Appendix 2: Asbestos

What is Asbestos?

Asbestos is a term used to describe naturally occurring fibrous hydrated silicates of which there are six common varieties.

Figure 12 below shows the different types of asbestos.

Figure 12: Types of Asbestos

Amosite (brown asbestos) and crocidolite (blue asbestos) have straight needle-like fibres which naturally split in their long axis producing very fine fibrils (thin fibres). In contrast chrysotile (white asbestos) has softer curlier hair-like fibres, which makes them useful for weaving and have been used to make asbestos cloth for centuries.

When these fibres are inhaled they behave in different ways in the lungs.

Chrysotile (magnesium silicate) fibres slowly lose magnesium, which leaches into body fluids making the fibre more easily digested by scavenger cells (macrophages). This reduces the body burden of the asbestos dust, and has led to the view that white fibres are less harmful.

Crocidolite (iron-sodium silicate) fibres are straight and rigid and can split longitudinally. They are more resistant to body fluids and can survive unchanged in the body for up to 40 years or more. The fine fibrils can migrate through the lung tissue to the lung lining (pleura).

Amosite (iron magnesium silicate) fibres are longer, making it useful for insulation. Again, the fibres remain unchanged in the body for years.

Asbestos Awareness in New Zealand

1938 The introduction to the Report of the Interdepartmental Committee on Silicosis refers to asbestos as follows:

"In the working of asbestos the dust produced gives rise to a pulmonary condition known as asbestosis, which, although different in its character from silicosis, causes a disease similar in some respects to it. Free silica is not associated with asbestos, yet the fibres produce a deadly pulmonary disease."

1951 In the Annual Report of the Department of Health Dr Garland, Director of the Division of Occupational Health, Notes:

"Asbestos is now being quarried in the Dominion, and the dust can be expected to cause a certain amount of lung damage unless proper precautions are taken."

1953 Notification of occupational diseases introduced. No specific dentification of asbestos-related lung disease.

1960 Occupational Health Notes on Diseases Arising from Occupation published by the Department of Health:

"The fibrosis of asbestos is diffuse ...there is some statistical evidence for an increased incidence of bronchogenic carcinoma."

1964 A New Zealand standard is set for asbestos fibres in air.

1968 Dr Copplestone, Assistant Director (Occupational Health) initiates a New Zealand asbestos survey.

1971 Dr Allingham, who succeeded Dr Copplestone, reports on the survey:

"207 workers surveyed. 101 workers x-rayed. 17 showed pleural changes (one case later confirmed as asbestosis)."

1977 Environmental Dust Laboratory established to identify asbestos fibres in air.

1978 Asbestos Regulations promulgated.

1981 The allowable concentration for asbestos fibres (other than crocidolite fibres) was reduced from 2 fibres/ml to 1 fibre/ml. Crocidolite remained at 0.2 fibres/ml over a 10-minute sampling period.

1982 Jim Butterworth, Auckland Secretary, NZ Engineers Union, expresses concern about long-term effects of asbestos on workers at James Hardie factory.

1983 Interim Report of Workers at James Hardie (unpublished) Kjellstrom T and Rennie F. Of 353 workers x-rayed, 53 showed parenchymal and/or pleural changes. An increasing percentage of abnormalities found over time since first exposure.

Asbestos Regulations replace 1978 regulations.

Gazette notice reduced air standard for crocidolite to 0.1 fibre/ml over 4 hours.

1984 Relative Cancer Risks from Exposure to Different Asbestos Fibre Types. J. Keir Howard, NZ Medical Journal 97; 646-9. In this review article, the point is made that:

"...considerable amounts of crocidolite were used in the past, particularly in insulation, and as New Zealand did not restrict the use of the amphiboles until well after most industrialised nations had done so, the use of blue asbestos continued for longer in this country."

Importation of blue and brown asbestos banned in New Zealand.

1987 Asbestos Regulations 1983, Amendment No. 1, tightens provisions for medical examinations.

1988 Thelma Bell, widow of asbestosis victim Clarrie, organises a public meeting in Christchurch.

Barry Brown, Secretary of the South Island Labourers Union, arranges for Maevis Watson, Occupational Health Nurse and Associate Professor Bill Glass from the Otago Medical School, to interview ex-Fletcher workers from the Mandeville Street plant.

Cate Brett - Christchurch Star - highlights the tragedy of asbestos use.

1989 Robin McKenzie, Engineer with NZED (New Zealand Electricity Department), is diagnosed as suffering from mesothelioma. In 1990, his lawyer took legal action against the Crown. Media coverage keeps up public concern.

1990 Review of Fletcher's Mandeville Street Factory (unpublished) Glass W.I. 103 workers contacted. 87 investigated. 47 cases of asbestos-related conditions (plus 7 probable cases). 12 deaths to date.

Hon. Bill Birch, Minister of Labour, establishes the Asbestos Advisory Committee in October to report on all aspects of asbestos exposure in New Zealand.

1991 Lung Cancer, Smoking and Exposure to Asbestos in New Zealand. Glass W.I; Kawachi I., Pearce N. Journal of Occupational Health Safety 7 (1).

"Case control studies based on NZ Cancer Registry showed that asbestos-related occupations were found to be associated with elevated risks of cancer in the lung, pleura and peritoneum. The risks of cancer in these three sites were highest among the group comprising machinery fitters, plumbers, welders, boilermakers, metal moulders, metal polishers and electricians."

Report of the Asbestos Advisory Committee presented to the Minister in April and Minister decides to implement the recommendations following Cabinet approval in August.

Tim Frederiksen establishes the Asbestos Victim and Support Group, which later became the Asbestos Disease Association of New Zealand.

1992 In March a National Asbestos Register was established (recommendation 4 of the Report). This Register was to be in two parts: Part 1 for those who had been exposed and Part 2 for those suffering from an asbestos-related disease. The Occupational Safety and Health Service of the Department of Labour was appointed to administer the registers.

ECNZ (Electricity Corporation of New Zealand) combines with the Department of Labour to publicise asbestos hazards.

An audit of floor sanders and work practices involving asbestos-backed vinyl sheeting in the Christchurch area was carried out by KD Sheat and published by OSH (Department of Labour).

ACC lump sum entitlements for asbestos-related claims ceased.

1993 The first Annual Report of the National Asbestos Registers confirming 199 cases of asbestos-related disease.

(March) Rights to initiate common law claims in regard to asbestos-related conditions ceased.

ECNZ establishes model asbestos surveillance programme of current and past employees.

Secondary cases of asbestos disease found to occur in family members of asbestos workers whose only exposure was to dust, brought to the home from the workplace.

1994 The second annual report reviews and confirms a total of 462 cases of asbestos-related diseases.

Visit by Professor Margaret Becklake, International Asbestos Authority, to advise on registers.

1995 Asbestos Exposure and Disease Notes for Medical Practitioners published by Department of Labour.

1995/96 The third annual report confirms 535 cases.

1996 The Management of Asbestos in the Non-Occupational Environment published by Ministry of Health.

1996/97 The fourth annual report of the National Asbestos Register notes an increase in occurrence of mesothelioma cases.

1997 The Asbestos Medical Panel published its first report based on a review of asbestos cement-exposed workers on the exposure register. 2257 notifications were reviewed. A positive finding was a non-specific association between cumulative asbestos exposure and a questionnaire diagnosis of asthma.

1998 Health and Safety in Employment (Asbestos) Regulations 1998 promulgated.

1999 Visit by Professor Corbett McDonald and Professor Alison McDonald to advise on updated information on mesothelioma.

Asbestos and the New Millennium published. Prepared by Lois Syret and Ed Grootegoed on behalf of The Asbestos Association of New Zealand.

2000 Mesothelioma in New Zealand, the second study by the National Asbestos Medical Panel.

Increased Mesothelioma Incidence in New Zealand. T Kjellstrom, P. Smartt. NZMJ, November.

Lung function changes in asbestos-exposed workers with pleural plaques, the third study by the National Asbestos Medical Panel.

2001 Asbestos New Zealand 2001, Lois J Syret and A.H. Grootegoed.

Occupational Safety and Health Review of Guidelines for the Management and Removal of Asbestos.

Asbestos Exposure in New Zealand. Bill Glass, New Ethicals, August.

2003 The New Zealand National Asbestos Registers 1992 to 2001, Lessons Learned. Presented at Asbestos Symposium Seoul National University, Korea by Bill Glass.

The Epidemic of Asbestos-related Diseases in New Zealand. Int. J. Occup - Environ Health 10.2 June 2004 Tord Kjellstrom.

2004 Mortality and Morbidity in Asbestos Exposure in New Zealand: The Hidden Legacy of Asbestos Exposure. NZ Med J 117; 117: 1 P Smartt.

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