Environmental health risks and benefits of the use of mosquito coils as malaria prevention and control strategy

Malaria is an infectious disease that causes many deaths in sub-Saharan Africa. In resource-poor malaria endemic communities, mosquito coils are commonly applied in households to repel the vector mosquito that transmits malaria parasites. In applying these coils, users have mainly been interested in the environmental health benefits potentially derived from repelling the mosquito, while oblivious of the environmental health risks that may be associated with exposure to emissions from the use of mosquito coil. This study evaluated the effectiveness of the mosquito coil, ascertained and/or estimated the toxic emissions that may emanate from the coil, and determined its overall appropriateness by conducting a risk-benefit analysis of the use of this strategy in malaria prevention at household levels. The repellent ability of mosquito coils was tested by conducting a mosquito knockdown/mortality test in experimental chambers synonymous of local room spaces and conditions. The gaseous and particulate emissions from the mosquito coil were also analysed. Additional scenarios were generated with the Monte Carlo technique and a risk-benefit analysis was conducted applying @Risk software. Mosquito mortality arising from the application of various mosquito coils averagely ranged between 24 and 64%, which might not provide adequate repellency effect. Emissions from the mosquito coil were also found to contain CO, VOCs, SO , NO , PM and PM . The Hazard Index of the respective pollutants characterized over a lifetime exposure scenario was low (