Looking forward: How can mercury contamination harm the next - - PowerPoint PPT Presentation

▶
looking forward how can mercury contamination harm the
SMART_READER_LITE
LIVE PREVIEW

Looking forward: How can mercury contamination harm the next - - PowerPoint PPT Presentation

Apr 25, 2023 317 likes •472 views

Looking forward: How can mercury contamination harm the next generation - the need for precaution Philippe Grandjean University of Southern Denmark Harvard School of Public Health Presenter: Philippe Grandjean, MD, DMSc Professor and Chair,

slide-1
SLIDE 1

Looking forward: How can mercury contamination harm the next generation - the need for precaution

Philippe Grandjean University of Southern Denmark Harvard School of Public Health

slide-2
SLIDE 2

Presenter: Philippe Grandjean, MD, DMSc

Professor and Chair, Environmental Medicine, University of Southern Denmark Adjunct Professor, Harvard School of Public Health Conflict of interest declaration: Research support only from public sources (NIH, EC, Danish research councils) Adviser to Danish National Board of Health Member of the Danish delegation at own expense No support from NGO organizers

slide-3
SLIDE 3

Focal Widespread Diffuse

slide-4
SLIDE 4

Sensitive brain development

  • Cell division*
  • Differentiation
  • Migration**
  • Axon formation***
  • Generation of synapses****
  • Weeding of synapses

*In third trimester about 12,000 nerve cells are formed every minute **Distances up to 1,000 times the size of the cell ***Total length by age 20 years: 176,000 / 149,000 km (m/f) ****Up to 1,000 new synapses per second early postnatally

slide-5
SLIDE 5

Development/ programming Functional maturation Neurological disease and degenerative changes Early-life exposures to neurotoxic chemicals

Developmental Origin of Health And Disease (DOHAD)

slide-6
SLIDE 6

Long-term follow-up of large birth cohorts

slide-7
SLIDE 7

NEUROANATOMY NEUROPHYSIOLOGY NEURO- DEVELOPMENT NEUROCOGNITIVE TRAITS testing DEVELOPMENTAL SYNDROMES clinical diagnosis

ADHD autism learning disability

TOXICANTS SOCIAL ENVIRONMENT

attention span s

  • c

i a l a d j u s t m e n t aggression introversion/ extroversion memory r e a d i n g s k i l l s i m p u l s i v i t y executive function ??? Asperger syndrome

GENETICS

Framework For Understanding

ECONOMIC IMPACT

Revised from In Harm’s Way

slide-8
SLIDE 8

Delayed electrical signals at higher mercury exposures (brainstem auditory evoked potentials at age 14 years)

Murata et al., Journal of Pediatrics, 2004

WHO exposure limit U.S.EPA exposure limit

Objective measure: Speed of electrical signals in the brain

slide-9
SLIDE 9

Modern imagining methods show that children with high prenatal pollutant exposure must activate brain regions not needed by controls

Increased prenatal exposure to MeHg (N = 3) Controls (N = 3)

(R.F.White et al., 2011)

Finger tapping with the left hand activates motor cortex on right AND left In non-exposed controls, only the right motor cortex is activated

slide-10
SLIDE 10

WISC-III outcomes Log10 (Cord Hg Slices (ng/g)) Total IQ Estimate (β) 95 % CI P-int. SNP Score (0-1) (n=193) 15.5 4.3 to 26.6 SNP Score (2-3) (n=486) 2.6

  • 4.8 to 10.2

0.23 SNP Score (4-7) (n=177)

  • 8.7
  • 20.2 to 2.9

0.003 Verbal IQ SNP Score (0-1) 13.9 2.6 to 25.2 SNP Score (2-3) 3.3

  • 4.6 to 11.3

0.28 SNP Score (4-7)

  • 3.3
  • 15.7 to 9.1

0.052 Performance IQ SNP Score (0-1) 13.1 0.2 to 26.0 SNP Score (2-3) 1.2

  • 7.0 to 9.4

0.36 SNP Score (4-7)

  • 12.9
  • 25.9 to 0.0

0.002

Genetic susceptibility: Change in IQ at age 8 for 10-fold increase in prenatal MeHg exposure and number of mutations in PGR, PON1, TF, and BDNF

Julvez J et al. Epidemiology, September 2013

slide-11
SLIDE 11

Time of recognition Neurotoxicant dose (inverted scale) Number of subjects affected

Silent pandemic

Neurotoxicity In adults Poisoning incidents Subclinical effects in child populations

Time course of recognition

  • f MeHg developmental neurotoxicity

Revised from Grandjean & Landrigan, Lancet, 2006

Genetic predisposition Hair-Hg < 0.5 <1 3-5 5-10 >10 >50

slide-12
SLIDE 12

Calculating the IQ value

  • Life-time earnings based on US data
  • Future earnings converted to present-day

value by discounting (3% per year)

  • National values for life-time earnings

adjusted for purchasing power parity

  • Additional adjustment for productivity
  • EU value ~€13,600 (2008) for 1 IQ point
  • Other benefits (intangible/direct) ignored

(Bellanger et al., 2013)

slide-13
SLIDE 13

Annual costs in Europe for IQ losses (€ billion) due to mercury

  • Denmark:

~0.1

  • Faroe Islands

~0.003

  • France:

~1.2

  • Italy:

~1.4

  • Spain:

~4.5

  • United Kingdom:

~0.4

  • Total EU:

~9.3

*From Bellanger et al., 2013)

slide-14
SLIDE 14

Complementing the Minamata Convention

  • In the short term, the convention will not

prevent excess exposures that are dangerous to developing brains

  • Dietary fish/seafood advisories are needed

and must be targeted to local conditions

  • Hair-mercury analyses are needed to

assess national and regional exposure levels – and to identify individuals at risk

  • Analytical capacity for hair-mercury exists

to provide assistance at a global level