Surveillance of work-related asthma in selected U.S. states using surveillance guidelines for state health departments--California, Massachusetts, Michigan, and New Jersey, 1993-1995.

PROBLEM/CONDITION: Cases of work-related asthma (WRA) are sentinel health events that indicate the need for preventive intervention. WRA includes new-onset asthma caused by workplace exposure to sensitizers or irritants and preexisting asthma exacerbated by workplace exposures. REPORTING PERIOD: This report reviews cases of WRA identified by state health departments from January 1, 1993, through December 31, 1995, as well as follow-up investigations of cases and associated workplaces conducted through June 30, 1998. DESCRIPTION OF THE SYSTEMS: State-based surveillance and intervention programs for WRA are conducted in California, Massachusetts, Michigan, and New Jersey as part of the Sentinel Event Notification Systems for Occupational Risks (SENSOR) cooperative agreement program, initiated by CDC's National Institute for Occupational Safety and Health (NIOSH). RESULTS: From 1993 through 1995, a total of 1,101 cases of WRA were identified by SENSOR surveillance staff members in California, Massachusetts, Michigan, and New Jersey. Of these 1,101 cases, 19.1% were classified as work-aggravated asthma, and 80.9% were classified as new-onset asthma. Objective evidence substantiating asthma work-relatedness was documented in the medical records of 3.4% of WRA cases identified in the two states (Michigan and New Jersey) where medical records are routinely reviewed for this information. Indoor air pollutants, dusts, cleaning materials, lubricants (e.g., metalworking fluids), and diisocyanates were among the most frequently reported causes of WRA. In addition, a well-recognized cause of occupational asthma - natural rubber latex - was identified in a new setting, the healthcare industry. The most common industries associated with WRA cases included transportation equipment manufacturing (19.3%), health services (14.2%), and educational services (8.7%). Air sampling for agents known to induce occupational asthma was performed in Michigan for comparison with established federal time-weighted average exposure limits. Sixteen (13.4%) of 119 workplaces tested had airborne concentrations exceeding NIOSH recommended exposure limits (RELs); 11 (9.1%) of 121 workplaces had concentrations exceeding permissible exposure limits (PELs) of the Michigan Occupational Safety and Health Act (MIOSHA) program. INTERPRETATION: The surveillance data findings confirm well-recognized causes of asthma and have identified new putative causes (e.g., cleaning materials and metalworking fluids). Because the surveillance program depends on physicians' recognizing asthma work-relatedness and reporting diagnosed cases, the data are considered an underestimate of the magnitude of the WRA problem. The data also indicate that physicians are not commonly performing objective physiologic tests to substantiate a WRA diagnosis. Workplace findings suggest a need to evaluate existing exposure standards for specific agents known to induce occupational asthma (e.g., diisocyanates). Case-based surveillance can help improve the recognition, control, and prevention of WRA. The SENSOR model also provides a mechanism for workers and physicians to request workplace investigations aimed at primary prevention for other workers. PUBLIC HEALTH ACTION: NIOSH and state health department representatives are working to establish a long-term agenda for state-based surveillance of work-related conditions and hazards. The results from the SENSOR WRA programs described in this report support inclusion of WRA as a priority condition warranting surveillance at the state level.

Surveillance for silicosis, 1993--Illinois, Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin.

PROBLEM/CONDITION: Silicosis is an occupational respiratory disease caused by the inhalation of respirable dust containing crystalline silica. Public health surveillance programs to identify workers at risk for silicosis and target workplace-specific and other prevention efforts are currently being field-tested in seven U.S. states. REPORTING PERIOD COVERED: Confirmed cases ascertained by state health departments during the period January 1, 1993, through December 31, 1993; the cases and associated workplaces were followed through December 1994. 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 (NIOSH), development of state-based surveillance and intervention programs for silicosis was initiated in 1987 in Michigan, New Jersey, Ohio, and Wisconsin and in 1992 in Illinois, North Carolina, and Texas. RESULTS: From January 1, 1993, through December 2, 1994, the SENSOR silicosis programs in Illinois, Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin confirmed 256 cases of silicosis that were initially ascertained in 1993. Overall, 185 (72%) were initially identified through review of hospital discharge data or through hospital reports of silicosis diagnoses; 188 (73%) were associated with silica exposure in manufacturing industries (e.g., foundries; stone, clay, glass, and concrete manufacturers; and industrial and commercial machinery manufacture). Overall, 42 (16%) cases were associated with silica exposure from sandblasting operations. Among the 193 confirmed cases for which information was available about duration of employment in jobs with potential exposure to silica, 37 (19%) were employed < or = 10 years in such jobs and 156 (81%) were employed > or = 11 years. A total of 192 primary workplaces associated with potentially hazardous silica exposures were identified for the 256 confirmed silicosis cases. Of these, nine (5%) workplaces were inspected by state health department (SHD) industrial hygienists, 19 (10%) were referred to the Occupational Safety and Health Administration (OSHA) for follow-up, and seven (4%) were routinely monitored by the Mine Safety and Health Administration. Of the 157 (82%) remaining workplaces, follow-up activities determined that 82 were no longer in operation, eight were no longer using silica, 18 were assigned a lower priority for follow-up, six were associated with building trades and could not be inspected because of the transient nature of work in the construction industry, and 43 workplaces were not inspected for other reasons. Fourteen (7%) of the 192 workplaces were inspected. At 10 of the 14 workplaces, airborne levels of crystalline silica were measured; in nine, silica levels exceeded the NIOSH-recommended exposure level of 0.05 mg/m, and in six, airborne silica levels also exceeded federal permissible exposure limits. ACTIONS TAKEN: Employee-specific and other preventive interventions have been initiated in response to reported cases. In addition, special silicosis prevention projects have been initiated in Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin. To facilitate the implementation of silicosis surveillance by other states, efforts are ongoing to identify and standardize core data needed by surveillance programs to describe cases and the workplaces where exposure occurred. These core variables will be incorporated into a user-friendly software system that states can use for data collection and reporting.

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.