Measuring Residential Secondhand Smoke Exposure

Cigarette smoking in the indoor environment can lead to peaks in PM2.5 level.  A peak exposure is the highest level of a substance that a person is exposed to at one time.  Peak exposures to pollutants may trigger harmful acute health effects. The objective of this study is to develop an approach to measuring peak exposures to PM2.5, investigate the feasibility of this approach for characterizing SHS exposure, and comparing the difference in SHS exposure between smoking and nonsmoking homes. PM2.5 refers to atmospheric particulate matter (PM) that have an aerodynamic diameter of less than 2.5 micrometers and are often included in air quality reports from environmental authorities and companies.

Residential secondhand smoke is especially of concern for children since they spend most hours at home and childhood is a critical time for lung development and maturation of the immune system.   A total of 41 children (21 with and 20 without SHS exposure based on self-report) from 28 families in New York City (NY, USA) were recruited.  Both personal and home PM2.5 continuous air monitoring was conducted for five consecutive days. In order to characterize PM2.5 peaks, an algorithm was developed to determine/define thresholds, start and end points of peaks, and baseline.

This study demonstrated the feasibility of peak analysis for measuring SHS exposure. Using this method, they found when children from smoking families were home, peak exposures of PM2.5 were six times that of those from non-smoking families. The study also found that peak exposures that children from families reporting smoking were exposed to SHS for 1.2 hour per day.  For children from smoking families, peak exposure lasted for 5% of their monitoring time, but accounted for 13% of their total exposure. Given the high toxicity of cigarette smoke and susceptibility of children, there is a need for continued efforts in reducing SHS exposure.

Zhang T, Chillrud SN, Yang Q, Pitiranggon M, Ross J, Perera F, Ji J, Spira A, Breysse PN, Rodes CE, Miller R, Yan B. Characterizing peak exposure of secondhand smoke using a real-time PM2.5 monitor. Indoor Air 2020 Jan; 30(1):98-107.