Assessment of the risk of occupational exposure to strontium chromate

Introduction
In carcinogen risk assessment, evaluating exposure by means of environmental and biological monitoring is a major step. This study describes a methodology for assessing the risk of occupational exposure to strontium chromate.

Methods
Exposure was assessed in 21 male workers using paints containing strontium chromate (exposed) and 20 male workers with no exposure to chemical substances (controls). A questionnaire was administered to all workers. Active personal samplers were worn by the paint-sprayers, who operated for 2 hours in a paint-spray booth with a downdraft extraction system wearing suitable personal protective equipment (particulate and organic vapor masks, gloves, tyvek overalls), and by the other exposed workers for 8 hours doing sandpapering, preparation and cleaning operations in the finishing area. On the environmental monitoring day, urine was collected at the beginning and end of the work shift in the exposed workers and only at the end of the shift in the controls, to determine urinary chromium (CrU). In 10 randomly selected exposed workers and 10 controls, Cr in plasma and red blood cells (RBC) was also determined.

Results
In the paint-spray booth strontium chromate, measured as Cr, ranged between 1.38 and 17.1 µg/m³, versus 0.02 to 0.07 µg/m³ in the finishing area. At the end of the work shift, CrU in the exposed workers was not different as compared with values at the beginning of the shift or in the controls. Plasma and RBC Cr was not different in exposed workers and controls.

Discussion
In the paint-spray booth there was evident exposure to strontium chromate but the use of adequate protective equipment prevented its absorption. Therefore, the health risk was considered to be negligible. Nevertheless, the institution of a register of workers exposed to carcinogens and health surveillance measures have been proposed, as indicated by the EU Norms safeguarding health and safety in the workplace.