Synthetic turf test results released by the New Jersey Department of Health and Senior Services (NJDHSS) on June 3rd confirmed lead chromate levels are well below that necessary to cause harm to children and athletes using the popular playing field surfaces.
"Our industry is proud of its unblemished record of human health and environmental safety since synthetic turf was first introduced more than 40 years ago," says Rick Doyle, President of the Synthetic Turf Council. "We are actively sharing information and cooperating with the NJDHSS, Consumer Product Safety Council (CPSC) and US Environmental Protection Agency to ensure the continued safety of the public."
Lead chromate has been used in a number of synthetic turf fields to extend the life of its colourfastness. Testing three fields in New Jersey with elevated lead levels, the NJDHSS focused on the bioaccessibility of synthetic turf, which it defines as "the fraction of a substance in a material that is soluble and made available for absorption" by the body. Findings validated the Synthetic Turf Council's position, based on science and expert opinion, that lead chromate's extremely low bioavailability prevents it from being readily absorbed by the human body.
From its tests, the NJDHSS reported that the amount of lead chromate contained in fibres from the three fields available for absorption in the intestine, which is where food altered by stomach acid is absorbed by the blood and lymphatic systems, ranged from 2.5% to 11%. We used the most extreme scenario, 11%, to calculate the amount of turf that would have to be ingested to equal the federal standard of 600 parts per million. In practical terms, it is virtually impossible for a child to be at risk from synthetic turf:
According to calculations made by forensic toxicologist Dr. David Black, a 23kg child would have to ingest over 46kg of synthetic turf to be at risk of absorbing enough lead to equal the minimum threshold of elevated blood lead. That level is even more unreachable than Dr. Black's original worst-case bioaccessibility, which was based on ingesting 10kg of turf.
The Consumer Product Safety Commission's guidance states that young children "should not chronically ingest more than 15 micrograms of lead per day from consumer products." Putting these test results in perspective, polymer and fibre engineering specialist Dr. Davis Lee calculated that a child playing on the three New Jersey fields would have to wipe his fingers on the turf and put them in his mouth 750 times in a day to receive enough lead to equal the CPSC threshold level.
Dr. David Black performed the same tests as the NJDHSS, using the same protocol during late May, which showed an average bioaccessibility of 4%. The results of the two tests are similar and validate the safety of synthetic turf, including the synthetic turf NJDHSS reported to contain concentrations of lead chromate of between 3,400 and 4,700 parts per million.
The industry continues to develop new technologies to enhance the safety and playability of synthetic turf. Over the past four decades, the product has made significant improvements. For example, more than 90% of the coloured fibres used in synthetic turf today contain lead chromate levels below the federal standard. Even so, our industry is voluntarily developing pigment formulations that continue to reduce lead chromate levels while maintaining high levels of quality and performance.
