4 research outputs found
Polybrominated Diphenyl Ether (PBDE) Accumulation by Earthworms (<i>Eisenia fetida</i>) Exposed to Biosolids‑, Polyurethane Foam Microparticle‑, and Penta-BDE-Amended Soils
Polybrominated diphenyl ether (PBDE)
flame retardants have been
used in consumer polymers at up to percent levels. While long viewed
as biologically inaccessible therein, PBDEs may become bioaccessible
following volatilization or polymer deterioration. PBDEs may then
enter soils via polymer fragmentation or following land application
of sewage sludge-derived biosolids. Studies of direct PBDE uptake
from these materials by soil organisms are scarce. We thus exposed
earthworms (Eisenia fetida) to artificial
soil amended with a Class B anaerobically digested biosolid (ADB),
an exceptional quality composted biosolid (CB), PBDE-containing polyurethane
foam (PUF) microparticles, and Penta-BDE-spiked artificial soil (SAS).
Worms accumulated mg/kg (lipid) ∑Penta-PBDE burdens from all
substrates. Biota-soil accumulation factors (BSAFs) for worms exposed
to ADB- and CB-amended soils were comparable after 28 d. BSAFs generally
decreased with increasing congener <i>K</i><sub>OW</sub> and substrate dosage. Biosolids-associated PBDE bioavailability
was lower than spiked PBDEs. BSAFs for worms exposed to PUF microparticles
ranged from 3.9 to 33.4, with ∑Penta-PBDE tissue burdens reaching
3740 mg/kg lipid. Congener accumulation patterns were similar in worms
and polyethylene passive sampling devices immersed in ADB-amended
soil coincident with exposed worms. However, passive sampler accumulation
factors were lower than BSAFs. Our results demonstrate that PBDEs
may accumulate in organisms ingesting soils containing biosolids or
waste plastics. Such organisms may then transfer their burdens to
predators or translocate them from the site of application/disposal
Brominated Flame-Retardants in Sub-Saharan Africa: Burdens in Inland and Coastal Sediments in the eThekwini Metropolitan Municipality, South Africa
Brominated
flame-retardant (BFR) additives are present in many
polymeric consumer products at percent levels. High environmental
concentrations have been observed near cities and polymer, textile,
and electronics manufacturing centers. Most studies have focused on
European, North American, and Asian locales. Releases are likely rising
most dramatically in countries with weak environmental and human health
regulation and enforcement, demand for electrical and electronic equipment
(EEE) is escalating, and importation of waste EEE occurs. Several
African countries meet these criteria, but little data are available
on burdens or sources. To better understand the extent of BFR environmental
dissemination in a southern African urban community, inland and coastal
sediments were collected in the eThekwini metropolitan municipality,
South Africa, and analyzed for polybrominated diphenyl ethers (PBDEs),
hexabromocyclododecane (HBCD), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate
(TBB), 2-ethylhexyl 2,3,4,5-tretabromophalate (TBPH), 1,2-bis (2,4,6-tribromophenoxy)
ethane (BTBPE), and decabromodiphenyl ethane (DBDPE). BFRs were detected
in all samples (<i>n</i> = 45). Concentration data are presented
on total organic carbon (TOC) normalized basis. ΣBFR ranged
from 114 to 47 100 ng g<sup>–1</sup>. Decabromodiphenyl
ether was detected in 93% of samples (mean concentration 3208 ng g<sup>–1</sup>) followed by TBB at 91% (mean conc. 545 ng g<sup>–1</sup>). Durban Bay is strongly influenced by urban runoff
and tidal hydrology, and sediments therein exhibited ΣPBDE concentrations
ranging from 1850 to 25 400 ng g<sup>–1</sup> (median
conc. 3240 ng g<sup>–1</sup>). These levels rival those in
the heavily impacted Pearl River Delta, China. BFRs likely enter the
South African environment during manufacture of BFR-containing products,
during and following product use (i.e., after disposal and as a result
of materials recycling activities), and from nonpoint sources such
as atmospheric fallout and urban runoff. These results underline the
need to investigate further the environmental burdens and risks associated
with BFRs in developing countries
In Situ Accumulation of HBCD, PBDEs, and Several Alternative Flame-Retardants in the Bivalve (<i>Corbicula fluminea)</i> and Gastropod <i>(Elimia proxima</i>)
Alternative brominated flame-retardants (BFRs), 2-ethylhexyl
2,3,4,5-tetrabromobenzoate
(TBB), 2-ethylhexyl 2,3,4,5-tetrabromophthalate (TBPH), 1,2-<i>bis</i>(2,4,6-tribromophenoxy) ethane (BTBPE) and decabromodiphenyl
ethane (DBDPE), are now being detected in the environment. However,
contaminant bioavailability is influenced by the organisms’
ecology (i.e., route of uptake) and in situ environmental factors.
We observed that the filter-feeding bivalve (<i>Corbicula fluminea)</i> and grazing gastropod (<i>Elimia proxima</i>), collected
downstream from a textile manufacturing outfall, exhibited TBB, TBPH,
and BTBPE concentrations from 152 to 2230 ng g<sup>–1</sup> lipid weight (lw). These species also contained additional BFRs.
Maximum levels of total hexabromocyclododecane diastereomers (∑HBCDs)
in these species were 363 000 and 151 000 ng g<sup>–1</sup> lw, and those of polybrominated diphenyl ethers (∑PBDEs)
were 64 900 and 47 200 ng g<sup>–1</sup> lw,
respectively. These concentrations are among the highest reported
to date worldwide. While BDE-209 was once thought to be nonbioavailable
and resistant to degradation, it was the dominant BFR present and
likely debromination products were detected. Contributions of α-
and β-HBCD were higher in tissues than sediments, consistent
with γ-HBCD bioisomerization. Mollusk bioaccumulation factors
were similar between HBCD and PBDEs with 4 to 6 bromines, but factors
for TBB, TBPH, and BTBPE were lower. Despite different feeding strategies,
the bivalves and gastropods exhibited similar BFR water and sediment
accumulation factors
Addressing the Issue of Microplastics in the Wake of the Microbead-Free Waters ActA New Standard Can Facilitate Improved Policy
The United States Microbead-Free
Waters Act was signed into law
in December 2015. It is a bipartisan agreement that will eliminate
one preventable source of microplastic pollution in the United States.
Still, the bill is criticized for being too limited in scope, and
also for discouraging the development of biodegradable alternatives
that ultimately are needed to solve the bigger issue of plastics in
the environment. Due to a lack of an acknowledged, appropriate standard
for environmentally safe microplastics, the bill banned all plastic
microbeads in selected cosmetic products. Here, we review the history
of the legislation and how it relates to the issue of microplastic
pollution in general, and we suggest a framework for a standard (which
we call “Ecocyclable”) that includes relative requirements
related to toxicity, bioaccumulation, and degradation/assimilation
into the natural carbon cycle. We suggest that such a standard will
facilitate future regulation and legislation to reduce pollution while
also encouraging innovation of sustainable technologies