Japanese study: Flame retardants likely shed toxic products into indoor dust

September 19, 2012

Dioxins are chemical compounds that are toxic, carcinogenic, and persistent organic pollutants. Due to their adverse effects, some types of dioxins are banned and/ or regulated internationally, and the World Health Organization sets limits on acceptable human exposure to these chemicals. 

Results in a recent paper published in Environmental Science & Technology indicate that Japanese indoor dust contained significant amounts of brominated dioxins, which may have come from flame retardants in TV casings and other plastics.

The authors first analyzed dust from homes and offices in Japan and found brominated dioxins. Then, they asked from where the brominated dioxins might be coming.  They found that the levels of PBDE flame retardants were strongly correlated with the levels of brominated dioxins in the indoor dust, suggesting that the flame retardants were the source of the brominated dioxins. Other studies confirm the relationship between PBDEs and brominated dioxins. These dioxins could be present in the initial flame retardant mixture, as dioxins were detected in several commercial PBDE mixtures by Hanari et al. Additionally, Kajiwara et al. found that brominated dioxins are formed when PBDEs in high-impact polystyrene and TV casings are broken down by sunlight exposure.

Since indoor dust is an important exposure route to dioxins for humans, especially children, this could be yet another example of the unfortunate consequences of adding flame retardants to TV enclosures and other consumer products.

Full reference:

Suzuki, G., Someya, M., Takahashi, S., Tanabe, S., Sakai, S., & Takigami, H. (2010). Dioxin-like activity in Japanese indoor dusts evaluated by means of in vitro bioassay and instrumental analysis: brominated dibenzofurans are an important contributor. Environmental science & technology, 44(21), 8330–6. doi:10.1021/es102021c