1 / 20

Environmental Impact on Congenital Anomalies CONCLUSIONS

Environmental Impact on Congenital Anomalies CONCLUSIONS. Luc Hens Human Ecology Department Vrije Universiteit Brussel E-mail: human.ecology@vub.ac.be. Issues. Problem formulation Methodological approaches Mechanisms Communications. Congenital Anomalies.

decker
Télécharger la présentation

Environmental Impact on Congenital Anomalies CONCLUSIONS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Environmental Impact on Congenital AnomaliesCONCLUSIONS Luc Hens Human Ecology Department Vrije Universiteit Brussel E-mail: human.ecology@vub.ac.be

  2. Issues • Problem formulation • Methodological approaches • Mechanisms • Communications Conclusions Kos, June 8-11th, 2005

  3. Congenital Anomalies commonly studied in relation to environmental exposure After Dolk and Vrijheid, 2003 Conclusions Kos, June 8-11th, 2005

  4. Chemicals associated with congenital anomalies in humans • Pharmaceuticals (DES, Thalidomide, Wafarin) • Hair dyes • Pesticides • Non-pesticide ED (bisphenol A, phtalates, TCDD, vinyl chloride) • Heavy metals (Pb, Hg, Cd, As, Cr and Ni) • Organic solvents (styrene) Conclusions Kos, June 8-11th, 2005

  5. Exposure conditions associated with congenital anomalies • Drinking water (heavy metals, nitrates, chlorinated substances) • Residence near (hazardous) waste deposit sites • Pesticides in agricultural areas • Air pollution • Food contamination (dioxins, PCBs) • Industrial point sources (smelters, incinerators) • Disasters (Hiroshima, Minamata) • (Working conditions : hair dressers) Examples in Kos 2005 workshop After Dolk and Vrijheid, 2003 Conclusions Kos, June 8-11th, 2005

  6. Problem situation • Embryonic and fetal life are sensitive periods to environmental exposures • Increasing number of chemicals and exposure conditions are associated with congenital anomalies • Increasing prevalence of selected congenital anomalies (hypospadias, cryptorchidism, gastroschisis) in industrialized countries • Convergence between pollutants in environmental health outcomes • Links between congenital anomalies, fertility and pregnancy loss (mechanisms?, risk factors?) Conclusions Kos, June 8-11th, 2005

  7. Epidemiological evidence • “Limited” • RR is significant for environmental exposure • Limitations3.1 statistical power, sensitivity, dilution3.2 consistency of diagnosis (e.g. hypospadias)3.3 “missing what is real” – “finding what is not real” Conclusions Kos, June 8-11th, 2005

  8. Risk figures Vrijheid and Dolk, 2005 Kristensen et al., 1997 Conclusions Kos, June 8-11th, 2005

  9. Risk figures Longnecker et al., 2002 Olea et al., 2005 Conclusions Kos, June 8-11th, 2005

  10. Developmental toxicological evidence • Standard tests exist (two generation essay) • Interesting developments (e.g. stem cells) • No single test Conclusions Kos, June 8-11th, 2005

  11. Clinical evidence • Historical examples of the alert physician1.1 Thalidomide1.2 Anticonvulsants1.3 PCBs • Systematic survelance of public health (Eurocat)2.1 “Limited” information2.2 Important methodological challenges2.3 More coordination necessary Conclusions Kos, June 8-11th, 2005

  12. Wildlife evidence • Selected cases1.1 EDs cause abortion in sea lions1.2 DDT/DDE cause cryptorchidism in rodents • Congenital defects in relation to pollution are found in:2.1 fish: intersex2.2 amphibians: intersex, gonidal dysgenesis, hermaphroditism2.3 Mammals: impaired reproduction, hermaphroditism, abnormal testes, impaired spermatogenesis • Fast accumulating evidence Conclusions Kos, June 8-11th, 2005

  13. Examples of mechanisms • Thalidomide : I and F growth factor mediated mechanism • Steroidogenesis in testes • Testicular dysgenesis syndrome (TDS) Conclusions Kos, June 8-11th, 2005

  14. Changing concepts • Not only dose matters (“practical threshold”) • Exposure window – sensitivity period – timing is crucial • Individual susceptibility • Long latency • Consider mixture (of chemicals, of chemicals with body molecules) Conclusions Kos, June 8-11th, 2005

  15. Information • Parents prior to conception • Prenatal service providers and counsellors (e.g. OTIS) • Decision makers3.1 principles3.2 messages Conclusions Kos, June 8-11th, 2005

  16. Core messages for couples • Be aware of pollutants in your lifestyle (cosmetics, medical drugs, food, pesticide use in gardening) • Care about your internal environment (long term) • Health practices: iodine intake, folic acid, antioxidants and breastfeeding Conclusions Kos, June 8-11th, 2005

  17. Core messages for counselors • Evaluate environmental aspects (not only genetics) • Defining and communicate risk • Bring down avoidable medication during pregnancy3.1 prescription behavior3.2 alternatives Conclusions Kos, June 8-11th, 2005

  18. Principles for decision making • “How much evidence is enough?”1.1 Bradford Hill criteria1.2 Related models (e.g. IPCC criteria) • Preventable conditions • Precautionary principles Conclusions Kos, June 8-11th, 2005

  19. Core messages for policy making • Even if the proportion of congenital anomalies attributable to environmental pollution might not be high, any excess cases represent a failure of our environmental health protection system • Precautionary new generation of standards • Growing evidence mainly from wildlife to bring EDCs under prior authorization under REACH Conclusions Kos, June 8-11th, 2005

  20. At last • Submit manuscripts not later than August 20th 2005 • THANK YOU Conclusions Kos, June 8-11th, 2005

More Related