Policy influence of formaldehyde exposure risk in air-conditioned office environment

Long-term measurement of indoor air quality (IAQ) over a general community could be a good approach to evaluate the influence of policy on pollutant exposure levels. However, this approach requires considerable measurement efforts and in many circumstances an updated data set will not be available. Formaldehyde is an indoor pollutant that presents a health hazard to building occupants in the long term. It is widely associated with common building materials and products. An IAQ policy for Hong Kong offices was initiated in 1997 to improve the indoor environment and occupants' health. A Bayesian risk analysis was used to evaluate the unbiased estimators of the exposure risk profiles, with the regional IAQ assessment results for offices in 1996, 1998-2001, 2004-2005. The results showed that the expected loss of life expectancy due to the life-time exposure to the airborne toxic substance formaldehyde for the air-conditioned offices of Hong Kong decreased from 0.45 day to 0.22 day, probably due to the implementation of the IAQ policy. The study is a useful reference for controlling the life-time exposure of formaldehyde in air-conditioned offices.