The traffic microenvironment accounts for a significant fraction of the total daily dose of inhaled air pollutants. The adverse effects of air pollution may be intensified in high altitudes (HA) due to increased minute ventilation (MV), which may result in higher deposition doses compared to that at sea level. Despite this, air quality studies in regions with combined high pollution levels and enhanced inhalation are limited. The main goals of this study are to investigate how the choice of travel mode (walking, microbus, and cable car ride) determines (i) the personal exposure to equivalent black carbon (eBC) and (ii) the corresponding potential respiratory deposited dose (RDD) in HA. For this investigation, we chose La Paz and El Alto in Bolivia as HA representative cities. The highest eBC exposure occurred in microbus commutes (13 μg m-3), while the highest RDD per trip was recorded while walking (6.3 μg) due to increased MV. On the other hand, the lowest eBC exposure and RDD were observed in cable car commute. Compared with similar studies done at sea level, our results revealed that a HA city should reduce exposure by 1.4 to 1.8-fold to achieve similar RDD at sea level, implying that HA cities require doubly aggressive and stringent road emission policies compared to those at sea level.
Bibliographical noteFunding Information:
Funding: The research leading to these results received funding from the European Union H2020 programme PAPILA (GA 777544).
The research leading to these results received funding from the European Union H2020 programme PAPILA (GA 777544). We greatly acknowledge the help from the scientific staff and the students of the Laboratory for Atmospheric Physics, IIF-UMSA, for joining us in the experiment. We would also like to thank the Institut de Reserche pour le Développment (IRD) for all the logistic support, and Paolo Laj and Gaelle Uzu for their help and scientific advice.
© 2020 by the authors.
- Air pollution
- Black carbon
- Personal exposure
- Respiratory tract deposition dose