Environmental Engineering Reference
In-Depth Information
development.in.social.interaction.and.communication.skills,.including.difi-
culties.in.verbal.and.nonverbal.communication.and.leisure.or.play.activities.
(Bernard.2001,.Autism.Society.of.America.2003).
Children's. exposure. to. heavy. metals. in. immunizations. has. been. a. long-
term. concern. of. autism. advocates.. All. the. heavy. metals. mentioned. earlier.
are. highly. toxic. to. brain. cells. and. other. body. systems. affected. by. autism..
Several.classic.features.of.autism,.such.as.speech.loss.and.loss.of.social.and.
communication.skills,.are.signature.traits.of.heavy.metal.poisoning.(Bernard.
2001)..Minamata.disease,.a.form.of.acute.mercury.poisoning.in.the.inhabit-
ants.of.a.ishing.village.located.at.Minamata.Bay.(Japan),.was.a.result.of.the.
exposure. of. fetus. to. mercury-contaminated. ish. consumed. by. the. mother..
Children. with. Minamata. disease. had. symptoms. indistinguishable. from.
mental.retardation.or.cerebral.palsy.(Kondo.2000)..In.addition,.acrodynia,.a.
disease.caused.by.mercury.in.infant.teething.powder,.was.reported.in.the.
early. 1900s.. Children. with. acrodynia. suffered. peeling. and. reddened. skin.
on.their.hands.and.feet.and.heightened.sensitivity.to.light.(Warkany.1966,.
Autism.Society.of.America.2003).
Heavy Metals in Hair, Urine, and Blood
A. hair. sample. can. provide. an. accurate. and. powerful. means. of. evaluating.
the.effects.of.cumulative,.long-term.exposure.to.toxins..As.the.hair.follicle.
grows,.toxic.elements.in.the.blood.are.absorbed.into.the.growing.hair.pro-
tein..Due.to.the.fact.that.scalp.hair.grows.at.an.average.of.1-2.cm.in.a.month,.
hair.elements.analysis.can.provide.a.temporal.record.of.element.metabolism.
that. has. occurred. during. the. previous. 1-10. months. (Bencko. 1995,. DTHM.
2004,.McDowell.et.al..2004).
Analyses. of. urine. samples. carried. out. to. detect. the. presence. of. heavy.
metal.content.are.believed.to.reveal.heavy.metal.exposure.over.the.previous.
2-3.months..It.is.believed.that.heavy.metal.excretion.after.a.dose.of.chelat-
ing.agent.tends.to.relect.the.body.burden.better.than.basal.excretion..In.the.
present. study. meso-2,. 3-dimercapto-succinicacid. (DMSA,. metal. chelating.
agent).was.used.to.remove.heavy.metals.(Baselt.and.Cravey.1989).
In.general,.whole.blood.element.analysis.is.used.as.a.diagnostic.method.
that.could.determine.imbalance,.insuficiency,.or.excess.of.certain.elements.
associated.with.essential.functions..Whole.blood.element.analyses.are.use-
ful.for.testing.elevated.or.excessive.levels.of.potentially.toxic.elements.such.
as. cadmium,. lead,. mercury,.nickel,. and. uranium. but. are. not.reliable. as. an.
indicator.of.total.body.burden.in.long-term.exposures.(Klaassen.1996).
Aims and Objectives of Present Research
Since. toxic. heavy. metals. can. enter. into. different. ecological. compartments.
of.our.environment.and.persist.for.a.long.period,.they.could.be.transferred.
into.food.chains,.biomagniied.in.species.of.higher.trophic.levels.and.inally.
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