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EnvironmentalHealthNews

On the cusp of a revolution: Public health and the environment. John Peterson Myers, Ph.D. Environmental Health Sciences. www.EnvironmentalHealthNews.org. Public Health Science. Mid-stream in a scientific revolution.

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EnvironmentalHealthNews

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  1. On the cusp of a revolution: Public health and the environment John Peterson Myers, Ph.D. Environmental Health Sciences www.EnvironmentalHealthNews.org

  2. Public Health Science Mid-stream in a scientific revolution Profound changes in how we think about links between contamination and human health. Dramatic opportunities for protecting the public’s health

  3. Elements of the revolution Some contaminants have effects at low exposure levels They are linked through science to a growing array of health impacts This new science opens the door to new approaches to protecting our health: reduce and substitute We’ve shown we can do this… we can do more and even better

  4. Moving toward a tipping point New public health science New materials science

  5. …but we’re not there yet Moving toward a tipping point Lack of political support Lack of public awareness Highly motivated opposition Problems with communication strategies, tools and skills

  6. Roots of the revolution The genetic basis of many human diseases ????

  7. Two ways to think about genes What we get from our parents Chemical manufacturing machines …nature’s nanotechnology

  8. C/EBPβ Adipocyte genes 422/aP2 C/EBPα SCD1 P-CREB PPARγ GLUT4 Ob gene Experiments with 3T3-LI pre-adipocytes

  9. Changes in gene expression Mother’s diet altered gene expression Mother’s exposure altered gene expression Jirtle et al. 2004 Newbold 2005

  10. What changes gene expression? “Classic Genetics” “Classic Environment” Heredity Diet Stress Other genes and signals they send Experience Environmental contaminants

  11. Genetics vs. Environment

  12. CONCEPTUAL SHIFTS Old… a disease that is linked to genes is a disease under hereditary control. New… a disease linked to genes is one vulnerable to environmental causes.

  13. CONCEPTUAL SHIFTS Old… toxins work by overwhelming the body’s defenses…by brute force. New… toxic compounds work by hijacking control of gene expression.

  14. CONCEPTUAL SHIFTS Old… only high levels matter New… impacts at everyday levels… levels people had become accustomed to calling “normal,” background levels… levels that couldn’t be measured 20 yrs ago.

  15. Everyday levels matter At truly low levels … it interferes with gene activation At high levels… arsenic kills people At moderately low levels… it causes a range of diseases Kaltreider et al. 2002

  16. Everyday levels matter * * 60 50 40 Prostate Weight (mg) 30 20 10 0 C’trol 2 20 Bisphenol A ng/g/day Timms et al. 2005 Nagel et al. 1997

  17. Wozniak et al. 2005 95% of Americans Everyday levels matter Quesada et al. 2003

  18. Everyday levels matter Large risks associated with phthalate levels to which 25% of American women are exposed Altered genital development in baby boys Swan et al. 2005

  19. CONCEPTUAL SHIFTS Old… high levels focuses attention on “them” New…low levels: it’s about me and my family …hugely important politically

  20. CONCEPTUAL SHIFTS Old… the dose makes the poison New… timing is crucial, individual variation in susceptibility important, and low doses can have effects not predicted by high dose studies.

  21. P-450 1A1 (CYP1A1) Variation in susceptibility Conventional wisdom: After many studies and metastudies, PCBs are not linked to breast cancer Zhang et al. 2004

  22. CONCEPTUAL SHIFTS Old… immediate cause and effect New… long latencies following developmental exposure. Fetal programming can cause life-long impacts

  23. Fetal programming APP gene: amyloid precursor protein Basha et al. 2005 …fetal origins of adult diseases

  24. Transgenerational impacts Anway et al. 2005

  25. CONCEPTUAL SHIFTS Old… take chemicals one at a time New… essential to consider the mixtures in which they always occur Mixtures of contaminants Mixtures with body chemistry Mixtures with other factors

  26. 46x Bullfrogs, danger and carbaryl Relyea 2003

  27. Bad news, good news Bad news… Widespread exposure to compounds that interfere with gene expression, sometimes at extremely low levels. Today’s epidemiology cannot be trusted to find real effects with these complications

  28. Bad news, good news Good news… A disease under genetic control may be one caused by environmental exposures. We will have the opportunity to prevent many diseases that heretofore have not been perceived as preventable.

  29. The science is just going to get stronger… Bad news, good news Good news… Studies just published Results headed to print Research underway

  30. Bad news, good news Good news… A disease under genetic control may be one caused by environmental exposures. We have shown with lead and POPs that society can decrease exposures once it reaches political consensus

  31. Next challenge • Incorporating this scientific revolution into a new generation of precautionary health standards • Providing green chemistry new design criteria and resources for needed research • Creating consumer awareness that will reward entrepreneurs

  32. Today’s epidemics Hormone-related cancers Endometriosis, autoimmunity Learning disabilities, ADHD Autism Degenerative diseases Pre-term birth Obesity Asthma Infertility

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