Validity, reliability and acceptability of wearable sensor devices to monitor personal exposure to air pollution and pollen: A systematic review of mobility based exposure studies

Wearable sensor devices that measure personal exposure to environmental pollutants are now more widely available as a result of technological advancements.

This review evaluates the international literature on the validity, reliability and acceptability of wearable air pollution and pollen sensor devices in the context of mobility based exposure assessment.

Both peer reviewed and grey literature were searched. The review on validity and reliability included only quantitative, field-based, and mobility-based studies involving human participants who carried wearable devices. For the assessment of sensor device acceptability, only qualitative studies were considered.

Four studies each were included in the reviews of reliability and acceptability of air pollution sensors, and six studies were included in the review of validity of air pollution sensors. No studies assessed the validity, reliability, or acceptability of pollen sensors. The correlation between personal air pollution sensors and reference monitors was stronger indoors than outdoors, indicated by higher correlation coefficients (r-values). In indoors, sensors demonstrated a strong correlation(r-values ≈ 1), particularly for PM2.5 and TVOC, while outdoor correlations, especially for PM1, were notably weaker. Sensors of the same brand demonstrated strong correlations with each other, both indoors and outdoors. Large, heavy, clumsy, attention-grabbing, and difficult to transport and operate air pollution sensors were unacceptable.

Wearable particulate matter sensor are generally reliable, but their validity decreases outdoors. Gaseous pollutant sensors vary in validity, with VOC sensors performing best. Personal air pollution sensors should be compact, quiet, and easy to use and carry. A research gap exists regarding wearable pollen sensor performance.