A study of personal exposure to nitrogen dioxide using passive samplers

A group of 60 people from an age of 22 to 45 was selected for a study of their personal exposure to nitrogen dioxide (NO2). All the participants were selected from the group of people who spent most of their time at home and in an air-conditioned office environment, which also represented the majority of the people in the population. Among this group of participants, 12 were selected to participate in a more detailed investigation on the NO2 levels in various locations in their home environment. It was found that the average personal exposure to NO2 of the 60 participants was 46.0 mu g/m(3), which was quite close to the average level of 47.3 mu g/m(3) of the 12 participants who were involved in the measurement exercises in their home environment. The 12 residential premises were studied for NO2 levels in different locations in both the indoor environment and the surrounding outdoor environment. It was found that the average NO2 level in the indoor environment (living room, bedroom and kitchen) was 55.2 mu g/m(3) while the corresponding outdoor NO2 level was 71.8 mu g/m(3). The study indicated that cooking activities in the kitchen had strong impact on the NO2 level. When cooking existed, the average indoor NO2 level was 59.7 mu g/m(3) and when cooking did not exist, the NO2 Level was 41.8 mu g/m(3). Average indoor to outdoor NO2 ratio was 0.80. The study indicated that the home environment showed the highest impact to the total personal NO2 exposure due to the relatively higher NO2 level caused by combustion effect in the kitchen as well as the long time period spent every day in this micro environment. NO2 level in an air-conditioned office was low and the impact from other outdoor sources was not significant due to the small amount of time spent in those micro-environments even though in some occasions the instantaneous levels would be high, (C) 2000 Elsevier Science Ltd. All rights reserved