Asbestos Exposure in New Zealand 1992 to 2005
Appendix 1: Background to the Registers
The National Asbestos Registers were established in March 1992 in line with the recommendations made to the Minister of Labour by the Asbestos Advisory Committee.
Formation of the Asbestos Advisory Committee
The Asbestos Advisory Committee was established in October 1990 as an ad hoc body to report to the Minister of Labour on issues relating to the health effects and use of asbestos in New Zealand, adequacy of controls and legislation, and clarification of the legal entitlements available for affected workers. This followed increasing public concern about the past and present effects of asbestos on workers, former workers and their families.
Establishment of the National Asbestos Registers
Recommendation 4 of the Report of the Asbestos Advisory Committee to the Minister of Labour advised:
"That an asbestos medical register be established for people who have been significantly exposed to asbestos. OSH should be the organisation responsible for establishing, maintaining and funding the medical register.
The medical register should be in two parts:
Part 1 - Those notified as having been exposed to asbestos;
Part 2 - Those notified as having an asbestos-related disease.
The system should allow movement of the name of a registered person from part 1 to part 2 of the register when indicated.
Notifications to part 1 of the medical register were to be made by those who felt that they had been exposed to asbestos, or by people acting on their behalf (and following consultation) such as an employer, union official, relative or friend.
Notification to part 2 of the medical register would be done by medical practitioners."
A Notifiable Occupation Disease System (NODS) was established in 1992 and asbestos registers have been incorporated in that scheme. This was in accordance with recommendation 5 of the Asbestos Advisory Committee.
Asbestos Exposure Register
- Exposed person notifies registrar
- Form sent by registrar
- Data coded (symptoms, work history, smoking history)
- Information booklet posted
The Occupational Safety and Health Service of the Department of Labour (OSH - no longer exists as a separate brand entity), in association with the Electricorp Production, undertook an extensive advertising campaign in March and April 1992. Advertisements were published in all the major newspapers, and several trade magazines.
The interest generated as a result of this campaign has ensured a high response rate for the exposure register. Notifications have been made by individuals, trade unions, occupational health nurses, doctors, the Asbestos Diseases Association of New Zealand and by some larger companies.
Notifications are directed to branch offices of the Department or directly to the registrar.
In recommendation 4, the committee had envisaged that people wishing to be recorded on the asbestos exposure register would have their exposure assessed at an office of the Department. Only those people who were judged as having had 'significant exposure' would then be recorded on this register. However, the huge response from those individuals who had been exposed made it impractical to screen registrants in this fashion.
Once a person has notified the Department of Labour that they have been exposed to asbestos, an asbestos exposure registration form is sent. The registration form collects information about the individual, their work exposure to asbestos and the state of their respiratory health.
When the completed form is returned to the registrar the details are recorded on a database. The individual is then sent a copy of Asbestos - A Deadly Dust, which is dedicated to asbestos and its associated health problems. If the person indicates that they have a family doctor, the doctor is informed that their patient has been included on the Asbestos Exposure Register, and is sent a copy of the Department's booklet Asbestos Exposure and Disease: Notes for Medical Practitioners.
Asbestos Disease Register
- Patient notified to register
- Information collected (clinical, occupational, x-ray, lung function)
- Information reviewed by medical panel
- Confirmation of diagnosis sent to patient and patient's doctor
Tenders for the National Asbestos Medical Panel were called for in 1991. A tender was accepted on 31 October 1991. The successful tender came form the group listed below:
Dr R Armstrong, Professor R Beasley, Dr J Crane, Associate Professor W Glass, Dr D Jones, Dr N Pearce
Dr Beasley retired upon his appointment as Professor of Medicine at the Wellington Clinical School. Dr Crane joined the national Occupational Asthma Panel. Dr D Fishwick joined the panel in 1997. He was subsequently appointed to a position in the Uunited Kingdom.
The first meeting of the panel was held in February 1992.
Associate Professor Glass was nominated as the panel's convenor.
The following members were appointed to the National Asbestos Radiological Panel: Dr Paul White, Dr George Foote, Dr Graeme Anderson.
The Registrar from 1991 to 1996 was Mr Craig Eades. From 1996 to 1998 the position was held by Ms Nicola Holden, and later in the year by Ms Andrea Eng until 1999 when Ms Louisa Thomas was appointed.
In 2002 Ms Jenny West was the Registrar with Mr Dougal McNeill Registrar in 2004 and Ms Gail Abel in 2006.
Processes for registering people
Notifications for the register come from two major sources. The first from doctors whose patients have been diagnosed, or were suspected of having, an asbestos-related disease. The second source of notification was from the individuals themselves. Once a notification was made to the Registrar, and consent has been gained from the person concerned, relevant medical records and a full occupational history are obtained.
Data collection
The data collected includes a medical history, an occupational history, chest x-ray, CT scan where available, lung function tests, and pathology reports. On notification being received by the registrar:
- An occupational health nurse visits the patient and conducts a health interview, a detailed occupational and social (including smoking) history.
- Relevant medical reports are obtained from general practitioners and physicians.
- A PA chest x-ray is obtained, and read by a radiologist according to ILO (1980) guidelines. CTs are used where available, and on occasions requested.
- Lung function data is obtained from physicians' reports or requested from respiratory laboratories. Where this is not possible, results are obtained from a test carried out by an occupational health nurse, using a portable spirometer.
- Pathology and postmortem reports are reviewed where available.
Exposure Index
D (Exposure Index) = A (Years) x B (Intensity) x C (Degree)
This is calculated for each job and total exposure is the sum of each D.
Data assessment
The National Asbestos Medical Panel reviewed the information obtained, calculated an exposure index (see below) and correlated the medical data.
Exposure index
An exposure index (D) was calculated from the product of years of asbestos exposure (A); intensity of exposure, using a 1-5 grading according to job category (B); and degree of exposure, using a 3-point grading (C).
Guidelines for calculating this index are shown below.
A = Total years of exposure in any one job
B = Job intensity as follows
- Mining, milling and processing = 5
- Boiler/lagging, rail carriages, shipyard, spraying insulation = 4
- Asbestos cement products, construction, demolition, removal = 3 Electrical, friction products = 2
- Loading, driving, environmental = 1
C = Degree of exposure (unprotected)
- Continuous (>50% of work) = 5
- Intermittent (20-50% of work) = 2
- Minimal (<20% or occasional) = 1
D = A x B x C for each job
- Exposure index = sum of all Ds
- Medical data
- Relevant respiratory symptoms and signs were recorded from the medical histories, and lung function data was classified into restrictive, obstructive, mixed or normal. Pathology reports were used to confirm mesotheliomas and classify lung cancers.
Classification of diagnostic categories
On the basis of the foregoing, the cases were placed into a primary diagnostic category of:
- mesothelioma
- lung cancer
- asbestosis
- pleural abnormalities (plaques, diffuse bilateral pleural thickening and effusions)
- other cancers
- obstructive lung disease without x-ray changes.
