Exposure to phosphine in maritime transport: a real and important occupational risk: a report of three cases

Abstract

In maritime transport, to assess the risks of insect pests spreading, fumigation is recommended by the Food and Agriculture Organisation. Fumigant mostly used for foodstuffs is the phosphine gas generated by the reaction of aluminium phosphide and moisture in the atmosphere. In this article, we first discuss phosphine toxicity to humans and then we describe three cases of occupational exposure in maritime transport of cereals. We found phosphine level higher than 20 ppm in tank atmosphere of bulk carriers and levels from 2 to 3.5 ppm in port silos and port warehouses where cereals were unloaded. Two weeks later, atmospheric measurements in a silo were still at 0.8 ppm. In this case, 3 workers described symptoms which could be linked with phosphine. Exposures to phosphine and cases in maritime transport are surely underestimated. Exposure could occur at sea, in harbour but also in port warehouses, trucks and silos or warehouses along logistic chain. All workers in the chain could be exposed. We can recommend research aiming at the development of alternative techniques using a less harmful gas for humans. At individual level, we propose that, along with the training for employees, workers potentially exposed should wear a test strip (phosphine detector strips) or a personal gas badge with appropriate maintenance.