Dr. Philippe Grandjean on Chemical Brain Drain
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EDC Strategy CHE partnership call Wednesday, April 16 th , 2014 Dr. Philippe Grandjean on Chemical Brain Drain: How the Next Generation's Brain Functions are Endangered by EDCs and Other Environmental Chemicals www.chemicalbraindrain.info
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How the Next Generation's Brain Functions are Endangered by EDCs and Other Environmental Chemicals by the Collaborative on Health and the Environment Dr. Philippe Grandjean suggests that new scientific insights reveal that the next generation's brain functions are endangered by environmental chemicals. The fetus is not protected by the placenta and therefore shares the mother's cumulated exposures to toxic chemicals. Infants and children are likewise exposed to a cocktail of foreign substances against which the body has no innate defense. Prenatal and early postnatal brain development is an extremely complex process that we now know is uniquely vulnerable. Lead, mercury and a few other substances have long been known to be toxic to brain development. Recent research suggests that many chemicals, perhaps thousands, may cause similar effects because they can gain access to the developing brain and exert their toxicity to brain cells. This new insight needs to be translated into public policy to protect the brain functions of the next generation. On this call Dr. Grandjean discussed what he terms "chemical brain drain" and how we might work to protect the brain health of future generations. Sources: http://www.healthandenvironment.org/partnership_calls/14316?res
Transcript of Dr. Philippe Grandjean on Chemical Brain Drain
EDC Strategy CHE partnership call
Wednesday, April 16th, 2014
Dr. Philippe Grandjean
on Chemical Brain Drain:
How the Next Generation's
Brain Functions are
Endangered by EDCs and
Other Environmental Chemicalswww.chemicalbraindrain.info
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Erroneous and dangerousassumptions:• The placenta protects the fetus• Children are just little adults• Poisonings are reversible• Proof is needed for regulation• Testing is too expensive
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Sensitive brain development• Cell division
In third trimester about 12,000 nerve cells are formed every minute
• Differentiation• Migration
Distances up to 1,000 times the size of the cell
• Axon formationTotal length by age 20 years: 176,000 / 149,000 km (m/f)
• Generation of synapsesUp to 1,000 new synapses per second early postnatally
• Weeding of synapses
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Brain development gone astray…in every case the mother was healthy, and it was not until more than three months after birth that the symptoms were recognized
Shoji Kitamura (1959)
Photo: W. Eugene Smith
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Focal
Widespread
Diffuse
5
10 30 50 70
90
70
50
30
Percent correct responses on MCAS math test in 4th grade
Average blood‐lead (µg/L) at preschool age
Averages for 351Massachusetts municipalities:Children bornin 1992and 1999
Exposure limit (CDC)(Jessica W
. Reyes, 2012)
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Chemical group Known in 2006 Newly identified
Metals/inorganic compounds
Arsenic*Lead*
Methylmercury*
Fluoride*Manganese*
Organic solvents (Ethanol)Toluene* Tetrachloroethylene*
Pesticides Chlorpyrifos*DDT/DDE*
Other organic compounds
Polychlorinated biphenyls (PCBs)*
Brominated diphenylethers*
Total 6 6
Chemical brain drainers
(Grandjean & Landrigan, Lancet Neurology, 2014)
*Endocrine disruptor, according to TEDX
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Time of recognition
Neurotoxicant dose (inverted scale)N
umbe
r of s
ubje
cts
affe
cted Silent pandemic
NeurotoxicityIn adults Poisoning
incidents
Subclinical effectsin child populations
(Grandjean and Landrigan, The Lancet, 2006)
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Chemical universe N ~ 100,000
Neurotoxic in lab tests N > 1,000
Neurotoxic to humans N > 200
Known neurotoxic to humans during development, N > 10
(Updated from Grandjean and Landrigan, The Lancet, 2006)
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The goal: Full integrity of the brain to allow optimal brain functions
We need it: The brain determinesbehavior, IQ, endocrine functions... and who we are
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What can be done?• Mothers, consumers can make choices to
decrease exposures• An OECD test protocol is available to test
for developmental neurotoxicity• New cell-based tests are faster, cheaper• Regulation of EDCs• Chemicals control needs to include focus
on brain development• International clearinghouse
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