Medical Screening Program for Sheet Metal Workers
The Sheet Metal Occupational Health Institute Trust (SMOHIT) was formed in 1985 by the Sheet Metal Workers International Association (SMWIA) and the Sheet Metal and Air Conditioning National Association to study the health hazards of the sheet metal industry. Sheet metal work includes tasks entailing fabrication or installation of metal products. Respiratory hazards identified with sheet metal work include exposure to asbestos, welding fumes, and man-made vitreous fibers, primarily fiberglass. Starting in 1986, SMOHIT contracted with clinical facilities in the United States and Canada to offer a standardized asbestos disease screening program for sheet metal workers who were first employed in the industry at least 20 years earlier. Participating medical facilities and physicians are chosen by Laura Welch , MD, in consultation with the staff of SMOHIT, based on the clinic’s experience in conducting similar screening programs in the past. The physicians agree to complete standardized reporting forms, to classify the chest x-rays using the ILO classification, and to follow the American Thoracic Society standards for conducting pulmonary function testing. Work and medical history questionnaires are self-administered and subsequently reviewed by the clinic staff. Results of the examinations are given to the individuals with a standardized notification letter, and also are discussed in a meeting held with all participants after the examinations. As of the end of 2012, more than 25,000 workers and 100 facilities had participated in the program.
SMOHIT/CPWR Research on Occupational Disease Among Sheet Metal Workers
Key findings from the SMOHIT-sponsored surveillance program for the United States are:
- An analysis of the 18,211 individuals who were examined between 1986 and 2004 was conducted. The mean age was 57.9 years, and the participants had worked an average of 32.9 years (+ 6 years) in the sheet metal trade. Twenty-three percent were current smokers, 49% were former smokers, and 28% had never smoked. 9.6% (1,745) had findings consistent with parenchymal disease (ILO > 1/0); 60% of those with ILO score > 1/0 were classified as 1/0, 34% as 1/1-1/2, and 6% as 2/1 or higher. 21% (3,827) had pleural scarring. There was a lower prevalence of asbestos related disease among those who began work after 1970 when compared to workers who began work before 1949. The strongest predictor of asbestos-related disease on chest x-ray was the calendar year in which the worker began sheet metal work, with work in a shipyard also an important risk.
- Sheet metal workers have a very high risk for mesothelioma, a cancer that is almost exclusively caused by asbestos.
- Sheet metal workers also have an elevated risk for lung cancer, beyond what would be expected based on smoking alone. Risk increases with increasing amount of asbestos-related disease on chest x-ray.
- Sheet metal workers with estimated high exposures to man-made vitreous fibers, primarily fiberglass, have more chronic bronchitis and obstructive lung disease than do sheet metal workers without that exposure.
- The task of hanging duct was associated with shoulder pain and shoulder injuries among both active and disabled sheet metal workers. Hand tool use and time spent in a sheet metal shop, which includes hand-intensive work, was associated with symptomatic hand cumulative trauma disorder.
- Current investigations in the SMOHIT sponsored surveillance program include:
• Causes of death among surveillance program participants
• Work factors associated with obstructive lung disease in sheet metal workers
• Impact of asbestos-related pleural disease on lung function in sheet metal