Abstract :
A pilot study was carried out in the cell houses of three chlor alkali plants to assess level of exposure to mercury vapors among workers by air and biological monitoring. Overall airborne mercury concentrations (mg/m3) were found to range from 0.05 to 0.42 (mean, 0.21, n = 68). 0.03 to 0.16 (mean, .08. n = 49), and 0.02 to 0.17 (mean, 0.04, n = 26), whereas urinary mercury levels (mg/liter) of the exposed workers of the respective plants ranged from 0.076 to 0.592 (mean, 0.207, SD, 0.107, n = 19), 0.015 to 0.220 (mean, 0.070, SD, 0.054, n = 16), and 0.013 to 0.275 (mean, 0.06, SD, 0.054, n = 23). Unattended mercury spillage on the floor and improper sealing of the lids of the end boxes of electrolysis cells were found to be main factors attributing to prevalence of mercury vapors in excess of the permissible exposure limit of 0.05 mg/m3. Based on the deficiencies observed, appropriate control measures have been suggested to reduce airborne mercury vapor concentrations in the work environment.
