The Fresh Air Wristband: A Wearable Air Pollutant Sampler

Evaluation of cumulative exposure to air pollutant mixtures has been challenging with traditional techniques due to the weight, limited battery life, and cost of the instrument. The performance of a novel wearable air pollutant sampler, the Fresh Air wristband, to passively concentrate nitrogen dioxide (NO2), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs) was investigated. The Fresh Air wristband consisted of a commercially available triethanolamine-coated pad to collect NO2 and a polydimethylsiloxane (PDMS) sorbent bar to sample VOCs and PAHs. Concentrations were measured off-line following the assessment period. The repeatability and rate of uptake of VOCs and PAHs by the PDMS sorbent bar were evaluated, and the Fresh Air wristband was tested as an exposure tool. The PDMS sorbent bar achieved reproducible uptake from ambient air with uptake rates varying from 2 to 5 days across compounds. Higher-molecular weight compounds (>180 g/mol) were retained well in the PDMS sorbent bar over multiday periods. The Fresh Air wristband was demonstrated as a personal exposure tool; exposures of school-aged children were found to differ by sex, asthma status, home kitchen characteristics, and mode of travel to school. The lightweight, wearable Fresh Air wristband will enable future longitudinal air pollutant exposure assessment in vulnerable populations.