Characterizations, Relationship and Potential Sources of outdoor and indoor particulate matter bound Polycyclic Aromatic Hydrocarbons (PAHs) in a community of Tianjin, Northern China

摘要

Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. Besides direct personal exposure measurement, residential indoor and outdoor samplings were considered as another pathway to estimate the personal exposure levels. However, due to unsubstantial data on the measurement and relationship analysis of residential indoor and outdoor particulate PAHs, efforts in assessing inhalation exposure of susceptible population to PAHs and its potential risks to lung cancer have been limited. This study measured 12 PAHs individuals simultaneously in residential indoor and outdoor environment at 36 homes in the same community during the non-heating period (August - September) and heating period (November- December) in 2009. Indoor and outdoor PAHs concentrations, profiles and I/O ratio in the two sampling periods were discussed. Indoor PAHs were comparable with outdoor concentrations in non-heating period, but lower in heating period. The average I/O ratio in both sampling periods were lower than 1, while the ratio in non-heating period were higher than those in heating period. Correlation analysis and coefficient of divergence were also applied to verify the difference between indoor and outdoor PAHs concentrations. All these results obtained were consistent, which could be interpreted as the better ventilation in non-heating period. To further support the influence of ventilation, linear regression and robust regression were also used to estimate the infiltration factor outdoor PAHs to indoor PAHs. The calculated infiltration factors obtained by the two models were similar in non-heating period, but vary greatly in heating period, which can be explained as the influence of ventilation. Potential sources were distinguished by using diagnostic ratio and principal component analysis, finding similar sources were influencing both indoor and outdoor particulate PAHs, such as coal combustion, vehicle exhaust and some industrial emissions.