Ecotoxicological implications of environmental contaminants on disease vectors: challenges in risk assessment and strategies for integrated vector management

Environmental contaminants such as heavy metals, pesticides, and industrial pollutants exert profound effects on the biology, behavior, and ecology of disease vectors, especially Aedes aegypti and Anopheles gambiae. These effects complicate control strategies and enhance the risk of insecticide resistance, thereby influencing the transmission dynamics of vector-borne diseases. This systematic review synthesizes evidence on how pollutants alter vector development, survival, reproduction, and host-seeking behaviors, often in synergy with insecticide exposure. Notably, sublethal contaminant levels induce enzymatic and genetic resistance mechanisms, including overexpression of cytochrome P450s and knockdown resistance (kdr) mutations. Current ecotoxicological risk assessment models fail to adequately account for multi-stressor environments or the unique characteristics of vector habitats. Integrated vector management is presented as a holistic approach that combines biological control, chemical reduction, community engagement, and environmental safety measures. However, its effectiveness depends on strong governance, consistent monitoring, and interdisciplinary collaboration. This review emphasizes the need for refined, context-specific risk assessments and adaptive vector control strategies that account for the complex ecological interactions between pollutants and disease vectors.