Calculated respiratory exposure to indoor size-fractioned polycyclic aromatic hydrocarbons in an urban environment.
Polycyclic aromatic hydrocarbons (PAHs) associated with inhalable particles are harmful to human health, especially to people in urban indoor environments. To evaluate human respiratory exposure to indoor PAHs properly, respiratory deposition fluxes of size-fractioned PAHs were estimated based on size-segregated distribution of PAHs in indoor air of an urban community of Guangzhou, China. The concentrations of ∑(16)PAH (sum of the 16 priority PAHs designated by the United States Environmental Protection Agency) were 28.9±10.0 ng/m(3), with the mean benzo(a)pyrene equivalent (BaPE) concentration at 4.1±1.6 ng/m(3). Particle size distributions of both ∑(16)PAH and BaPE concentrations peaked in the 1.0-1.8 μm fraction. The mean respiratory deposition flux of ∑(16)PAH was 5.9 ng/h, and accumulation mode particles contributed 20.5-83.8% of the respiratory deposition fluxes for individual PAHs. In addition, 8.6-10.2% of inhaled ∑(16)PAH were calculated to be deposited in the alveoli region, with accumulation particles as the largest contributor. In particular, ultrafine particles contributed 0.4-21.7% of individual PAHs deposited in the alveoli region, more than twice the fraction of the PAHs in the ultrafine particles (0.2-8.5%). Finally, lifetime cancer risk via inhalation of indoor particulate PAHs may be greater than the cancer risk guideline value (10(-6)), depending on specific assumptions used in this risk assessment.
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Kai
K
Zhang
Bao-Zhong
BZ
Zhang
Shao-Meng
SM
Li
Charles S
CS
Wong
Eddy Y
EY
Zeng
D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity; D016902:Air Pollution, Indoor; D001564:Benzo(a)pyrene / Q000032:analysis; D002681:China; D004781:Environmental Exposure; D006801:Humans; D009369:Neoplasms / Q000209:etiology; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000633:toxicity*; D012137:Respiratory System / Q000187:drug effects; D018570:Risk Assessment; D014505:Urban Population
D000393:Air Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D001564:Benzo(a)pyrene