Measurement and health risk assessment of PM2.5, flame retardants, carbonyls and black carbon in indoor and outdoor air in kindergartens in Hong Kong

Polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) through indoor PM2.5 and dust, carbonyl compounds and black carbon aerosol were all detected in five Hong Kong kindergartens, and might present non-cancer risk and cancer risk to children. The PM2.5 levels of the five kindergartens were higher, and several of them exceeded the WHO standard. Formaldehyde was the most abundant air aldehyde.