Health risk and bioaccessibility assessment of lead in waste from the Malaysian Lynas rare earth processing plant using an in vitro DIN gastrointestinal model

This study examines the bioaccessibility of lead from water leach purification (WLP) waste collected from the Malaysian Lynas rare earth processing plant using an in vitro DIN digestion model. A contamination factor (Cf) value of 2.7 was obtained from study results, which is considered to be a moderate level of Pb contamination in WLP waste. The bioaccessibility of Pb in digested WLP waste ranged between 0.064 ± 0.010 to 0.080 ± 0.010% and 0.018 ± 0.013 to 0.103 ± 0.046% in the gastric and gastrointestinal phases f, respectively, during the 5-hour study period. To evaluate the human health risks associated with Pb in WLP waste, the bioaccessible estimated daily intake (BEDI) and bioaccessible target hazard quotient (BTHQ) were calculated. The values obtained for children exceeded the recommended safe limit, in contrast to the values obtained for adults, indicating potential human health risks. The results of this study suggest that the WLP waste from Lynas waste disposal facility should be further evaluated and monitored to eliminate any adverse health effects associated with accidental human exposure to Pb.