Toxicological profiling and health hazard characterization of pesticides widely used in Tanzania unmarked.

The toxicity of many pesticides to humans and their contribution to various health problems continue to increase rapidly. This study highlights the inherent effects of highly hazardous pesticides (HHPs) used in smallholder agricultural systems. Primary data were collected through interviews, while secondary data came from scientific databases and search engines, including Scopus, PubMed, Web of Science, and Google Scholar. A total of 810 respondents participated in the study. The characterization of health and environmental impacts was based on the active ingredients mostly used, especially those that have been discontinued, withdrawn, or banned in other regions due to their harmfulness. The toxicological profile focused on effects such as neurotoxicity, reproductive toxicity, developmental toxicity, immunotoxicity, genotoxicity, carcinogenicity, and endocrine disruption. Results show that over 150 active ingredients are used in pesticides, some of which are classified as highly hazardous pesticides (HHPs). Key pesticides like lambda-cyhalothrin, glyphosate, 2,4-dimethylamine, mancozeb, chlorpyrifos, profenofos, cypermethrin, carbendazim, paraquat, atrazine, and carbofuran dominate smallholder farming. The widespread use of HHPs in Tanzania, under current conditions, constitutes a significant public health and environmental crisis, suggesting that knowledge does not always translate into safe practices. The combination of inherently hazardous pesticides, inadequate regulatory oversight, and unsafe handling practices creates a perfect storm of exposure. Strengthening laws and regulations around pesticide registration, post-market monitoring, and enforcement is urgently needed to protect human health and the environment.