Coccidioides exposure and coccidioidomycosis among prison employees, California, United States

Responding to a request by corrections agency management, we investigated coccidioidomycosis in prison employees in central California, a coccidioidomycosis-endemic area. We identified 103 cases of coccidioidomycosis that occurred over 4.5 years. As a result, we recommended training and other steps to reduce dust exposure among employees and thus potential exposure to Coccidioides.

Acute symptoms associated with asphalt fume exposure among road pavers

BACKGROUND

Although asphalt fume is a recognized irritant, previous studies of acute symptoms during asphalt paving have produced inconsistent results. Between 1994 and 1997, the National Institute for Occupational Safety and Health (NIOSH) evaluated workers at seven sites in six states.

METHODS

NIOSH (a) measured exposures of asphalt paving workers to total (TP) and benzene-soluble particulate (BSP), polycyclic aromatic compounds, and other substances; (b) administered symptom questionnaires pre-shift, every 2 hr during the shift, and post-shift to asphalt exposed and nonexposed workers; and (c) measured peak expiratory flow rate (PEFR) of asphalt paving workers when they completed a symptom questionnaire.

RESULTS

Full-shift time-weighted average exposures to TP and BSP ranged from 0.01 to 1.30 mg/m(3) and 0.01 to 0.82 mg/m(3), respectively. Most BSP concentrations were <0.50 mg/m(3). Asphalt workers had a higher occurrence rate of throat irritation than nonexposed workers [13% vs. 4%, odds ratio (OR) = 4.0, 95% confidence interval (CI): 1.2-13]. TP, as a continuous variable, was associated with eye (OR = 1.34, 95% CI: 1.12-1.60) and throat (OR = 1.40, 95% CI: 1.06-1.85) symptoms. With TP dichotomous at 0.5 mg/m(3), the ORs and 95% CIs for eye and throat symptoms were 7.5 (1.1-50) and 15 (2.3-103), respectively. BSP, dichotomous at 0.3 mg/m(3), was associated with irritant (eye, nose, or throat) symptoms (OR = 11, 95% CI: 1.5-84). One worker, a smoker, had PEFR-defined bronchial lability, which did not coincide with respiratory symptoms.

CONCLUSIONS

Irritant symptoms were associated with TP and BSP concentrations at or below 0.5 mg/m(3).

Responding to a bioterrorist attack: environmental investigation of anthrax in New Jersey

A bioterrorism attack using the United States postal system to deliver a hazardous biological agent to specific targets created multiple environmental and occupational exposure risks along the path of the anthrax-containing letters. On October 18, 2001, a suspected case of cutaneous anthrax was confirmed in a postal worker from the Trenton Processing and Distribution Center where at least four suspect letters were postmarked. Over the next three weeks, a team of investigators collected samples at 57 workplaces in New Jersey as part of a comprehensive environmental investigation to assess anthrax contamination as a result of this bioterrorist attack. A total of 1369 samples were collected with positive sample results found in two mail processing and distribution centers, six municipal post offices, and one private company. This large-scale epidemiological and public health investigation conducted by state and federal agencies included environmental evaluations utilizing general industrial hygiene principles. Issues of sampling strategy, methods, agency cooperation and communication, and site assessment coordination are discussed.

Environmental sampling for spores of Bacillus anthracis

On November 11, 2001, following the bioterrorism-related anthrax attacks, the U.S. Postal Service collected samples at the Southern Connecticut Processing and Distribution Center; all samples were negative for Bacillus anthracis. After a patient in Connecticut died from inhalational anthrax on November 19, the center was sampled again on November 21 and 25 by using dry and wet swabs. All samples were again negative for B. anthracis. On November 28, guided by information from epidemiologic investigation, we sampled the site extensively with wet wipes and surface vacuum sock samples (using HEPA vacuum). Of 212 samples, 6 (3%) were positive, including one from a highly contaminated sorter. Subsequently B. anthracis was also detected in mail-sorting bins used for the patient's carrier route. These results suggest cross-contaminated mail as a possible source of anthrax for the inhalational anthrax patient in Connecticut. In future such investigations, extensive sampling guided by epidemiologic data is imperative.

Validity of empirical models of exposure in asphalt paving

AIMS

To investigate the validity of empirical models of exposure to bitumen fume and benzo(a)pyrene, developed for a historical cohort study of asphalt paving in Western Europe.

METHODS

Validity was evaluated using data from the USA, Italy, and Germany not used to develop the original models. Correlation between observed and predicted exposures was examined. Bias and precision were estimated.

RESULTS

Models were imprecise. Furthermore, predicted bitumen fume exposures tended to be lower (-70%) than concentrations found during paving in the USA. This apparent bias might be attributed to differences between Western European and USA paving practices. Evaluation of the validity of the benzo(a)pyrene exposure model revealed a similar to expected effect of re-paving and a larger than expected effect of tar use. Overall, benzo(a)pyrene models underestimated exposures by 51%.

CONCLUSIONS

Possible bias as a result of underestimation of the impact of coal tar on benzo(a)pyrene exposure levels must be explored in sensitivity analysis of the exposure-response relation. Validation of the models, albeit limited, increased our confidence in their applicability to exposure assessment in the historical cohort study of cancer risk among asphalt workers.

Hypersensitivity reactions and specific antibodies in workers exposed to industrial enzymes at a biotechnology plant

Thirty-six employees who produced industrial enzymes from selected strains of bacteria and fungi were evaluated by epicutaneous threshold testing and enzyme-linked immunosorbent assays (ELISA) for specific IgE and IgG antibodies. The workers complained of 'asthma- and flu-like' symptoms, which generally lessened away from work. The enzymes evaluated were: alpha-amylase (1,4-alpha-d-glucan glucanohydrolase) from Bacillus licheniformis (alpha ABl), B. subtilis formation 1 (alpha A1Bs) and B. subtilis formation 2 (alpha A2Bs); purified alpha-amylase from B. licheniformis (C alpha ABl) and A. oryzae (C alpha AAo); alkaline protease from B. licheniformis (APBl) and purified alkaline protease (CAPBl); amyloglucosidase (1,4-alpha-d-glucan glucohydrolase) from A. niger (AGAn) and purified amyloglucosidase (CAGAn). Statistically significant increases (P > 0.05) in the proportion of workers having positive skin tests to CAPBl, AGAn and CAGAn were found. Significantly elevated (P > 0.05) mean specific IgE results were observed for C alpha AAo CAGAn and AGAn, and elevated (P > 0.05) mean specific IgGs were observed for C alpha AAo, CAGAn, AGAn, alpha A1Bs, alpha AB1 and alpha A2Bs. These results indicate that occupational exposure to some industrial enzymes can cause immediate-onset cutaneous hypersensitivity reactions, pulmonary function deficits and significantly elevated specific antibody levels. Our results are equivocal as to whether work-related respiratory and cutaneous hypersensitivity reactions are antibody mediated, as there was no statistically significant association between these reactions and specific IgE or IgG levels.