Industry-wide medical surveillance of California flavor manufacturing workers: Cross-sectional results.

BACKGROUND: Two cases of bronchiolitis obliterans in flavor manufacturing workers prompted California health and labor agencies to initiate industry-wide surveillance. METHODS: Companies' physicians submitted cross-sectional questionnaire and spirometry data for 467 workers in 16 workplaces. We compared prevalence ratios of respiratory symptoms, diagnoses, and abnormal spirometry to a general population sample. We calculated odds ratios for risk factors for spirometric obstructive abnormality. RESULTS: Flavoring workers were 2.7 times more likely than the general population to have severe airways obstruction. Risk factors identified for 18 cases with obstruction from six companies included younger age, Hispanic ethnicity, liquid and powder production work, greater company diacetyl usage, and having a coworker with obstruction. Severity of obstruction was related to tenure. At least 12 workers had probable occupational fixed airways obstruction. CONCLUSIONS: The flavoring industry risk of severe lung disease justifies lowering flavoring exposures and medical screening for secondary prevention until worker safety is demonstrated.

Identification of mold and dampness-associated respiratory morbidity in 2 schools: comparison of questionnaire survey responses to national data.

BACKGROUND: Dampness and mold problems are frequently encountered in schools. Approximately one third of US public schools require extensive repairs or need at least 1 building replaced. This study illustrates how national data can be used to identify building-related health risks in school employees and students. METHODS: School employees (n = 309) in 2 elementary schools (schools A and B) with dampness and mold problems completed standardized questionnaires. Responses were compared with participant responses from the 3rd National Health and Nutrition Examination Survey and were indirectly standardized for gender, age, smoking status, and (for school B) race. Uncontrolled comparisons were made to responses from a study of office workers, as well as between responses from school employees in different sections of the school buildings designated by decade of construction. RESULTS: Employees from both schools had excess work-related throat and lower respiratory symptoms, as well as eye, nasal, sinus, and wheezing symptoms. School B employees also had excess physician-diagnosed asthma and work-related fatigue, headache, and skin irritation. Employees in sections of the school buildings that were categorized as having greater dampness and mold contamination had more frequent upper and lower respiratory symptoms than employees working in other building sections. CONCLUSIONS: This noncostly type of analysis of indoor air quality complaints can be used to motivate and prioritize building remediation in public schools where funds for building remediation are usually limited.

Characteristics of dusts encountered during the production of cemented tungsten carbides.

Inhalation of cobalt (Co) and tungsten carbide (WC) particles, but not Co or WC alone, may cause hard metal disease, risk of which does not appear to be uniform across cemented tungsten carbide (CTC) production processes. Inhalation of Co alone or in the presence of WC may cause asthma. Hypothesizing that aerosol size, chemical content, heterogeneity, and constituent compaction may be important exposure factors, we characterized aerosols from representative CTC manufacturing processes. Six work areas were sampled to characterize aerosol size distributions (dust, Co) and 12 work areas were sampled to characterize physicochemical properties (using scanning electron microscopy with energy dispersive x-ray spectrometry [SEM-EDX]). Bulk feedstock and process-generated powders were characterized with SEM-EDX and x-ray diffraction. The dust mass median diameter was respirable and the cobalt respirable mass fraction was highest (37%) in grinding. Morphology of particles changed with processing: individual, agglomerate, or aggregates (pre-sintered materials), then mostly compacted particles (subsequent to sintering). Elemental composition of particles became increasingly heterogeneous: mostly discrete Co or W particles (prior to spray drying), then heterogeneous W/Co particles (subsequent work areas). Variability in aerosol respirability and chemical heterogeneity could translate into differences in toxicity and support detailed characterization of physicochemical properties during exposure assessments.