Determination of lead in human calculi and its effects on renal function of lead occupational workers

Seventy five samples of renal and eighteen samples of supra gingival calculi of lead recycling workers were collected over the period of seven years (2008-2014) and studied for the accumulation of lead. The results were compared with those of non exposed subjects. The lead content of calculi was investigated for its dependence on type and composition of calculi, blood lead, job status and duration of exposure. The effect of blood lead and renal calculi was also investigated in relation to kidney function of respective subjects. The mean lead levels of various types of calculi were found to follow the order as phosphate > oxalate > urate > cystine while single principal group of supra gingival calculi resulted in lower levels of metal. The lead content of calculi positively correlated with phosphate content of both of the renal (r = 0.655) and supra gingival calculi (r= 0.866). Impaired renal function was more pronounced in active workers and depended on blood lead levels in addition to presence of metal in renal calculi. (author)