The effects of lindane and linuron on calcium metabolism, bone morphometry and the kidney. Experiments were performed to investigate the effects of lindane and linuron on calcium metabolism, femur morphometry and nephrotoxicity. Long-Evans hooded rats were dosed daily for 10 weeks with 0, 10 or 20 mg lindane or 10, 20 or 40 mg linuron/kg body weight beginning at weaning. Lindane significantly decreased urinary calcium concentration, serum alkaline phosphatase concentration and the cross-sectional medullary area of the bone. Lindane was nephrotoxic at both dose levels as demonstrated by elevated kidney weights, kidney-to-body-weight ratios, enzymuria, tubule regeneration and hyaline droplet degeneration. Linuron significantly reduced medullary cross-sectional area at the two higher dose levels and decreased the total femur cross-sectional area at the highest dose level in the absence of effects on calcium excretion. Femur density and strength were also significantly reduced at the highest dose level of linuron. Neither compound affected the serum concentrations of parathyroid hormone or 1,25-dihydroxy Vitamin D3.