Most countries are not on track to eliminate their supplies of highly hazardous compounds called polychlorinated biphenyls (PCBs), contrary to a 2028 deadline established by the Stockholm Convention, a new study has found.
The report, published in Environmental Science & Technology on Wednesday, found that more than 10 million tons of PCB-containing materials remain around the world — endangering public health and the environment around the world.
PCBs are carcinogenic organic contaminants that were widely used for their insulating and fire-retardant capabilities, the authors noted. While the compounds were banned in the late 1970s by many countries, including the U.S. and Canada, many of these chemicals still exist in transformers, capacitors and other materials.
The Stockholm Convention on Persistent Organic Pollutants, signed in May 2001, called upon signatory parties to phase out the use of PCBs in equipment by 2025 and ensure their elimination entirely by 2028, according to the United Nations Environment Program.
To date, 181 nations have become parties to the convention. The U.S. has yet to ratify the convention, stressing that it lacks “the authority to implement all of its provisions,” according to the State Department.
While most countries are party to the convention, 42 percent of these signatories remain unaware of the amounts and locations of PCB stocks in their country, according to the authors, who are based at U.S., Canadian and Czech institutions.
“We’re only six years out from the Stockholm Convention’s deadline to responsibly eliminate PCB stocks, but shockingly little progress has been made,” co-author Lisa Melymuk, assistant professor of environmental chemistry at Czechia’s Masaryk University, said in a statement.
Just 30 percent of signatory nations are on track to meet the 2028 goals set in the Stockholm Convention, the authors found.
The U.S., the world’s largest producer and user of PCBs, has reduced its stocks by only around 3 percent since 2006, according to the study.
Despite having the financial capacity to responsibly eliminate these compounds, the U.S. has set not regulatory deadlines to do so, the researchers noted.
PCB inventory in the U.S. is also poorly documented in comparison to that of Canada or the Czech Republic, the authors found.
“With effective regulations and good governance, Canada has successfully managed and destroyed its PCB stocks,” co-author Miriam Diamond, a professor in the University of Toronto’s Department of Earth Sciences and School of the Environment, said in a statement.
That said, Diamond stressed that Canada has failed to apply “this ‘lesson learned’ from PCBs to other highly hazardous chemicals.”
The authors also cited a lack of administrative, financial and policing capacities as obstacles to successfully managing global PCB stocks — particularly in low-income countries. They noted, however, that such countries were not responsible for most PCB production or use.
Such failures do not bode well for the management of other toxic compounds found in products and the environment, such as chlorinated paraffin chemicals and per- and poly-fluoroalkyl substances (PFAS) known as “forever chemicals,” the scientists warned.
“Global mismanagement and inequities make elimination of these persistent chemicals unlikely,” co-author Veena Singla, a senior scientist at the Natural Resources defense Council, said in a statement.
“This analysis is an international wake-up call to limit the production of hazardous chemicals, like PCBs,” Singla added. “We just can’t clean up the mess that they create.”