Epidemiology and Trends of ARDs A Global Perspective Ken Takahashi, MD, PhD, MPH Professor of Environmental Epidemiology, Director of WHOCC for Occupational Health, University of Occupational & Environmental Health, Japan 1 Helsinki Asbestos Conference 11-13 Feb 2014, Hanasaari
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Epidemiology and trends of asbestos-related diseases at Helsinki Asbestos 2014
Presented by Professor Ken Takahashi from the University of Occupational and Environmental Health, Japan.
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Epidemiology and Trends of ARDsA Global Perspective
Ken Takahashi, MD, PhD, MPHProfessor of Environmental Epidemiology,
Director of WHOCC for Occupational Health,University of Occupational & Environmental Health, Japan
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Helsinki Asbestos Conference11-13 Feb 2014, Hanasaari
OBJECTIVEWhat is important in the epidemiology and trends
of ARDs which may contribute to conference aim?
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International Conference on Monitoring and Surveillance of ARDsHelsinki Criteria Update Meeting
What is important in the epidemiology and trends of ARDs from a global perspective?
IARC MonographVol. 100C, September 2012
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Long-standing vs Added Endpoints “potency of differences with respect to lung cancer or mesothelioma for fibres of various types and dimensions are debated, (but) the fundamental conclusion is that all forms of asbestos are ‘carcinogenic to humans’ (Group 1)”
NEW !!larynx & ovarycolorectum,
stomach & pharynx
Environ Health Perspect 2008
Epidemiology vs Economy
Landmark Epi Studies1955 Richard Doll (BJIM)1st epidemiologic study on UK ASB factory workers on LC risk (O/E = 11/0.8)
1960 Wagner JC (BJIM)33 cases of mesothelioma working/living near S African crocidolite mine
1964 Selikoff (JAMA)American insulation workers at very high mortality risk for cancer of lung, GI tract and mesothelioma
By around 1960 …− Robust epi studies (scientific reasons) emerged− Substitute materials, e.g., fiberglass, increasingly
available
(Virta, USGS)
World production of 200 M tons during 1900-2013 > 160 M tons (80%) was 1960+Recent consumption dominated by developing countries CHR asbestos
ARDs vs Environmental ExposureConventional knowledge:
− Primary route of exposure is occupational− Para-occupational, household and environmental exposure can cause ARDs
Kurumatani & Kumagai. Am J Respir Crit Care Med, 2008
In Japan/Korea: Environmentally induced MM legally compensated (“Relief” Law)
Epi studies reporting environmentally induced lung cancer
RECENT
Usage vs Asbestos-Specific-JEM
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Developed Countries
Developing Countries
Construction material, ie, asbestos-cement Remaining (in situ) Thriving
Anti-friction/heat material, Insulation, etc.
Historically yes but mostly phased out
Continuing (variable degrees)
Diversity of industries, occupations and products must be considered For developed countries > compensation and epi research For developing countries > roadmap to ban and control measures during transition
Countries vs Asbestos Situations
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Percentage agreement between 2 countries is:Pr(a) = (60 + 241) / 435 = 69.2%
Percentage inconsistencies where• Japan (Y) and Korea (N) = 99/435 = 22.8%• Korea (Y) and Japan (N) = 35/435 = 7.6%
Code Major Occupations Sub-
major Minor Unit
1 Managers 4 11 312 Professionals 6 27 923 Technicians and Associate Professionals 5 20 844 Clerical Support Workers 4 8 295 Services and Sales Workers 4 13 406 Skilled Agricultural, Forestry and Fishery Workers 3 9 187 Craft and Related Trades Workers 5 14 668 Plant and Machine Operators and Assemblers 3 14 409 Elementary Occupations 6 11 330 Armed Forces Occupations 3 3 3
10 43 130 436
Asbestos-related
KoreaTotal
Yes No
Japan
Yes 60 99 159
No 35 241 276
Total 95 340 435
(Findings for occupations and industries were similar)
paper in preparation
Chrysotile vs Amphiboles
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CHR is carcinogen
Evidenceabundant
No controversy
Relative Potency
Evidence inconclusive
Controversy lingers
carcinogen
biopersistence Amph>CHRAm
phib
ole
CHR contaminated by Amph
Limits with epi studies ?!
Estimating ARLC burden from MESO MortalityBJC 2012, McCormack et al
<Ratio 1 : ARLC-to-MESO Ratio> • CRO : 0.7 (0.5 to 1.0) to 1 [n=6 ]• CHR : 6.1 (3.6 to 10.5) to 1 [n=16]
• AMO : 4.0 (2.8 to 5.9) to 1 [n=4]; Mixed : 1.9 (1.4 to 2.6) to 1 [n=31]
1. Ratios show the low potential of CHR to produce MESO2. MESO cannot be used (too low, too unstable) to estimate EXP3. Major effect of CHR is LC (ARLC)
Except for CRO, ARLC is larger than MESOFor CRO, MESO risk is high & ARLC is just slightly lowerFor CHR, MESO risk is “due to amph exposure”
Based Quebec study and relies on bio-persistence theory
• Uses heterogeneous datasets not adequately controlled for latency a/o exposure
• Shortcomings undermine conclusions and recommendations
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• None of raised concerns are substantiated; minimising CHR risk > misinterpretation• Emphasized were
− Lung cancer risk by CHR− Benefits of smoking
cessation for formerly exposed workers
Relies on IARC (1987) not IARC (2012)Refers to Hodgson (2000) not Hodgson (2010) : narrower fiber-type differences
Underestimates CHR potency!
Original vs Updated StudyHodgson & Darnton
• Systematic Review (AOH, 2000)
• Meso Risk for CHR:AMO:CRO = 1:100:500 – for LC, “less clear cut”
• Cohort: Textile workers in N. Carolina + Quebec Miners
• Updated by including Loomis study (OEM,2009) [“meso risk by CHR is higher by factor of 10”] leading to significant revision of numbers (OEM, 2010)
• [Meso Risk for CHR:AMO:CRO = 1:10:50]− Criticisms emerged for omitting this revision
• “Risk by CHR exposure (N.Carolina textile) is much higher than (Quebec) mines”
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Chrysotile as Cause of MesotheliomaHill’s Criteria (Lemen: IJOEH, 2004)
9 Items of Hill’s Criteria (Sir Bradford Hill, 1965)1 Strength of Association 1 Risks observed in many countries
and over many decades. Background level probably 1 per Million; Risks increase from environmental to para-occupational to occupational; Risk detected for CHR with very low to nil amph contamination; ANTH meso risk is probably low (Karjalainen; Tuomi).3 Meso risk + at exposure levels lower than PELs (Iwatsubo)6 CHR fibers highly detectable in meso linings 8 Intra-tracheal injection, intrapleural, inhalation studies. Superfine asbestsos (SFA; <5 micron) most carcinogenic.
CHR per se can induce MESO when TREM or other amph are not detected.As there is no 100% pure CHR, (arguing) meso carcinogencity of CHR is academic at best.
Global Consensus
Culminated in:1. IARC Monographs from 1977 onwards2. Helsinki Criteria (1997)3. IPCS Environ Health Criteria by WHO (1998)
Supported by governmental agencies: EPA, OSHA, CDC, NIOSH, DHHS, PHS and FDA
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Relative Potency: CHR vs Amph
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1:100:500 1:10:50 1:?:?
Meso
“It is prudent & in the public interest to consider all fiber types as having comparable carcinogenic potency in its qualitative assessment of meso risk.” “Engagement in argument has prevented timely and appropriate health protective actions.” (EPA, 1989)
I venture to say, it is prudent & in the interest of developing countries… Argument will only prevent timely and appropriate protective actions !
Developing Countries vs CHR Asbestos
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Reason Solution Role of Epi
1. Public Health argument losing against economic argument
Empower Public Health argument
+++ local epi
evidence may be needed
a. middle of high growth
b. own burden not evident
c. failure to learn lessons
2. Relative Potency argument used to justify “controlled use”
Demythologize Controlled Use argument
+++ a. lobbied by exporters
b. used by industry
c. believed by administrators
“Heavy burden of ARDs in (developed) countries is attributable to their heavy dependence on ASB several decades earlier.” (Inter-agency Workshop, WHO, ILO, RCS)
“Evidence continues to show that national burdens of ARDs are directly proportional to national consumption of asbestos.” (Concept Note of AAI-6, WHO)
“The most efficient way to eliminate ARD is to stop using all types of asbestos.”
Key message by WHO (2006) on Elimination of ARDs …
prompted at all levels of preventionHCU should aspire to promote global
perspective, i.e., account for situation of developing countries
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International Conference on Monitoring and Surveillance of ARDsHelsinki Criteria Update (HCU) Meeting
Epidemiology and Trends of ARDsA Global Perspective
Ken Takahashi, MD, PhD, MPHProfessor of Environmental Epidemiology,
Director of WHOCC for Occupational Health,University of Occupational & Environmental Health, Japan
24
Helsinki Asbestos Conference11-13 Feb 2014, Hanasaari
1. Diandini R, Takahashi K* et al. Am J Ind Med 2013, 56:993-1000.2. Pham VH, Le VG et al. Safety Health Work 2013, 4:117-21.3. Park EK, Takahashi K* et al. Cancer Sci 2012, 103: 1751-5.4. David AM, Ogawa H and Takahashi K. Int J Occup Environ Health 2012, 18:22-8.5. Lim JW, Koh D et al. Safety Health Work 2011, 2:201-209.6. Vanya D, Takahashi K* et al. Bull World Health Organ 2011, 89: 716-24.7. Le GV, Takahashi K* et al. Respirology 2011, 16:767-75.8. Park EK, Takahashi K* et al. Environ Health Perspect 2011, 119: 514-8.9. Takahashi K and Kang S-K. Safety Health Work 2010, 1:103-6.10. Le GV, Takahashi K* et al. Environ Health Perspect 2010, 118:116-9.11. Takahashi K (editorial). Occup Med (London) 2008, 58:384-385.12. Nishikawa K, Takahashi K* et al. Environ Health Perspect 2008, 116:1675-1680.13. Lin R-T, Takahashi K* et al. Lancet 2007, 369: 844-849.14. Murayama T, Takahashi K et al. Am J Ind Med 2006, 49: 1-7.15. Takahashi K and Karjalainen A. Int J Occup Environ Health 2003, 9: 244-8.