A review of heavy metals bioaccumulation in insects for environmental monitoring

Abstract Background Heavy metal pollution from industrial, mining, and agricultural sources threatens ecosystems and human health. Insects, with their ecological diversity and sensitivity to environmental changes, are promising bioindicators for monitoring such contamination. Methods A systematic review was conducted using Web of Science, Scopus, and PubMed, searching for peer-reviewed studies (2000–2024) on insects as bioindicators of heavy metal pollution. Using the search string "insects AND ('heavy metals' OR 'heavy metals') AND (bioaccumulation OR bioindicators OR biomonitoring)," 50 studies were selected based on their focus on insect taxa, metal bioaccumulation, and ecological or physiological responses. Results Insect taxa, including Chironomidae, Carabidae, and Apis mellifera, effectively detect metals like lead (Pb), cadmium (Cd), and mercury (Hg) across aquatic, terrestrial, and agricultural ecosystems. Analytical techniques, such as comet assays and atomic absorption spectroscopy, reveal responses like DNA damage, deformities, and population shifts. Insects’ abundance, ease of sampling, and sensitivity enhance their biomonitoring utility. Conclusions Insects are reliable, cost-effective tools for assessing heavy metal pollution. This review highlights research gaps, including underrepresented taxa and regions, and advocates for standardized insect-based monitoring to support sustainable environmental management.