Background: Personal air pollution exposure (PAPE) is the product of pollutant concentration and minute ventilation V'_m. Standard exposure techniques do not address the space-time variability of air pollution, both indoor and outdoor, and the intra and inter subject variability in V'_m.

Aims and objectives: This study has the aim of validating a new wearable system for PAPE evaluation. It consists of a body sensor network collecting both physiological (heart and respiratory rate) and environmental parameters, as the concentration of pollutants (PM1, PM2.5, PM10, CO_x, tVOC, NO₂).

Methods: 20 healthy subjects were enrolled in a 4.5 km walk in Milan. Environmental parameters were collected continuously while physiological parameters were collected in static conditions in 7 specific acquisition points. The PAPE was calculated using pollutant concentration sampled by the developed system. Measured physiological parameters were used with a V'_m model (Greenwald, R. et al. PloS one 2019;14:7), employing the Global Lung Function Initiative method for FVC estimation.

Results: Statistically significant differences in pollutant concentration were found between morning and afternoon but also between acquisition points in the same test session. Respiratory rates were significantly different between subjects but also among different acquisition points for the same subject. PAPE to PM2.5 is underestimated with the standard method for most subjects, on average by 6.77% (maximum 21%).

Conclusions: This system is proven to be accurate and with an high space-time resolution. Hence, it is suitable for epidemiological studies, giving a powerful tool to assess the actual inhaled dose of pollutants.