommendations for
croplastics, a silent intruder in our freshwater systems. Beyond the oceans, these tiny pollutants are finding
practice and policy. The first study identitheir way into our freshwater systems—sources of our drinking water and habitats to diverse wildlife.
fies a need for a coordinated monitoring
strategy for microplastics, which would
necessitate developing standardized methods for measuring, characterizing, and reporting microplastics in
via the Great Lakes Water Quality Agreement, the longstanding
the region—a need also emphasized by the Auditor General of
commitment between the two countries that outlines binational
Ontario in their recently published State of the Environment in
priorities and actions to resolve transboundary environmental
Ontario report.
problems in the Great Lakes. Microplastics could be included
Put simply, the concentrations of microplastics in the Great
as a Toxic Chemicals sub indictor for ecosystem health under
Lakes need to be monitored and reported on a consistent, longAnnex 10 of the agreement or be designated as a Chemical of
term basis. This will help stakeholders understand the trends,
Mutual Concern under Annex 3. Both actions would ultimately
exposure risks, and potential sources.
necessitate a monitoring strategy and risk assessment and manThe second study identifies a need to develop an ecological
agement framework for microplastics be developed and implerisk assessment and management framework for the region,
mented in the region.
where different levels of microplastics present in the water and
Today, an International Joint Commission working group, cosediment would trigger specific management actions.
led by Rochman and Hataley along with Drs. Karen Kidd and
For this to be successful, bilateral collaboration between the
Rebecca Rooney, is leading the charge in developing monitoring
U.S. and Canada is necessary.
and risk assessment frameworks, with aims to protect the Great
One way forward to address the issue binationally could be
Lakes from persistent plastic pollution.
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WATER C AN ADA • NOV EMBER/ DECEMBER 2023
WAT E R C A N A D A . N E T
