鉛蓄電池廠鉛塵之生物攝取率研究

Abstract

This study was conducted to characterize the physicochemical properties of the lead powder/dust from a lead battery plant, and estimate their relative bioavailability. Ninety male Sprague-Dawley rats were fed with lead-dosed mixtures at the target doses of 5 and 10 mg/Kg BW/day, respectively, during the specified study periods. Results shows that lead powder for anode and the lead dust from the cathode plate manipulating process consisted of both lead element and lead oxide while the other types of lead powder or dust were found composed of lead element only. Also, it is shown that the lead powder was the smallest in particle size with a mode of 11~12 um, while 66%~75% of lead dust from plate manipulating process and 27% of that from plate cutting process were composed of particle size less 250 um. Lead powder for anode plate, lead dust from the anode electrode plate manipulating process, and from the plate cutting process were mostly composed of lead and/or its compounds, in terms of weight percentage. Generally speaking, the blood lead levels increased inversely with the particle size of the lead powder and/or dust, and reached the plateau level around the 4 th week for the low dose group and about the 2 nd week for the high dose group. At the same lead exposure dose, the bioavailability of lead uptake vary from 30.9% for the lead dust from anode plate manipulating process with size range of 106um~250um to 245.1% of lead powder for anode plate with size mode of 12 um, depending on the lead source and the time period of blood collection. The observations in the present study provide important parameters for the improved risk assessment of exposure to lead dust in the lead battery plant, especially for inadvertent ingestion and/or ingestion of coarse particles transferred from the naso-pharyngeal area to the gastro-intestinal tract.