regular exposure to lead dust and fumes reduces sperm density, motility and viability and lowers semen volume causing infertility among workers of lead acid battery factories, claim researchers at Kolkata's Regional Occupational Health Centre and Jadavpur University.

"Sophisticated imaging techniques like scanning electron microscopy uncovered sharp depressions, membrane folding and granular texture at sperm head surfaces due to lead exposure,' says Amal Roy Chowdhury, who led the researchers. Lead has long been a prime suspect in inducing male infertility among occupationally exposed people. The findings appeared in a recent issue of the Indian Journal of Physiology and Pharmacology (Vol 49, No 2).

For the study, the scientists randomly chose 80 lead acid battery factory workers aged 31-45 years in Kolkata. They were divided into two groups: one comprising 30 workers with daily exposure of eight hours over 7-10 years (low exposure) and the other comprising 50 workers with eight hours of daily exposure over 10-15 years (high exposure). They were compared with 40 non-occupationally exposed control subjects.

Samples were collected from all subjects and analysed for sperm density, total count, motility, semen volume and viscosity and structural deformities as per the protocol recommended by the World Health Organization. One part of the semen samples and 2 ml of morning, fasting, and venous blood were stored at