HC Deb 02 April 1998 vol 309 cc599-601W
Dr. Godman

To ask the Secretary of State for the Environment, Transport and the Regions (1) what health consequences, expressed in terms of numbers of mesotheliomas or lung cancers in smokers and non-smokers per million persons exposed, are assumed to result from occupational exposure to chrysotile asbestos at airborne fibre concentrations of (i) 0.6, (ii) 0.5 and (iii) 0.3 fibres/millilitre for 40 hours per working week for 20 years; and if he will make a statement; [36744]

(2) what health consequences, expressed in terms of numbers of mesotheliomas or lung cancers in smokers and non-smokers per million persons exposed, are assumed to result from environmental exposure to chrysotile asbestos at airborne fibre concentrations of (i) 0.01, (ii) 0.001 and (iii) 0.0001 fibres/millilitre for 140 hours per week for (a) 10, (b) 20 and (c) 40 years; and if he will make a statement. [36745]

Angela Eagle

Whilst the risks to health of white asbestos are scientifically established, there is considerable quantitative uncertainty about the health consequences of exposure to chrysotile asbestos. This is illustrated by Health and Safety Executive (HSE) estimates shown in the following tables, based on two key occupational cohorts: the Quebec chrysotile mines, and an asbestos textile plant in Carolina. The estimates are extrapolated from observations made at very much higher exposure levels.

Average lifetime risk of lung cancer per million men exposed to chrysotile
Duration of exposure (years) Cohort study used to estimate risk
Exposure scenario Textiles Mining
Per week 10.00 500.00 25.00
140 hours per week at 0.01 f/ml 20.00 1,000.00 50.00
at 0.01 f/ml 40.00 1,750.00 90.00
40 hours per week at 0.6 f/ml 20.00 17,500.00 850.00

Average lifetime risk of mesothelioma per million men exposed to chrysotile
Duration of exposure (years) Cohort study used to estimate risk
Exposure scenario Textiles Mining
Per week 10.00 35.00 6.00
140 hours per week at 0.01 f/ml 20.00 55.00 8.00
at 0.01 f/ml 40.00 60.00 9.00
40 hours per week at 0.6 f/ml at 0.6 f/ml 20.00 900.00 125.00

The risks are average estimates from working populations with a mixture of smokers and non-smokers. Smoking does not affect the risks for mesothelioma but smokers are estimated to have a 50 per cent. higher risk of lung cancer than shown in the table and non-smokers a risk about ten times lower. Based on past smoking patterns, women's average risk will be about half the average male risk.

Risks at exposure concentrations other than those shown can be estimated pro-rata, although this may be an overestimate at very low exposures.

The environmental risk from asbestos has been examined in a report commissioned by Department of the Environment, Transport and the Regions from the Medical Research Council's Institute for Environmental Health—'Fibrous Materials in the Environment'. The report identifies background ambient levels of respirable asbestos fibres may range from 0.000001 to 0.0001 f/ml. Most indoor air concentrations of asbestos are below 0.0002 f/ml which rises to around 0.0005 f/ml in buildings which contain asbestos in good condition. At these low levels of exposure, there is no significant risk of mesothelioma or lung cancer. Cigarette smoking remains the major cause of cancer.

I am pleased that Health and Safety Commission (HSC) will be issuing a consultative document on asbestos within the next four weeks proposing a wide range of additional legislation to protect workers. The current occupational exposure control limit for chrysotile is 0.5 f/ml (averaged over any continuous four hour period) and HSC propose to lower this limit to 0.3 f/ml and to impose duties on employers to ensure that exposure is controlled as far below this level as is reasonably practicable.

Dr. Godman

To ask the Secretary of State for the Environment, Transport and the Regions what account the decision not to implement a total ban on the importation and use, or re-use, of chrysotile asbestos took of the relative risks to health associated with chrysotile asbestos and possible substitutes; and if he will make a statement. [36746]

Angela Eagle

The decision of the Health and Safety Commission (HSC) to delay consultation on further restrictions on the use of chrysotile asbestos was taken in the light of an interim opinion by a European Commission Scientific Committee. This Committee concluded that insufficient evidence had been provided to justify a conclusion that substitute fibres are safer than chrysotile. The Government's resolve to pursue further necessary restrictions on chrysotile asbestos remains. HSC is expediting the presentation of further scientific justification for the use of substitutes to the European Commission.

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