Performance of self-reported occupational exposure compared to a job-exposure matrix approach in asthma and chronic rhinitis.

OBJECTIVES: Self-reported exposure to vapours, gas, dust or fumes (VGDF) has been widely used as an occupational exposure metric in epidemiological studies of chronic lung diseases. Our objective was to characterise the performance of VGDF for repeatability, systematic misclassification, and sensitivity and specificity against exposure likelihood by a job-exposure matrix (JEM). METHODS: We analysed data from two interviews, 24 months apart, of adults with asthma and chronic rhinitis. Using distinct job as the unit of analysis, we tested a single response item (exposure to VGDF) against assignment using a JEM. We further analysed VGDF and the JEM among a subset of 199 subjects who reported the same job at both interviews, using logistic regression analysis to test factors associated with VGDF inconsistency and discordance with the JEM. RESULTS: VGDF was reported for 193 (44%) of 436 distinct jobs held by the 348 subjects studied; moderate to high exposure likelihood by JEM was assigned to 120 jobs (28%). The sensitivity and specificity of VGDF against JEM were 71% and 66%, respectively. Among 199 subjects with the same job at both interviews, 32% had a discordant VGDF status (kappa = 0.35). Those with chronic rhinitis without concomitant asthma compared to asthma alone were more likely to have a VGDF report discordant with the JEM (OR 3.6, 95% CI 1.4 to 9.0; p = 0.01). Rhinitis was also associated with reported VGDF in a job classified by the JEM as low exposure (OR 3.9, 95% CI 1.6 to 9.4; p = 0.003). CONCLUSION: The VGDF item is moderately sensitive measured against JEM as a benchmark. The measure is a useful assessment method for epidemiological studies of occupational exposure risk.

Control of occupational and environmental hazards.

This article provides an overview of the control of occupational and environmental exposures. Two case studies illustrate common questions that arise in the primary care setting, regardless of specialty practice. The focus of these case studies is to offer pragmatic recommendations on how best to prevent occupational and environmental illness and injury through use of a hierarchy of controls.

Termination of employment.

The following questions and recommendations, taken from Jeffrey Hirsch & William Farrell's Labor and Employment in Rhode Island, provide a synopsis of the basic issues which employers should consider before making a decision to fire an employee: 1. Review all documentation and other company records considered when making the decision. Make sure all stated policies were followed by management. 2. Interview all managers who provided input on the decisions. 3. Be satisfied that the decision was made for the correct reason. 4. Was the employee aware that termination was likely? Can you document that awareness? 5. Was the individual given an opportunity to improve his or her performance? 6. Has the company discharged others for similar reasons in the past? 7. Has the company acted promptly and avoided relying on "stale" offense? 8. Is the employee protected by anti-discrimination statutes? (i.e. race, age, sex, national origin, handicapped or religion)? 9. Meet with the employee personally; do not discharge by phone or letter unless absolutely necessary. 10. Have a "passive" management witness at the meeting. 11. Conduct the meeting in a private area where other employees will not be able to see or hear the discussion. 12. Both the executive and management witness should prepare file memoranda concerning what is said at the discharge meeting. 13. Always tell the employee the reason for her or his discharge. 14. Discuss health insurance continuation (COBRA). 15. Discuss life and disability insurance, and pension/profit sharing status. 16. Discuss other issues, such as references and out placement policies. By taking the time to follow these suggestions and answer these questions, an employer can feel more secure that the termination has been conducted properly, and minimize the chances of becoming implicated in legal action related to the termination.

Formate in serum and urine after controlled methanol exposure at the threshold limit value.

Methanol will be present as a new air pollutant when methanol-powered vehicles are introduced in the United States. Little is known about the effect of low-dose methanol exposure. It is controversial whether or not formate, the main metabolite responsible for methanol's acute toxicity, is a sensitive biological marker of toxicity or exposure. We studied the effect of a 4-hr exposure at rest to 200 ppm of methanol vapors on endogenous serum formate and on urinary formic acid excretion. A randomized, double-blind study of human exposure to a constant concentration of methanol was performed in a whole-body exposure chamber. Twenty-six healthy volunteers, each serving as his or her own control, participated in sham and methanol exposures. Urine (at 0, 4, 8 hr) and serum specimens (15 time points over 8 hr) collected before, during, and after the exposure were measured for formate. We found no significant differences in serum formate concentration between exposure and control conditions either at any time point or for area under the curve. Mean concentrations at the end of the exposure were: exposed 14.28 +/- 8.90 mg/l and control 12.68 +/- 6.43 mg/l. A slight, but nonsignificant (p = 0.08), increase in urine formate excretion rate was found at 4 hr (exposed 2.17 +/- 1.69 mg/4 hr and control 1.67 +/- 1.02 mg/4 hr). Age, sex, folic acid level, and smoking were not significant covariates. At 200 ppm, methanol exposure does not contribute substantially to endogenous formate quantities. Serum and urine formate determinations are not sensitive biological markers of methanol exposure at the threshold limit value.