Suicide by pesticide poisoning in India: a review of pesticide regulations and their impact on suicide trends.

backgroundPesticide self-poisoning is a common means of suicide in India. Banning highly hazardous pesticides from agricultural use has been successful in reducing total suicide numbers in several South Asian countries without affecting agricultural output. Here, we describe national and state-level regulation of highly hazardous pesticides and explore how they might relate to suicide rates across India.

methodsInformation on pesticide regulation was collated from agriculture departments of the central government and all 29 state governments (excluding union territories). National and state-level data on suicides from 1995 to 2015 were obtained from the National Crime Records Bureau (NCRB). We used joinpoint analysis and negative binomial regression to investigate the trends in suicide rates nationally and in Kerala, in view of the robust measures Kerala has taken to restrict a number of HHPs, to identify any effect on suicides.

resultsAs of October 2019, 318 pesticides were registered for use in India, of which 18 were extremely (Class Ia) or highly (Class Ib) hazardous according to World Health Organization toxicity criteria. Despite many highly hazardous pesticides still being available, several bans have been implemented during the period studied. In our quantitative analyses we focused on the permanent bans in Kerala in 2005 (of endosulfan) and 2011 (of 14 other pesticides); and nationally in 2011 (of endosulfan). NCRB data indicate that pesticides were used in 441,918 reported suicides in India from 1995 to 2015, 90.3% of which occurred in 11 of the 29 states. There was statistical evidence of lower than expected rates of pesticide suicides (rate ratio [RR] 0.52, 95% CI 0.49-0.54) and total suicides nationally by 2014 (0.90, 0.87-0.93) after the 2011 endosulfan ban. In Kerala, there was a lower than expected rate of pesticide suicides (0.45, 0.42-0.49), but no change to the already decreasing trend in total suicides (1.02, 1.00-1.05) after the 2011 ban of 14 pesticides. The 2005 ban on endosulfan showed a similar effect - lower than expected pesticide suicides (0.79, 0.64-0.99), but no change to the decreasing trend of total suicides (0.97, 0.93-1.02) in 2010. There was no evidence of a decline in agricultural outputs following the bans.

conclusionHighly hazardous pesticides continue to be used in India and pesticide suicide remains a serious public health problem. However, some pesticide bans do appear to have impacted previous trends in the rates of both pesticide suicides and all suicides. Comprehensive national bans of highly hazardous pesticides could lead to a reduction in suicides across India, in addition to reduced occupational poisoning, with minimal effects on agricultural yield.