Environ Sci Pollut Res DOI 10.1007/s11356-016-6294-0
REVIEW ARTICLE
Scenario of organophosphate pollution and toxicity in India: A review Shardendu Kumar 1 & Garima Kaushik 1 & Juan Francisco Villarreal-Chiu 2
Received: 28 September 2015 / Accepted: 14 February 2016 # Springer-Verlag Berlin Heidelberg 2016
Abstract The present study on organophosphate deals with the reports on pollution and toxicity cases throughout India. The use of pesticides was introduced in India during the 1960s which are now being used on a large scale and represents the common feature of Indian agriculture. Use of organophosphates as a pesticide came as an alternative to chlorinated hydrocarbons due to their easy degradability. Although these xenobiotics degrade under natural condition, their residues have been detected in soil, sediments, and water due to their non-regulated usage practice. The over-reliance on pesticides has not only threatened our environment but contaminations of organophosphate residues have been also detected in certain agricultural products like tea, sugars, vegetables, and fruits throughout India. This paper highlights many of the cases where different organophosphates have been detected exceeding their respective MRL values. Some organophosphates detected are so hazardous that even WHO has listed them in class 1a and class 1b hazardous group. Presence of their residues in blood, milk, honey, and tissues of human and animals revealed their excessive use and bioaccumulating capabilities. Their intentional or unintentional uptake is causing thousands of deaths and severity each year. Most of the
Responsible editor: Philippe Garrigues * Garima Kaushik
[email protected];
[email protected]
1
Department of Environmental Science, School of Earth Science, Central University of Rajasthan, Ajmer, Rajasthan Pin 305817, India
2
Universidad Autónoma de Nuevo León, Facultad de Ciencias Químicas, Laboratorio de Biotecnología, Av. Universidad S/N Ciudad Universitaria, San Nicolás de los Garza, Nuevo León CP66451, Mexico
toxicity cases presented here are due to their uptake during a suicidal attempt. This shows how easily these harmful substances are available in the market. Keywords Pesticides . Hydrocarbons . Organophosphates . Degradability . Xenobiotics . MRLs
Introduction The term pesticide covers a wide range of compounds including insecticides, fungicides, herbicides, rodenticides, molluscicides, nematocides, plant growth regulators, and others. Among these, organochlorine (OC) insecticides, used successfully in controlling a number of diseases, such as malaria, and typhus, were banned or restricted after the 1960s in most of the technologically advanced countries. The introduction of other synthetic insecticides, i.e., organophosphate (OP) insecticides in the 1960s, carbamates in 1970s, and pyrethroids in 1980s, and the introduction of herbicides and fungicides in 1970s–1980s contributed greatly in pest control and agricultural output (Akhtar et al. 2009). The Government of India has taken steps to ensure the safe use of pesticides. The Insecticides Act which was promulgated in 1968 and enforced on 1 August 1971 in India envisages to regulate the import, manufacture, sale, transport, distribution, and use of insecticides, with a view to prevent risks to human beings or animals, and for matters connected therewith. It was desirable as a prerequisite to the enforcement of the Insecticides Act, to evaluate the magnitude of pesticide pollution in the country and related health hazards to ensure their safe use for the benefit of the society. The National Institute of Occupational Health (NIOH), Ahmedabad, a body of the Indian Council of Medical Research and several other national laboratories, farm universities, and other R and D organizations have been
Environ Sci Pollut Res
engaged in toxicological evaluation of pesticides, synthesis of safer molecules, and evaluation of environmental contamination due to pesticides. There is a sequential rise in the production and consumption of pesticides in India during the last three decades. However, the consumption pattern of these chemicals in India differs with rest of the world (Mathur 1999) (Tables 1 and 2). The domestic demand in India accounts for about 76 % of the total pesticides used in the country as against 44 % globally (ICMR Bulletin. Sept. 2001). The three commonly used pesticides, HCH (only gamma-HCH is allowed), DDT, and malathion, account for 70 % of the total pesticides consumption and these are still preferred by the small farmers because they are cost-effective, easily available, and display a wide spectrum of bioactivity (Gupta 2004). Out of the total consumption of pesticides, 80 % are in the form of insecticides, 15 % are as herbicides, 1.46 % are fungicides, and less than 3 % are others. In comparison, the worldwide consumption of herbicides is 47.5 %, insecticides is 29.5 %, and fungicides is 17.5 %, and others account for 5.5 % only. The consumption of herbicides in India is probably low, because weed control is mainly done by hand weeding (Gupta 2004).
Table 2 Top pesticide-consuming states in India during 2005 to 2010 (as per official data of the Directorate of Plant Protection, Quarantine and Storage, Govt. of India) Sl. number State
Total pesticides consumed (in metric tones)
1
Uttar Pradesh 39,948
2
Punjab
29,235
3 4
Haryana Maharashtra
21,908 16,480
5 6
Rajasthan Gujarat
15,239 13,430
7
Tamil Nadu
12,851
All India
210,600
Source: http://ppqs.gov.in/PMD.htm#variousPest
people who may be exposed to large amounts. The organophosphorus pesticides are less persistent in water, soil, food, and feed for animals than the organochorine pesticides; however, they are relatively soluble in water and are highly toxic. It can be absorbed by all routes, including inhalation, ingestion, and dermal absorption.
Organophosphates
Organophosphate insecticide usages and pollution status
Organophosphorus compounds are degradable organic compounds containing carbon-phosphorus (C-P) bonds, used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. They are organic derivatives of phosphorus, usually esters, amides or thiol derivatives of phosphoric, phosphonic, phosphinic, or thiophosphoric acids with two organic and additional side chains such as cyanide, thiocyanate, and phenoxy group (Soltaninejad and Shadnia 2014). Their ability to degrade under natural conditions made them an attractive alternative to the persistent organochlorine pesticides, such as DDT, aldrin, and dieldrin. Some studies have showed that organophosphate pesticides degrade rapidly by hydrolysis on exposure to sunlight, air, and soil (Dhas and Srivastava 2010). Besides this, small amounts can be detected in food and drinking water. Although organophosphates degrade faster than the organochlorines, they have acute toxicity, hence, posing risks to
Organophosphate compounds are used as a replacement for organochlorines due to their less persistent nature, but their extensive and non-regulated use has caused a major threat for our environment and life. They are widely used since a few decades in agriculture for pest control and crop protection, thousands of these compounds have been screened and over a hundred among them have been marketed for these purposes (Kumar et al. 2010). Commonly used organophosphates in India are malathion, methyl parathion, chlorpyrifos, diazinon, dichlorvos, fenitrothion, phorate, and monocrotophos (Table 3). The responsible authority for registering pesticides for use on crops to control pests and weeds is the Central Insecticides Board and Registration Committee (CIBRC), which falls under the Ministry of Agriculture and Farmer Welfare. Organophosphates registered under Section 9 (3) of the Insecticides Act, 1968 for use in the country are listed in Table 4.
Table 1 Usages of pesticides in India (Gupta 2004)
Agriculture Public health Industrial Domestic Personal Material building
For control of pests, weeds, rodents, etc. For control of malaria, filariasis, dengue, Japanese encephalitis, cholera, and louse-borne typhus Control of vegetation in forests and factory sites; fumigation of buildings and ships Household and garden spray; control of ecto-parasites in animals and birds Application of clothing and skin; control of ecto-parasites (fleas, lice) Incorporation of paints, timber, glues, plastic protection, sheeting, foundation of buildings, etc.
Environ Sci Pollut Res Table 3 Most consumed organophosphates in the country (during 2005 to 2010) Sl. Number
Organophosphate types
Quantity (in metric tones)
1
Phorate
10,763
2
Methyl parathion
8408
3 4
Monocrotophos Chlorpyrifos
8209 7354
5
Malathion
7103
6 7
Quinalphos Dichlorvos
6329 5803
Source: http://ppqs.gov.in/PMD.htm#variousPest
Pollution and contamination status Studies upon agricultural soil, sediments, and water have showed contamination of different types of organophosphates more or less throughout India (Table 5). According to a report, residues of organophosphates like phorate, malathion, and ethion were detected in the sediments of Tarnadmund, Nedugula, and Bison swamp wetlands of Nilgiris district (SACONH report). Soil sample taken from paddy-wheat, paddy-cotton, and sugarcane fields of Hisar, Haryana, were found contaminated with the residues of chlorpyriphos, malathion, and quinalphos. (Kumari et al. 2008). In this series, Bishnu et al. (2009) have also detected residues of ethion and chlorpyrifos from the soils of tea fields of West Bengal region. Three OPs namely chlorpyriphos, quinalphos, and ethion were detected above their respective maximum residue limit (MRL) values in the agricultural field of Idukki district, Kerala where cardamom plantations were going on (Jacob et al. 2014). Water pollution due to organophosphates is also a danger bell for the deterioration of our environment from these xenobiotics. Some studies have shown that agricultural area for vegetables, cotton, and horticultural crops are the main sources of water pollution due to pesticides (Mathur 1999; Kumari et al. 2008; Pujeri et al. 2011). Concentration of chlorpyriphos ethyl was found in the range of 0.0002 to 0.004 mg/L in the certain lakes of Bijapur (Karnataka) (Pujeri et al. 2011). Similarly, groundwater near paddy, cotton, and sugarcane fields around Hisar, Haryana, were found contaminated with chlorpyriphos residues above the regulatory limits (Kumari et al. 2008). Surface and ground water sampled from Vidarbha region of Maharashtra have been found polluted with the OPs like dichlorovos, ethion, parathion-methyl, phorate, chlorpyrifos, and profenofos; among the sites, detected levels of organophosphates were more in the surface water than the groundwater (Lari et al. 2014). Water bodies around tea fields of some West Bengal regions have also showed the presence of ethion in trace amounts (Bishnu et al. 2009).
The over-reliance on pesticides has not only threatened our environment, but contaminations of organophosphate residues have been also detected in certain agricultural products like tea, sugars, vegetables, and fruits (Table 5). Monocrotophos, a suspected mutagen and neurotoxicant, has been found in 27 samples in the range of 0.026–0.270 mg/kg across tea brands made by various companies including Tata, Hindustan Unilever, Kho Cha, Royal Girnar, Goodricke, Wagh Bakri, and Golden Tips. This pesticide is not approved for use on tea and is classified as highly hazardous (class Ib) by the World Health Organization. Presence of another organophosphate, ethion (metabolite of the unapproved pesticide, Chlormephos), detected in 22 of the tea samples is most likely due to its direct use on tea (Greenpeace India report 2014). Earlier, dependence of tea plantations over ethion pesticide was also identified by Gurusubramanian et al. (2008). Samples of made tea and fresh tea leaves taken from Hill and Dooars regions of West Bengal were also found contaminated with organophosphate like ethion and chlorpyrifos. In this study, organophosphates were detected higher in fresh tea leaves than in made tea (Bishnu et al. 2009). A similar study carried out in cured leaves of a tea sp. Camellia Sinensis in South India has reported the contamination with residues of organophosphates like ethion and quinalphos (Kottiappan et al. 2013). Seenivasan and Muraleedharan (2011) carried out similar type of survey over 912 tea sample collected from South India; data obtained by him proved that only 0.5 % of samples had residues of ethion and quinalphos below their MRL value along with other categories of pesticides. Not only the tea, sugar samples from a factory outlet tested by Sinha et al. (2011) were also found contaminated with residues of chlorpyriphos. Vegetables have always been an essential component of the human diet in India. A wide range of organophosphate pesticides are globally used for the protection of vegetable cultivation against pests since they get heavy pest infestation easily. Contamination of vegetables with organophosphates has also showed their extensive and unregulated use in agriculture. Methyl parathion, chlorpyriphos, and malathion contamination were identified in vegetables of different seasons in northern India. The concentration of these pesticides were found below the established tolerances but continuous consumption of such vegetables can lead to their accumulation in the receptor’s body and may prove fatal in the long-term (Bhanti and Taneja 2007). Residual levels of organophosphorous insecticides were found highest followed by carbamates, synthetic pyrethroids, and organochlorines above their respective MRL value in the winter vegetable samples collected from Hissar, Haryana (Kumari et al. 2003). Similar work carried by Kumari et al. (2004) over 84 farm gate samples of seasonal vegetables like brinjal, okra, cauliflower, cabbage, cucumber, etc., among which residues of monocrotophos, quinalphos, and chlorpyriphos were detected exceeding the MRL value in some of the
Environ Sci Pollut Res Table 4
Organophosphates registered under Section 9 (3) of the Insecticides Act, 1968 for use in the country as of 31 Dec. 2014
Types
Trade name
Mol. formula
LD50, oral (mg/kg)
LD50, dermal (mg/kg)
Acephate Anilophos Chlorpyrifos Chlorpyriphos-methyl Diazinon Dichlorvos Dimethoate Edifenphos Ethion Ethoprop Fenamiphos Fenitrothion Fenthion Iprobenfos Malathion Monocrotophos Oxydemeton-methyl
Orthene Arozin Dursban, Lorsban Reldan Spectracide Vapona, DDVP Cygon, De-Fend Hinosan, EDDP Ethanox, Ethiol, Hylemox, Nialate Mocap Nemacur Sumithion Baytex, Tiguvon Vikita Carbophos,American Cyanamide Wankophos Meta systox-R
C4H10NO3PS C13H19ClNO2PS3 C9H11Cl3NO3PS C7H7Cl3NO3PS C12H21N2O3PS C4H7Cl2O4P C5H12NO3PS2 C14H15O2PS2 C9H22O4P2S4 C8H19O2PS2 C13H22NO3PS C9H12NO5PS C10H15O3PS2 C13H21O3PS C10H19O6PS2 C7H14NO5P C6H15O4PS2
945–1400 472 32 to 1000 1530 1250 56–108 235 100 208 61 10 500 180–298 550–680 5500 17–20 50
– 2000 2000 >2000 – 75–210 >400 615 838 2 >2000 1416 330–1000 >3710 >2000 126 150
Parathion-methyl
Zofos, Azaophos
Phenthoate Phorate Phosalone Phosphamidon Pirimiphos-methyl Profenofos Propetamphos Quinalphos Temophos Terbufos Triazophos Trichlorfon
PAP Thimet Zolonc Dimecron Actellic Dyfonate Blotic, Safrotin and Seraphos. Chemidor, chemolux Abate Counter, contraven Hostathion Dylox, neguvon
C10H14NO5PS-CH4 C12H17O4PS2 C7H17O2PS3 C12H15ClNO4PS2 C10H19ClNO5P C11H20N3O3PS C11H15BrClO3PS C10H20NO4PS C12H15N2O3PS C16H20O6P2S3 C9H21O2PS3 C12H16N3O3PS C4H8Cl3O4P
6 249–270 2–4 85 13–20 2050 358 75 to 119 62–137 1300–8600 1.3–1.74 57–59 150–649
50 >5000 20–30 390 26 1505 1610 825–2300 1250–1400 >4000 – >2000 2000–4000
Acephate, chlorpyrifos, diazinon, dichlorvos, dimethoate, fenitrothion, fenthion, malathion, monocrotophos, methyl parathion, phorate, phosphamidon, quinalphos, triazophos, and trichlorfon are the organophosphate pesticides which are listed and used in India but banned/severely restricted in some countries including in Europe and the USA (India for Safe food, http://www.indiaforsafefood.in/farmingcontinues.html) Dicrotophos, disulfoton: refused registration Source (MoEF-India, Insecticides act, 1968, World Health Organization 2009, http://ppqs.gov.in/PMD.htm#variousPest)
samples. Another study over farmgate samples of vegetables from Ramanagara district of Karnataka, have showed their contamination with organophosphates, organochlorines, and pyrethroids among which residues of organophosphate insecticides were found above their respective maximum residue limits (Anand and Somasekhar 2012). In a similar type of study over farmgate and market vegetables sampled from Jaipur have revealed their contamination with organophosphates namely monocrotophos, quinalphos, dimethoate, and chlorpyriphos from below to above their residual limits (Singh and Gupta 2002). According to a report, vegetables including
leafy, root, modified stem, and fruity vegetables from a local market of Lucknow city have showed contamination of organophosphates like anilophos, dichlorvos, dimethoate, diazinon, and malathion above their maximum residual limit (Srivastava et al. 2011) while chlorpyriphos and monocrotophos were detected below their residual limit in locally grown vegetables from Nanded, India (Chandra et al. 2014). A similar study carried out by Mukharjee (2003) showed contamination of residues of six organophosphorus insecticides in samples of vegetables in and around Delhi above the prescribed tolerance limit. In another investigation by Sinha et al. (2012) over
South India South India Hill and Dooars regions of West Bengal Northern India Hisar, Haryana
Tea
Made tea, fresh tea leaves
Winter vegetable
Anilophos, dichlorvos, dimethoate, diazinon and malathion Chlorpyriphos and monocrotophos
Ethion, monocrotophos, quinalphos, chlorpyriphos, fenitrothion, diazinon etc. profenofos, chlorpyrifos, Dimethoate, malathion, Quinalphos, Methyl parathion, Ethion, and Phorate Acephate, chlorpyrifos, Profenophos, Quinalphos, Fenamiphos Dimethoate, Chlorpyrifos, Profenophos, Quinalphos, and Malathion chlorpyrifos
Lucknow City Nanded, Maharashtra In and around Delhi Jaipur Hyderabad Andhra Pradesh Punjab Andhra Pradesh Different factory outlets of India
Leafy, root, modified stem, and fruity vegetables Seasonal vegetables
Farm vegetables
Farm gate and market vegetables
Vegetable from street outlets
Vegetable from farmers' field
Cauliflower Fruits like Banana, Guava, Orange, Grapes etc. Sugar
Malathion, methyl parathion, quinalphos, chlorpyrifos and chlorpyrifos methyl Monocrotophos, quinalphos, dimethoate, Chlorpyriphos,
Acephate, chlorpyriphos, dichlorvos, monocrotophos, phorate and profenofos
Hisar, Haryana Ramanagara district of Karnataka
Farm gate seasonal vegetables
Dimethoate, malathion, fenitrothion, monocrotophos, phosphamidon, quinalphos, and chloropyriphos Monocrotophos, quinalphos and chlorpyriphos
Methyl parathion, chlorpyriphos, and malathion
Ethion and chlorpyrifos
Ethion and quinalphos
Ethion and quinalphos
Dichlorovos, ethion, parathion-methyl, phorate, chlorpyrifos and profenofos Monocrotophos and ethion
Farmgate seasonal vegetables
Seasonal vegetables
Tea
Tea leaves of sp. Camellia Sinensis
Chlorpyriphos
Hisar, Haryana
Lake water Water samples adjacent to the tea gardens Groundwater from tubewells Vidarbha region of Maharashtra Across India
Chlorpyriphos ethyl Ethion
Idukki, Kerala Bijapur, Karnataka West Bengal
Soil from Cardamom field
Surface and ground water
Ethion and chlorpyrifos
West Bengal Chlorpyriphos, quinalphos and ethion
Phorate, malathion and ethion Chlorpyriphos, malathion and quinalphos.
Nilgiris district Hisar, Haryana
Sediment from wetlands Soil from paddy-wheat, paddy-cotton, and sugarcane fields Soils from tea fields
Detected Organophosphates
Study site
Reported contamination of different samples with residues of organophosphates
Sample type
Table 5
Kumari et al. 2008
Pujeri et al. 2011 Bishnu et al. 2009
Jacob et al. 2014
Bishnu et al. 2009
SACONH report Kumari et al. 2008
Below
Below to Above
Below
Below to above
Above
Below to above
Below to above
Below
Above
Above
Above
Below to slightly Above Below to moderate Above
Below
Above
Above
Sinha et al. 2011
Harinathareddy et al. 2014
Mandal and Singh 2010
Harinathareddy et al. 2014
Sinha et al. 2012
Singh and Gupta 2002
Mukharjee 2003
Chandra et al. 2014
Srivastava et al. 2011
Anand and Somasekhar 2012
Kumari et al. 2004
Kumari et al. 2003
Bhanti and Taneja 2007
Bishnu et al. 2009
Seenivasan and Muraleedharan 2011
Greenpeace India report 2014 Kottiappan et al. 2013
Moderate to above Lari et al. 2014
Above Below to moderate Below
Below to moderate Above
Above Above
reference MRLa/ Permissibleb limit
Environ Sci Pollut Res
Cotton growing belt of Haryana Himachal Pradesh
Butter and ghee
Above Above
Bhopal, Madhya Pradesh Allahabad
Sanghi 2003 Srivastava et al. 2008
Amaraneni and Pillala 2001
CSE report, 2015 Singh et al. 2008 Ramesh and Selvanayagam 2015
Choudhary and Sharma 2009 CSE report 2006
Kumari et al. 2005
BIS Permissible limit of pesticides in water is 0.001 mg/l but there is no any prescribed/permissible limit set for soil or sediment. So any alteration in this limit in water or any trace detection in the soil can be treated as contamination
b
www.codexalimentarius.org/input/download/report/701/al31_24e.pdf
a
The MRL value (only for the different crops) has been given by the European Union and WHO/FAO joint standard programme. The latest report of this came in 2008 entitled BREPORT OF THE FORTIETH SESSION OF THE CODEX COMMITTEE ON PESTICIDE RESIDUES^
Malathion, chlorpyrifos, and methyl parathion Methyl parathion
Above
Kolleru Lake, Andhra Pradesh Malathion and chloirpyrifos
Moderate Above
Below to above
tissue samples of fishes Channa striata and Catla catla Breast milk Bovine milk
Chlorpyriphos and malathion
Gujarat and Maharastra Punjab Monocrotophos, chlorpyrifos, malathion and phosphamidon River Gomti from north India Chlorpyrifos Kolavai lake, Chengalpet, Chlorpyrifos Tamil Nadu
Above
Above
MRLa/ reference Permissibleb limit
Human blood Blood of fish Rita rita Muscle tissue samples of fish Cirrhinus mrigala
Malathion, dimethoate and quinalphos
Chlorpyriphos
Detected Organophosphates
Soft drinks
Honey
Study site
Sample type
Table 5 (continued)
Environ Sci Pollut Res
Environ Sci Pollut Res
vegetables from farmers’ market and local outlets of Hyderabad revealed their contamination with 18 different organophosphates. Organophosphates like profenofos, chlorpyrifos, dimethoate, malathion, etc. have been reported in vegetable from farmers’ field of Andhra Pradesh (Harinathareddy et al. 2014). Brassica oleracea, an important cruciferous vegetable crop of India, sampled from Punjab, showed a detectable amount of different organophosphates but all were found below their respective MRL value (Mandal and Singh 2010). Detection of the residues of these xenobiotics in certain fruits like banana, pomegranate, sweet orange, guava, apple, and grapes have also been reported by the researchers across India (Pujeri et al. 2011; Sinha et al. 2012; Harinathareddy et al. 2014). The presence of organophosphates residues is not limited up to vegetables and agricultural products only, but they have also showed their presence in certain animal and food products like ghee, butter, honey, soft drinks, etc. (Table 5). Butter and ghee samples collected from rural and urban areas of cotton growing belt of Haryana showed contamination of chlorpyriphos (Kumari et al. 2005). Honey, being a natural product manufactured by honey bees is supposed to be free from any extraneous material, but honey samples from Himachal Pradesh were found contaminated with malathion residue (Choudhary and Sharma 2009). This indicates how these xenobiotics get accumulated in the consumer’s body. Two organophosphate pesticide residues namely chlorpyriphos and malathion were detected in the samples of cold drinks (Limca and Coca-Cola) manufactured in Gujarat and Maharashtra. Chlorpyrifos was detected in 100 % of the samples analyzed in the range of 0.17 ppb to 20.43 ppb, which is 200 times the BIS limit of 0.1 ppb for individual pesticides, whereas malathion was present in 39 % of the samples in the range of nil to 3.11 ppb (CSE report 2006).
Table 7 Survey of acute poisoning cases (%) due to organophosphorus pesticides in India (Gupta 2004) Symptoms
Cases (%)
Vomiting Nausea Miosis Excessive salivation Blurred vision Giddiness Headache Disturbances in consciousness Sinus tachycardia Sinus bradycardia Depression of ST segment
96 82 64 61 54 93 84 44 25 6 6
Organophosphates are less persistent in nature and have less bioaccumulation ability, but across the globe, residues of pesticides have been also found in human blood, urine, breast milk, semen, adipose tissue, amniotic fluid, and umbilical cord blood (Table 5). In India, there are several reports indicating the presence of OP residues in human and animal parts. Cumulative exposure to pesticides may come from food, water, air, dust, soil, etc. (CSE report 2005). The presence of organophosphorus pesticides in blood means that they do persist in the body for good amount of time. According to CSE report (March 2005), monocrotophos, chlorpyrifos, malathion, and phosphamidon were detected in human blood samples randomly selected from four different villages of Punjab which were the total contributors among all the pesticides detected. Likewise, residues of malathion, chlorpyrifos, and methyl parathion were detected in breast milk from Bhopal, Madhya Pradesh (Sanghi 2003). Bovine milk from Allahabad region is also found contaminated with the residues of methyl parathion which is classified as class 1a hazardous group by WHO (Srivastava et al. 2008). Due to their ease of transport in aquatic ecosystem, accumulation of some organophosphate residues have also been reported in fishes. During study over the fishes, blood of fish namely Rita rita from the river Gomti of northern India has been found bioaccumulated with the traces of chlorpyrifos (Singh et al. 2008), whereas bottom feeder Cirrhinus mrigala was found contaminated with the chlorpyriphos in the Kolavai lake of Chengalpet, Tamil Nadu (Ramesh and Selvanayagam 2015). A similar type of research over tissue sample of two fish species namely Channa striata and Catla catla revealed their contamination with malathion and chlorpyrifos by Amaraneni and Pillala (2001). Organophosphate toxicity cases Organophosphates were developed during the early nineteenth century as an insecticide, but their effects on insects, which are similar to their effects on humans, were discovered in 1932 (USEPA). The organophosphate compounds are most commonly associated with serious human toxicity, accounting for more than 80 % of pesticide-related hospitalizations (Kumar et al. 2010). The WHO-recommended classification of organophosphates by hazard which are registered in India (2009) have been given in Table 6. Many organophosphates are potent nerve agents, functioning by inhibiting the action of acetylcholinesterase (AChE) in nerve cells upon entering the body through ingestion, inhalation, or dermal exposure. The inhibitory effect on the acetylcholinesterase enzyme leads to a pathologic excess of acetylcholine in the body. Victims of organophosphate poisoning typically die because they cannot breathe (Than 2013). Nicotinic manifestations occur in severe cases and late in the course; these comprise of fasciculation and neuromuscular paralysis (Singh and Khurana 2009). They
Environ Sci Pollut Res
are also identified as potential carcinogens. Acephate, dichlorovos, and phosphamidon are the three organophosphate pesticides registered and used in India which are classified as potential carcinogens by the USEPA (http://www. indiaforsafefood.in/farminginindia.html). They have showed acute toxicity, posing risks to people who may be exposed to large amounts. The Poison Information Centre in NIOH, Ahmedabad reported that organophosphates were responsible for the maximum number of poisoning (73 %) among all agricultural pesticides (Table 7). The potential adverse impact on human health from exposure to pesticides is likely to be higher in countries like India due to easy availability of highly hazardous products, and low risk awareness, especially among children and women (Singh and Sharma 2000; Singh and Khurana 2009; Kumar et al. 2010). In India, the first report of poisoning due to pesticides was reported from Kerala in 1958, where over 100 people died after consuming wheat flour contaminated with parathion (Gupta 2004). In a study on patients of acute OP poisoning, muscarinic manifestations such as vomiting (96 %), nausea (82 %), miosis (64 %), excessive salivation (61 %), and blurred vision (54 %) and CNS manifestations such as giddiness (93 %), headache (84 %), disturbances in consciousness (44 %) were the major presenting symptoms (Agrawal et al. 2010). Cases of organophosphorus compound poisoning deaths were found more in rural (62.05 %) as compared to urban areas (37.95 %), as there is more farming activity in rural areas (Parmar et al. 2014). Organophosphate poisoning is one of the commonest types of poisoning in India for suicidal attempt (Singh and Sharma 2000; Singh and Khurana 2009). In 1995, National Poison Information Center (NPIC) was established at the All India Institute of Medical Sciences, New Delhi. Data on the pattern of poisonings in north India accumulated at this center suggest that suicidal poisoning with household agents is the most common modality of poisoning (Singh and Khurana 2009). A prospective study was done in Shri Aurobindo Medical College Hospital, Indore during 1 January 2012 to 20
Table 6 The WHO recommended classification of Organophosphates by hazard which are registered in India (World Health Organisation 2009)
August 2013. A total of 100 cases were diagnosed with history of pesticide poisoning during this period; the most common (46 cases) poison detected was organophosphates (Waghmare et al. 2014). Organophosphate poisoning can be resulted in to complicated intermediate syndrome and organophosphateinduced delayed polyneuropathy (Singh and Sharma 2000; Khosya et al. 2013). After a case study of over 28 patients of two organophosphate viz. malathion and diazinon suicidal cases, 25 patients recovered and 3 patients died in the intensive respiratory care unit (IRCU) of L.T.M.G. Hospital, Mumbai. All patients included in the study had neck muscle weakness or weak gag reflex, clinical signs of cholinergic crisis, pulmonary edema, or aspiration pneumonia that were likely to require ventilator support (Chhajed et al. 2000). Similarly, upon diagnosis of 94 patients of organophosphate cases in Kasturba hospital, Manipal, the most common compound detected was chlorpyrifos followed by methyl parathion. It was seen that majority of patients (about 27.7 %) were doing household jobs; this signifies the ease with which the compounds are available to the common man (Raghavan et al. 2014). Monocrotophos, methyl parathion, and quinolphos were found as the most common pesticides consumed for the suicidal attempt upon a study over 116 cases of organophosphorous poisoning at the new civil hospital and government medical college, Surat (Gupta et al. 2006). A study upon 137 patients in Gayatri Hospital, Gandhinagar, during the period of 2 years (2012–2014), the maximum of cases were suicidal (57.66 %) in nature followed by accidental (42.34 %) (Parmar et al. 2014). Similarly, upon investigation over methyl parathion poisoning cases in Kasturba hospital, Manipal, 98.2 % cases were found of suicidal attempt among which respiratory failure was the commonest complication (Palimar et al. 2005). A preference of organophosphates for suicidal attempt was found more over any other type of poison upon study over suicidal poisoning in Southern India (Kanchan and Menezes 2008) and in a tertiary care hospital in rural South India (Jaiprakash et al. 2011). Warangal district in Andhra Pradesh, Southern India, records over one thousand
Extremely hazardous (class Ia)
Highly hazardous (class Ib)
Moderately hazardous (class II)
Slightly hazardous (class III
Parathion-methyl
Fenamiphos
Acephate, anilophos
Chlorpyriphos-methyl
Phosphamidon
Monocrotophos
Chlorpyrifos, diazinon,
Malathion
Terbufos
Oxydemeton-methyl
Dichlorvos, dimethoate,
Temophos
Propetamphos
Ethion, fenitrothion,
Triazophos
Fenthion, phenthoate, Phosalone, phorate, Pirimiphos-methyl, Profenofos, quinalphos, Trichlorfon
Environ Sci Pollut Res
pesticide poisoning cases each year and hundreds of deaths. One such attempt has been made by reviewing the data in a district government hospital for the years 1997 to 2002, where 96 % had intentionally poisoned themselves with an organophosphate like monocrotophos, chlorpyrifos, and quinalphos (Rao et al. 2005). The poisons responsible for most of the mortality were found to be organophosphate pesticides (65 %) in Kasturba Medical College, Manipal during the study period of 2 years (Singh and Unnikrishnan 2006). During the period of August 2001 to July 2002 in Stanley hospital, Chennai, 165 patients with organophosphate poisoning were analyzed; the most common organophosphate identified was methyl parathion along with chlorpyrifos and diazinon. About 51 % patients were found having the features of moderate and severe acute cholinergic crisis based on their serum cholinesterase (SChE) activity, among them 40 patients died (Shivakumar et al. 2013). The linear relationship between the WHO hazard class of organophosphate pesticides and mortality in acute organophosphate poisoning, mandates the restriction of the sale of organophosphate compounds associated with higher lethality among humans. This fact seems valid after a study over 251 patients where hospital mortality was found maximum with class I organophosphate poisoning cases in Christian Medical College and Hospital, Vellore (Peter et al. 2010). Organophosphate poisoning cases in India is not limited up to the suicidal cases, but their unintentional and accidental uptake have also caused severe toxicity and deaths. According to the World Health Organization (WHO), one million serious unintentional poisonings occur every year (Singh and Khurana 2009). Overexposure to pesticides can occur before spraying because of easy access for children, lack of adequate labeling, after spraying operations (Kumar et al. 2010), or by keeping food stuffs in empty containers of pesticides (Than 2013: BBC report). The first report by Karunakaran of this type of accidental poisoning due to pesticides was from Kerala in 1958, where over 100 people died after consuming wheat flour contaminated with parathion (Gupta 2004). An accidental case has been found in female cotton growers of Warangal and Mahabubnagar district in Andhra Pradesh, which showed neurotoxic/systemic signs and symptoms upon exposure to organophosphate pesticide while mixing concentrated chemicals and refilling spraying tanks (Mancini et al. 2005). A mid-day meal case in Saran district of Bihar, India on 16 July 2013 caused the death of 23 children. Later on, forensic report confirmed the traces of monocrotophos in the container of cooking oil where it had been placed (BBC Report). A similar case of mid-day meal poisoning has been reported from Mashrakh village of Bihar, where serious illness has been identified in the children, aged four to 12 (Than 2013). Organophosphate compound toxicity by parenteral route has also been diagnosed by Pandit et al. (2011) in which they observed the patient with delayed
symptoms like altered sensorium, and respiratory distress. During a study over profile of unnatural deaths in Manipal from a period of 1994–2004, organophosphate insecticides were found to account for more than 65 % of poisoningrelated fatalities (Kumar et al. 2006). Organophosphate toxic effects have also been reported in some other vertebrate and invertebrates in India. It is reported that malathion cause histopathological changes in earthworm, Eisenia foetida, procured from the vermicompost unit of Rajasthan College of Agriculture, Udaipur. These changes include ruptured cuticle, deformed circular and longitudinal muscles in integument and distorted ventral nerve cord (Bansiwal and Rai 2010). Toxicity behavior of organophosphate have been studied over embryonic and larval stages of Zebrafish (Danio rerio) which revealed their abnormal development, skeletal defects, and altered heart morphology in a concentration-dependent manner, which leads to alterations in the swimming behavior (Pamanji et al. 2015). Serum transaminases have been found to be increased significantly in rats on exposure to dichlorovos and monocrotophos, ultimately leading to liver injury, blood oxidative stress, and decreased body weight (Dwivedi and Flora 2011). Interestingly, the body weight of male rats did not show any significant change; however, a significant reduction had been observed in the testes upon experimentally dosing them with chlorpyriphos at the dose levels of 7.5, 12.5, and 17.5 mg/kg b.wt./day for 30 days. In this case, chlorpyriphos also brought about marked reduction in epididymal and testicular sperm counts in exposed males and a decrease in serum testosterone concentration (Joshi et al. 2007). Their toxicity is not limited to the acute phase; however, the chronic effects have long been noted. While high-level exposure to organophosphates can lead to death in the short-term, several studies have suggested chronic low-level exposure can also have serious health consequences like neurological disorders such as attention deficit hyperactivity disorder, or ADHD (Than 2013). Several neurobehavioral changes and effects like drowsiness, confusion, lethargy, anxiety, emotional lability, depression, fatigue, and irritability have been termed together as ‘chronic organophosphate-induced neuropsychiatric disoders (COPIND) (Singh and Sharma 2000). Some of these symptoms could be attributed to the sequelae of convulsions, anoxia, respiratory failure, and cardiac arrhythmias that these patients might have suffered during the acute cholinergic syndrome (Savage et al. 1988). Neurotransmitters such as acetylcholine (which is affected by organophosphate pesticides) are profoundly important in the brain’s development, and many organophosphates have neurotoxic effects on developing organisms, even from low levels of exposure such as impaired memory and concentration, disorientation, severe depressions, irritability, confusion, headache, speech difficulties, delayed reaction times, nightmares, sleepwalking and drowsiness, or insomnia. An
Environ Sci Pollut Res
influenza-like condition with headache, nausea, weakness, loss of appetite, and malaise has also been reported. The main target organs are the nervous system, respiratory tract, and cardiovascular system. Degradation products in the environment are not toxic to any significant extent. Thermal decomposition products may be harmful by inhalation and skin contamination. Toxicity may also be due to the effects of solvent vehicles or other components of formulated pesticides (BBC Report). Organophosphates along with other contaminants can cause a synergistic effect. Co-exposure to dichlorvos, monocrotophos, and sodium meta arsenite have been found to be significant in the inhibition of the brain and serum AChE levels along with significant increase in hepatic reactive oxygen species and brain thiobarbituric acid reactive substances, suggesting synergism (Dwivedi and Flora 2011).
Conclusion There is a sequential rise in the production and consumption of pesticides in the India during the last few years. Currently, among the various groups of pesticides that are being using in India, organophosphorus pesticides form the major and most widely used group. Although organophosphate compounds are widely used as a replacement for organochlorides, their extensive and non-regulated use and easy availability has caused a major threat for our environment as well as living ones. Some organophosphates which have been used in India extensively include monorotophos, phorate, methyl parathion, malathion, chlorpyrifos, diazinon, phorate, quinalphos, ethion, etc. which are mostly highly to moderately hazardous according to WHO. Interestingly, many among the organophosphates registered under Section 9 (3) of the Insecticides Act, 1968 for use in India are banned/severely restricted in some countries including Europe and the USA. They are less persistent in the environmental but traces of their residues have been detected by many of the researchers in soil, water, vegetables, and certain food products. Along with this, residues of certain organophosphates have also been found in human blood, urine, breast milk, etc.; that means they do persist in the body for a good amount of time. There is a guideline for the application of specific organophosphate on specific plants but some cases in this study showed their complete negligence. People in India are frequently using these compounds for attempting suicide due to its ease of availability; among them, some have recovered well when early diagnosis and specific treatment are given. There is a guideline for their sale, usage, and specificity to crops, but there is a need of proper implementation and awareness. Early recognition and appropriate treatment of
particularly acute poisoning are essential in order to minimize the causalities and mortality from these potentially lethal compounds. They are naturally degradable but enhanced degradation strategies are still to be needed so that their chances of accumulation and related health hazards are minimized.
References Agrawal A, Pandey RS, Sharma B (2010) Water pollution with special reference to pesticide contamination in India. J Water Res Prot 2: 432–448 Amaraneni SR, Pillala RR (2001) Concentrations of pesticide residues in tissues of fish from Kolleru lake in India. Environ Toxicol 16:550– 556 Anand GSR, Somasekhar RK (2012) Monitoring of pesticide residues in farmgate samples of vegetables in Karnataka, India. Int J Sci Nat 3: 563–570 Akhtar MW, Sengupta D, Chowdhury A (2009) Impact of pesticides use in agriculture: their benefits and hazards. Interdisciplinary Toxicol 2: 1–12 Bansiwal K, Rai N (2010) Assessment of malathion toxicity in certain organs of earthworm, Eisenia Foetida. Bioscan 5:473–476 Bhanti M, Taneja A (2007) Contamination of vegetables of different seasons with organophosphorous pesticides and related health risk assessment in northern India. Chemosphere 69:63–68 Bishnu A, Chakrabarti K, Chakrabarti A, Saha T (2009) Pesticide residue level in tea ecosystems of Hill and Dooars regions of West Bengal, India. Environ Monit Assess 149:457–464 Chandra S, Kumar M, Mahindrakar AN, Shinde LP (2014) Effect of washing on residues of chlorpyrifos and monocrotophos in vegetables. Int J Adv Res 2:744–750 Chhajed PN, Athavale AU, Saibannavar AJ, Gandewar KL, Shah AC (2000) Acute organophosphate compound and carbamate poisioning: A study of 36 cases in the intensive respiratory care unit, L.T.M.J. Hospital, Mumbai. Downloaded free from http://www. lungindia.com Accessed 05 March 2015 Choudhary A, Sharma DC (2009) Pesticide residues in honey samples from Himachal Pradesh (India). Bull Environ Contam Toxicol 80: 417–422 CSE Report; March 2005, Analysis of Pesticide Residues in blood samples from villages of Punjab, CSE/PML/PR-21/2005. http:// indiaenvironmentportal.org.in/files/Punjab_blood_report.pdf CSE Report; August 2006, Analysis of pesticide residues in soft drinks. http://www.indiaenvironmentportal.org.in/files/labreport2006.pdf Dhas S, Srivastava M (2010) An assessment of phosphamidon residue on mustard crop in an agricultural field in Bikaner, Rajasthan (India). Eur J Appl Sci 2:55–57 Dwivedi N, Flora SJS (2011) Concomitant exposure to arsenic and organophosphates on tissue oxidative stress in rats. Food Chem Toxicol 49:1152–1159 Gupta PK (2004) Pesticide exposure—Indian scene. Toxicology 198:83– 90 Gupta SK, Kumar S, Sheikh MI (2006) Study of organophosphorus poisoning in Surat, India. J Indian Acad Forensic Med 28:0971–0973 Gurusubramanian G, Rahman A, Sarmah M, Ray S, Bora S (2008) Pesticide usage pattern in tea ecosystem, their retrospects and alternative measures. J Environ Biol 29:813–826 Harinathareddy A, Prasad NBL, Devi LK (2014) Pesticide residues in vegetable and fruit samples from Andhra Pradesh, India. J Biol Chem Res 31:1005–1015
Environ Sci Pollut Res ICMR Bulletin. Sept. 2001. Pesticide pollution: trends and perspective, 31, ISSN 0377-4910 India For Safe Food: http://www.indiaforsafefood.in/ Accessed on 30/01/ 2015. Insecticides Act, 1968, India; http://cibrc.nic.in/insecticides_act.html Accessed on 29 January 2015 Jacob S, Resmi G, Mathew PK (2014) Environmental pollution due to pesticide application in cardamom hills of Idukki, District, Kerala, India. Int J Basic Appl Res 1:27–34 Jaiprakash H, Sarala N, Venkatarathnamma PN, Kumar TN (2011) Analysis of different types of poisoning in a tertiary care hospital in rural South India. Food Chem Toxicol 49:248–250 Joshi SC, Mathur R, Gulati N (2007) Testicular toxicity of chlorpyrifos (an organophosphate pesticide) in albino rat. Toxicol Ind Health 23: 439–444 Kanchan T, Menezes RG (2008) Suicidal poisoning in Southern India: gender differences. J Forensic Legal Med 15:7–14 Khosya S, Gothwal SK, Banga V, Meena R (2013) Malathion poisoning presented as intermediate syndrome and organophosphate induced delayed polyneuropathy in succession: a case report. J Clin Case Rep 3:1–2 Kotttiappan M, Dhanakodi K, Annamalai S, Anandhan SV (2013) Monitoring of pesticide residues in South Indian tea. Environ Monit Assess 185:6413–6417 Kumar SV, Fareedullah M, Sudhakar Y, Venkateswarlu B, Kumar A (2010) Current review on organophosphorus poisoning. Arch Appl Sci Res 2:199–215 Kumar TSM, Kanchan T, Yoganarasimha K, Kumar GP (2006) Profile of unnatural deaths in Manipal, Southern India 1994–2004. J Clin Forensic Med 13:117–120 Kumari B, Madan VK, Kathpal TS (2008) Status of insecticide contamination of soil and water in Haryana, India. Environ Monit Assess 136:239–244 Kumari B, Kumar R, Madan VK, Singh R, Singh J, Kathpal TS (2003) Magnitude of pesticidal contamination in winter vegetables from Hisar, Haryana. Environ Monit Assess 87:311–318 Kumari B, Madan VK, Singh J, Singh S, Kathpal TS (2004) Monitoring of pesticidal contamination of farmgate vegetables from Hisar. Environ Monit Assess 90:65–71 Kumari B, Singh J, Singh S, Kathpal TS (2005) Monitoring of butter and ghee (clarified butter fat) for pesticidal contamination from cotton belt of Haryana, India. Environ Monit Assess 105:111–120 Lari SZ, Khan NA, Gandhi KN, Meshram TS, Thacker NP (2014) Comparison of pesticide residues in surface water and ground water of agriculture intensive areas. J Environ Health Sci Eng 12:1–7 Mandal K, Singh B (2010) Magnitude and frequency of pesticide residues in farmgate samples of cauliflower in Punjab, India. Bull Environ Contam Toxicol 85:423–426 Mancini F, Van Bruggen AH, Jiqqins JL, Ambatipudi AC, Murphy H (2005) Acute pesticide poisoning among female and male cotton growers in India. Int J Occup Environ Health 11:221–232 Mathur SC (1999) Future of Indian pesticides industry in next millennium. Pesticide Info 24:9–23 Mukharjee I (2003) Pesticides residues in vegetables in and around Delhi. Environ Monit Assess 86:265–271 Palimar V, Saralaya KM, Arun M, Mohanty MK, Singh B (2005) Profile of methyl parathion poisoning in Manipal, India. J Indian Soc Toxicol 1:35–37 Pamanji R, Yashwanth B, Bethu MS, Leelavati S, Ravinder K, Rao JV (2015) Toxicity effects of profenofos on embryonic andlarval development of Zebrafish (Danio rerio). Environ Toxicol Pharmacol 39: 887–897 Pandit V, Seshadri S, Rao SN, Samarasinghe C, Kumar A (2011) A case of organophosphate poisoning presenting with seizure and unavailable history of parenteral suicide attempt. J Emerg Trauma Shock 4: 132–134
Parmar P, Rathod GB, Rathod S, Parikh A (2014) Organophosphorus compound poisoning- demographic profile in Gandhinagar, Gujarat. J Forensic Toxicol Pharmacol 3:1–4 Pesticide contamination in select wetlands of Nilgiris district with special reference to sediments and fish, Sálim Ali Centre for Ornithology and Natural History (SACONH), Coimbatore. Report Submitted to Keystone Foundation, Kotagiri, Nilgiris District. http:// indiabiodiversity.org/biodiv/content/projects/project-b03d1ee66962-4b3d-a8a0-750076f97483/682.pdf. Accessed on 06 April 2015 Pesticide residues in tea samples from India, Report produced by Greenpeace India, August 2014. http://www.greenpeace.org/india/ Global/india/image/2014/cocktail/download/TroubleBrewing.pdf Accessed on 15 January 2015 Peter JV, Jerobin J, Nair A, Bennett A (2010) Is there a relationship between the WHO hazard classification of organophosphate pesticide and outcomes in suicidal human poisoning with commercial organophosphate formulations? Regul Toxicol Pharmacol 57:99– 102 Pujeri US, Pujar AS, Hiremath SC, Yadawe MS (2011) The status of pesticide pollution in surface water (lakes) of Bijapur. Int J Appl Biol Pharm Technol 1:436–441 Raghavan P, Amar R, Nayak VC (2014) Profile of organophosphate insecticides poisoning in Kasturba hospital, Manipal, South India. J Pharm Sci Innovation 3:73–77 Ramesh BK, Selvanayagam M (2015) Pesticides pollution in water, sediment and fishes of Kolavai lake in Chengalpet, Tamil Nadu, India. IntJ Chemical Concepts 1:9–14 Rao CHS, Venkateswarlu V, Surender T, Eddleston M, Nick A (2005) Pesticide poisoning in South India—Opportunities for prevention and improved medical management. Trop Med Int Health 10:581– 588 Report of the fortieth session of the codex committee on pesticide residues (2008) Joint FAO/WHO food standards programme. Codex Alimentarius Commission. Thirty-first Session Geneva, Switzerland. ALINORM 08/31/24. Sanghi R (2003) Organochlorine and organophosphorus pesticide residues in breast milk from Bhopal, Madhya Pradesh, India. Human Exp Toxicol 22:73–76 Savage EP, Keefe TJ, Mounce LM (1988) Chronic neurological sequelae of acute organophosphate poisoning. Arch Environ Health 43:38– 45 Seenivasan S, Muraleedharan NN (2011) Survey on the pesticide residues in tea in South India. Environ Monit Assess 176:365–371 Shivakumar S, Mohammed IR, Raghavan K, Geetha S (2013) Organophosphorus poisoning—a study of 165 cases from Chennai. J. Assoc Physician India. DOI: 10.13140/ RG.2.1.1757.2960 Singh B, Gupta A (2002) Monitoring of pesticide residues in farmgate and market samples of vegetables in a semiarid, irrigated area. Bull Environ Contam Toxicol 68:747–751 Singh S, Sharma N (2000) Neurological syndrome following organophosphate poisoning. Neurol India 48:308–313 Singh B, Unnikrishnan B (2006) A profile of acute poisoning at Mangalore (South India). J Clin Forensic Med 13:112–116 Singh G, Khurana D (2009) Neurology of acute organophosphate poisoning. Neurol India 57:119–125 Singh PB, Singh V, Nayak PK (2008) Pesticide residues and reproductive dysfunction in different vertebrates from North India. Food Chem Toxicol 46:2533–2539 Sinha SN, Bhatnagar VK, Doctor P, Toteja GS, Agnihotri NG, Kalra RL (2011) A novel method for pesticide analysis in refined sugar samples using a gas chromatography–mass spectrometer (GC–MS/MS) and simple solvent extraction method. Food Chem 126:379–386
Environ Sci Pollut Res Sinha SN, Rao MVV, Vasudev K (2012) Distribution of pesticides in different commonly used vegetables from Hyderabad, India. Food Res Int 45:161–169 Soltaninejad K, Shadnia S (2014) History of the Use and Epidemiology of Organophosphorus Poisoning. Basic and Clinical Toxicology of Organophosphorus Compounds ISBN 978-1-4471-5625-3-2, 25-34. Srivastava AK, Trivedi P, Srivastava MK, Lohani M, Srivastava LP (2011) Monitoring of pesticide residues in market basket samples of vegetable from Lucknow City, India: QuEChERS method. Environ Monit Assess 176:465–472 Srivastava S, Narvi SS, Prasad SC (2008) Organochlorines and organophosphates in bovine milk samples in Allahabad region. Int J Environ Res 2:165–168 Than K (2013) Organophosphates: A common but deadly pesticide. Published for National Geographic Society. Downloaded from-
http://news.nationalgeographic.com/news/2013/07/130718-organophosphates-pesticides-indianfood-poisoning.html Waghmare CS, Nigam M, Mishra PK, Patel S (2014) The study of investigational profile of common pesticide poisoning cases admitted at SAIMS. Indore J Indian Acad Forensic Med 36:52–54 World Health Organisation (2009) The WHO recommended classification of pesticides by hazard and guidelines to classification 2009. WHO, Geneva, ISSN 1684-1042 http://ppqs.gov.in/PMD.htm#variousPest. Official site of Directorate of Plant Protection, Quarantine and Storage, Ministry of agriculture & farmer welfare, Govt. of India. Accessed on 28/12/2015 http://www.bbc.com/news/world-asia-23390972, Accessed on 2 February 2015
