[Exposure to metals, metalloids and their compounds in heavy metals refining]

In the process of heavy metals refining, workers are first of all exposed to metals, metalloids (As, Se) and their compounds. Moreover, they are exposed to sulphuric acid and dusts (about 2% SiO2).

Several dozen workers in two Polish plants were studied (Cu, Pb, Cd, Zn, and Ag refining processes, production of Ni sulphate and production of Se). Cd, Ni, Se, Cu, Pb, As and Ag were determined by atomic absorption spectrometry (AAS) with graphite tube, whereas ZnO (as Zn) by AAS with air-acetylene flame. Sulphuric acid was determined by the method given in PN-91/Z-04056/02, and dust (total and respirable fraction) by gravimetric methods.

High concentrations of lead were found in the workplace air in both plants. Occupational exposure indicators for lead were much higher than the Polish MAC value. Exposure to arsenic and its compounds was a serious problem in one of the plants. Concentrations of the other chemical agents were generally below the Polish MAC values.

Even though in many cases no risk is posed by individual metals and metalloids, total exposure is another matter. The total exposure indicator for present metals and metalloids at most workstations in both plants was higher than 1. In general, risk posed by metals and metalloids is high or even very high in the heavy metal refining industry.