Bioenvironmental control of industrial malaria at Bharat Heavy Electricals Ltd., Hardwar, India--results of a nine-year study (1987-95).

A bioenvironmental model to control malaria at Bharat Heavy Electricals Ltd. in Hardwar was developed by using existing resources to reduce mosquito breeding. The civil maintenance department carried out major source reduction work by filling pits, low lying areas, ditches, etc., with fly ash from a coal-fired power station, construction of stand posts and proper drainage, mosquito proofing of overhead tanks, and preventive maintenance of the water supply and the sewage system. The project staff has applied 1) expanded polystyrene beads to underground tanks, leaking sluice valve chambers, and blocked sewage manholes; 2) biolarvicides to water accumulated in factory scraps, blocked drains, and riverbed pools, and 3) larvivorous fish to storm water drains, effluent ponds, and drains for the effective control of mosquito breeding. Improved surveillance and treatment coupled with comprehensive developmental schemes were additional tools to gain community support. As a result of intervention measures, the vector density in the township was significantly lowered compared to that of a control area, and there was a drastic reduction in malaria incidence compared to that of the preintervention year: only 190 cases were recorded in 1995, compared to 3,049 cases in 1985. The study has shown that malaria control in an industrial township through an integrated control approach is practical, sustainable, and economically feasible and reduces insecticide pollution in the environment.