Organophosphate toxicity and occupational exposure

The ubiquitous organophosphates present a continuing health hazard in agriculture, public health eradication programmes and as chemical warfare agents. Despite significant progress in understanding the potential mechanisms of toxicity far beyond the commonly accepted mechanism of cholinesterase inhibition in intentional exposures, the precise health effects following occupational exposures are yet to be completely defined. A much greater understanding exists of the clinical features of organophosphate poisoning. These are characterized by a triphasic response involving an initial acute cholinergic phase, an intermediate syndrome (both associated with high mortality) and a disabling but non-lethal delayed polyneuropathy. The delayed polyneuropathy may occur in the absence of the cholinergic or intermediate phases. However, progress is still required in order to improve the quantification and assessment of occupational exposures and the implementation of appropriate preventive measures. Finally, evidence-based guidelines for appropriate or optimal therapeutic interventions following poisoning are required urgently and collaborative work with colleagues in developing countries, where the occurrence of organophosphate exposures is more frequent, may provide the answers.