Investigation of a fatality from nonoccupational aluminum phosphide exposure: Measurement of aluminum in tissue and body fluids as a marker of exposure

This case study reports our clinical and laboratory investigation of the accidental death of a pregnant rural woman related to phosphine exposure from stored grain fumigated with aluminum phosphide (AIP₃) pellets. Environmental data (housing proximity to fumigated grain and meteorologic conditions at the time) coupled with clinical data (tachycardia and the rapid development of pulmonary edema with no antecedent clinical abnormalities) suggested possible toxicant effects. Gross and microscopic autopsy findings demonstrated pulmonary edema. Because phosphine generated from the phosphide is highly reactive and unstable, our laboratory strategy for this investigation focused on the quantitative analysis of aluminum (AI) in blood, gastric contents, and in lung tissue to test the possibility of fumigant intoxication. We recovered 713 ng/ml AI from blood (normal laboratory range 2 to 42 ng/ml). Laser mass spectral analysis of lung tissue demonstrated high concentrations of AI in alveolar macrophages (> 200 ppm) with little or no AI in adjacent lung tissue. Control lung tissue from an urban autopsy case matched by age, sex, and smoking habits showed no demonstrable AI. We conclude that AI may be a useful marker for AIP₃ exposure.