Pilot study of personal, indoor and outdoor exposure to benzene, formaldehyde and acetaldehyde

There is a lack of data for health risk assessment of long term personal ex posure to certain ubiquitous air pollutants present particularly in urban a tmospheres. The relationship between ambient background concentrations and personal exposure is often unknown. A pilot campaign to measure indoor concentrations, outdoor concentrations a nd personal exposure to benzene, formaldehyde and acetaldehyde was conducte d in a medium sized French town. A strong contribution to total personal ex posure was observed from indoor sources, especially for formaldehyde and ac etaldehyde, suggesting that indoor sources are dominant for these compounds . For benzene, the average personal exposure exceeded a 10 mu gm(-3) limit value, although this was not the case for the ambient background concentrat ion. For formaldehyde, the limit level was also exceeded. Observations sugg est that true personal exposure cannot be determined directly from measurem ents pertaining from fixed ambient background monitoring stations. It is ho ped that this will be taken into consideration by the bodies responsible fo r monitoring air pollution and the future European Air Quality Directive.