The economy of Africa is largely dependent on agriculture, and nearly 59% of the population makes their living from farming [20]. Despite that, the African continent has a contribution of 2–4% of global market share of pesticides which also accounts for the lowest rate of their usage in the world [20]. Due to increasing population, the food demand has been projected to enhance at a rapid rate in the next three decades and thus, demand of pesticides, herbicides and fungicides is also likely to enhance [21]. Table 1 summarizes the usage of pesticides in various African countries based on their area in the 2010 and 2014. The data show that the usage of pesticides declined in Congo and Mauritius, while in Sudan, Malawi, Togo and Rwanda, it increased in the years 2010–2014.
Table 1 Pesticide usage in African countries in the years 2010 and 2014, index on the basis of their area.Full size table
In order to maintain high yields and profits, pesticide usage becomes a necessity in agriculture [23]. Also, most of the governments encouraged the usage of pesticides since 1970 and in 1990s, amendment in several policies led to reduction in input subsidies. Such changes in policies resulted in even less monitoring by the governments. Due to this, more inflow occurred from the informal channels that caused enhanced usage of pesticides, leading to an increased import value by 261% from 2000 to 2010 [23]. Inadequate regulatory mechanisms also result in import of pesticides which are banned, and lack of awareness in the farmers causes poor pesticide practices. Pesticide registration in Western Africa is a multi-national process called as Comité Sahélien des Pesticides (CSP) [24]. It was reported that in Niger, due to limited capacity of CSP, 44% of pesticide dealers are unlicensed. Also, the registered chemicals account for only 8%, while 38% of pesticides have incomplete labels and 6% are unlabeled [25]. The same report also specified that 27% of the tested pesticides did not state the active ingredients and 30% of them belonged to poor quality. Apart from Niger, CSP was not able to implement its laws strictly in other parts also, and as a result, the pesticide importers, distributers and users could not be certified. Furthermore, among the domestically produced pesticides, the high-quality ones are exported, while the low-quality pesticides are supplied to local farmers [24]. Hence, the African market is unregulated and does not comply with the code of conduct laid out by Food and Agriculture Organization due to which most of the pesticides used are untested leading to the enhanced risks.
In Africa, lack of knowledge about the usage of pesticides has also led to the usage of those pesticides which fall under WHO risk classification system. According to Pesticide Risk Reduction Program (PRRP, [26]), in Ethiopia alone, out of 302 registered pesticides, 160 contained active ingredients which were classified as WHO class II chemicals (moderately hazardous). Case studies of other African countries also showed the usage of pesticides which were hazardous according to the WHO risk classification system. A study by Obopile et al. [27] in Botswana showed that over 50% of farmers use malathion and cypermethrin as pesticides and these are WHO class II chemicals. The same study also pointed that in Botswana, methomyl is used by 7.1% of farmers, demeton-S-methyl is used by 2.7% farmers, and dichlorvos is used by 1.8% farmers, and all these chemicals are classified under WHO class Ib pesticides (highly hazardous). A similar study conducted by Oluwole and Cheke [28] in Nigeria established that maximum farmers (78%) use monocrotophos which comes under WHO class Ib chemicals. Other pesticides that were reported included atrazine and metolachlor which fall under WHO class III chemicals (slightly hazardous), and lindane, copper sulfate and paraquat which are WHO class II chemicals. Nyirenda et al. [29] reported the usage of monocrotophos (Ib) by 41% farmers in Zambia, while in Malawi, parathion, a WHO class Ia pesticide (extremely hazardous), is used by over 25% of farmers. Other commonly used active ingredients in pesticides include glyphosate (III), malathion (III), chlorpyrifos (II), cypermethrin (II), deltamethrin (II), dimethoate (II), endosulfan (II), fenitrothion (II) and profenofos (II). These mentioned pesticides are frequently used in Benin, Ethiopia, Ghana and Senegal [30].
The common risk linked with pesticide usage is the resistance of the pests that leads to destruction of the crops despite appropriate application. It has been reported in western part of Africa that the use of pyrethroids has caused resistance in tomato bollworm (Heliothis armigera Hübner) and diamondblack moth (Plutella xylostella L.) [23, 31]. Also, resistance to pyrethroids and organophosphates was seen in an aphid (Aphis gossypii Glover), while a whitefly (Bemisia tabaci Gennadius) has been reported to develop resistance against pyrethroids, organophosphates and neonicotinoids [32, 33].
The use of pesticides in agriculture is increasing rapidly in developing countries, especially in Southeast Asia [34, 35]. WHO has reported that approximately 20% of pesticides are used in developing countries with increasing rate of usage. An annual increase in import of pesticides is reported as 61% for Cambodia, 55% for Laos and 10% for Vietnam [36].
The manufacturing of pesticides in India started in 1952, with the production of benzene hexachloride, followed by DDT. The synthesis of pesticides increased enormously. In 1958, India manufactured over 5000 metric tonnes of pesticides which increased to 85,000 metric tonnes in the mid-1990s with the registration of 145 pesticides and the major pesticides produced are insecticides [37]. India is one of the major pesticides producing countries in Asia with annual production of 90,000 tonnes, and it stands at twelfth position in the world in the manufacturing of pesticides [38]. In the past, India used and exported organochlorine pesticides on large scale including DDTs and HCHs [39]. Similarly, in Pakistan, the pesticides usage started in 1954 with the import of 250 metric tonnes [40]. The pesticides consumption in Pakistan increased to 78,132 tonnes per annum in 2003 [38, 41]. During Green Revolution period, thousands of tonnes of pesticides had been imported from Europe and the USA to control crop pest infections, locust control and suppression of malaria in Pakistan [42]. Use of pesticides in Bangladesh was low until 1970. The pesticide usage increased tremendously from 2200 million tonnes in 1980–1982 to 6500 million tonnes in 1992–1994 [43]. In Nepal, the first reported use of pesticides was DDT in 1956, which was followed by other organochlorines, organophosphates, carbamates and synthetic pyrethroids. It has been reported by plant protection division of department of agriculture, approximately 55.8 metric tonnes of pesticides is used annually in Nepal [44]. In Sri Lanka, the pesticides are mainly used in agriculture sector. DDT was the first pesticide used in Sri Lanka after World War II for malaria eradication. Pesticides were introduced in Thailand and Vietnam in mid-1950s. In Vietnam, the use of pesticides accelerated in mid-1980s during economic liberalization. The use of pesticides in agriculture increased from 20 to 30 million kg, and it further increased to 77 million kg in 2007 [45].
In China, pesticide production started in 1950 with the manufacturing of DDT. China has become the largest pesticide manufacturing country during past 50 years of development. In China, pesticides are mainly used for rice production. The consumption of pesticides in China has increased from 76 million tonnes in 1991 to 146 million tonnes in 2006. Japan is one of the largest pesticide consumers in the world and has biggest pesticide market in Asia [46]. Table 2 shows the consumption of different pesticides in the Asian countries.
Table 2 Annual pesticide consumption in different Asian countries [47]Full size table
In Australia, farmers have been prepared to incur higher chemical costs to cope with pests effectively. Primary categories of pesticides are herbicides, insecticides, fungicides and some growth regulators, overall costing a total market value of A$187 million annually [48]. Herbicides costs include use of alternate herbicide and mixtures along with higher concentration rates posing an extra cost of A$8/ha. A pictorial description of pesticide consumption in Australia is shown in Fig. 1. Several concerns affect choice for herbicide selection including possible development of herbicide resistance, price of herbicide, residual impact on non-target organisms including operators and community, market implications and overall impact on other strategies such as integrated pest management [49].
Weed infestation leads to great reductions in crop productivity along with deteriorating the quality of the production. Application of herbicides for effective weed control upsurges agricultural productivity, making it desirable option for farmers. Herbicide utilization proves an effective approach for controlling weeds; however, overuse of these herbicides causes several complications such as development of herbicide-resistant biotypes due to the overuse of herbicides having common mode of action [50]. Evolution of herbicide-resistant weed biotypes is a serious problem that is now infesting crops throughout Australia [51,52,53]. Conservational agricultural systems completely rely on the use of efficient herbicides owing to their low cost and selective weed control in intensive farming systems [54]. However, development of herbicide resistance under continues use of herbicides has increased an average cost of A$55/ha for effective weed control [48].
Under continuous use of herbicides for selective weed control, development of herbicide resistance in weed biotypes has become the overwhelming threat for effective weed control in global wheat production system [54]. Application of herbicide in higher concentrations has resulted in creating more diversity in herbicide resistance. Weed populations in wheat crop are now frequently resistant and contain numerous mechanisms conferring herbicide resistance [55]. In Australia, herbicide-resistant weeds such as L. rigidum, Avena spp., R. raphanustrum, Bromus spp. and Hordeum spp. have been the most dramatic and extensive weeds [50, 51, 56,57,58,59]. Moreover, excessive application of pesticides/weedicides develop resistance in pests/weeds, thus making it difficult to control their population. In Australia, a dramatic increase in the population of herbicide-tolerant ryegrass in different regions has been reported (Fig. 2). Some weeds have also developed resistance against herbicides which work by the mechanisms like ACCase inhibition [60, 61] and ALS inhibition [62]. In Western Australia, it has been reported that common weed Avena has also developed resistance against those herbicides which work on the mechanism of inhibiting activity of acetyl-CoA carboxylase [63]. Similarly, L. rigidum, another widely spread annual weed in Western Australia, has observed to gain resistant mechanism against ACCase- and ALS-inhibiting herbicides like diclofop methyl and sulfometuron [59]. These results suggested to adopt conservation agriculture or to control weed proliferation via crop weed competition approach.
Fig. 2(modified after Peterson et al. [64])
Abundance of herbicide-resistant ryegrass population in different regions of Australia.
Full size image
The infestation of agricultural lands in the European countries has occurred rapidly due to enhanced application of insecticides, herbicides, fungicides and chemical-based fertilizers. This eventually has resulted in loss of natural habitat and heterogeneity of the farmlands and other landscapes [65, 66]. A joint survey of seven European countries including Latvia, Denmark, Germany, the Netherlands, Finland, Sweden and the UK was done on the usage of pesticides in their urban or the non-agricultural amenities [67]. In the urban areas, herbicides constitute the major pesticide contaminants. The analysis was carried in different regions and demonstrated wide variation in political interest and public discussion on “use of pesticides in urban areas”, regulation and availability of statistical data on pesticide usage. Moreover, it was reported that Denmark, the Netherlands, Germany and Sweden had a very strong political as well as public interest in lowering the application of herbicides in their urban areas to control weed. Although the UK is undergoing an episode of enhanced awareness and stringent regulations, Finland and Latvia have no specific regulation for lowering pesticide usage [67]. Although the use of pesticide has enhanced in Finland, the rate is comparatively lower when compared to other European regions [68]. It was estimated to be 5–6 metric tonnes of pesticides with active ingredients per year. A survey in 2007 was carried out in 80 Finish municipalities. One-fifth of these municipalities reported occasional of these pesticides and only about 15% of these municipalities used pesticides [67]. Determinations of pesticide in 8 different hot springs were carried out by Karasali et al. [69] in Greece. From 26 different samples, pesticides were reported in 14 of them although they did not exceed the European Union Maximum Acceptable Concentration (MAC). Lindane (γ-BHC) was the most commonly occurring pesticide. It was found in 35% samples with levels ranging from 0.005 to 0.01 µg/L. Few other pesticides detected included propachlor, phorate and chlorpyrifos ethyl, but were below the permissible limits.
Table 3 summarizes pesticide usage in European countries in the years 2010 and 2014, index on the basis of their area. Tabulated data showed that a few European countries including Denmark, France, Austria and the Netherlands reduced pesticide usage, while in others like Germany, Greece, Ireland, Czech Republic, Spain and Portugal, the usage was enhanced.
Table 3 Pesticide usage in European countries in the years 2010 and 2014, index on the basis of their area.Full size table
Pesticide and fertilizer usage in the Ukraine region was lowered from 4.2 million tonnes nutrient in 1990 to about 518 tonnes nutrient in the year 2004. Specifically, in the case of wheat, the quantity of pesticides applied in the year 1990 was 149 kg/ha which was reduced to 26 kg/ha in the year 2003. There are approximately 170 pesticides used in Ukraine of which 49 were extremely toxic, stable and super accumulative [70]. Approximately, 20% Ukraine agricultural land is polluted with DDT and 4% is contaminated with hexachlorocyclohexane [71]. In the urban areas of Ukraine, near the pesticides storehouses are still the main source of pesticide in the soil. Since long time, these stores have been used to store large quantities of hazardous pesticides [72]. The approximate pesticide product used in 2000 was about 3.1 kg/ha in the agricultural lands of Slovenia [73]. Fava et al. [74] investigated the presence of 43 hazardous pesticides and their pesticide residue on the basis of their sales, physical–chemical data and monitoring in the Italian region. Of these, 12 compounds were identified in the drinking water as determined by the European Directive 98/83/EC. It was determined that the total concentration of specific pesticides and their metabolites were more than 0.5 µg/L. Triazine levels were found to be more than 1.02 µg/L. Ferencz and Balog [75], estimated the quantity of wide arrays of pesticide in water, food stuff and soil samples from the Central Romanian region. The most significant pollutants are as follows: (1) α-hexachlorocyclohexane (6 ng/L), (2) γ-hexachlorocyclohexane (4 ng/L), (3) diazinon (20 ng/L), (4) dichlorvos (20 ng/L) in different water samples. The level of DDT was 20 µg/kg and DDE was 50 µg/kg in the contaminated soil. Table 4 elaborates pesticide usage (kg/ha) in European countries in the years 2001–2012 in the arable land and permanent crops. The countries are indexed on the basis of area (Table 4).
Table 4 Pesticide usage (kg/ha) in European countries in the years 2001–2012 in the arable land and permanent cropsFull size table
In the autumn session of 2000, Environmental Protection Agency proposed that the pesticides which had glyphosate as one of their bioactive ingredients which was applied to the hard surfaces [76], are restricted or banned to be used on the hard surfaces. Therefore, the weed control in these areas is no longer carried out by applying these pesticides [77]. The statistical details of Danish Environmental Protection Agency in the years 1995–2007 revealed that the pesticide usage is reduced by 288 tonnes to 5.1 tonnes of active ingredient, and in the case of pesticide, it has been reduced by 81% of total pesticides. In 2000, A “Plant Protection Products” Trade and Usage division was setup in Latvia, Europe, and in late 2002 a “Plant Protection Products” Circulation Control Organization was established. In the Netherlands, in 2004 a National Administrative Organization Water (NAOW) was formed to control “weeds on hard surfaces.” Their goal was to develop cost-effective and permissible practice to control weeds [67]. A statistical analysis of usage of pesticides is carried out every year by the “Sewdish Chemical Inspectorate” since the year 2006 [67]. The government local authorities are making efforts in the UK to improve the efficacy of cleaner, greener and safe surrounding agenda [78].
European countries have developed certain imperative legislation in regard to pesticides usage and these include (1) Directive 2009/128/EC approved by European Parliament and Council in the year 2009: This directive is employed to attain techniques to sustainably use pesticides; (2) Regulation (EC) No. 1107/2009, proposed in the European Parliament and Council in the year 2009: This regulation maintains Plant Protection Products on the market; and (3) Regulation (EC) No. 396/2005 was proposed in the year 2005 by the European Parliament and Council: It monitors the MRLs of pesticide in the food products as well as animal and plant derived feeds [22]. Furthermore, the Russian government has formulated certain policies to enhance the availability of pesticide and their usage. These policies led to an increase in import, subsidies to farmers to procure pesticides and construction of manufacturing plants [79]. Another European Community (EC) Pesticide Legislation on the agricultural lands in Ireland determined that around 5% of agriculture area in the northern region of Ireland accounts for 69% of land treated with pesticides [80]. It was further reported in 2014 that fruit crop-growing areas of Northern Ireland had 30 types of pesticides with active constituents applied to approximately to 34,763 ha [81]. Presently in the Northern Ireland, the Pesticide Legislative Regulations are applied through Control of Pesticide Regulation, 1997, and Control of Substances Hazardous for Health and Regulation, 2003 [80].
In North America, herbicides are largely used as chemical tool to manage weeds due to high labor cost in these areas [82]. Likewise, the use of certain insecticides to manage insects that cause vector-borne diseases like malaria is the only feasible option for prevention [83]. The main use of pesticides in the USA is in the agriculture industry [84]. Annually, 500 million kg of pesticides are used in the USA at a cost of $10 billion per year [85]. Atwood and Paisley-Jones [86] formulated a report and found that the USA accounts for approximately 16–18% of total world pesticide expenditure. Among the agriculture sector, herbicides (~ 59%) accounted for major pesticide expenditure, followed by insecticides (~ 14%) and fungicides (~ 10%). The magnitude of herbicide usage not only intensifies on croplands but on the wild lands as well. The researchers from University of Montana revealed that in the year 2010, approximately 200 tonnes of herbicides were sprayed on 1.2 million acres federal and tribal wild lands of USA [87]. However, in spite of its extensive implementation in the USA, pests mainly insects, weeds and pathogens ruin 37% of crops [88]. According to the report of Pimentel et al. [89], the use of insecticides (chiefly organochlorines, organophosphates and carbamates) in the USA has increased 10 times from 1945 to 2000; however, the damage caused by insects to crop also doubled from 7 to 13% during this period. Atwood and Paisley-Jones [86] listed 25 most commonly used pesticides in the agricultural fields and found that 12 are herbicides, two insecticides, four fungicides, five are fumigants and two are plant growth regulators. Among the different pesticides used in the agricultural fields, glyphosate is the most used active pesticides since 2001, followed by atrazine and metolachlor-S. Wagner et al. [90] illustrated manifold increment in the usage of herbicides in croplands of the USA. They further confirmed that glyphosate was the most active ingredients that not only harm the herbs and grasses but also pose potential threat to the native vegetation [90]. Benbrook [91] documented that since 1974, above 1.6 billion kg of active ingredients of glyphosate have been applied in the USA which contributes to 19% of the estimated global use. The researcher further documented that in the last 10 years, US farmers sprayed over two-thirds of the total volume of glyphosate from 1974 to 2014 which is approximately 1.0 kg/ha [91]. A report from Allied Market Research (AMR) demonstrated that the volume of glyphosate ingredient is expected to grow at a compound annual growth rate (CAGR) of 5.7% during 2014–2020 [92]. According to this report, the USA will hold the largest herbicide market share in North America and would produce 85% of North America market revenue in 2020 [92]. Further, in non-agriculture sectors such as home and garden, 2, 4-D is the most commonly used pesticide and is ranked first among other known pesticides. Currently, the insecticides consumption in the USA has declined due to shift toward biopesticides and other natural plant products.
Similarly, in Canada, 35 million kg of pesticides are used annually in agricultural fields [93]. Herbicides are the most prominent and widely used chemical pesticides in Canada [94]. Moreover, herbicides cover approximately 96% of total pesticides applied in Prairie Provinces of Canada [93]. In a survey made in the year 2011, 69% of the Canadian agricultural crop lands were reported to apply herbicides in order to mount the crop productivity [95]. Wilson [96] used crop insurance data from Manitoba and found that 2 million kg of herbicides are used annually in the province. According to Verrin et al. [97], the commonly used pesticides in British Columbia includes 2, 4-D, diazinon, dicamba, atrazine and simazine. These agricultural herbicides can directly cause mortality of species since they are chemically toxic [98]. Recently, statistics showed that the total amount of pesticides imports to Canada comprised of 1.32 billion U.S. dollars [99].
Mexico is the third largest market of agrochemicals in North America, and its market is growing at a CAGR of 5.2% during 2017–2022. The major agrochemicals include insecticides and herbicides that account for approximately 36% of the total market [100]. Earlier, Mexico ranked sixth in the world for the use of DDT (dichlorodiphenyltrichloroethane) [101]. Wong et al. [102] reported that between the years 1947 and 2000, approximately 250 kilotonnes of DDT was used in the country; however, the use of DDT was successfully halted by 2000 [103]. Mexico actively participates in different international agreements dealing with pesticides; however, studies have reported that Mexico still uses some pesticides such as paraquat, endosulfan, lindane, methyl bromide, parathion and malathion that are banned in other industrialized countries [104].
In South America, pesticide sale increased 30% between 2003 and 2004 and was projected to increase from 5.4 billion (US $) in 2004 to 7.5 billion (US $) by 2009. The average annual growth rate for this period was 5%. Pesticides like 2, 4-D, paraquat, methamidophos, methomyl, endosulfan and chlorpyrifos had the maximum share in pesticide sale. In some countries of South America, mean usage rate of pesticides in arable lands determined by FAO is 6.5–60 kg/ha [105]. In Brazil, during the year 2013, it has been reported that half million tonnes of pesticides were marketed. Moreover, it has also been noticed that over 90% Brazilian farmers are dependent on pesticide usage [106], and the country has estimated to had used over 673 million tonnes of pesticide in 2008 [107]. The sale of pesticides increased 945.5% in Brazil between 1998 and 2008. In the year 1996, out of total sold pesticide, herbicides were sold most (56.1%) followed by insecticides (26%) and fungicides (15.4%) [108]. Soares and de-Souza Porto [109] evaluated the environmental, social and health cost due to intensive pesticide use in Brazil. They have reported that the cost of acute poisoning to around 64% using insecticides and herbicides in maize which may reach up to 85% in the next ten years.
In Argentina, agrochemical application has significantly enhanced and it has been observed that total consumption has inclined from 73 to 236 million kg/year over last decade. This accounts for turnover of 2381.16 million (US $) in the year 2012. Out of all pesticides sold during this period, maximum was herbicides (64%) followed by fungicides (20%) and insecticides (16%) [110]. In Argentina, pesticide market is mostly captured by herbicides (86.8% and mostly used herbicides are glyphosate, 2,4-D and atrazine) followed by insecticides (6.2% and mostly used insecticides are cypermethrin, chlorpyrifos, lambda-cyhalothrin) and fungicides (2.7% including epoxiconazole, tebuconazole and metconazole) [111]. During the time period from 1974 to 2003, in Colombia the registration of pesticide sharply increased to 400 from 186 active ingredients [112].