Curve Analysis of Airborne BTEX Concentration in Vehicles

Abstract

Benzene, toluene, ethylbenzene and xylenes (BTEX) lead to cabin air pollution, which is harmful to passengers and drivers. In order to decrease the harm, the BTEX attenuation with time is analyzed by monitoring the BTEX concentrations in 38 vehicles with Air Sampler and Gas Chromatograph and by the curve estimation regression with the SPSS statistical software. Results show that the optimum attenuation curve between the BTEX pollution (y) and time (x) is a cubic equation with one variable, in which \(y_{\text{benzene}} = {-}0.004x^{3} + 0.228x^{2} {-}5.787x + 130.803\), \(y_{\text{toluene}} = {-}0.007x^{3} + 0.451x^{2} {-}12.510x + 326.425\), \(y_{\text{ethyl benzene}} = {-}0.003x^{3} + 0.212x^{2} {-}5.345x + 118.780\) and \(y_{\text{xylenes}} = {-}0.008x^{3} + 0.505x^{2} {-}12.777x + 289.001\). When the BTEX pollution is zero, the attenuation time is 3.4–4.2 years. The BTEX diffusion from in-vehicle materials can last for several years so that the BTEX attenuation and control is a long-term process.