Exposure to vehicular pollution and assessment of respiratory function in urban inhabitants.

Particulate matter less than PM(10) and aromatic chemicals formed during incomplete combustion of organic matter are major environmental pollutants because of their toxic potential. The present study reports on the respiratory morbidity pattern of people exposed to auto exhaust as a result of the traffic load consisting of three varieties of vehicles (heavy, medium, and light) at three different points: North (B), South (E), and Central (C) regions of Kolkata, India. Particle size distribution was analyzed by an Anderson cascade impactor and volatile organic compounds (VOCs) were analyzed by sorbent tube and capillary gas chromatography with flame ionization detector. Levels of VOCs, particularly benzene and toluene (at B, 15.2 and 20.1 microg/m(3); at E, 67.4 and 74.6 microg/m(3), and at C, 40.7 and 61.3 microg/m(3), respectively), were found to be appreciably high in three sites in Kolkata compared with the values reported by the U.S. EPA. PM(10) concentrations also have been found to be higher than the Central Pollution Control Board of India's permissible standard (</=10 microm: B, 535.9; E, 909.2; C, 1114.5 microg/m(3); <10-3.3 microm: B, 269.8 microg/m(3); E, 460.1; C, 679.2 microg/m(3); and <3.3-0.4 microm: B, 266.1; E, 449.1; C, 435.3 microg/m(3)). Pulmonary function tests (PFT) of 505 inhabitants were performed in the three different areas using Spirovit SP-10 and Wrights peak flowmeter. The traffic load in the vicinity supported the occurrence of higher respiratory functional deterioration. PFT status showed restrictive (3.76%), obstructive (3.17%), and combined restrictive and obstructive types (1.98%) of impairment. Higher restrictive impairments in males might be due to their combined occupational and environmental exposures. The rate of increase of the number of vehicles on the roads of the city adds to the risk of greater problems due to exposure to hazardous substances that are less than PM(10), in particular, polycyclic aromatic hydrocarbons and VOCs.