External and internal dose in subjects occupationally exposed to ochratoxin A

Ochratoxin A (OA) is a ubiquitous mycotoxin that can contaminate foods, drinks, and animal feeds worldwide. Humans and animals can therefore absorb this toxin via the gastrointestinal tract after ingestion of contaminated products. OA is known to exert toxic effects, particularly on the renal system, and the International Agency for Research on Cancer (IARC) classified it as a "possible human carcinogen" (Group 2B). The measurement of OA serum levels is an effective method of evaluating internal doses. Inhalation of airborne OA can represent a source of additional exposure. We determined the levels of serum OA in workers exposed to airborne dust originating from the handling or processing of contaminated foods.

We carried out area and personal sampling for airborne OA determination in three industries where coffee, cocoa beans, and spices, foods highly susceptible to contamination, were being processed. OA levels in the serum of six healthy workers employed in these factories were measured in samples collected at the end of the work shift.

Airborne OA measured in the three industries, both by personal and area sampling, ranged from < 0.003 to 8.15 ng/m(3), while the levels measured in the breathing zone of the six workers who agreed to biological monitoring varied from 0.006 to 0.087 ng/m(3). OA serum levels ranged from 0.94 to 3.28 ng/ml, the latter values rather largely exceeding those of the control group (0.03 to 0.95 ng/ml).

Our findings suggest that occupational exposure to this mycotoxin may represent a health risk for workers, especially if preventive and protection measures are not adopted in the workplaces. Airborne exposure levels can result in an increase of OA levels in serum, and this finding suggest that environmental and biological monitoring should be undertaken in workplaces where OA-contaminated products are handled or processed.