Study of worker's exposure to Tantalum-bearing particles in a mining and metallurgical plant.

The objective of this study was to assess worker exposure to mineral dust particles, and a metabolic model, based on the model adopted by ICRP, was applied to assess human exposure to Ta, and predicted values of Ta concentrations in excreta. The occupational exposure to Th, U, Nb, and Ta-bearing particles during routine tasks to obtain Fe-Nb alloys was estimated using air samplers and excreta samples. Ta concentrations in food samples and in drinking water were also determined. The results support that workers were occupationally exposed to Ta-bearing particles, and also indicate that a source of Ta exposure for both workers and the control group was the ingestion of drinking water containing soluble compounds of Ta. Therefore, some Ta compounds should be considered soluble compounds in gastrointestinal tract. Consequently, the metabolic model based on ICRP metabolic model and/or the transfer factor f 1 for Ta should be reviewed and the solubility of Ta compounds in gastrointestinal should be determined.