1. Clean Air: Haven’t We Done Enough? Chris Carlsten, MD MPH University of British Columbia Chris Carlsten University of British Columbia Humboldt Kolleg May 13, 2011,

2. Clean Air: Haven’t We Done Enough? Chris Carlsten, MD MPH University of British Columbia NO!

3. Clean Air: Haven’t We Done Enough? Chris Carlsten, MD MPH University of British Columbia NO!

4. Clean Air: Haven’t We Done Enough? Chris Carlsten, MD MPH University of British Columbia YES!

5. Exposure Control: Are There Limits to What We Should Aim For? Chris Carlsten, MD MPH University of British Columbia YES!

6. Exposure Control: Are There Limits to What We Should Aim For? SOMETIMES!

7. Complexity and Caveats Chris Carlsten, MD MPH University of British Columbia Exposures are complex rather than isolated Safe substitutes may not exist Thresholds and dose-response are often unknown Gene-by-environment interactions are unlimited Vulnerable populations are often without advocates The value of health is subjective (makes cost-benefit difficult) Competing community values (i.e., fuel burning) Industry manipulation of science and policy

8. Complexity and Caveats Chris Carlsten, MD MPH University of British Columbia Exposures are complex rather than isolated Safe substitutes may not exist Thresholds and dose-response are often unknown Gene-by-environment interactions are unlimited Vulnerable populations are often with advocates The value of health is subjective (makes cost-benefit difficult) Competing community values (i.e., fuel burning) Industry manipulation of science and policy … every exposure is unique …

9. CIGARETTES …little redeeming value …adequate substitutes (pleasures) A global ban is the ultimate solution In this case, there are NO limits to what we should aim (once production stops, exposure will soon)

10. Chris Carlsten, MD MPH University of British Columbia Science, Advocacy and Politics Join Forces  A (Partial) Success Story

11. Chris Carlsten, MD MPH University of British Columbia Since 1987: Incidence of smoking has decreased ~1% per year www.cancer.gov www.lungusa.org

12. Chris Carlsten, MD MPH University of British Columbia Since 1987: Incidence of lung cancer has decreased ~1% per year www.cancer.gov www.lungusa.org 1987 = peak lung cancer incidence

13. ASBESTOS has value There are worthy substitutes (synthetics, wood fiber, etc)

14. In this case, there are NO limits to what we should aim for in terms of reducing production In terms of reducing exposure, safe lower threshold unclear so complete avoidance is reasonable There is a powerful industrial incentive to minimize those substitutes Approx 500K tonnes per year x $500 per ton = $250,000,000/year

15. Asbestos NO limits to what we should aim for in terms of reducing production Safe lower threshold unclear, so complete avoidance is reasonable Canadian hypocrisy lambasted by prominent journals

16. Traffic-related air pollution (TRAP) Chris Carlsten, MD MPH University of British Columbia Pope et al NEJM 2009

17. Carlsten in Albert (Ed) 2008 [Brook RD] 0.001 um= nanometer Diesel exhaust, cigarette smoke

18. Traffic-related air pollution (TRAP) No known safe lower limit! Chris Carlsten, MD MPH University of British Columbia Pope et al Circulation 2009

19. Traffic-related air pollution (TRAP) Huge population-level benefits of reduction “In view of both the magnitude of the risk and the prevalence in the population, air pollution is an important trigger of myocardial infarction, it is of similar magnitude (PAF 5–7%) as other well accepted triggers such as physical exertion, alcohol, and coffee. Our work shows that ever-present small risks might have considerable public health relevance” of British Columbia Nawrot et al Lancet 2011

20. Aero-allergens Synergy Carlsten et al ERJ 2010

21. Aero-allergens Synergy Are There Limits to What We Should Aim For? Don’t Know Yet… Carlsten et al ERJ 2010

22. Traffic-related air pollution (TRAP) Vulnerable populations Kerkhof et al THORAX 2010 NOTE: rs10759931 is a TLR4 SNP

23. Traffic-related air pollution (TRAP) Vulnerable populations Vulnerable populations Elaina MacIntyre

24. Summary Chris Carlsten, MD MPH University of British Columbia Every exposure is unique – the reasonable exposure limit for most is subject to reasonable debate Genetics can elucidate or obscure important relationships Over time, we appreciate toxicity at lower exposure levels Valid research is an invaluable tool for addressing “limits”

25. A final perspective… Chris Carlsten, MD MPH University of British Columbia Respect the precautionary principle If an action or policy has a suspected risk of causing harm the burden of proof that it is not harmful falls on those taking the action OR Lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation