Clinical findings of irritation among chromium chemical production workers

Abstract

Background: Several reports of workers in chromate production and chromeplating have indicated that exposure to hexavalent chromium is associated with skin and nasal irritation. Methods: A cohort of 2,357 workers first employed between 1950 and 1974 at a chromate production plant was identified. Clinical findings of irritation were identified by a physician as a result of routine examinations or visits to the medical clinic by members of the cohort. Percentages of the cohort with various clinical findings, the time from hire to occurrence of the first finding, and the mean and median annual hexavalent chromium (measured as CrO3) concentration for the job title where the clinical finding first occurred were determined. A proportional hazards model was used to evaluate the relationship between hexavalent chromium exposure and first occurrence of each of the clinical findings. Results: Nasal irritation and nasal ulceration were the most common clinical findings reported, occurring in more than 60% of the cohort. The average time to first occurrence of these findings was less than 3 months, whereas the time to first occurrence of the other findings ranged from 10 to 22 months. Median exposure to hexavalent chromium at the time of occurrence for most of the findings was about 20 μg/m3. The proportional hazards model indicated that ulcerated nasal septum, irritated skin, and perforated eardrum were significantly associated with ambient hexavalent chromium exposure; all clinical findings with the exception of conjunctivitis and irritated skin were associated with the calendar year of hire, with the risk being lower as the calendar year of hire became more recent. Annual average ambient hexavalent chromium concentrations generally dropped in the plant over the period of the study. Conclusion: Workers in the chromate production plant in this study experienced a variety of nasal and skin irritations. Irritated and ulcerated nasal septa, in particular, were quite common clinical findings, occurring in over 60% of the cohort, and they occurred in relatively short periods of time - less than 3 months from date of hire. Annual average concentrations of chromium may not be a good predictor of clinical findings of irritation.