Polybrominated Diphenyl Ethers in China: Sources, Trends, and Their Adverse Impacts on Human Health - Environmental Contamination: Health Risks and Ecological Restoration - page 134

potent.thyroid.hormone.mimetics..A.hypothesis.that.PBDEs.may.also.serve.
as.risk.factors.for.autism.emerges,.when.these.data.are.considered.in.com-
bination.with.the.extensive.literature.on.stage-dependent.effects.of.thyroid.
hormone.on.aspects.of.brain.development,.an.implication.speciically.related.
to.autistic.brains.(Messer.2010).
Based.on.animal.models,.it.has.been.revealed.that.the.large-scale.commer-
cial.Deca-BDE.mixture.used.in.China.is.less.toxic.than.lower-brominated.
PBDEs..However,.Deca-BDE.decomposes.to.lower.BDE.congeners,.and.rats.
and. mice. fed. with. food. contaminated. by. the. PBDE. mixture. have. been.
shown.to.develop.thyroid.problems..It.is.speculated.that.many.of.the.thy-
roid.effects.of.PBDEs.are.speciic.to.the.species.of.test.animals.(Chen.et.al..
2006b)..Subtle.behavioral.changes.have.been.observed.in.animals.exposed.
to. PBDEs. as. infants.. One. possible. explanation. for. the. behavioral. effects.
may.be.related. to. changes.in.the.thyroid.because.the.development.of.the.
nervous. system. is. dependent. on. thyroid. hormones.. Results. from. animal.
testing.also.showed.that.PBDEs.may.impair.the.immune.system..In.addi-
tion,.it.has.been.observed.that.rats.and.mice.that.were.exposed.to.PBDEs.
developed.liver.tumors..Although.it.has.not.been.proved.whether.PBDEs.
will. cause. cancer. in.humans,. the. fact.that.cancer.patients. have.high. con-
centrations.of.ΣPBDEs,.BDE-47,.and.BDE-209.should.not.be.overlooked.(Qin.
et.al..2009).
BDE-209.possesses.the.toxic.activity.of.antiproliferation.and.induction.of.
apoptosis.in.tumor. cells. in vitro .. BDE-47.causes. a. concentration-dependent.
decrease.in.cell.proliferation.and.is.cytotoxic.and.genotoxic.to.SH-SY5Y.cells.
in vitro ,. which. results. in. the. loss. of. neuronal. characteristics. and. adversely.
affects. learning. ability. (He. et. al.. 2007,. Zhang. et. al.. 2007).. The. toxicologi-
cal. end. points. of. concern. for. environmental. levels. of. ΣPBDEs. are. likely. to.
be. thyroid. hormone. disruption,. neurodevelopmental. deicits,. and. cancer.
(McDonald.2002).
According.to.Table.7.9,.it.could.not.be.conirmed.whether.cancer.patients.
who. had. the. disease. had. high. concentrations. of. several. BDE. congeners,.
such.as.BDE-47,.99,.100,.153,.154,.BDE-209,.and.total.PBDEs,.based.on.the.
data.collected.from.the.e-waste.sites.in.Zhejiang.Province..However,.the.
patients. contained. a. rather. high. concentration. of. PBDEs. in. their. body.
(kidney,. liver,. and. lung),. with. BDE. 47,. BDE-209,. and. ΣPBDEs. reaching.
38.7-53.6,. 172-192,. and. 118-270.ng/g. lipid,. respectively,. when. compared.
with. healthy. people.. In. some. human. samples,. BDE-209. concentrations.
were. up. to. 38,888-72,964.ng/g. lipid. in. cancer. patients. living. around. the.
e-waste.site.in.Zhejiang.Province.(Zhao.et.al..2009)..Our.recent.study.con-
ducted.in.Hong.Kong.showed.that.BDE-47.and.ΣPBDEs.reached.2.65-3.50.
and.10.8-13.8.ng/g.lipid,.respectively,.from.the.subcutaneous.fat.and.vis-
ceral. fat. of. patients. with. uterine. leiomyomas,. which. were. two. to. three.
times. higher. than. the. levels. found. in. healthy. people. (Qin. et. al.. 2009)..
Chao. et. al.. indicated. that. pregnant. women. exposed. to. rather. low. PBDE.