WORKING FOR A HEALTHY FUTURE

INSTITUTE OF OCCUPATIONAL MEDICINE . Edinburgh . UK www.iom-world.org

Prioritizing action on occupational carcinogens in Europe

The McCallum Lecture

JW Cherrie, M Gorman Ng, A Shafrir, M van Tongeren, A Searl, A Sanchez-Jimenez (IOM)

R Mistry, M Sobey, C Corden (AMEC UK)

L Rushton and S Hutchings (Imperial College)

Other project team members: J Lamb (IOM), O Warwick and M-H Bouhier (AMEC UK), T Kaupinnen and P Heikkila (Finnish Institute of Occupational Health), H Kromhout (IRAS, University of Utrecht), L Levy (IEH, Cranfield University)

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Robert Ian McCallum, CBEb.14 Sept 1920 d.15 Feb 2009

“Robert Ian McCallum, former professor of occupational health at the University of Newcastle, was probably the most distinguished occupational physician of his era.”

Royal College of Physicians

http://munksroll.rcplondon.ac.uk/

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A quote from Marx…

“It is better to remain silent and be thought a fool, than to open your mouth and remove all doubt.”

Groucho Marx

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Background…

• Over 1 million cancer deaths in Europe each year and about 5% may be due to work

• The commonest cancers are:• breast cancer (13.5% of all cancer cases and 29% of

cancer cases in women)• colorectal cancers (12.9%) and • lung cancer (12.1%)

• Important differences incidence between countries • e.g. about a two fold difference for men between the

highest (Hungary) and the lowest (Bulgaria)

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Workplace causes

• Lag between first exposure and diagnosis may be 40-50 years

• IARC lists 107 agents that have been classified as carcinogenic to humans (Group 1)• 59 agents classified as probably carcinogenic to

humans (Group 2a) and 267 classified as possibly carcinogenic to humans (Group 2b)

• Main occupational carcinogens are asbestos, shift work, mineral oils, solar radiation, silica, diesel engine exhaust plus coal tars and pitches

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Revision of the EU Carcinogens Directive

• The European Commission are considering amending directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work

• Before the EC proposes new initiatives it has to assesses the potential economic, social and environmental consequences.

• It is a process that prepares evidence for political decision-makers on the advantages and disadvantages of possible policy options by assessing their potential impact.

http://ec.europa.eu/governance/impact/index_en.htm

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Process generated substances…

• For the process generated substances there is a two step process as they are currently not in the scope of the directive since not classified as EU category 1 or 2 carcinogen

• Can be brought into scope by including them in Annex I.

• Then as a secondary consideration, ask whether we need an OEL and of ‘yes’ at what numerical value?

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Outline of the talk…

• Outline the SHEcan project to carryout a Socioeconomic, Health and Environmental impact assessment for 25 carcinogenic substances

• Describe the main results from the work in relation to prioritizing interventions

• Discuss some of the issues that have arisen in doing the work

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The SHEcan project…

Estimate exposure levels

Estimate number exposed

Assess risk

Socioeconomic/Environment impact

Management and stakeholder consultation

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Substances considered…

In Annex III

OELs Suggested by EC

Process generated

Typical OELs

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Methods…

• Exposure levels reliant on stakeholder data or when unavailable published sources

• Risk assessment reliant on epidemiological studies or analogy

• Health impact carried out using carefully reviewed methodology developed for British cancer burden study

• Socioeconomic assessment based on EC guidance

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Exposure assessment…

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Exposure decreases over time…

Creely KS et al. (2007) Trends in inhalation exposure--a review of the data in the published scientific literature. Ann Occup Hyg.; 51(8): 665-678.

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1973 1974 19751

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100

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f(x) = INF exp( − 2.00333226615499 x )R² = 0.740621920392391

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Health impact…

• Aims to provide estimates of current cancer deaths and registrations due to occupation and future trends under different scenarios of change

• Measure of burden used is the AF - proportion of cases attributable to exposure; needs:• risk of disease associated with the exposure of concern (e.g.

relative risk (RR) – obtained form epidemiological literature• proportion exposed in the population

• To take into account latency we defined the risk exposure period (REP) for:• Solid tumours: 10-50 years; e.g. 1961-2000 for 2010• Haematopoietic cancers: up to 20 years; e.g. 1991-2010

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Possible future scenarios...

• Estimates made for alternative scenarios of change in exposure levels or numbers exposed• Baseline scenario - based on pattern of past exposure, but

no future change in exposed numbers or levels

• Baseline trend scenario - based on pattern of past and current exposure, and on linear projections up to 20 years into the future, after which levels assumed constant due to prediction uncertainty.

• Intervention scenarios: introduction or reductions in exposure limits in 2010 (results in future changes in levels of exposure and proportions exposed to these.

• Assumed ‘full compliance’ (i.e. >99% of exposures < OEL)

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Socioeconomic impacts…

• Assessed impact of baseline exposure (disability and death)

• Assigned values to those impacts based on:• Value of life-years lost• Cost of illness or willingness to pay to avoid cancer• Different figures for non-melanoma skin cancer versus other types

• Then assessed value of impacts avoided through reduced workplace exposure levels across the population exposed (i.e. difference from baseline)

• Based on reduction of exposure to the proposed OEL

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Discounting future costs and benefits

• All costs and benefits over time in this study were discounted using a 4% discount rate as recommended by the EC Impact Guidelines • Costs mostly occur

today• Benefits mostly arise

many years in the future

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Number of people currently exposed…

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% currently above the proposed OEL…

currently

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Baseline health assessment…

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Cancer cases prevented by OEL…

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Crystalline silica - Registrations

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Cost-benefit ratio…

Note, zero compliance costs because exposure was already assessed to be below the OEL investigated.

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Strength of evidence…

• Respirable crystalline silica• Chrome VI• Hardwood dust• Diesel engine exhaust• Rubber fume• Benzo[a]pyrene• Trichloroethylene• Hydrazine• Epichlorohydrin• O-Toluidine• Mineral oils as used engine oil• MDA

Strong case

A case

A limited case

Uncertainty

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Conclusions…

• This approach can help guide policy • Focus on the occupational carcinogens that

contribute most to the health burden, which could contribute importantly towards the goal of eliminating occupational cancer

• Better information is needed about the extent of exposure to occupational carcinogens