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COPD study in the aluminium industry (ALIAS)
started Autumn 2012 and is to be terminated December 2015
Participating plants:
- Rio Tinto Alcan á Íslandi
- Alcoa Fjarðaál
- Alcoa Lista
- Alcoa Mosjøen
- Hydro Aluminium Høyanger
- Hydro Aluminium Karmøy
- Hydro Aluminium Sunndal
- Hydro Aluminium Årdal
- Hydro Vigelands Brug
- Kubikenborg Aluminium
- Sør-Norge Aluminium
Background
Chronic obstructive pulmonary disease (COPD) is characterized by increased respiratory resistance. Definition of COPD has changed over the past 50 - 60 years. The definition of the disease that is used today both internationally and in Norway was developed by GOLD (Appendix 1). GOLD came up with the first definition in 2001. The last revision came in 2011. Common to both of these definitions is that COPD is diagnosed by spirometry (Appendix 2), that the disease is characterized by chronic inflammation of the airways and lung tissues and that this inflammation is caused by exposure to harmful particles and gases. Smoking is by far the main cause of COPD, but constantly several studies suggest that exposures to dust and gas in the atmosphere may contribute to the development of the disease. It should also be emphasised that the disorder can be prevented.
Repeated examinations by spirometry of older people show that lung function falls as we age, also in healthy people. This happens right from 25 to 30 years of age. People who develop COPD have a faster drop in lung function than people that stay healthy. When the values have fallen below a certain limit, we say that they have developed COPD. There are several degrees of severity of the disease. Moreover, it tends to worsen over time as the patient ages. Patients with advanced COPD are rarely employable. The number of people who die of COPD is increasing in Norway and most other countries. By 2020 one figures that COPD will be the 4th main cause of death worldwide.
In the aluminium industry employees are exposed to both particles and gases that can be harmful to the respiratory tract and lungs. Therefore, one may well imagine that COPD is a topical issue in this industry. Moreover, the aluminium industry has well developed occupational health services (OHS) working preventive. They can thus identify people who develop COPD and may arrange preventive action.
Moreover, the OHS in the aluminium industry has ever since 1986 performed systematic monitoring of employees in the pot rooms in terms of respiratory disorders. This work was initiated to monitor the incidence of asthma among employees. Monitoring consisted of yearly follow-ups of pot room operators with questions form about respiratory symptoms, smoking habits and work tasks. In addition, it has been performed yearly spirometry surveys.
Since asthma and COPD has a number of common features, this surveillance provides a basis to determine whether the exposure in pot rooms contributes to the development of COPD. It can be about a direct influence that leads to COPD or indirectly by allowing people with asthma to develop a chronic increased respiratory resistance (COPD).
In addition to good health surveillance over many years, the aluminium industry has performed a systematic exposure monitoring with equipment for personal sampling to the registration of the work atmosphere. These measurements were related to defined job categories in the pot rooms. Job categories are also listed for individual operators who have participated in the health surveillance. This work was to a large extent co-ordinated between the plants through AMS. Furthermore, it should also be added that several of the Norwegian aluminium plants were among the first companies to introduce smoking restrictions.
Objectives for the survey
If one combines environmental data and health data, one can examine whether there is an increased risk of COPD for pot room operators by examining the annual drop in lung function and whether the number of new cases of COPD increases with increasing exposure to dust or fluorides.
The time has come to leverage the data collected to investigate whether there is a correlation between the incidence of COPD and exposure. The goal of such survey is to
- create a job exposure matrix for electrolysis operators
- examine the impact of smoking intervention on respiratory function and the incidence of COPD
- investigate the association between exposure and
- the annual drop in lung function (ml/year).
- number of new cases of COPD per year.
Material
The survey will be limited to the Norwegian aluminium plants and first and foremost one will concentrate on a cohort 1 (1986 - 95, 10 years). Health data for this cohort is already ready with anonymized data (see Appendix 3). This cohort contains also health data (including anonymized) from the control group in the Hydro Holmestrand, Fundo Høyanger and (at that time) Vegvesenet in Mosjøen. Since this data is anonymized, one does not need informed consent.
Exposure
The aluminium industry made during the 1980s use of a system of registration of exposure in pot rooms. Equipment for personal sampling was used. Here is also included a standardized job classification of the tasks. There have been some differences between the plants when it comes to the content of these job codes. Job content for each of the codes used may have been somewhat different between the plants, and it may certainly have changed somewhat during the time elapsed since this work began. Lessons learned from the ALSA study are that it is needed to update at each plant. This task must be executed by the project manager in consultation with the supervisors and those who have been responsible for the personal sampling.
Organizing
Professor Vidar Søyseth, Akershus University Hospital, is leading the project.
Appendix 1: GOLD
GOLD is short for Global Initiative of Obstructive Lung Disease as collaboration between the World Health Organization (WHO) and the National Heart Lung and Blood Institute (NHLBI). WHO is an organization of the UN system, while the NHLBI is a part of the National Institutes of Health (NIH), which is an institution under the USAs Department of Health and Human Services Department. WHOs and NHLBIs collaboration on COPD started in the late 1990s and were put together in the organisation GOLD (Global Initiative of Obstructive Lung Disease, www.goldcopd.org). The academic part of GOLD is headed now by prominent members of the American and the European Pulmonary Physician Association (ATS and ERS).
Appendix 2: Spirometry
Spirometry is measured by so-called dynamic lung volumes. The two most important are called forced volume capacity (FVC), forced expiratory volume (FEV1) for one second. The test is performed by having the person to draw in the breath until the lungs are completely filled and then blowing out in full force for at least 6 seconds. FVC is the volume that he or she has blown out when the blow is terminated. FEV1 is the volume that he or she has blown out during the first second.
Appendix 3: Cohort 1
Includes the so-called ALSA study from 01.01.86 - 31.12.95. There were seven Norwegian plants (Lista, Karmøy, Høyanger, Søral, Årdal, Sunndal, Mosjøen) and 1 from Sweden (Gränges) and 1 from Iceland (Isal). Control groups came from Holmestrand (rolled), Fundo (RIM manufacturer, Høyanger) and Veivesenet (Mosjøen). Annual surveys with questionnaires and spirometry.
Acronym ALIAS
stands for Airflow Limitation In the Aluminium induStry
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