es5044547_si_001.pdf (837.63 kB)
Particle Size Distribution of Halogenated Flame Retardants and Implications for Atmospheric Deposition and Transport
journal contribution
posted on 2014-12-16, 00:00 authored by Krzysztof Okonski, Céline Degrendele, Lisa Melymuk, Linda Landlová, Petr Kukučka, Šimon Vojta, Jiří Kohoutek, Pavel Čupr, Jana KlánováThis
study investigates the distribution of polybrominated diphenyl
ethers (PBDEs), hexabromocyclododecane (HBCD) and a group of novel
flame retardants (NFRs) on atmospheric aerosols. Two high volume cascade
impactors were used to collect particulate fractions of ambient air
over a one year period at urban and rural sites. The majority of FRs
were found on the finest aerosols (<0.95 μm). Concentrations
of HBCD were higher than those of ΣPBDEs. Moreover, we noted
seasonality and spatial differences in particle size distributions,
yet a large portion of the observed differences were due to differences
in particulate matter (PM) itself. When normalized by PM, the size
distributions of the FRs exhibited much greater heterogeneity. Differences
existed between the FR distributions by molecular weight, with the
higher molecular weight FRs (e.g., BDE-209, Dechlorane Plus) distributed
more uniformly across all particulate size fractions. The seasonal,
spatial, and compound-specific differences are of crucial importance
when estimating dry and wet deposition of FRs as smaller aerosols
have longer atmospheric residence times. Estimated wet and dry deposition
of four representative FRs (BDE-47, BDE-209, HBCD, and Dechlorane
Plus) using size-segregated aerosol data resulted in lower deposition
estimates than when bulk aerosol data were used. This has implications
for estimates of long-range atmospheric transport and atmospheric
residence times, as it suggests that without size-specific distributions,
these parameters could be underestimated for FRs.