PURPOSE OF THE STUDY.
To compare an intervention by using air cleaners and health coach intervention to reduce secondhand smoke (SHS) exposure, particulate matter (PM), air nicotine, and urine cotinine concentrations, and to increase symptom-free days (SFDs) in children with asthma residing with a smoker.
The study enrolled children ages 6 to 12 years with a physician diagnosis of persistent asthma who were living with a smoker (>5 cigarettes a day).
This was a randomized 3-arm controlled trial. All study groups received asthma education over 4 nurse-home visits. Study groups included (1) the control group (high-efficiency particle air cleaners were placed in the home after the final home-monitoring visit), (2) the air cleaner group (air cleaners were placed in the home for 6 months), and (3) the air cleaner plus health coach group (air cleaners for 6 months and a behavioral intervention). Changes in PM, air nicotine, and urine cotinine concentrations as well as SFDs were measured, and the child’s SHS exposure was evaluated based on the caregiver’s report of smoking frequency.
Changes in mean fine and coarse PM (PM2.5 and PM2.5–10) concentrations (baseline to 6 months) were significantly lower in both air cleaner groups compared with the control group (mean differences for PM2.5 concentrations: control, 3.5 μg/m3; air cleaner only, −19.9 μg/m3; and air cleaner plus health coach, −16.1 μg/m3 [P = .003]; and PM2.5–10 concentrations: control, 2.4 μg/m3; air cleaner only, −8.7 μg/m3; air cleaner plus health coach, −10.6 μg/m3 [P = .02]). SFDs were significantly increased in both air cleaner groups compared with the control group (P = .03). No differences were noted in air nicotine, urine cotinine concentrations, or SHS exposure measures. The health coach provided no additional reduction in PM concentrations.
Use of air cleaners in homes of children with asthma was associated with significant reduction in PM concentrations and increase in SFDs. The reduced PM levels were not sufficiently decreased to meet the US Environmental Protection Agency’s standards for outdoor air quality. Although the use of air cleaners resulted in significant reduction in PM concentrations and an increase in SFDs, it was not enough to decrease exposure to SHS.
This study suggests that the use of air cleaners may be helpful in the reduction in indoor PM concentrations and in increasing SFDs, which may be a viable intervention suggestion for the homes of urban children with asthma who live in homes with smokers. The authors suggest that use of high-efficiency particle air cleaners is a more cost-effective approach compared with treatment with a leukotriene modifier, which revealed similar increases in SFDs in other studies. However, further studies are needed that take into account adherence to use of air cleaners and for SHS exposures outside the home. Of course, implementing a smoke-free home policy should be first considered ideally, especially in the homes of children with asthma.
- Copyright © 2012 by the American Academy of Pediatrics