ABSTRACT
In view of the insufficient source profiles for emissions from nonmetal mineral products manufacturing processes in China, a dilution sampling system was used to collect PM10 and PM2.5 samples from glassmaking, ceramics, and firebrick manufacturing sources between February and June of 2017. The characteristics of 50 chemical components in the samples were studied to identify source profiles. The results showed that the dominant composition of particulate matter in glassmaking plant profiles was Na, with percentages ranging from 9.2% to 18.5%. Ceramics profiles were enriched in Al, Si, Ca, and Fe, with percentages ranging from 1.7% to 8.7%. Refractory brick and shale manufacturing process profiles were characterized by high abundances of SO42- (36.9%-48.1%) and NH4+ (7.7%-17.0%). Chemical components in the source profiles varied with the different fuel types and desulfurization, denitrification, and dedusting methods. The coefficients of divergence (CD) between PM2.5 and PM10 from the same process were similar except for the results from the shale manufacturing process (CD values>0.3), thus indicating that the elements profiles of PM2.5 might be similar to those in PM10. Profiles of the same particle size from different processes were significantly different from one another, with CD values ranging from 0.42 to 0.76. The CD values for float glass and medicinal glass, and the CD values for the two ceramic enterprises were relatively small. The distributions of weighted differences (R/U ratios) were used to compare the differences of components between the source profiles, and results showed that the identified components for glass manufacturing, ceramic manufacturing, fireproof bricks, and page rock bricks were Na and As, Al and Ti, NO3- and NH4+, and SO42- and NH4+, respectively.
ABSTRACT
Inhalatory and dermal exposures of on-duty vehicle inspection workers to polycyclic aromatic hydrocarbons (PAHs) in Beijing were investigated from April 18 to May 17, 2011. Exposure levels to particulate PAHs for the vehicle inspection workers at gasoline, bus and diesel lines were found to be 56.07 ng m(-3), 111.72 ng m(-3) and 199.80 ng m(-3), respectively. A probabilistic risk assessment framework was integrated with the toxic equivalence factors (TEFs) and the incremental lifetime cancer risk (ILCR) approaches to quantitatively estimate the exposure risk for vehicle inspection workers of the three work lines. The median values of inhalation risk were estimated to be 3.7 × 10(-7), 5.0 × 10(-7) and 1.37 × 10(-6), respectively, while the median dermal ILCR values were 7.05 × 10(-6), 6.98 × 10(-6) and 1.28 × 10(-5), respectively for gasoline, bus, and diesel inspection workers. Total ILCR was higher than the acceptable risk level of 10(-6), indicating unacceptable potential cancer risk.
