How do agricultural chemicals affect the environment

Withers and Tony J. Buy chapter. Pesticides Steven Bailey, John P. Reade, Alastair Burn and Susan Zappala. Lampkin, Jo Smith and Laurence G. Aquaculture Colin F. Horticulture Rosemary H. Collier, Jerry V. Cross and Xiangming Xu. Subject Index Buy chapter.

Print publication date 30 Sep Informetrics analysis and visualization , and have used limited sources of data e. In addition, the research scale for most review studies has been narrow, focusing on a specific type of agricultural chemical input e.

To our knowledge, only a few scholars have reviewed the impact of agricultural chemicals on water, soil and human health conjunctively [ 1 , 25 , 26 ].

The present study addresses these limitations and utilizes a robust quantitative approach i. We aim to systematically and objectively present the research evolution of the literature conducted on the macro-environmental effects induced by excessive use chemical inputs i.

The field of Informetrics deals with the quantitative analysis of information, aiming to reveal patterns and associations of information objects, their production, structure and dissemination [ 27 ]. Citation analysis is a core method in Informetrics.

With feature statistics, citation analysis can effectively find common domains of knowledge for analyzed records. Cluster analysis comes from the notion of automatic categorization for similar abstract objects based on the theory of machine learning, and aims to cluster analogous members and divide unrelated objects.

Mapping knowledge domain enables to reveal relevant research frontiers and frameworks, and intuitively demonstrates the development process of a discipline or knowledge using graphical representations and tools. Second, we conduct the preprocessing stage i. Query reformulation is a critical phase of searching and collecting target articles [ 28 ]. After identifying the subject terms, we scanned selected databases i.

The time span used for this query is from to last updated on 21 October The data preprocessing phase aims to unify inconsistent formats and units of data from different systems or platforms [ 29 ]. This paper adopts three methods i.

Then, for knowledge representation, we use citation network analysis via CitesSpace and formed 6 nodes and 5 edges. Finally, based on the revised pagerank index, we employ the Gelphi platform to form a co-work matrix, which is an efficient method for analyzing and exploring potential rules and interplay amid various literature records.

Figure 1 shows the knowledge-mapping model established in this paper. Special attention is paid to mining and interpreting the distinctive nodes in order to further understand the knowledge baseline and research frontiers for the topic of interest.

Using clustering and visualization analysis with the construction of a co-word matrix, this study offers a summary of the main and timely areas of interest or concern, as well as major objects and research methods used in the research of this topic. The following section provides the results for a set of Informetrics Theory-based analyses: document co-citation analysis, document citation-clustering and co-words analysis via co-occurrence network of subject terms. Citation analysis explores the citation relationship and co-occurrence patterns of original papers and their references.

It aims to reveal the knowledge connection, knowledge structure and knowledge rules of the target scientific area. A time-dimensional visualized intellectual landscape is constructed and provided in Part B of Figure 1. In the past 30 years, researches on the environmental impacts from agricultural chemical inputs could be divided into three stages, namely early stage from to B1 , middle stage from to B2 and late stage from to B3.

Using the results from citation analysis, we identify two proliferous authors, Yi-fan Li and Dana W. Kolpin, for the research topic of interest i. These two authors were selected based on the number of authored and published journal articles and their consistent contribution to the aforementioned research topic in the last three decades.

For illustration purposes, we use their research to exemplify the evolution of the lines of inquiry and investigation in the discipline over the three identified stages. As shown, in the early stage, researches mainly focused on the application of agricultural chemicals, pollutants emissions and the degree of concentration in the environment.

The measurement of pollution in the environment is the salient line of inquiry in this early stage. For decades, he has dedicated his career to study the effects of persistent organic pollutants POPs on the ecological environment.

In the first stage, articles authored or co-authored by Li focus on the pollution degree of POPs, the usage rate of hexachlorocyclohexane and their impact on the environment [ 30 — 32 ]. Another salient author in the early stage in Dana W. In the first stage, his researches mainly focused on assessing the levels of selected pesticides and their metabolites in groundwater or streams in the USA [ 33 — 38 ].

Articles published within the period of the middle stage focused on to the analysis of influence mechanisms, including pollutant generation mechanism, source analysis, transmission channel and source sink relationship. During this stage, Li and colleagues studied the gridded emission inventories of hexachlorocyclohexane and the aspects that stimulate the transport of hexachlorocyclohexane.

His research concentrated in exploring the sources and transport mechanism of POPs in the environment [ 39 — 42 ]. Similarly, Kolpin, in the second stage, mainly focused on the environmental occurrence, transport and the ultimate fate of many synthetic organic chemicals after their intended use.

He paid special attention to the organic wastewater contaminants in the groundwater and streams in the USA. Specifically, he monitored the concentrations, analyzed the source and transport paths, mined the impact on the environment and put forward relevant control strategies [ 43 — 47 ].

In the late stage, researchers mainly studied the specific types of pollutants e. Publications during this stage normally focused on a specific geographical area e.

Articles by Li, in the third stage, mainly researched sources and distributions of Dechlorane plus or PAHs in specific parts of China and their implications for human exposure. His studies further explored the sources, characteristics and potential human health risks of POPs in water, soil and the atmosphere within a certain geographical area [ 48 — 53 ]. Kolpin, in the late stage, primarily investigated the occurrence of chemical contaminants in water plants e. Our findings suggest that the three stages identified i.

B1, B2 and B3 for the topic of interest reflect the evolution and sequential advancement of knowledge in the field. The B1 stage mirrors the foundational knowledge research conducted about the presence of pollutants in the environmental media. As observed, the B1 stage informs the B2 phase by providing scientific data and evidence about agricultural chemical inputs and chemical contaminants in the environment.

The B3 stage is the current research frontier, which explores the occurrence and potential risks of chemical pollutants in specific contexts. For instance, in the latter stage, publications mainly revolve around the response mechanisms of environmental systems to chemical pollutants and on the potential risk for human health and ecological health induced by chemical pollutants.

The transition from the initial stage B1 to the current research frontier B3 reflect the gradual progression in research for this topic: assessment of the situation, evaluation of overall impact, and analysis of transdisciplinary and context-specific impact.

High-cited frequency clustering, a meso-scope method of knowledge representation, interprets feature blocks from the perspective of knowledge content characteristics, and then abstracts similar research topics. Table 1 lists the top five highest-frequency articles in the first two clusters i.

Table 1. Top five highest-frequency articles in the first two clusters and top dive pivot nodes in Cluster A3. To assess the research focus of environmental impacts induced by agricultural chemical inputs, this paper conducts cluster optimization with the relevant literature review.

The results show that researches about this topic primarily consists of three clusters, namely A1 the upper part in Figure 2 , A2 the middle part in Figure 2 and A3 the lower part in Figure 2. Research studies within the A1 cluster largely focus on the effects of pesticides and veterinary drugs on the environment.

Particularly, the distinctive light green region on the left side of A1 represents key research on the impact of pesticide exposure on wildlife and human conducted at end of s [ 72 , 73 , 86 ]. It is worth noting that articles in cluster A1 have been frequently cited since year , and may be conceived as the initial stage of research on agricultural chemicals and their impact on the environmental.

Furthermore, the A2 cluster contains publications with emphasis on the effects of chemical fertilizer applications for the environment, especially on farmland. Specifically, the research in the A2 cluster addresses the topic of soil problems due to the improper application of chemical fertilizer.

For example, articles within this cluster study the loss of soil elements due to the non-proportional application of chemical fertilizer and soil acidification due to the excessive use of chemical fertilizers [ 52 , 74 , 76 , 77 ].

This cluster also embodies investigations on ways to promote sustainable management practices for cultivated land without compromising the global food demands and security [ 75 , 87 , 88 ]. Research within cluster A3, represented nodes situated in the middle of the network, includes novel methods and technologies for monitoring and controlling the environmental impact of agricultural chemicals inputs [ 79 , 80 , 89 , 90 ]. Specifically, these methods include techniques to determine pollutant sources e.

As shown in Figure 3 , three areas are circled out in A3, which represent five significant records. For instance, studies within Cluster A3 explore specific techniques to monitor chemical pollutants in the environment and lays the foundation for pollutant measurement, sources and characteristic analysis and environmental impact assessment.

Interestingly, research stem from this line of inquiry connects previous research on pesticide contamination and monitoring captured by Clusters A1 and A2 [ 85 , 89 , 91 — 97 ].

Finally, A3 cluster research dealing with techniques to control chemical pollutants in the environment connects previous research on the environmental impact of the application of chemical fertilizer Cluster A1 and studies on strategic practices for reducing environmental impact of fertilizer pollutants while ensuring food security and promoting the sustainable development of agricultural industry Cluster A2 [ 87 , 98 — ].

In this section, we utilize co-occurrence network of subject terms, a micro-level method in informetrics, to analyze and generate a list of high-frequency keywords. Table 2 presents the top five subjects words for seven identified categories. Table 2. Top five subject terms in seven categories. The carrier category in Table 2 represents the carrier of chemical pollutants, namely the subject that exerts influence on the environment. The most frequent terms in this category are pesticide and fertilizer.

Other high-frequency terms include organochlorine pesticides and nitrogen fertilizer. Our findings reveal that based on the evaluated records, pesticide and fertilizer in agricultural chemicals are the main source of pollutants research in the literature.

The category of environmental object represents objects affected by agricultural chemical inputs. In the context of our study, the most frequent terms objects are soil, water and air.

Other high-frequency words include groundwater, wastewater, surface water and sewage sludge. Our results indicate that water, soil and air are the most researched environmental media when it comes to pollution derived from pesticides and fertilizers.

Specifically, our findings suggest that researchers have focused on monitoring the concentration and diffusion of agricultural chemicals in soil, water and atmosphere. In addition, climate change is a frequent term in this category, with emphasis on the impact mechanism of agricultural chemicals on the atmospheric environment.

The process category include research dealing with the process of agricultural chemicals exerting impacts on the environment. The most frequency terms include pollute, leach, irrigation, runoff and eutrophication. It indicates that studies about the phenomenon of water eutrophication caused by the loss of nitrogen and phosphorus in the process of rainfall or irrigation has been of great concern and merited the attention of researchers.

The cycle category represents the biogeochemical cycle, that is, the transfer process of the chemical elements needed by a living organism between the organism and the environment.

Nitrogen and phosphorus have the highest frequency among chemical elements, and it indicates that studies mainly focus on effects of excessively using agricultural chemicals on the process of nitrogen and phosphorus cycles.

Meanwhile, the degradation of nitrogen, phosphorus and other chemical pollutants in the environment, especially biodegrade, appear to be another salient topic. The method category represents research methods and management strategies, including research methods for exploring the environmental impact of agricultural chemical inputs, as well as management strategies for reducing the environmental hazards induced by agricultural chemicals.

Model and risk assessment are the top two frequency terms. Other high-frequency terms include bioremediation, integrated pest management, monitor and passive sample.

This indicates that assessing the environmental risk and controlling the usage of agricultural chemicals based on various models have deemed relevant and timely issues in the literature.

For example, researchers have collected samples based on various means such as passive air samplers and used various risk indicators to assess the environmental impact of agricultural chemicals.

In addition, studies have extensively explored measures and strategies e. The agricultural object category includes the high-frequency words, such as wheat, fish, maize, rice, plant and crop. Overall, this category reflects the major research emphasis on the crops and fisheries.

Indicator category includes the different factors used when assessing the environmental impact induced by agricultural chemicals. The most frequent terms include heavy metal, nitrate, POP, organophosphate, pesticide residue and endocrine disruptor. Our results indicate that chemical pollutants including metal nitrate, pesticide and residue heavy have been widely investigated as major determinants of pollution.

Importantly, we find that the extant literature has predominantly examined the effect and risk of pollutants for bodies of water, soil organism, air, fishes, bees and human health. Finally, to better understand the key nodes and their relationships among the categories, we conduct a visualized analysis in the Gephi platform based on the co-occurrence relationship, PageRank value and the seven identified categories see Figure 4.

Based on the PageRank value, we identified the top three categories. The difference in thickness for the graphed lines denote the strength of links or connections. As shown in Figure 4 , agriculture and environment, pollute and environment, pesticide and environment, and nitrate and leach have a strong semantic relation.

The mutually beneficial cooperation among different research institutes and countries plays a key role in promoting the development of science and technology. Citation number analysis and co-authorship analysis are important methods for evaluating the cooperation and research level of different institutes and countries.

In the present paper, we first summarize the global development trends based on citation statistics of different countries.

Then, we employ co-authorship metrics to analyze the scientific knowledge communication and organization distribution in the collaboration network. Ultimately, we present an overall knowledge-sharing network among different countries and institutions.

This indicates that based on direction, the current research is in the middle and preliminary stage of a rapid forecasted development, and the volume of scientific knowledge is expected to grow dramatically with optimistic future predictions. Our findings suggest that prior to , Asian and South American countries, such as China, India and Brazil, lagged far behind in terms of technological advancement when compared to developed countries such as the USA, Canada, Australia and some European countries e.

UK, France, Germany and Holland , the same trend is observed for the number of publication amounts generated and growth rates. In recent years, the gap has narrowed down significantly, which can be attributed to the strengthening and investment in science and technology especially the advancement of environmental science and ecological science in Asian and South American countries.

It is noticeable that, in China, the number of articles grew significantly from 54 to during —15 period. Then in , the number of publications articles produced by China surpassed the number of publications generated in USA articles. Interestingly, the citation growth rate has gradually decreased in developed countries, such as the UK and Holland, but has steadily increased in developing countries, such as India and Brazil. This result reveal the cooperation among countries in the newly advanced economic development i.

Brazil, Russia, India, China and South Africa in order to advance and promote the technology and innovation in the agricultural sector. Moreover, results from co-authorship network analysis suggest that institutions and organizations based in North America, East Asia and Europe are the major research contributors; this trend is visualized via Google Earth View see part A of Figure 6.

Each area has established close cooperation relations. Data statistics and visualization can help to discover rules and distributions of academic collaborations within this topic.

As shown in part B of Figure 6 , the co-author communities are identified in the large linked network. Greater density indexes are marked by deeper colors in the thermodynamic diagram. From the perspective of integrative power and global influence in terms of technological cooperation and innovation alliance, national academic research organizations and primarily governmentally-funded institutions , such as the Chinese Academy of Sciences, French National Institute of Agricultural Research, United States Department of Agriculture—Agricultural Research Service and Agriculture and Agri Food in Canada exert greater leadership than other organizations, such as colleges and universities see Table 3.

As shown, the Chinese Academy of Sciences, ranked first, has cooperated with organizations in research related to this topic. The Chinese Academic of Sciences, the China Agricultural University, and Michigan State University have cooperated in research dealing with the status and trends in the distribution, sources and risk of agricultural chemicals in aquatic environments in China [ — ].

Furthermore, Cornell University, in conjunction with multiple universities and scientific research institutes e. The University of California-Davis and Cornell University have also researched on agricultural chemicals in plant and soil and their potential risks [ , ]. Finally, Wageningen University and the China Agricultural University have jointly collaborated in terms of research involving nutrient i.

Table 3. Detailed information of scientific research organizations-based co-authorship weights. Using informetrics theory-based methods i. From a macro-level view, citation network analysis shows that the impact of agricultural chemicals on the environment can be divided into three periods.

In the early stage —99 , studies mainly focus on the application of agricultural chemicals, pollutant emissions and their concentration in various environmental media. In the late stage —16 , studies mainly focus on discussing the influence of specific pollutants on various environmental medias and comparing the changes under different conditions. Citation-clustering analysis, a meso-level method, shows that the main research directions include the effects of pesticides and veterinary drugs on the environment A1 , the influence of fertilizer application on environmental and food safety A2 , and the technologies and strategies for monitoring and controlling the impact of agricultural chemicals on environment A3.

The A3 cluster contains special pivot nodes in the knowledge network, connecting A1 and A2, providing research in A1 and A2 with technical supports for revealing the impacts.

From a micro-level perspective, results from co-occurrence network of subject terms analysis, show that pesticides and chemical fertilizer are the main types of agricultural chemicals. As for pollutant types, POPs, heavy metals, nitrates and pesticide residue in environmental media appear to be of major interest and concern.

Moreover, agricultural chemical inputs and their environmental impact derived from the production of wheat, maize and rice seem to be main focal point. For environmental objects impacted by agricultural chemicals, particular attention in the literature has been paid to soil, air and water, studying the potential risks of environmental pollution to fishes, bees and human health. For example, plants depend on a variety of soil microorganisms to transform atmospheric nitrogen into nitrates, which plants can use.

Common landscape herbicides disrupt this process: triclopyr inhibits soil bacteria that transform ammonia into nitrite Pell et al. Mycorrhizal fungi grow with the roots of many plants and aid in nutrient uptake. These fungi can also be damaged by herbicides in the soil. One study found that oryzalin and trifluralin both inhibited the growth of certain species of mycorrhizal fungi Kelley and South, Roundup has been shown to be toxic to mycorrhizal fungi in laboratory studies, and some damaging effects were seen at concentrations lower than those found in soil following typical applications Chakravarty and Sidhu, ; Estok et al.

Triclopyr was also found to be toxic to several species of mycorrhizal fungi Chakravarty and Sidhu, and oxadiazon reduced the number of mycorrhizal fungal spores Moorman, Pesticide sprays can directly hit non-target vegetation, or can drift or volatilize from the treated area and contaminate air, soil, and non-target plants.

Some pesticide drift occurs during every application, even from ground equipment Glotfelty and Schomburg, Despite the fact that only limited research has been done on the topic, studies consistently find pesticide residues in air. Nearly every pesticide investigated has been detected in rain, air, fog, or snow across the nation at different times of the year U.

Many pesticides have been detected in air at more than half the sites sampled nationwide. Herbicides are designed to kill plants, so it is not surprising that they can injure or kill desirable species if they are applied directly to such plants, or if they drift or volatilise onto them.

Many ester-formulation herbicides have been shown to volatilise off treated plants with vapors sufficient to cause severe damage to other plants Straathoff, In addition to killing non-target plants outright, pesticide exposure can cause sublethal effects on plants. Phenoxy herbicides, including 2,4-D, can injure nearby trees and shrubs if they drift or volatilise onto leaves Dreistadt et al.

Exposure to the herbicide glyphosate can severely reduce seed quality Locke et al. It can also increase the susceptibility of certain plants to disease Brammall and Higgins, This poses a special threat to endangered plant species.

The U. Fish and Wildlife Service has recognized 74 endangered plants that may be threatened by glyphosate alone U. Exposure to the herbicide clopyralid can reduce yields in potato plants Lucas and Lobb, Some insecticides and fungicides can also damage plants Dreistadt et al. Pesticide damage to plants is commonly reported to state agencies in the Northwest. Oregon Dept. Plants can also suffer indirect consequences of pesticide applications when harm is done to soil microorganisms and beneficial insects.

Pesticides including those of new the generation, e. Other studies have identified the ability of some of these compounds to undergo short-range atmospheric transport Muir et al. One long-term study that investigated pesticides in the atmosphere of British Columbia BC , dating from Belzer et al.

Atrazine, malathion, and diazinon, highly toxic chemicals identified as high-priority pesticides by Verrin et al. Dichlorvos is a decomposition product of another pesticide, Naled Dibrom Hall et al.

Captan and 2,4-D showed the highest concentrations and deposition rates at these two sites, followed by dichlorvos and diazinon Dosman and Cockcraft, Air concentrations of currently used pesticides in Alberta were investigated in at four sampling sites that were chosen according to geography and pesticide sales data Kumar, Triallate and trifluralin were the two mostly detected pesticides at the four sites. South of Regina, Saskatchewan, in and , 2,4-D reached 3. Triallate, dicamba, bromoxynil concentrations were also higher in peak concentration of 4.

In a more recent study, Waite et al. Some acid herbicides were also investigated in South Tobacco Creek, Manitoba during — Once again, maximum concentrations occurred during periods of local use Rawn et al. A neutral herbicide, atrazine, was also investigated in Rawn et al. Pesticides are found as common contaminants in soil, air, water and on non-target organisms in our urban landscapes.

Once there, they can harm plants and animals ranging from beneficial soil microorganisms and insects, non-target plants, fish, birds, and other wildlife. Chlorpyrifos, a common contaminant of urban streams U. Geological Survey, , is highly toxic to fish, and has caused fish, kills in waterways near treated fields or buildings US EPA, Herbicides can also be toxic to fish.

EPA, In a series of different tests it was also shown to cause vertebral deformities in fish Koyama, The weed-killers Ronstar and Roundup are also acutely toxic to fish Folmar et al. The toxicity of Roundup is likely due to the high toxicity of one of the inert ingredients of the product Folmar et al. In addition to direct acute toxicity, some herbicides may produce sublethal effects on fish that lessen their chances for survival and threaten the population as a whole.

Glyphosate or glyphosate-containing products can cause sublethal effects such as erratic swimming and labored breathing, which increase the fish's chance of being eaten Liong et al.

Several cases of pesticide poisoning of dolphins have been reported worldwide. Because of their high trophic level in the food chain and relatively low activities of drug-metabolising enzymes, aquatic mammals such as dolphins accumulate increased concentrations of persistent organic pollutants Tanabe et al. Dolphins inhabiting riverine and estuarine ecosystems are particularly vulnerable to the activities of humans because of the restricted confines of their habitat, which is in close proximity to point sources of pollution.

River dolphins are among the world's most seriously endangered species. Populations of river dolphins have been dwindling and face the threat of extinction; the Yangtze river dolphin Lipotes vexillifer in China and the Indus river dolphin Platanista minor in Pakistan are already close to extinction Renjun, ; Perrin et al. In addition to habitat degradation such as construction of dams Reeves and Leatherwood, , boat traffic, fishing, incidental and intentional killings, and chemical pollution have been threats to the health of river dolphins Kannan et al.

Earlier studies reported concentrations of heavy metals Kannan et al. The Ganges river basin is densely populated and heavily polluted by fertilizers, pesticides, and industrial and domestic effluents Mohan, In addition to fish, other marine or freshwater animals are endangered by pesticide contamination.

Exposure to great concentrations of persistent, bioaccumulative, and toxic contaminants such as DDT 1,1,1-trichloro-2,2-bis[ p -chlorophenyl]ethane and PCBs has been shown to elicit adverse effects on reproductive and immunological functions in captive or wild aquatic mammals Helle et al.

Aquatic mammals inhabiting freshwater systems, such as otters and mink, have been reported to be sensitive to chemical contamination Leonards et al. EPA, ; Sanders, The weed-killer trifluralin is moderately to highly toxic to aquatic invertebrates, and highly toxic to estuarine and marine organisms like shrimp and mussels U. Since herbicides are designed to kill plants, it makes sense that herbicide contamination of water could have devastating effects on aquatic plants.

In one study, oxadiazon was found to severely reduce algae growth Ambrosi et al. Algae is a staple organism in the food chain of aquatic ecosystems. Studies looking at the impacts of the herbicides atrazine and alachlor on algae and diatoms in streams showed that even at fairly low levels, the chemicals damaged cells, blocked photosynthesis, and stunted growth in varying ways U. Water News Online, The herbicide oxadiazon is also toxic to bees, which are pollinators Washington State Department of Transportation, Herbicides may hurt insects or spiders also indirectly when they destroy the foliage that these animals need for food and shelter.

For example spider and carabid beetle populations declined when 2,4-D applications destroyed their natural habitat Asteraki et al. Non-target birds may also be killed if they ingest poisoned grains set out as bait for pigeons and rodents US EPA, Avitrol, a commonly used pigeon bait, poses a large potential for ingestion by non target grain feeding birds. It can be lethal to small seed-eating birds Extoxnet, Brodifacoum, a common rodenticide, is highly toxic to birds.

Herbicides can also be toxic to birds. Exposure of eggs to 2,4-D reduced successful hatching of chicken eggs Duffard et al. Herbicides can also adversely affect birds by destroying their habitat. Glyphosate treatment in clear cuts caused dramatic decreases in the populations of birds that lived there MacKinnon et al.

Despite the continuing usage, little is known about the impacts of OCs in bird populations in developing countries. Among the countries that continue to use OCs, India has been one of the major producers and consumers in recent years. As a consequence, wild birds in India are exposed to great amounts of OC pesticides Tanabe et al.

Use of OCs in tropical countries may not only result in exposure of resident birds but also of migratory birds when they visit tropical regions in winter. The Indian sub-continent is a host to a multitude of birds from western Asia, Europe and Arctic Russia in winter Woodcock, Hundreds of species of waterfowl, including wading birds such as plovers, terns and sandpipers, migrate each winter to India covering long distances Grewal, While concentrations of OC pesticides in wholebody homogenates of birds have been reported elsewhere Tanabe et al.

A few studies related to the decline in the populations of bats in various parts of the world to OC exposure were also being conducted Altenbach et al. The world population of bats was estimated to be 8. These observations indicate that bats can accumulate high concentrations of OCs and may be affected by their potential toxic effects.

The flying fox or the new world fruit bat, short-nosed fruit bat and Indian pipistrelle bat are resident species and are very common in South India.

Their habitat is mainly agricultural areas, rock caves, and abandoned houses in domesticated areas. Insects constitute an important diet for many bats, allowing the passage of OCs in their body Mc Bee et al. Similarly, several studies reported OCs in a variety of biota including humans and wildlife from India Senthilkumar et al.

However, no study has used whole body homogenates of birds, which is important to evaluate biomagnification features and body burdens of OCs Mc Bee et al. Earlier studies used specific body tissues to estimate biomagnification of OCs. However theoretically, estimation of biomagnification factors requires whole body concentrations rather than specific tissue concentrations.

The data on environmental-cum-health risk assessment studies may be regarded as an aid towards a better understanding of the problem.

Data on the occurrence of pesticide-related illnesses among defined populations in developing countries are scanty. Generation of base-line descriptive epidemiological data based on area profiles, development of intervention strategies designed to lower the incidence of acute poisoning and periodic surveillance studies on high risk groups are needed. Our efforts should include investigations of outbreaks and accidental exposure to pesticides, correlation studies, cohort analyses, prospective studies and randomised trials of intervention procedures.

Valuable information can be collected by monitoring the end product of human exposure in the form of residue levels in body fluids and tissues of the general population.

The importance of education and training of workers as a major vehicle to ensure a safe use of pesticides is being increasingly recognised. Because of the extensive benefits which man accrues from pesticides, these chemicals provide the best opportunity to those who juggle with the risk-benefit equations. What is required is to weigh all the risks against the benefits to ensure a maximum margin of safety.

The total cost-benefit picture from pesticide use differs appreciably between developed and developing countries. For developing countries it is imperative to use pesticides, as no one would prefer famine and communicable diseases like malaria. It may thus be expedient to accept a reasonable degree of risk. Our approach to the use of pesticides should be pragmatic. In other words, all activities concerning pesticides should be based on scientific judgement and not on commercial considerations.

There are some inherent difficulties in fully evaluating the risks to human health due to pesticides. For example there is a large number of human variables such as age, sex, race, socio-economic status, diet, state of health, etc.

But practically little is known about the effects of these variables. The long-term effects of low level exposure to one pesticide are greatly influenced by concomitant exposure to other pesticides as well as to pollutants present in air, water, food and drugs. Pesticides are often considered a quick, easy, and inexpensive solution for controlling weeds and insect pests in urban landscapes.

However, pesticide use comes at a significant cost. Pesticides have contaminated almost every part of our environment. Pesticide residues are found in soil and air, and in surface and ground water across the countries, and urban pesticide uses contribute to the problem.

Pesticide contamination poses significant risks to the environment and non-target organisms ranging from beneficial soil microorganisms, to insects, plants, fish, and birds. Contrary to common misconceptions, even herbicides can cause harm to the environment.

In fact, weed killers can be especially problematic because they are used in relatively large volumes. The best way to reduce pesticide contamination and the harm it causes in our environment is for all of us to do our part to use safer, non-chemical pest control including weed control methods.

The exercise of analysing the range and nature of benefits arising from pesticide use has been a mixture of delving, dreaming and distillation. There have been blind alleys, but also positive surprises. This is reflected in the imbalance in the number of published scientific papers, reports, newspaper articles and websites against and for pesticides. The colour coding for types of benefit, economic, social or environmental, reveals the fact that at community level, most of the benefits are social, with some compelling economic benefits.

At national level, the benefits are principally economic, with some social benefits and one or two issues of environmental benefits. It is only at global level that the environmental benefits really come into play. There is a need to convey the message that prevention of adverse health effects and promotion of health are profitable investments for employers and employees as a support to a sustainable development of economics. There is thus every reason to develop health education packages based on knowledge, aptitude and practices and to disseminate them within the community in order to minimise human exposure to pesticides.

National Center for Biotechnology Information , U. Journal List Interdiscip Toxicol v. Interdiscip Toxicol. Published online Mar. Wasim Aktar. Author information Article notes Copyright and License information Disclaimer. Correspondence address : Md.

E-MAIL: ni. Keywords: pesticides, India, quality of food, environment. This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article has been cited by other articles in PMC. Introduction The term pesticide covers a wide range of compounds including insecticides, fungicides, herbicides, rodenticides, molluscicides, nematicides, plant growth regulators and others.

Production and usage of pesticides in India The production of pesticides started in India in with the establishment of a plant for the production of BHC near Calcutta, and India is now the second largest manufacturer of pesticides in Asia after China and ranks twelfth globally Mathur, Open in a separate window. Figure 1. Benefits of pesticides The primary benefits are the consequences of the pesticides' effects — the direct gains expected from their use.

Improving productivity Tremendous benefits have been derived from the use of pesticides in forestry, public health and the domestic sphere — and, of course, in agriculture, a sector upon which the Indian economy is largely dependent. Vector disease control Vector-borne diseases are most effectively tackled by killing the vectors. Quality of food In countries of the first world, it has been observed that a diet containing fresh fruit and vegetables far outweigh potential risks from eating very low residues of pesticides in crops Brown, Other areas — transport, sport complex, building The transport sector makes extensive use of pesticides, particularly herbicides.

Hazards of pesticides Direct impact on humans If the credits of pesticides include enhanced economic potential in terms of increased production of food and fibre, and amelioration of vector-borne diseases, then their debits have resulted in serious health implications to man and his environment.

Impact on environment Pesticides can contaminate soil, water, turf, and other vegetation. Surface water contamination Pesticides can reach surface water through runoff from treated plants and soil.

Ground water contamination Groundwater pollution due to pesticides is a worldwide problem. Soil contamination A large number of transformation products TPs from a wide range of pesticides have been documented Barcelo' and Hennion, ; Roberts, ; Roberts and Hutson, Effect on soil fertility beneficial soil microorganisms Heavy treatment of soil with pesticides can cause populations of beneficial soil microorganisms to decline.

Contamination of air, soil, and non-target vegetation Pesticide sprays can directly hit non-target vegetation, or can drift or volatilize from the treated area and contaminate air, soil, and non-target plants. Non-target organisms Pesticides are found as common contaminants in soil, air, water and on non-target organisms in our urban landscapes. Conclusion The data on environmental-cum-health risk assessment studies may be regarded as an aid towards a better understanding of the problem.

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