What are Chemicals of Mutual Concern?

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Kevin Bunch
November 09, 2016
  When the United States and Canada signed the Great Lakes Water Quality Agreement of 2012, the two countries agreed to draw up a list of chemicals of mutual concern (CMCs): human-made substances that pose a threat to human health and the environment that the governments want to target for binational action. The governments have agreed to an initial list of CMCs and are drafting strategies on how to reduce their presence in the Great Lakes region and deal with existing contamination. In May 2016, the first eight CMCs were announced by the countries. The list includes mercury, flame retardants like hexabromocyclododecane (HBCDs) and polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), perfluorinated compounds (PFOAs, PCOS and PFCAs), and short-chain chlorinated paraffins (SCCPs). The names are as messy as their impacts are long-lasting and far-reaching, as they can build up in tissues and cause health problems for animals and people alike.
Hamilton Harbour, located on the western end of Lake Ontario, is just one site in the Great Lakes dealing with the chemicals of mutual concern named by the United States and Canada. Credit: Environment and Climate Change Canada
Hamilton Harbour, located on the western end of Lake Ontario, is just one site in the Great Lakes dealing with the chemicals of mutual concern named by the United States and Canada. Credit: Environment and Climate Change Canada

The two parties released a series of reports on each chemical. The researchers found that even though most PCBs were banned in the 1970s and usage for special circumstances such as in scientific instruments and transformers has fallen for decades, levels still routinely exceed guidelines and drive fish consumption advisories in all the Great Lakes. This is because the chemicals are long-lasting, are wrapped up in the food web and bioaccumulate in those species further up the chain, such as lake trout or gulls.

According to a series of documents from the CMC Identification Team – comprised of experts from both countries and appointed by the governments - mercury is also on a downward trend in the Great Lakes, but is still at threatening levels to the environment and human health. Moreover, a 2015 IJC report on air deposition of mercury in the Great Lakes found that mercury levels in some species of fish are increasing. PBDE concentrations in fish like walleye and lake trout, along with sediment and gull eggs, exceeded safe guidelines and show no clear evidence of declining at this point; the same is true for the perfluorinated compounds, according to the Identification Team.

A gull incubates its eggs near Saginaw Bay, Michigan. Legacy contaminants such as PCBs have been found in the eggs even recently. Credit: US Fish and Wildlife Service
A gull incubates its eggs near Saginaw Bay, Michigan.  Legacy
contaminants such as PCBs have been food in eggs recently. 
Credit:   US Fish and Wildlife Service 

But what do these chemicals do to living creatures? HBCDs are toxic to aquatic species and can cause respiratory, gastrointestinal and skin irritation in humans. PBDEs can impact thyroid and metabolic systems. Mercury can cause a slew of neurological problems ranging from speech and motor skills to cognitive development issues in children. PCBs can cause skin irritation in adults and development issues in children, as well as cancer in animals. The effects of perfluorinated compounds isn’t well known, but studies suggest it could increase cancer rates.

Compiling a list is just the first step, and the governments are now drafting strategies to deal with CMCs. According to the Great Lakes Water Quality Agreement) and its annex on CMCs, plans being considered include research, monitoring, surveillance, and pollution prevention and control actions. The IJC also is working on a series of recommendations for a strategy on PBDEs, with a final report due this fall.

In Canada, all eight CMCs are already covered by the Canadian Environmental Protection Act of 1999’s list of toxic substances, as well as under its Chemicals Management Plan. CMCs already are subject to federal risk management efforts by the government, which include environmental guidelines at the federal level. Environment and Climate Change Canada (ECCC) also is supporting the creation of provincial guidelines to help deal with CMCs. ECCC handles monitoring and surveillance for water quality in the Great Lakes watershed.

In the United States, the Environmental Protection Agency handles the monitoring and surveillance of water quality – including the effects of CMCs -- in the watershed, and funds research on the trends, presence and effects of CMCs through the Great Lakes Restoration Initiative. The chemicals are regulated in the US depending on how they’re used and released, and where they are made. Those regulations exist on the federal, state and local level, though for the federal government those efforts stem from the Toxic Substances Control Act, updated most recently on June 22, 2016. In the PROP, the US government notes that it will be more closely aligning its federal actions with those on state and local levels to improve its CMC-specific efforts around the Great Lakes.

The two countries have just started – naming the first CMCs was only one step in the process - and they are drafting a second set of CMCs to add to the binational list and coming up with strategies to address the initial eight. An initial nomination period that allowed for the public to forward chemicals for consideration ended on Aug. 29, 2016. There is no timeline on when the second round of chemicals will be announced.

 

 

  Industrial areas, like this one on the St. Clair River near Sarnia, Ontario, have historically been one source for the pollutants found in the CMC list in the Great Lakes basin. Credit: Environment and Climate Change Canada
 

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

 

Picture of Kevin Bunch
Kevin Bunch

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.