A new study from researchers at the University of British Columbia (UBC) has found that artificial turf fields in Metro Vancouver — installed at many area schools and parks — are leaching a chemical lethal to coho salmon into municipal stormwater systems.
And the study finds that the contamination from 6PPD-quinone, a chemical known to kill salmon, persists long after the fields are installed.
Researchers traced this chemical to crumb rubber infill made from recycled tires, which is widely used on turf fields.
Traces of other toxicants, including copper and zinc, were also found near fields made with material from old vehicle tires.
“An average turf field contains about 125 tonnes of crumb rubber, roughly 20,000 tires,” said Katie Moloney, a PhD student in environmental engineering in UBC’s Scholes Lab, in a news release. “With fields typically lasting a decade or more, they can become long-term sources of tire-derived pollution entering stormwater pipes, and ultimately fish-bearing waterways—frequently without treatment.”
The study is peer-reviewed and accepted for publication by the Royal Society for Chemistry. Assistant civil engineering Prof. Rachel Scholes supervised the research.
Researchers began looking into the contamination after North Vancouver streamkeepers reported dead salmon in streams adjacent to a turf field in 2023.
Samples were taken from 12 fields, nine of which used the crumb rubber infill. One field was six years old, but drainage samples still contained chemical amounts deadly to juvenile coho salmon. Researchers found the risk is compounded in areas where multiple fields drain into the same stream.
“Every time it rains, these fields release a mix of chemicals into the drainage system,” Moloney said. “That needs to be taken seriously.”
The study’s authors proposed solutions, such as placing filters in storm drain pipes or using non-rubber infills. But some of those materials are more expensive than crumb rubber, and natural solutions such as cork are prone to freezing in the winter.