Metal Phosphide Poisoning in Suicide Cases: A Four-Year Retrospective Forensic and Socio-demographic Study from Asyut Governorate, Upper Egypt (2021–2024)

Background: Metal phosphide compounds, most notably aluminum and zinc phosphide, are extremely toxic pesticides that are associated with a high case-fatality rate following intentional ingestion. In Upper Egypt, these compounds are frequently implicated in suicide, yet region-specific forensic data remain limited. Objective: To retrospectively characterize the forensic, toxicological, and sociodemographic profiles of confirmed suicide deaths due to metal phosphide poisoning in Asyut Governorate, Upper Egypt, from 2021 to 2024. Methods: A retrospective observational study was conducted on suicide-related metal phosphide poisoning deaths examined at the Forensic Medicine Authority, Asyut Branch. Data were obtained from medico-legal autopsy records, toxicology laboratories, and available hospital files. Included cases were confirmed suicides with toxicological evidence of metal phosphide and concordant medico-legal findings. Biological specimens were screened using the silver nitrate/phosphine test and confirmed by gas chromatography– mass spectrometry. Statistical analysis was performed using chi-square tests, with significance set at p < 0.05. Results: All 245 cases were toxicologically confirmed and classified as suicide. Autopsy findings were characteristic of phosphine toxicity, with petechial hemorrhages (89.0%), pulmonary edema (84.0%), and hepatic and renal congestion (79.9%) being most frequent. A garlic-like odor in viscera was documented in 54.9% of cases. Case frequency declined in 2022 but increased thereafter, peaking in 2024, with a significant upward temporal trend (χ² for trend = 37.69, p < 0.001). The third decade of life was most affected across both sexes, with marked sex-related seasonal variation and a consistent predominance of rural cases. Conclusions: Intentional metal phosphide poisoning remains a major cause of suicide- related mortality in Asyut Governorate, highlighting the urgent need for regulatory control and targeted suicide prevention strategies.