PM-bound polycyclic aromatic compounds (PACs) in two large-scale petrochemical bases in South China: Spatial variations, sources, and risk assessment

Abstract

Polycyclic aromatic compounds (PACs) are potential pollutants emitted from the petrochemical industry, whereas their occurrence and sources in petrochemical regions are still poorly known. The present study revealed the spatial variations, compositional pro les, sources and contributions, and health risks of PMbound PACs in two large-scale petrochemical bases (GDPB and HNBP) in South China. The concentrations of parent polycyclic aromatic hydrocarbons (PAHs) were 7.14 ± 3.16 ng/m 3 for ∑ 18 PAHs and 0.608 ± 0.294 ng/m 3 for the PAHs with molecular weight of 302 amu (MW302 PAHs) in the GDPB base and 2.55 ± 1.26 ng/m 3 and 0.189 ± 0.088 ng/m 3 in the HNPB base. Oxygenated PAHs (OPAHs) showed comparable concentrations to the parent PAHs in both the bases and nitrated PAHs (NPAHs) had the lowest mean levels (260 pg/m 3 and 59.4 pg/m 3 in the two regions). Coronene, 2,8dinitrodibenzothiophene, and dibenzo[a,e] uoranthene showed remarkably higher contributions to the PAC and can be PAC markers of the petrochemical industry source. Five sources of PACs were identi ed respectively in both petrochemical bases by the positive matrix factorization (PMF) model. The vehicle (and ship) tra c exhaust was the primary source of PACs (contributed 33% to the ∑PACs), and the sources related to the coking of coal and heavy petroleum and re nery exhaust were identi ed in both bases, with contributions of 10−20%. PACs in GDPB also contributed from secondary atmospheric reactions (17.3%) and the usage of sulfur-containing fuels (20.9%), while the aromatics industry made a signi cant contribution (20.1%) to the PACs in the HNPB region. The cumulative incremental lifetime cancer risks (ILCRs) induced by inhalation of PM-bound PACs in both petrochemical bases were low (10 − 8 -10 − 6 ). For the sources related to the petrochemical industry, coking activities and the aromatic industry were the signi cant contributors to the ∑ILCRs in GDPB and HNPB, respectively.