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

Eliminating occupational cancer

John Cherrie

IOSH National Safety Symposium 2014

I wantto

ELIMINATE workplace

cancer

Summary…

• Workplace cancer has been a problem for some time

• How many people die from occupational cancer in Britain?

• What are the main causes?• What will the future hold?• Can we really eliminate

occupational cancer?

Europe’s dirtiest factory…

• Malcolm Carhart died from lung cancer

• Fred Richards had bladder cancer and survived

• 300 other men who worked at the Phurnacite plant in South Wales had their health damaged by their work Mr Fred Richards

This was a coal carbonization plant

Mortality in the plant…

• We carried out a mortality study in the plant in 1987• 17 year follow-up• 620 men included

• Increased cancer mortality• Lung – about 1.5x the expected numbers• Stomach – 1.6x• Prostate – 1.5x• Bladder – 2.7x

• Non-melanoma skin cancer commonly reported

Understanding the causes

• In 1981 Richard Doll and Richard Peto were commissioned by the US government to assess the relative importance of the “environment” in causing cancer

• Their aim was to identify the proportion of cancer that is preventable

Sir Richard Doll

Sir Richard Peto

Attributable fractions…

About 4% (2 – 8%)

Cancer burden in the UK…

• Designed to update Doll and Peto’s estimate for occupational cancer burden• Current burden (2010) • Future burden (to 2060+)

• Funded by HSE to inform policy• Method based on:

• Risk of Disease (relative risk from published literature)• Proportion of population exposed

• Estimation for IARC groups 1 (definite) and 2A (probable) carcinogens and occupational circumstances

Rushton L, Hutchings SJ, Fortunato L, et al. Occupational cancer burden in Great Britain. Br J Cancer 2012;107:S3–S7.

Attributable fraction…

5.3% (4.6 – 6.6%)

Men = blueWomen = red

Not all carcinogens are equally important

85% of the cancer cases come from the top ten chemical agents

Some good news…

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.

Aerosols

Some good news…

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.

Gases and vapours

Burden should be decreasing…

• If exposure is decreasing then it seems likely that the future burden will also be lower

• Assumes • Risk is related to exposure• Prevalence of exposure is not increasing• The aging population is not

distorting the picture

So what does the future hold?• We have estimated future cancer burden in Britain

for a range of interventions for a number of workplace carcinogens• AFs estimated for forecast years, e.g. 2010, 2020 …

2060• Assume 10-50 years latency for solid tumours e.g.

lung cancer, 0-20 years for leukaemia• Some past and some future exposure until 2060 • Workers at the beginning (2010) assumed to be of all

working ages• Workers recruited through employment turnover are

assumed to be only aged 15-24

Hutchings, S., Cherrie, J., van Tongeren, M., & Rushton, L. (2012). Intervening to Reduce the Future Burden of Occupational Cancer in Britain: What Could Work? Cancer Prevention Research. doi:10.1158/1940-6207.CAPR-12-0070

Crystalline silica…

• Assessed baseline scenario• Introduction of new limit values:• 0.05 mg/m3 and • 0.025 mg/m3

• Improved compliance with limits:• From 33% • to 90%

Silica – Cancer incidenceBaseline, 0.1 mg/m3, 33% compliance OEL = 0.05 mg/m3, 33% complianceOEL = 0.025 mg/m3, 33% compliance

Silica – Cancer incidence

OEL =0.1 mg/m3, 90% compliance OEL = 0.05 mg/m3, 90% complianceOEL = 0.025 mg/m3, 90% compliance

Silica – cancer incidence

Silica – cancer incidence

Successful interventions

Agent Intervention

Solar radiation Reduce time outdoors, wear suitable clothes, use sun screen

Diesel engine exhaust

90% comply with an OEL of 1 mg/m3

Shift work < 5-years night shift work for women

Asbestos 90% comply with an OEL of 0.001 fibres/ml

Welders Improved ventilation, wear respiratory protection

Elimination…

• Focus on the top-ten carcinogens• Encourage more effective controls along

with more stringent enforcement• “Elimination” achieved when future

occupational cancer burden less than 0.1% of all cancer registrations

• Monitor exposure and undertake an assessment of future burden as a leading indicator

Questions…