Poisoning and envenomations are worldwide problems but the major effects are felt in the developing world. At least 250,000–350,000 people die every year from acute pesticide poisoning59 and many more suffer from acute or chronic occupational exposure,38,74 hundreds of thousands of people are affected by groundwater arsenic contamination in Bangladesh and India,116 and an estimated 20,000–94,000 humans die each year from snake bites.80 Outbreaks of plant food–derived poisoning affect whole communities,32 and leaks from poorly regulated chemical plants affect urban areas as the Bhopal disaster did in 1984.112
The resources for dealing with these problems are limited. Public health education about poisons and laws limiting access to the most highly toxic chemicals are practically absent in much of the developing world. Rudimentary public health infrastructures make the western model of a toxicology consult service impractical. Clinical toxicology is frequently not a recognized specialty and patients are evaluated by general physicians with little training, although often with great experience. Diagnostic facilities are few, effective treatment options even rarer. Where antidotes exist, there is rarely enough knowledge or experience to know how to use them.23 Intensive care beds for long-term ventilation are scarce.
Variations in poisoning patterns within any given country may be significant, especially when comparing wealthier urban centers with agrarian, often poorer, rural areas. While the majority of healthcare and academic resources are concentrated in urban centers, it is in the countryside where much of the mortality from acute poisoning occurs. The accessibility of pesticides to rural people, and their lethality, has a profound influence on global poisoning patterns.
A systematic review suggested that at least 250,000, and probably 350,000, deaths occur each year from acute pesticide self-poisoning around the world.59 The annual number of deaths from occupational or unintentional poisoning is unknown but was estimated 20 years ago at 20,000.73 The majority of self-harm deaths occur in Asia, particularly in China and India.59 Around 3000–6000 ventilators are required each day for ventilation of pesticide-poisoned patients,59 with many patients requiring ventilation for weeks.46 The World Health Organization now considers pesticide poisoning to be the single most important global means of suicide, accounting for more than one-third of all suicides.17
While many classes of pesticides are implicated in fatal self-poisonings, organic phosphorous (OP) insecticides appear to be responsible for the majority of pesticide-related deaths.42 Deliberate self-poisoning with OP insecticides puts a high cost on the healthcare system. In one study examining the experience in Sri Lanka, OP insecticide poisoning was responsible for 943 of 2559 (36%) admissions to a secondary hospital for poisoning.48 The case fatality for OP poisoning was 21%, and pesticide poisoned patients occupied 41% of all medical intensive care beds. Similar situations have been reported from across the world.42 In all likelihood, such studies underestimate the mortality associated with intentional ...