International Review of Surveillance and Control of Workplace Exposures: NOHSAC Technical Report 5
3.4 Operators of surveillance systems
Workers’ health surveillance is conducted within most industrialised countries and focuses on a range of injuries, illnesses and diseases, using a variety of centralised reporting systems. Notably the Surveillance of Work-related Occupational Respiratory Disease (SWORD) has been in place in the UK since 1989. This system originally focused on respiratory disease and has, over time, evolved into separate but linked systems known collectively as the Occupational Disease Intelligence Network (ODIN). The ODIN network now reports on infectious disease, skin disease, hearing loss and mental ill-health by hospital specialists and by occupational physicians and is colloquially known as Occupational Physicians Reporting Activity (OPRA). A 1997 inclusion to the ODIN scheme is MOSS (Musculoskeletal Occupational Surveillance Scheme). This reporting scheme, which operates with the full support of the British Society of Rheumatology, describes the pattern of new cases of work-related musculoskeletal disease within the UK. The relationship between the systems is illustrated in Figure 5.
Various workers’ health surveillance systems in Australia have been identified by Sim, O’Keeffe and Shaw. The focus of this review is, however, on work environment surveillance systems, and workers’ health surveillance systems will not, therefore, be discussed further, except where their co-relation with work environment surveillance systems demands this. This is not to imply that workers’ health surveillance systems are of any lesser importance in the general discipline of occupational health surveillance.
The USA and continental Europe reflect the regions where there is similarly activity in regard to work environment surveillance. While there is limited critical information and evaluation of these systems in the formal literature, a number of national approaches have been described. In the USA, for example, NIOSH pioneered hazard surveillance in the workplace by designing and conducting the 1972–1974 National Occupational Hazard Survey (NOHS), the 1981–1983 National Occupational Exposure Survey (NOES), and the 1984–1989 National Occupational Health Survey of Mining (NOHSM). The databases developed from these three surveys represent unique resources for associating potential chemical, physical and biological agents with industries and occupational groups. The data have been a primary source of information for NIOSH, regulatory agencies, health professionals, researchers, and labour organisations in establishing priorities for prevention strategies that include medical and engineering interventions, development of occupational standards and the identification of research needs.
Nurminen and Karjalainen estimated the proportion of annual deaths related to occupational factors in Finland. A Finnish job exposure matrix supplied data on the prevalence of exposure for specific agents and the level of exposure among exposed workers. The attributable fraction of work-related mortality in the relevant disease and age categories was estimated. They obtained estimates for specific important diseases including lung cancer, ischemic heart disease, chronic obstructive pulmonary disease and stroke.
The Finnish Institute of Occupational Health (FIOH) collects, analyses, evaluates and disseminates information on occupational hazards, health and work organisations. FIOH maintains the following registers and databases on exposures for surveillance, hazard control, epidemiology and risk assessment purposes:
- Finnish Job Exposure Matrix (FINJEM Exposure Information System)
- Register of Occupational Hygiene Measurements
- Register of Workers Exposed to Carcinogens (ASA Register)
- Biomonitoring Database, (5) International Database on Exposure Measurements in the Pulp, Paper and Paper Product Industries
- International Information System on Occupational Exposure to Carcinogens (CAREX).
Stamm has described the German Berufsgenossenschaften (BG) MEGA, which is the chemical workplace exposure database of the Institute for Occupational Safety (BIA). The inspectorates of the BGs conduct workplace measurements of chemical and biological agents and all data are stored in the MEGA-database. MEGA is used by BIA and the BGs for prevention, epidemiological questions and investigations of occupational diseases.
Occupational exposure data measured by the hygiene laboratories in Hungary have been collected for more than 20 years. The data refer to the air contaminants and to the biological monitoring.
Ritchie and Cherrie have described a prototype occupational exposure database that was developed as part of a study to retrospectively collect chemical exposure data from UK industry. The data dictionary for the database was constructed using existing recommendations on core data elements developed by working groups from the ACGIH and the European Union. The study also made use of existing job and workplace coding schemes. The practicalities of gathering the data by voluntary donation, its storage in a database, and the transfer of suitably anonymised data to the UK Health and Safety Executive’s National Exposure Database system were investigated and assessed.
Professional bodies are also engaged with the subject. Following the recommendations of the European Working Group on Exposure Databases, a Working Group (on Storage of Data of Measurements of Occupational Exposure) of the Dutch Occupational Hygiene Society developed a guideline. This guideline concentrates on the data elements required when storing exposure data. Van Dyke et al have reported the development of an occupational exposure database and surveillance system for use by one industry-based group of health and safety professionals at a former US nuclear weapons production facility. The system was developed with the intent of helping health and safety personnel not only to manage and analyse exposure monitoring data, but also to identify exposure determinants during the highly variable clean-up work.
References to work environment surveillance in Australia and New Zealand in the formal literature are very few. In the major study of magnitude of the occupational disease in Australia, Kerr et al refer to the large gaps in the knowledge about industry and social costs of hazardous substance-related illness and disease, and while national databases provide a fairly broad perspective of the problem, they do not permit the examination of the detail that is needed to reduce the burden of hazardous substance exposure. They envisage a national surveillance strategy that includes exposure surveillance as one component. In their review of the burden of occupational disease and injury in New Zealand, Driscoll et al identify that there is little information available on occupational exposures in that country and “the information that was available was rarely comprehensive” (p169). The authors suggest that an increased focus on exposures seems appropriate.
In regard to industry-based surveillance systems and databases, the UK Health and Safety Executive has stored chemical exposure data in their National Exposure Database for some years. However, it has been difficult to persuade industry and other organisations to contribute to this resource. Cherrie et al also report on a project to devise a cost-effective method of obtaining occupational exposure data on chemicals from UK industry and other sources.
Marchant et al have described a voluntary workplace safety programme for workers involved in the manufacture, fabrication, installation and removal of glass wool and mineral wool products. The exposure database included approximately 6,000 exposure samples at the time of writing, making it the most extensive exposure dataset on record for glass wool and mineral wool. Also in the construction sector, Becker, Flanagan and Akladios have described the development of an ACGIH construction industry silica exposure database.
Farmers in British Columbia (BC), Canada have been shown to have unexplained elevated proportional mortality rates for several cancers. This has led to the establishment of a quantitative agricultural job exposure matrix (JEM), containing exposure assessments from 1950 to 1998. This JEM was developed to document historical exposures and to facilitate future epidemiological studies. Available information regarding BC farming practices was compiled, and checklists of potential exposures were produced for each crop. Exposures identified included chemical, biological and physical agents.
In Australia, Benke et al developed a task exposure database (TED) to facilitate data collation for construction of a task exposure matrix (TEM) for a series of studies on cancer and respiratory morbidity in the alumina and primary aluminium industry. Following the construction of job classifications for the study sites, the site hygienists identified all historical air monitoring time-weighted average (TWA) data from their respective sites. The earliest data were sampled in the late 1970s, and over 17,000 personal samples were recorded over the eight sites over a twenty-year period.
Money has described the European chemical industry’s needs and expectations for workplace exposure data. He explains that information on exposure data was characterised by its inconsistent quality and significant gaps. These were particularly apparent amongst small- and medium-sized companies. He describes the European Chemical Industry Council (CEFIC) initiative to develop a tool which aims, by virtue of it being seen as an integral part of business management software, to collect relevant exposure information across key sectors of the chemical industry. In regard to compiling a quantitative exposure database, Caldwell et al point out that an all too common limitation of the published literature was the incomplete reporting of results of exposure estimates by the authors.
Sabic et al’s review of possible applications of the NOHSC minimum dataset in Australia noted that there is a variety of data held by individual employers, including registers of hazardous substances present at the workplace, and records of health surveillance for prescribed substances. They recognised that these data have the potential to provide information on exposure but appear to be fragmented, and the degree of under-reporting and its statistical validity is not clear. They conclude that, at this stage, information from such data sources should be treated with caution.
In 2003, Smulders undertook a review and analysis of a selection of 23 European OSH monitoring systems. These systems included workers’ health surveillance and work environment surveillance systems that employed a variety of data collection techniques (i.e. worker surveys, databases, registers of accidents, diseases and/or absenteeism, policy-directed systems and intervention, and OSH management oriented systems). Smulders reports that many of the 23 European OSH monitoring systems reviewed include many more aspects than the health and safety aspects, as defined in the narrow definition of the EC (accidents, diseases and stress). The review suggests that the systems fall into one of three groups; group 1 systems represent the traditional health and safety outcome monitoring systems; group 2 systems (with their emphasis on different work and working conditions, as well as accidents and ill-health) tend to be much more quality of work systems, based on surveys and qualitative assessments; group 3 systems (with their emphasis on safety, substances and OSH management) seem to represent an intermediate position. Smulders recommends that the results of this study should be examined in relation to the work and health country profiles report by Rantanen et al. This report recommends core indicators for:
- an OHS system (such as human resources in labour safety inspection, labour safety at workplaces, occupational health services; coverage of occupational health services)
- working conditions (noise, dangerous products or substances, asbestos and pesticide consumption, carrying or moving heavy loads, working at very high speed, working at least 50 hours per week)
- OSH outcomes (fatal and non-fatal work accidents, occupational diseases, perceived work ability).
The Smulders study shows that there are almost no monitoring systems available that include all the “core indicators”. The use of more than one monitoring system per country seems to be needed to gather the information for these work and health country profile reports. Multi-source reports prepared yearly in Germany and the Netherlands have much in common with the work and health country profile reports advocated by the FIOH and the WHO.