3 research outputs found
Bioaccumulation of Persistent Halogenated Organic Pollutants in Insects: Common Alterations to the Pollutant Pattern for Different Insects during Metamorphosis
Few
studies have examined the accumulation and fate of persistent
halogenated organic pollutants (HOPs) in insects. We measured HOPs,
including dichlorodiphenyltrichloroethanes (DDTs), polychlorinated
biphenyls, and halogenated flame retardants, in insects from four
taxonomic groups collected from an e-waste site. Dragonfly larvae
collected from a pond contained the highest concentrations of all
chemicals except DDTs, while the litchi stinkbugs contained the lowest.
Different insect taxa exhibited different contaminant patterns which
could be attributed to their habitats and feeding strategies. Bioaccumulation
factors for dragonfly larvae and biomagnification factors for moth
and grasshopper larvae were significantly positively correlated with
the octanol–water partition coefficient of the chemicals (log <i>K</i><sub>OW</sub> < 8). Common nonlinear correlations between
the ratio of larval to adult concentrations and log <i>K</i><sub>OW</sub> were observed for all taxa studied. The ratio of concentrations
decreased with increasing values of log <i>K</i><sub>OW</sub> (log <i>K</i><sub>OW</sub> < 6–6.5), then increased
(6 < log <i>K</i><sub>OW</sub> < 8) and decreased
again (log <i>K</i><sub>OW</sub> > 8). This result implies
that the mechanism that regulates organic pollutants in insects during
metamorphosis is common to all the taxa studied
Using Compound-Specific Stable Carbon Isotope Analysis to Trace Metabolism and Trophic Transfer of PCBs and PBDEs in Fish from an e‑Waste Site, South China
Two fish species (mud carp and northern
snakehead) forming a predator/prey
relationship and sediment samples were collected from a pond contaminated
by e-waste. The concentrations and stable carbon isotope ratios (δ<sup>13</sup>C) of individual polychlorinated biphenyl (PCB) and polybrominated
diphenyl ether (PBDE) congeners were measured to determine if compound-specific
carbon isotope analysis (CSIA) could be used to provide insight into
the metabolism and trophic dynamics of PCBs and PBDEs. Significant
correlations were found in the isotopic data of PCB congeners between
the sediment and the fish species and between the two fish indicating
identical origin of PCBs in sediment and fish. Most PCB congeners
in the fish species were enriched in <sup>13</sup>C compared with
the PCB congeners in the sediments as a result of isotopic fractionation
during the metabolism of PCBs in fish. The isotopic data of several
PCB congeners showing isotopic agreement or isotopic depletion could
be used for source apportionment or to trace the reductive dechlorination
process of PCBs in the environment. The PCB isotopic data covaried
more in the northern snakehead than in the mud carp when compared
to the sediment, implying that a similar isotopic fractionation occurs
from the prey to the predator fish for a PCB congener possibly due
to similar metabolic pathways. The PBDE congener patterns differed
in the three sample types with a high abundance of BDE209, 183, 99,
and 47 in the sediment, BDE47, 153, and 49 in the mud carp and BDE47,
100, and 154 in the northern snakehead. The isotopic change of BDE
congeners, such as BDE47 and BDE49, in two fish species, provides
evidence for biotransformation of PBDEs in biota. The results of this
study suggest that CSIA is a promising tool for deciphering the fate
of PCBs and PBDEs in the environment
Polychlorinated Biphenyls (PCBs) in Human Hair and Serum from E‑Waste Recycling Workers in Southern China: Concentrations, Chiral Signatures, Correlations, and Source Identification
Hair
is increasingly used as a biomarker for human exposure to
persistent organic pollutants (POPs). However, the internal and external
sources of hair POPs remain a controversial issue. This study analyzed
polychlorinated biphenyls (PCBs) in human hair and serum from electronic
waste recycling workers. The median concentrations were 894 ng/g and
2868 ng/g lipid in hair and serum, respectively. The PCB concentrations
in male and female serum were similar, while concentrations in male
hair were significantly lower than in female hair. Significant correlations
between the hair and serum PCB levels and congener profiles suggest
that air is the predominant PCB source in hair and that hair and blood
PCB levels are largely dependent on recent accumulation. The PCB95,
132, and 183 chiral signatures in serum were significantly nonracemic,
with mean enantiomer fractions (EFs) of 0.440–0.693. Nevertheless,
the hair EFs were essentially racemic (mean EFs = 0.495–0.503).
Source apportionment using the Chemical Mass Balance model also indicated
primary external PCB sources in human hair from the study area. Air,
blood, and indoor dust are responsible for, on average, 64.2%, 27.2%,
and 8.79% of the hair PCBs, respectively. This study evidenced that
hair is a reliable matrix for monitoring human POP exposure