Benzene series compounds pollution inside Passenger cars in Tangshan.

Objective To understand the situation of benzene series compounds pollution inside some Passenger cars in Tangshan and provide data for the formulation of corresponding countermeasures for the prevention and control of the pollution. Methods One hundred and twenty-two cars used for different periods of time were selected from March, 2009 to May, 2009 and the concentrations of benzene,toluene and xylene were determined.At the same time the basic situation (car type, date of manufacture) was investigated with questionnaire. Results The disqualified rate of benzene, toluene, xylene were 14.8%(18/122), 26.2%(32/122) and 20.5%(25/122) respectively. Eighty-one cars did not meet the standard, accounting for 66.4 %(81/122). The median of benzene, toluene, xylene in the cars used within six months were 0.086, 0.900, 0.400 mg/m3 respectively. The exceeded rate of benzene, toluene, xylene inside the cars which were used for not more than six months were 28.6%(10/35), 57.1%(20/35), 60.0%(21/35) respectively. The concentrations of benzene series compounds decreased gradually later on. The concentrations of benzene inside the cars with adsorbent were lower, the concentrations of toluene inside the highgrade cars were higher and the concentrations of xylene inside the cars with leather seats was higher. Conclusion Benzene, toluene, xylene pollution inside cars has been showed in this investigation in Tangshan. The concentrations of benzene series compounds are associated with using time, adsorbent, car grade and the seat material.