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

Abstract

BackgroundMalaria 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.MethodsThe 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.ResultsMosquito 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, SO2, NO2, PM2.5 and PM10. The Hazard Index of the respective pollutants characterized over a lifetime exposure scenario was low (< 1 for each pollutant), which suggests that the concentrations of the specific chemicals and particulate matter emitted from the mosquito coil may not constitute adverse environmental health risk.ConclusionAlthough the risk of morbidity from the use of the mosquito coil was low, the coil yielded limited protection as a mosquito avoidance method. It may, therefore, have a reduced benefit in controlling malaria and should be applied sparingly in a highly regulated manner only when traditionally proven effective vector control strategies are not available or too expensive for resource-poor malaria endemic regions.

Assessment of Indoor Levels of Carbon Monoxide Emission from Smoldering Mosquito Coils Used in Nigeria

“…Similar to what was observed by Hogarh et al 12 , the present study also observed the presence of CO during the characterization of emissions from smoldering mosquito coils. However, while Hogarh et al 12 reported that the observed level of CO did not pose any health risk based on life time exposure hazard index, the levels obtained in this study are above the permissible limit set by WHO.…”

Factors associated with sub-microscopic placental malaria and its association with adverse pregnancy outcomes among HIV-negative women in Dar es Salaam, Tanzania: a cohort study

“…These findings support the protective role of alternative malaria control measures [52,54]. However, others have suggested that mosquito coils have low mosquito repellency ability [51], and their effect on malaria prevention is not well established [55].…”

“…It has been shown that SP-IPTp can treat even sub-microscopic infection, but does not prevent new infections [14]. Hence, other malaria vector control strategies such as mosquito coils [51], fumigation [52], and treated bed nets [52,53] are also used for malaria control. We found that not using these preventive methods was associated with an increased risk of sub-microscopic placental malaria.…”

Variation of preventive practices and its association with malaria infection in eastern Indonesia: Findings from community-based survey

“…At household-level, malaria risk factors determined by the number of inhabitants, household condition, household economic condition (income), insecticide-treated nets (ITNs) ownerships, and the ability to access healthcare facilities [17][18][19][20]. Some research also shows prevention efforts at the individual level include the use of repellent, mosquitoes coil, electric rackets, and electric mosquito repellent [21][22][23]. In our knowledge, there is a shortage of evidence regarding variation in preventive practices applied by rural communities in eastern Indonesia.…”