Presentation given as the McCallum Lecture at the 2012 BOHS conference.

1. WORKING FOR A HEALTHY FUTURE
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)
INSTITUTE OF OCCUPATIONAL MEDICINE . Edinburgh . UK www.iom-world.org

2. Robert Ian McCallum, CBE
b.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/ 2

3. 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
3

4. 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)
4

5. 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
5

6. 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
6

7. 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?
7

8. 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
8

9. The SHEcan project…
Management and stakeholder consultation
Manufactured
Review OEL setting procedures
generated
4 Process
Hardwood
chemicals
and VCM
Review exposure control
19
Socioeconomic/Environment impact
Assess risk
Estimate exposure levels
Estimate number exposed
9

10. Substances considered…
In Annex III
OELs Suggested by EC
Process generated
10

11. 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
11

12. Exposure assessment…
12

13. Exposure decreases over time…
Creely KS et al. (2007) Trends in inhalation exposure--a review of the data in
the published scientific literature. Ann OccupHyg.; 51(8): 665-678. 13

14. VCM levels in a English PVC plant
1000
y = 2E+30e-2.00x
VCM concentration (ppm)
R² = 0.740
100
10
1
1973 1974 1975
14

15. 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
15

16. 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)
16

17. 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
17

18. 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
18

19. 19

20. Number of people currently exposed…
20

21. currently
% currently above the proposed OEL…
21

22. Baseline health assessment…
22

23. Cancer cases prevented by OEL…
23

24. Crystalline silica - Registrations
24

25. Cost-benefit ratio…
Note, zero compliance costs because
exposure was already assessed to
be below the OEL investigated.
25

26. Strength of evidence…
• Respirable crystalline silica Strong case
• Chrome VI
• Hardwood dust
• Diesel engine exhaust A case
• Rubber fume
• Benzo[a]pyrene
• Trichloroethylene
A limited case
• Hydrazine
• Epichlorohydrin
• O-Toluidine
• Mineral oils as used engine oil
• MDA Uncertainty
26

27. 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
27