Children's microenvironmental exposure to PM and ozone and the impact of indoor air filtration.

BACKGROUND

In highly polluted urban areas, personal exposure to PM and O occur daily in various microenvironments. Identifying which microenvironments contribute most to exposure can pinpoint effective exposure reduction strategies and mitigate adverse health impacts.

METHODS

This work uses real-time sensors to assess the exposures of children with asthma (N = 39) in Shanghai, quantifying microenvironmental exposure to PM and O. An air cleaner was deployed in participants' bedrooms where we hypothesized exposure could be most efficiently reduced. Monitoring occurred for two 48-h periods: one with bedroom filtration (portable air cleaner with HEPA and activated carbon filters) and the other without.

RESULTS

Children spent 91% of their time indoors with the majority spent in their bedroom (47%). Without filtration, the bedroom and classroom environments were the largest contributors to PM exposure. With filtration, bedroom PM exposure was reduced by 75% (45% of total exposure). Although filtration status did not impact O, the largest contribution of O exposure also came from the bedroom.

CONCLUSIONS

Actions taken to reduce bedroom PM and O concentrations can most efficiently reduce total exposure. As real-time pollutant monitors become more accessible, similar analyses can be used to evaluate new interventions and optimize exposure reductions for a variety of populations.