It is well known that transit micro-environments (MEs) can contribute to a high exposure and to a high relative inhaled dose to atmospheric pollutants, despite the time spent in these kinds of MEs are relatively small [1]. Scientific literature [2,3] show that in recent years, several studies have been carried out with the aim of evaluating the commuter exposure, considering the MEs frequented by subject. However, it should be emphasized that most studies regard the evaluation of exposure to pollutants and not the estimated dose inhaled by subjects. The aim of this work is therefore to assess the exposure to different atmospheric pollutants and to estimate the relative inhaled dose, associating concentration data to personal physiological measurements.

The measurement of personal exposure was performed continuously, along a predetermined route, which included different commuting MEs. The chosen route intends to represent the path of a typical commuter. Personal exposure to air pollutants was performed via portable direct reading instruments for the evaluation of NO₂ and PM fractionated concentration. The acquisition of various physiological parameters (such as the heart-beat) was carried out by a heart rate monitor, which can also provide GPS position. All instruments have been set with an acquisition rate of 1 minute.

The combined use of different monitoring instruments has allowed us to continuously characterize the concentrations of pollutants investigated according to the most appropriate measurement metrics. The exposure data were associated with the subject's residence time in a given ME and to the pulmonary ventilation value (calculated from the subject's heart rate, acquired during the whole monitoring period), in order to obtain an estimate of the dose of the various pollutants inhaled by the subject. The results were analyzed according to the different MEs and means of transport, in order to identify the factors that most influence the inhaled dose.

References

[1] Dons, E., Laeremans, M., Orjuela, J. P., Avila-Palencia, I., Carrasco-Turigas, G., Cole-Hunter, T., Anaya-Boig, E., Standaert, A., De Boever, P., Nawrot, T., Götschi, T., de Nazelle, A., Nieuwenhuijsen, M., Int Panis, L., 2017. Wearable Sensors for Personal Monitoring and Estimation of Inhaled Traffic-Related Air Pollution: Evaluation of Methods. Environ. Sci. Technol., 51 (3), 1859–1867.

[2] de Nazelle, A., Bode, O., Orjuela, J. P., 2017. Comparison of air pollution exposures in active vs. passive travel modes in European cities: A quantitative review. Environ. Int., 99, 151–160.

[3] Karanasiou, A., Viana, M., Querol, X., Moreno, T., de Leeuw, F., 2014. Assessment of personal exposure to particulate air pollution during commuting in European cities-Recommendations and policy implications. Sci. Total Environ., 490, 785–797.