Fwd: ED-COM: Hg and PCB synnergy

[ttweed@wildrockies.org (Tony Tweedale)]

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>Date: Thu, 21 Oct 1999 13:36:15 -0700
>To: endohealth@onenw.org
>From: Carol Dansereau <cdansereau@watoxics.org>
>Subject: Fwd: ED-COM: Mercury and PCBs
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>Reply-To: Carol Dansereau <cdansereau@watoxics.org>
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>=====  A message from the 'endohealth' discussion list  =====
>
>>To:  ed-com@igc.topica.com
>>From: Davis Baltz <dbaltz@igc.org>
>>Subject: ED-COM: Mercury and PCBs
>>Date: Wed, 20 Oct 1999 11:59:02 -0700
>>Reply-To: ed-com@igc.topica.com
>>MIME-Version:  1.0
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>>X-RCPT-TO: <cdansereau@watoxics.org>
>>Status: U
>>
>>-- forwarded from Ted Schettler --
>>
>>Tuesday, October 19, 1999
>>Subject: Mercury and PCBs
>>
>>An abstract of a publication soon to appear in EHP was recently circulated
>>reporting synergism between Hg and PCBs in an in vitro system using
>>dopamine production from sections of rodent brain as the endpoint being
>>monitored.  PCBs and mercury together synergistically diminished dopamine
>>production - that is, the effect was more pronounced than would be expected
>>from adding the effects observed when each chemical was used alone.   This
>>is the work of Richard Seegal in Albany NY.  Dr. Seegal presented this work
>>at a neurotoxicology conference in Little Rock AR on Oct. 18.
>>
>>Later the same day, Dr. Paul Stewart (SUNY Oswego) reported on their
>>attempts to replicate the work of the Jacobsons in Michigan, assessing the
>>long term effects of prenatal exposure to PCBs on neurological development
>>and function.  Stewart and colleagues have tracked the cognitive and
>>behavioral development of about 300 children in NY for more than 3 years.
>>Cord blood PCB levels have been predictive of neurobehavioral changes
>>immediately after birth (Brazelton Neonatal Assessment Scale) and of
>>performance on later testing including Fagan Test of Infant Intelligence at
>>1 year and McCarthy Scales of Children's Abilities - including the memory
>>subscales - at 3 years of age.
>>
>>Strikingly, the investigators have also found an interaction between
>>mercury and PCBs on the McCarthy Scales.  The marker for mercury exposure
>>in utero was maternal hair levels.  ALL mothers had hair levels of mercury
>>less than 2.7 ppm - investigators stratified the mother-infant pairs into
>>three groups - maternal hair levels 0-0.39, 0.4-0.59, and 0.6-2.7 ppm.
>>Neurological effects in the offspring showed an interactive effect
>>(synergism) between prenatal PCB and mercury exposure, even at these very
>>low levels of mercury.  (For comparison purposes, maternal hair levels of
>>mercury in the Seychelles study ranged from about 2 or 3 to 27 ppm and no
>>effects on neurological development were identified.  It is notable that
>>PCB levels in the Seychelles study were non-detectable.)
>>
>>The Oswego study not only confirms the Jacobson work up until this age of
>>the study subjects, but shows a striking interaction of PCB and low level
>>mercury exposure.  It is also an in vivo example of what Seegal reports in
>>vitro.  The results of testing in these children in later years will be of
>>great interest.  Implications for risk assessment and public health are
>>substantial.
>>
>>Ted Schettler
>>
>>
>>
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>>
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>Carol Dansereau, J.D.                           Phone: 206-632-1545
>Extension 13
>Organizational Director,                        Fax: 206-632-8661
>Washington Toxics Coalition, 4649 Sunnyside Ave., N, Suite 540-E,  Seattle,
>WA  98103
>cdansereau@watoxics.org;   http://www.watoxics.org
>
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