Assessing human toxicity and ecotoxicity impacts of agricultural pesticide use in Iran based on the USEtox model

The human health and ecotoxicity impacts of agricultural pesticide use in Iran in 2022 were estimated. The impacts of agricultural pesticide use in Iran by pesticide, crop, and province were assessed based on the USEtox model in terms of disability-adjusted life year (DALY) for human health and potentially disappeared fraction of freshwater ecosystem species (PDF) for ecotoxicity. The annual mass of agricultural pesticide use in Iran in 2022 was 17,188 tons, consisting of herbicides (46.2 %), insecticides (30.0 %), and fungicides (23.8 %). The DALYs and DALY rate (per 100,000 people) of agricultural pesticide use in Iran were determined to be 25,140 and 29.4, respectively. The ecotoxicity impact of agricultural pesticide use in Iran was calculated to be 3.35 × 10⁺¹² PDF m³ d. Over 79 % of the human health and ecotoxicity impacts of agricultural pesticide use were attributed to six pesticides (chlorpyrifos, deltamethrin, ethion, phosalone, thiodicarb, and abamectin) and eight crops (pistachio, apple, fig, vegetables, date, orange, wheat and barley, and cotton). While the contributions of the pesticides to the human health and ecotoxicity impact were not the same, chlorpyrifos ranked highest in both human health (28.8 %) and ecotoxicity (49.9 %) impacts. The highest provincial human health and ecotoxicity impacts of agricultural pesticide use were observed in Tehran (4,201 DALYs) and Fars (3.66 ×10⁺¹¹ PDF m³ d), respectively. The provincial human health and ecotoxicity impacts were mainly driven by population and cropland area, respectively. Given the considerable human health and ecotoxicity impacts, developing national and provincial action plans for more sustainable use of pesticides in Iran is strongly recommended.