LAUSR

BACKGROUND Sewage treatment plant workers (STPs) are exposed to gaseous pollutants (H2S) and bioaerosols and their health is at risk. METHODS Gaseous pollutants and bioaerosols (inhalable dust, 1,3 beta D-glucans and endotoxins) were evaluated in two sewage treatment plants (STPs) of Ahmedabad city, India. The concentration of H2S, CO, CH4 and Cl2 were monitored in two process areas of STPs using real-time gas detectors. The dust, 1,3 beta D-glucans and endotoxins were evaluated as per standard methods. RESULTS The mean concentration of H2S exceeded the permissible exposure limit of 10 ppm, whereas the concentration of other gaseous pollutants (CO, Cl2 and CH4) were below the permissible exposure limits of Indian Factories Act, 1948. The inhalable dust concentration was also within the permissible exposure limit of 10 mg/m3 as per Indian Factories Act, 1948. CONCLUSIONS Significant exposures to gaseous and bioaerosols were found in the work environment of STPs. The paired t-test result showed a significant difference between two STPs for H2S, 1,3 beta D-Glucans and endotoxins. STPs were advised to reduce the exposure to H2S and bioaerosols as per CPCB guidelines applicable to India to prevent health effects.