An outbreak of chromium ulcer in a manufacturing plant.

On May 23, 1989, managers of a manufacturing plant requested an investigation of an outbreak of hand ulceration and skin discoloration among workers. The plant has manufactured kitchen ranges for 30 years and employs approximately 633 hourly workers. The affected employees worked in the enamel department, where metallic range tops are coated with a "ground coat" or sprayed with an enamel coloring, and then baked in ovens at 1200F. Our evaluation included physical examinations, environmental sampling, and a questionnaire eliciting information concerning skin ulceration job history, demographics, and use of protective practices. We identified 10 enamel department workers (13.5%) who developed chromium ulcers between January 1st and June 30th, 1988. Ulcers were found on hands, forearms, periumbilical area and/or axillae. Within the enamel department, workers who handled conveyer hooks used to suspend range tops as they passed through the oven were at greatest risk (rate ratio (RR) = 12.44, 95% confidence interval (CI) = 2.90-53.35). Workers who wore gloves were protected from developing ulcers (RR = 0.08, 95% CI = 0.01-0.60). Normally, trivalent chromium (Cr+3) does not cause skin ulcers unless it is oxidized to hezavalent chromium Cr+6). The enamel used contained only Cr+3, not Cr+6, but analysis of hooks that had passed through the oven revealed Cr+6 on their surface. A mechanical failure of the oven resulted in the formation of sharp edges of the parts and consequently causing the abrasion of exposed skin. We believe Cr+3 was converted to Cr+6 during the baking process which associated with the mechanical failure of the oven causing this outbreak.

Evaluation of a smoke evacuator used for laser surgery.

A preliminary study was conducted to determine the effectiveness of a smoke evacuation system used in laser surgery. A 30 W medical CO2 continuous wave (CW) laser was used to make cuts in a pork chop to simulate smoke production during laser surgery. A commercially available smoke evacuation system was used to control the smoke from the simulated surgery. The smoke concentration was measured at 6 in and at 3 and 4 ft from site of laser interaction. The nozzle of the smoke evacuator was located at distances of 2, 6, and 12 in from the surgical site to measure the relative effectiveness of the control. Complete control of smoke was achieved when the nozzle was located at 2 in, but significant amounts of smoke escaped when the nozzle was located at 6 and 12 in. Suggestions for the use of the smoke evacuation system and areas for further study are given.