Exposure and Management of the Health Risk for the Use of Formaldehyde and Xylene in a Large Pathology Laboratory

Background: Formaldehyde and xylene are two hazardous chemicals widely used in pathology laboratories all over the world. The aim of this work was to survey a large volume pathology lab, measuring exposure of workers and residents to formaldehyde and xylene, and verify the efficacy of the undertaken preventive actions and the accomplishment with occupational limit values. Methods: Environmental, personal, and biological monitoring of exposure to formaldehyde and xylene in different lab rooms and in 29 lab attendants was repeated yearly from 2017 to 2020. Continuous monitoring of airborne formaldehyde was performed to evaluate the pattern of airborne concentrations while specific tasks were performed. Several risk management and mitigation measures, including setting a new grossing room, reducing the number of samples to be soaked in formaldehyde, and improving the lab practices and equipment, such as the use of chemical hoods, were undertaken after each monitoring campaign, based on the results obtained from the exposure monitoring. Results: Significant exposures to formaldehyde in pathologists and residents, especially during the grossing of samples, were observed in the first 2 years, with exposure exceeding the occupational exposure limit value; the following surveys showed that the risk management and mitigation measures were effective in reducing airborne concentrations and personal exposure. Xylene, assessed with both environmental and biological monitoring, was always well below the occupational exposure limit value and biological limit values, respectively. Conclusion: Critical exposure to air formaldehyde in attendants of a pathology laboratory could be reduced with the re-organization of lab spaces, new and improved work procedures, and awareness and training initiatives.