After concerns were raised that the water-based wood preservative CCA might expose the public to unacceptable levels of arsenic, the South African Wood Preservers Association (SAWPA) commissioned INFOTOX to investigate the potential health risks associated with CCA-treated wooden structures at playgrounds.
INFOTOX, an independent company specialising in toxicology, is headed by the country's best practitioners. Dr Willie van Niekerk and his team completed an assessment that shed light on the health issues that were raised.
'"It was important to separate commercial matters from emotional arguments and look at what the scientific evidence tells us," says Bertus Coetzee. The traditional thinking was that traces of arsenic might rub off on children's hands while they interacted with CCA-treated wooden playground equipment, or that arsenic might leach into the surrounding soil where children are likely to play.
Various studies around the world have focused on measuring dislodged arsenic via urine samples or by rubbing treated structures with cloth or paper that could then be analysed.
Stilwell and Gorny (1997) conducted a comprehensive study of arsenic concentrations in soil under CCA treated decks and playgrounds. The levels were found to be of "no pertinent significance", especially given the fact that the soil in certain areas of South Africa has highter naturally occurring levels of arsenic.
The INFOTOX report cites the most recent research: in a biomonitoring study by Lewis et al (2010), saliva and urine samples from children who played at a CCA playground were compared with samples from children who played at a non-CCA playground. The researchers concluded that there was no statistically-proven difference in arsenic exposure between the two groups. They further found that exposure to arsenic from food and water is estimated to be higher than from exposure to arsenic at playgrounds.
"We are pleased to see the report's scientific conclusion that CCA poses no risks to the public," says Bertus. "Dolphin Bay will continue to offer the industry the best wood preservatives on the market."