Distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans in various sizes of airborne particles.
We investigated the particle size distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in atmospheric samples collected at four sites. The largest amounts of particle-bound PCDD/F were found on small particles with aerodynamic diameters (dae) of less than 1.1 microns that accounted for over 50% of the total PCDD/F, contributing mostly to the toxicity and providing over 47% of the total TEQs (Toxicity Equivalents) loading. PCDF showed about twice the concentration of the PCDD in the total TEQs. The total PCDD/F concentration for accumulation mode particles (dae < 1.1 microns) ranged from 8.2 to 16 pg/m3 and that on coarse particles (dae > 1.1 microns) from 3.5 to 8.6 pg/m3. Five to eight percent of the total PCDD/F was found on large particles of dae > 7 microns. It was observed that the PCDD/F homologue profiles on large particles were different from the small particles and the fraction of less chlorinated PCDD/F in the homologue groups increased with increasing particle size. The reentrainment of soil particles including PCDD/F did not significantly influence the PCDD/F on the large particles. Two plausible mechanisms, the mass transfer of the gas phase PCDD/F on the particle surface and the contribution of the large size fly ash emitted from incinerators are proposed to explain the observed PCDD/F homologues partitioning among particle size fractions.
Kurokawa
Y
Y
Department of Environmental Sciences, Fukuoka Institute of Health and Environmental Sciences, Japan.
Takahiko
M
M
Matayoshi
N
N
Satoshi
T
T
Kazumi
F
F
D000397:Air Pollution / Q000032:analysis*; D001572:Benzofurans / Q000032:analysis*; D004784:Environmental Monitoring; D017745:Incineration; D010316:Particle Size; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D012037:Refuse Disposal
D001572:Benzofurans; D000072317:Polychlorinated Dibenzodioxins