Description
Recent studies have demonstrated that activity indoors contributes to increased levels of airborne particulate matter (PM). Inhalation of PM is known to lead to adverse health effects in children including asthma. This research aims to determine whether children could be exposed to higher levels of particulate matter than adults in the same room due to activity near the floor and their shorter stature. This study uses data from a study (Healthy Homes 3), which measured thirdhand smoke pollution in the homes of individuals that recently quit smoking. This study used recorded minute-by-minute PM levels using two stationary personal DataRAM (pDR) passive air monitors at two elevations, children's height (0.2 meters) and adult height (1.5 meters), inside the rooms in the homes where the most cigarette smoking occurred. Sampling ran for an average of 20 hours. Twenty-eight homes were analyzed for differences in PM concentrations at the two elevations. The overall median mass concentrations were slightly higher at children's height (20.0 _g/m_) than adult height (18.5 _g/m_). There was a bigger difference in medians between PM mass concentrations at the different elevations in homes with children or pets (27.0 _g/m_ for low elevation and 22.0 _g/m_ for high elevation) than homes with no children or pets (19.0 _g/m_ for low elevation and 18.0 _g/m_ for high elevation). The median number of peaks and minutes spent above 50 _g/m_ and 100 _g/m_ were higher at low elevations in homes where children or pets lived than in homes where no children or pets lived (peaks above 50 _g/m_ at low elevations were 1.0 peaks/hr as compared to 0.5 peaks/hr at high elevations, and median number of minutes spent above 50 _g/m_ was 4.3 minutes/hr at low elevations and 2.0 minutes/hr at high elevations). In homes where children or pets lived, the median peaks and minutes spent above 50 _g/m_ were higher at children's height than at adult height. Overall, median PM mass concentrations were significantly higher at the children's elevation than at the adult elevation (p = 0.022). These findings demonstrate that the influence of children or pet activity might contribute to higher levels of PM at children's height than adult height. As a result, children may be prone to higher levels of exposure than adults living in the same home. This also demonstrates that indoor air pollution may come from resuspension of particles in homes where smoking occurred. While this data showed that PM was significantly higher at low elevation when children or pets lived in the home, the differences were small and were based on a limited sample size. Significant limitations of this study included a lack of information as to occupant activities, and the fact these were stationary monitors in one room only.
