Particle deposition modeling and atmospheric aerosol quantification: a case study in Fortaleza (Ceará) - Brazil

Abstract

Fortaleza is currently a large metropolis located in northeastern Brazil, the city goes through a constant demographic growth and significant increase of the local vehicular fleet. Currently, public policies for urban mobility in the city are being developed, such as encouraging the use of bicycles in cycle lanes, however these cycle-lanes are located in major high traffic routes in the city. In view of the above, the present study aims to simulate the deposition of atmospheric particles in users of cycle lanes (cyclists), in the vicinity of a large vehicular traffic road in. Fortaleza.The concentrations of particles (0.3 μm, 0.5 μm, 1.0 μm, 2.5 μm, 5.0 μm and 10 μm) were measured with a portable particle sizer (DT 9881 CEM) and the concentration distributions for the sized particles were measured in the Dosimetry of Multiple Path Particles (MPPD).The measured particles had higher concentrations at peak times (6:00a.m. - 9:00 a.m.) and (5:00 a.m. 7:00 p.m.), from 5:00 p.m. to 7:00 p.m. in average values 29% ± 8.3% higher, with the days of Saturday registering the lowest concentrations. In cyclists, particle deposition was more significant, with particles of 0.3 μm and 0.5 μm depositing more representatively in the tracheobronchial (TB) and pulmonary (PUL) regions. Particles of diameter 1.0 μm, 2.5 μm, 5.0 μm and 10 μm were most representative deposited in the extrathoracic (ET) and TB regions. Our results suggest that the use of cycle lanes, in the vicinity of traffic routes, may exacerbate the deposition of particles in the respiratory system, possibly leading to health risks.