Three hundred and fourteen pesticides were registered in India as of August 2019 (table 1), twelve with some restrictions on their use (table 2) [52, 53]. Four of these pesticides are WHO toxicity class Ia (extremely hazardous) compounds (bromadiolone, captafol, phorate, phosphamidon) while fourteen are WHO toxicity class Ib (highly hazardous) compounds (beta-cyfluthrin, carbofuran, coumatetralyl, cyfluthrin, dichlorvos, edifenphos, methomyl, monocrotophos, oxydemeton-methyl, propetamphos, sodium cyanide, tefluthrin, triazophos and zinc phosphide). Many of these compounds are used within India at rates of several thousand tonnes annually [40], indicating widespread availability of pesticides with high acute toxicity.
Ninety-five WHO toxicity class II pesticides are also registered, some of which are highly toxic after ingestion [21], with case fatalities often greater than 10% as shown by a large prospective secondary hospital case series from Sri Lanka [39] (paraquat 42.7%, dimethoate 20.6%, quinalphos 12.1%, alachlor 11.1%, profenofos 11.0%, propanil 10.9%, and carbosulfan 10.7%) [39]. Thirty-one class III (slightly hazardous) pesticides and 47 class U (unlikely to present acute hazard) pesticides are registered in India.
Three fumigants are registered for use in India—aluminium phosphide, DD mixture (dichloropropene and dichloropropane), and methyl bromide. Although not classified by the WHO, aluminium phosphide is extremely toxic after self-poisoning, with a case fatality often exceeding 50% after ingestion of the previously common 56% 3 gram tablets [54–59].
An additional 116 non-fumigant pesticides registered for use in India are not yet classified by the WHO for toxicity, and five pesticides listed by the WHO as obsolete are also registered for use. None of these compounds have their consumption reported by the Department of Chemicals and Petrochemicals [40], which could indicate that they do not constitute a large part of the market.
National regulatory actions
Thirty-nine pesticides have been banned nationally since 1989 (table 3) [60–64], including ten HHPs (bold in table 2) identified in previous studies as being important for suicide in South Asia [21, 39, 65–69]. An additional 26 pesticides have been refused registration or withdrawn from the market (table 3, footnote) [52, 60, 70–73].
In 2015, the Indian government set up the Anupam Verma Committee to review the continued use of 66 pesticides that have been banned or restricted for farming use in other countries [32]. In 2016, it recommended a ban on 13 pesticides, phasing out of 6 pesticides by 2020, and further review of 27 pesticides in 2018 [74, 75]. The Ministry of Agriculture partially implemented the recommendations in August 2018, banning 10 pesticides, placing restrictions on 2, and scheduling six bans for 2020 including several WHO Class Ia HHPs (table 2). Two pesticides had been recommended for a complete ban but were only restricted: sodium cyanide was banned for insecticidal use while trifluralin was restricted to use on wheat. DDT was not banned and its sole permitted use by the Ministry of Health was maintained.
Endosulfan was banned by the Supreme Court of India in May 2011, with the final stocks disposed of or exported by January 2017 [60]. According to the Department of Chemicals and Petrochemicals, no more endosulfan was produced domestically after the ban [41].
Overall, these regulatory actions have included national bans of ten HHPs that are relevant to pesticide suicides (table 2). Another eleven have been restricted in their use, for example ‘not to be used on vegetables’, or are only available in certain formulations (table 3). However, effective enforcement of these partial restrictions has proven difficult [76–78]. Monocrotophos, for example, despite being banned for use on food crops, is still widely used by farmers on vegetables as well as on its main permitted use for cotton [78, 79], as demonstrated by the Ministry of Agriculture’s “Monitoring of Pesticide Residues at National Level” scheme frequently identifying monocrotophos at above the maximum residue limit in samples of vegetables from markets and at the farm gate [75, 80].
State regulatory actions
Kerala, Punjab and Sikkim have passed separate laws permanently banning some pesticides, whilst Karnataka and Maharashtra have implemented temporary bans.
Kerala permanently banned endosulfan in October 2005 [81] and 14 other pesticides, many relevant for suicide, in January 2011—two WHO class Ia, four class Ib, five class II, two class III and one listed by the WHO as obsolete (table 2) [33, 82]. Bans for some of these pesticides have now been announced by the Central Government: methoxy ethyl mercuric chloride and methyl parathion in 2018 and phorate and triazophos in 2020. However, nine pesticides banned in Kerala remain in use nationally with no plans for regulatory action (anilofos, atrazine, carbofuran, edifenphos, monocrotophos, paraquat dichloride, profenofos, thiobencarb and tricyclazole).
Punjab, using the provision of the Insecticides Act that allows states to refuse renewal of pesticide licenses once they expire, decided not to renew licenses of 20 pesticides in 2018, including the HHPs carbosulfan, endosulfan, fenitrothion, methomyl, monocrotophos, phorate and phosphamidon (table 2) [28, 34, 83]. Sikkim banned all inorganic agricultural inputs, including HHP, in 2014 under the Sikkim Agricultural, Horticultural Input and Livestock Feed Regulatory Act [36]. Pesticides were withdrawn from agricultural use in the state by 2016 [35].
Temporary bans have taken place in Maharashtra and Karnataka (table 2). In November 2017, Maharashtra state requested that the Central Government ban five pesticides inhaled by victims of an accidental mass poisoning in Yavatmal district. The state also banned five formulations of these compounds for 60 days, including acephate 75% and monocrotophos 36% (table 2). The ban only applied to five districts and other formulations were still permitted [84]. Karnataka banned endosulfan in February 2011 for 60 days [85], shortly before the Supreme Court banned the compound nationally in May of that year [60]. Kerala was thus the only state that applied permanent pesticide bans within the period studied, and was, therefore, the only state for which we performed time series analysis to assess the effects of those bans.
Suicides
The NCRB recorded 133,623 deaths from suicide in 2015 [43], of which 23,930 (17.9%) were due to pesticides. From 1995 to 2015, 441,918 pesticide suicides and 2,451,410 suicides from all methods were recorded in India. Suicide rates from all methods, all poisons, pesticides and other poisons are shown in figure 1. Also presented in this figure is data on combined agricultural yield in kg/hectare of rice, wheat, cotton and 26 other important crops, as compiled by the Ministry of Statistics and Programme Implementation. This data is indexed to the yield recorded in the year 2001 and shows an increasing trend despite the pesticide bans that have taken place.
The majority of pesticide suicides (90.3%) occurred in eleven of the 29 states: Maharashtra, Andhra Pradesh, Madhya Pradesh, Tamil Nadu, West Bengal, Kerala, Telangana, Karnataka, Gujarat, Odisha and Chhattisgarh (figure 2). These states account for approximately 54.1% of the total population of India [45], and 84.2% of suicides by all methods in India. Maharashtra had the largest number of pesticide suicide deaths from 1995–2015 with 84,194 (19.2% of total), followed by Andhra Pradesh with 77,394 (17.6% of total) (figure 3).
Throughout most of the study period the pesticide suicide rate was highest in Andhra Pradesh and Telangana. Annual pesticide suicide rates for the eleven states with the highest numbers of pesticide suicides are plotted in figure 4 and the change in pesticide suicide rates for all states in map format in figure 5. Equivalent data for suicides by all methods is displayed in figures 6 and 7, where Kerala had the highest rate for most of the study period before being superseded by Chhattisgarh.
The national total and pesticide suicide rates were lower than expected, based on previous trends, for each year after the 2011 national ban on endosulfan (table 4). The reduction was larger for pesticide suicide (48% [95% CI 46 to 51%] less than expected by 2014) than total suicides (10% [95% CI 7 to 13%] less than expected by 2014).
In Kerala, after the 2011 ban on 14 other pesticides, the rate of pesticide suicides fell further than expected based on previous trends (55% [95% CI 51–58%] lower than expected in 2014), but there was no evidence of a change to the pre-existing downward trend in total suicides (table 4). The 2005 ban on endosulfan similarly did not appear to affect the trend in total suicides, but there was statistical evidence of a reduction in pesticide suicides rates compared to pre-ban trends (1999–2005) (table 5).
The large increase in pesticide suicides in 2015 was mostly due to increased numbers in Karnataka (increase of 2,818, or 501.4%), Tamil Nadu (increase of 1,591, or 92.9%) and Andhra Pradesh (increase of 1,830, or 55.1%) (figure 2). However, all three of these states saw large decreases in suicides coded as “consuming other poison” over the same period—2,138 for Karnataka, 1,142 for Tamil Nadu and 1,168 for Andhra Pradesh. These are nearly as large as the increases in pesticide suicides, suggesting that changes in coding may have contributed to the rise. Inclusion of the year 2015 in our time series analysis changed one of our conclusions—there was evidence of a decline of total suicide rate as well as pesticide suicide rate in Kerala during that year relative to 2011. The increase in the national pesticide suicide rate in that year was not large enough to change our conclusions about the trend since 2011 (table 6).