International trends in systemic human exposures to 2,4 dinitrophenol reported to poisons centres

Background 2,4 dinitrophenol (DNP) is a toxic industrial chemical that reduces body weight and body fat by uncoupling oxidative phosphorylation but at the risk of severe dose-related toxicity. Increases in human DNP exposures have been reported in the United Kingdom, the United States and Australia in recent years, but little information is available for other countries. This study was performed in collaboration with the World Health Organization (WHO) to establish international rates of systemic DNP-related exposures and deaths, as reported to poisons centres. Methods Poison Centres listed in the WHO Directory of Poison Centres were contacted by email. Data were requested on numbers of enquiries relating to systemic DNP exposure by year, sex and clinical outcome (fatal/non-fatal) for the period January 2010 to September 2020. Results Responses were received from poisons centres in 38 countries which reported 456 separate cases of DNP exposure (303 male, 125 female, 28 sex not reported). Annual case numbers increased from 4 in 2010 to 71 in 2015, with subsequent reductions to 53 in 2019. On a population basis, case rates were higher in Australasia, Europe and North America than in Asia, Africa, and South or Central America, but with substantial differences in rates between countries within the same continent. When mortality data was available, case fatality was high (11.9%, 95% CI 9.0, 15.4) with no significant difference between females (11.3%, 95% CI 6.4, 18.9) and males (12.6%; 95% CI 9.1, 17.1; odds ratio 0.86, 95% 0.45, 1.73, p = 0.72). Conclusions Substantial increases in calls to poisons centres regarding human systemic exposures to DNP internationally between 2010 and 2015, especially those in Europe, Australia and North America, with fatal outcomes common. Countries affected should consider appropriate additional measures to further reduce the risk of human exposure to this hazardous chemical.