Silicosis in the 1990s.

OBJECTIVE: To describe state-based surveillance for silicosis that estimates prevalence of this condition, describes characteristics of affected individuals, and targets public health interventions. DESIGN: The data presented are a case series of patients with silicosis reported to a state health department. Patients were interviewed using a standardized questionnaire, chest radiographs interpreted by a "B-reader," pulmonary function tests obtained from medical records, and follow-back investigations conducted at the worksites where the cases had been exposed to silica. SETTING: All individuals with silicosis in the state of Michigan reported to the Michigan Department of Public Health (MDPH). SUBJECTS: Individuals included in this article were reported from 1987 through 1995. Cases were reported by hospitals, physicians, the state workers' compensation bureau, or from death certificates. Only data on individuals who met the criteria for silicosis developed by the National Institute for Occupational Safety and Health (NIOSH) are included. RESULTS: Between 1987 and 1995, 577 people were reported to MDPH who met the NIOSH criteria for silicosis. About 60% of the reports came from hospitals. The disease is occurring mainly among men born before 1940 who began working in a Michigan ferrous foundry in the 1930s or 1940s and worked there > 20 years. Over 40% of the patients are black. The overall annual average incidence rate of silicosis among black men (14.3 cases per 100,000) is seven times higher than among white men (2.1 cases per 100,000). The individuals identified with silicosis generally have severe disease. Almost 30% have progressive massive fibrosis and another 31.7% have advanced simple silicosis. Only about a third of all patients have normal results of breathing tests. Thirteen percent had been told they had tuberculosis (includes both clinical disease and a positive skin test). They have an increase of over 300% in the likelihood of dying of nonmalignant respiratory disease, both restrictive and obstructive, and an 80% increase in the likelihood of dying of lung cancer. Despite the severity of disease, over 45% of the individuals had not applied for workers' compensation. Although silicosis typically occurs after a long duration of exposure to silica, some individuals developed silicosis after a relatively short time. Three people developed silicosis who began working with silica in the 1980s, 18 in the 1970s, and 66 in the 1960s. Initial industrial hygiene follow-up inspections where the individuals had worked showed ongoing exposure above recommended and/or legal levels. Repeated inspections to these same facilities have subsequently shown reductions in silica exposure. CONCLUSION: This state-based surveillance system has proved useful in characterizing individuals with silicosis, estimating its prevalence, increasing the medical community's awareness of the condition, and targeting effective public health interventions.

Surveillance for occupational asthma--Michigan and New Jersey, 1988-1992.

PROBLEM/CONDITION: A case of occupational asthma is a sentinel health event indicating a need for preventive intervention. REPORTING PERIOD COVERED: 1988-1992. DESCRIPTION OF SYSTEMS: As part of the Sentinel Event Notification System for Occupational Risks (SENSOR) Program, initiated by CDC's National Institute for Occupational Safety and Health in 1987, state-based surveillance and intervention programs for occupational asthma (OA) have been under development in Michigan and New Jersey. The initial 5-year projects in these states have been completed. RESULTS: From 1988 through 1992, the SENSOR programs in these states identified a total of 535 cases of occupational asthma and related conditions. Of these 535 cases, 328 cases met the SENSOR surveillance case definition for OA. In addition, 128 cases were classified as possible OA, 42 as reactive airways dysfunction syndrome, and 37 as occupationally aggravated asthma. In both Michigan and New Jersey, manufacturing was the industrial sector with the largest proportion of cases. In Michigan, > 40% of the case-patients worked in transportation equipment manufacturing. In New Jersey, 15% of case-patients worked in manufacturing of chemicals and allied products. Overall, isocyanates were the most frequently reported asthma-causing agents (19.4% of cases). Follow-up industrial hygiene sampling measured suspect agents at airborne concentrations generally below the permissible exposure limits established by the Occupational Safety and Health Administration. INTERPRETATION: In its first 5 years, the SENSOR system has led to the identification of previously unrecognized causes of occupational asthma. Overall findings indicate the need for more comprehensive control of such well-known occupational allergens as the isocyanates. In addition, SENSOR interventions have prompted improvements in protection for workers. ACTIONS TAKEN: Approaches to state-based surveillance and intervention for OA are being developed through newly funded 5-year SENSOR projects in four states (California, Massachusetts, Michigan, and New Jersey). The goal is to develop a model for effective state-based OA surveillance that can be applied by any state health department.

Silicosis surveillance--Michigan, New Jersey, Ohio, and Wisconsin, 1987-1990.

PROBLEM/CONDITION: Improved surveillance for silicosis is needed to target interventions to prevent this occupational lung disease caused by the inhalation of crystalline silica dust. REPORTING PERIOD COVERED: 1987-1990. DESCRIPTION OF SYSTEMS: State-based silicosis surveillance and intervention programs have been developed in Michigan, New Jersey, Ohio, and Wisconsin as part of the Sentinel Event Notification System for Occupational Risks (SENSOR) Program, initiated in 1987 by the National Institute for Occupational Safety and Health (NIOSH). RESULTS: From 1987 through 1990, the SENSOR program confirmed a total of 430 cases of silicosis reported from these four states. Overall, approximately 60% of these cases were in workers employed in primary metal industries, although the types of industries in which cases occurred varied by state. Some cases were attributable to relatively recent exposure, including new cases in seven persons first exposed since 1980 in New Jersey. Silicosis case reports have prompted measurement of respirable silica concentrations at 25 Michigan work sites, and 14 (56%) of these sites were found to have levels that exceeded the legally permissible exposure level. INTERPRETATION: The silicosis surveillance and intervention strategies piloted by state health departments in the NIOSH-funded SENSOR Program have demonstrated the feasibility and effectiveness of identifying specific silica-using work sites that need preventive intervention. ACTIONS TAKEN: On the basis of initial experience in these four states, NIOSH developed guidelines for state-based silicosis surveillance and awarded SENSOR cooperative agreements to three additional states where the applicability of these surveillance methods will be further evaluated.