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

What do you mean by “eliminate”?

John CherrieI want

to

ELIMINATE

workplace

cancer

Summary…

• Elimination is a realistic possibility• Elimination will be achieved when

workplace exposures are projected to cause much less than 1% of all cancers

• What needs to be done in workplaces to reduce exposure?

• How effective are the control measures?

For communicable diseases…

• Control: The reduction of disease incidence. prevalence, morbidity or mortality to a locally acceptable level as a result of deliberate efforts

• Elimination of disease: Reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts

• Eradication: Permanent reduction to zero of the worldwide incidence of infection

Dowdle WR. (1996)The principles of disease elimination and eradication. Bulletin of the World Health Organization; 76(Suppl 2): 22-25.

Elimination of occupational cancer….• …elimination of the disease as a public

health problem (i.e. reduction of cases below what is considered to be a public health risk)

• What might be suitable target level for occupational cancer?

• Reduction of incidence of occupational cancers to <<1% of all cancers?

Cherrie. We can eliminate occupational cancer from chemicals. Occupational Medicine (2008) vol. 58 (5) pp. 314-315

We know what to do…• Minimise emission, release and spread of substances• Take into account all relevant routes of exposure• Control exposure by measures that are proportionate

to the health risk• Choose the most effective and reliable control

options• Where needed provide suitable personal protective

equipment• Review regularly all elements of controls• Inform and train all employees • Ensure control measures does not increase overall

risk

http://www.hse.gov.uk/coshh/detail/goodpractice.htm

Range of possible control measures…• Elimination / substitution• Process modification

• Change form of materials• Reduce temperature

• Isolation and segregation• General ventilation• Local ventilation• Maintenance, supervision,

education• Personal Protective Equipment

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.

Aerosols

Effectiveness of substitution…

• Successes• Bladder cancer in the rubber industry and β-

naphthylamine • Toluene for benzene

• However, substitutions are complex and may have unexpected consequences• use of citrus oil rather than trichloroethylene,

but… • d-limonene when oxidized presents risks as a

skin allergen

Exposure Control Efficacy Library

• Review of literature on the effectiveness of enclosures, local ventilation and other controls at source• 90 peer-reviewed papers• Wide variation in effectiveness

• The data published since the ECEL report was prepared broadly supports the original analysis

• Effectiveness in experimental or semi-experimental studies higher than other situations

Fransman et al. Development and Evaluation of an Exposure Control Efficacy Library (ECEL). Annals of Occupational Hygiene (2008) vol. 52 (7) pp. 567-575.

ECEL

Fransman et al. Development and Evaluation of an Exposure Control Efficacy Library (ECEL). Annals of Occupational Hygiene (2008) vol. 52 (7) pp. 567-575

ECELRisk Management Measure n Estimated

efficacy (%)95% confidence

interval

LEV in general 280 82 78 to 84

LEV + enclosure 9 86 69 to 94

Integrated 133 87 84 to 90

Mobile 4 61 -28 to 88

General ventilation 42 43 17 to 61

Assigned Protection Factors

Effectiveness of repiratory protection…

Effectiveness of behavioural interventions

• Results from a systematic review • 550 potentially relevant articles identified • 10 were considered informative

• Behavioural interventions had a limited positive impact upon exposure

• Not sufficient to just raise awareness of risks and controls, need to equip workers with skills to act on that knowledge

Lunt JA, Sheffield D, Bell N, et al. (2011) Review of preventative behavioural interventions for dermal and respiratory hazards. Occup Med (Lond);61:311–20.

Summary…• Focus on a practical definition of

elimination is helpful• Strategies to control exposure are well

understood• The effectiveness of the approaches we

use is less well defined, but there is sufficient data to know: • Respirators > Fixed local ventilation > Mobile

local ventilation > General ventilation > Behavioural controls

• There is great variability in effectiveness within a type of control measure