Comprehensive Evaluation of Mosquito Repellent Products: Efficacy, Safety, and Public Health Implications

Abstract Mosquito-borne diseases such as dengue, chikungunya, and malaria remain major public health challenges in South Asia, particularly in Bangladesh, where mosquito repellents are widely used as primary preventive tools. This study presents a comparative evaluation of commonly used repellent products, including mosquito coils, liquid vaporizers, aerosols, DEET-based creams, and natural formulations, focusing on their efficacy, duration of protection, and potential health risks. Efficacy was assessed using controlled laboratory methods, including chamber-based exposure and arm-in-cage tests against Aedes aegypti. Safety was evaluated in vivo using a rat model through clinical observations, hematological and biochemical profiling, and histopathological examination. The results indicated an overall mean effectiveness of 85%, with DEET-based creams demonstrating the highest efficacy (95%) and natural repellents the lowest (70%). Mosquito coils provided the longest protection duration (∼10 hours) but posed the most severe health hazards due to combustion-related emissions. Toxicological findings revealed that prolonged coil exposure induced significant physiological damage, including reduced body weight gain, elevated leukocyte counts, decreased hemoglobin, altered liver and kidney biochemical markers, and severe histopathological damage in lung, liver, and skin tissues. Vaporizers and aerosols resulted in comparatively milder physiological changes. In contrast, DEET-based products and natural formulations demonstrated negligible systemic toxicity, preserving normal organ structure and function. Overall, the study highlights a clear efficacy–safety trade-off. Based on these findings, vaporizers or aerosols are preferred for ventilated indoor use, DEET-based repellents are recommended for prolonged outdoor activities, and natural formulations serve as ideal alternatives for vulnerable populations (children, pregnant women, the elderly, and those with respiratory sensitivities). These results underscore the need for informed consumer selection, integrated vector management strategies, stronger regulatory oversight, and the development of sustainable, low-toxicity mosquito-repellent technologies.