Exposure to pesticides and the associated human health effects

Pesticides are applied to control weeds and insect infestation in agricultural fields and various pests and disease carriers. As the modes of action for pesticides are not species-specific, concerns have been raised about risks associated with their exposure through various routes. The main objective of this study was to assess farmers’ perception towards agricultural pesticides and associated human health impact in Misrak Badawacho Woreda, Ethiopia. Community-based cross-sectional study was used to assess farmers’ perception towards agricultural pesticides and associated human health impact. Systematic random sampling technique was used to select study subjects. Structured questionnaires were used to collect data. Data were entered and analyzed using SPSS 20. Descriptive statistics were used during this study. About 361 study subjects completed the questionnaires. Among the studies subjects (81%) of them were males and 19% were females. The results showed that commonly applied pesticides comprised of herbicides (55%), fungicides (28%), Veterinary control (14%) and insecticides (3%). About 54% of the farm workers were used normal clothe, 17% were used boots,11% were used eye glass, 8% were used handkerchief, 3% were used mask and 2% were used Cotton during pesticide application. From total study subjects 38% do not follow instructions during pesticide application and 55% reuse pesticide containers for storing food and water in the home. Majority (93%) reported that they had suffered from pesticide-related health signs and symptoms during or after application of pesticides. Itching and skin irritation was the common symptom (74%) followed by headache (68%) during pesticide application. Generally the Farm workers had poor handling practices during pesticide application. Therefore continuous pesticide training programs for workers could be implemented.

در سال‌‌‌های اخیر نگرانی‌های زیادی درباره اثرات آفت‌کش‌ها روی موجودات غیر‌ هدف به‌وجود آمده است. بقایای ناشی از مصرف سموم شیمیایی آفت‌کش سبب آلودگی محیط‌زیست گردیده و سلامتی انسان‌ها را در معرض خطر جدی قرار داده است. محدوده مطالعاتی هشتگرد با وسعتی حدود 1170 کیلومتر مربع بدلیل نزدیکی به کلان‌شهر تهران و تمرکز تعداد زیاد واحدهای کشاورزی، صنعتی وخدماتی دارای موقعیت سیاسی- اقتصادی مهمی می‌باشد. این مقاله اثرات منفی حشره‌‌‌‌‌‌‌‌کش‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌های عمده مصرف شده در منطقه هشتگرد و میزان ریسک بالقوه و محیطی آن‌ها را با استفاده از شاخص تأثیر زیست‌محیطی (EIQ) مورد بحث و بررسی قرار می دهد. نتایج این تحقیق نشان می‌دهد در میان حشره‌‌‌‌‌‌‌‌کش‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌های عمده مصرفی در منطقه هشتگرد سمیت بالقوه ایمیداکلوپراید (کنفیدور) و تأثیر محیطی مزرعه‌ای مالاتیون بیشتر بوده است. بیشتربن خطر در هر سه جزء کارگران مزرعه، مصرف کننده و اکولوژیک مربوط به سم ایمیداکلوپراید بود که این سم را به عنوان خطرناک‌ترین حشره‌‌‌‌‌‌‌‌کش‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌‌عمده مصرفی در منطقه مطرح کرد. شاخص EIQ برای سموم ایمیداکلوپراید، دیازینون، مالاتیون و فوزالون بیشترین تأثیر‌پذیری را از بخش اثر اکولوژیک گرفته که به‌ترتیب 7/105، 75/81، 25/63 و 25/58 بوده است. در خصوص سم دلتامترین قسمت کارگران مزرعه بیشترین تأثیر را بر روی نمره نهایی EIQ داشته است. هم‌‌چنین نتایج نشان داد که بر اساس شاخص تأثیر زیست‌محیطی، بیشترین مخاطرات زیست‌محیطی ناشی از سوم حشره‌کش در منطقه هشتگرد به‌دلیل عدم شناخت مناسب و انتخاب غیرصحیح برخی از حشره‌کش‌ها و استفاده بیش از اندازه آن‌ها می‌باشد.

Pesticide application provides significant economic benefits to farmers by increasing the production and yield of food and fibers. They help in preventing vector-borne diseases. Some of the evidence suggests that their repeated use adversely affects human health and the environment. Experimental models, epidemiological studies, and clinical evidence show exposure to pesticides as a major risk for humans as they target different organs and systems in the body by multiple mechanisms involving receptor activation like nuclear receptor, estrogen receptor, and steroidal receptor. The mode of action of pesticide exposure is not species specific and there is a need for growing concern about the risk associated with pesticide exposure in the environment through various routes (food, drinking water, air, and soil). The health hazards caused by them range from acute (e.g. headache, dizziness, eye, and skin irritation) to chronic impacts (e.g. cancer, thyroid, asthma, diabetes). It is difficult to assess the risk associated with these pesticides because of the involvement of various factors (like level of exposure, type of pesticides, environmental characteristics of affected area). Development of techniques like environmentally friendly alternative pesticides (EcoSMART) and Integrated Pest Management (IPM) are required in order to reduce the impact of pesticides.

To feed the ever-growing global population, we need to produce more food and livelihood opportunities from less per capita arable land and available water. Providing ample food is only the first part of challenge, the second and more important challenge is to produce this in a safe and sustainable manner [1]. Most of the cultivated crops/varieties have reached their yield plateau, hence protection of crops to harvest maximum is one of the ways to meet the increasing demands of food and to attain global food security on sustainable basis. There are about 67,000 pest species that damage agricultural crops, and a significant portion of agricultural inputs is required for pest management to protect the crop. Pesticides are extensively used in the intensive agriculture to control pests, diseases, weeds, and other crop enemies to reduce yield losses and maintain the product quality. Insect-pests management in high yielding varieties by extensive use of synthetic pesticides has certainly provided protection to crops; but it has also raised concerns about pesticide residues in the food and the environment [2]. This pest management strategy adversely affects even beneficial organisms, leave harmful residues in food, feed and fodder, and causes environmental pollutions. Human exposure to pesticides occurs primarily through contaminated food, feed and drinking water. Their adverse effects depend on toxicity of pesticides, method of application, the dosage applied, their adsorption on soil colloids, the weather conditions prevailing after their application, and how long the pesticides persist in the environment. Therefore, assessment of risks of pesticides either on human health or on the environment is not an easy and accurate process because of differences in the periods and levels of exposure, and the types of pesticides used. Hence, the need of the day is to produce maximum from the decreasing availability of natural resources without adversely affecting the environment.

Description of the conditionAgriculture has wide-ranging global impacts which extend to economic growth, poverty reduction, food security, livelihoods, rural development and the environment (Green et al., 2005).Agriculture is the main source of income for around 2.5 billion people in the developing world (FAO, 2003, p. 1).In addition, around 70 percent of the global extreme poor -or over one billion people -lives in rural areas in low and middle income countries (IFAD, 2010, p.233), most of whom rely directly or indirectly on agriculture for their livelihoods.Investment in agriculture has been shown to have beneficial impacts on agricultural growth and poverty reduction (Fan & Rao, 2003).Moreover, the poorest population quintiles benefit significantly more from agricultural growth than growth in other sectors of the economy (United Nations, 2008; World Bank, 2007).The modernisation of farming practices in the 1960s and 70s during the 'Green Revolution' improved agricultural yields substantially in those areas it reached and raised national production and food security (IFAD, 2001).However, two key challenges emerged (van den Berg & Jiggins, 2007).The first problem was that poor farmers were being left behind, particularly in sub-Saharan Africa where many were not reached by modernisation approaches.In addition, those technologies promoted were not appropriate to the challenges facing smallholders in the African context, particularly women farmers (Inter-Academy Council, 2004).Second, modernisation was also associated with adverse environmental and health consequences, relating to water pollution, declining soil quality, soil erosion, pest resistance and loss of biodiversity.A particular problem emerged around environmental and health consequences of chemical pesticides use.Chemical pesticides have been heavily promoted and publicly subsidised under the modernisation agenda to such an extent that their overuse led to insect pests becoming resistant and causing major outbreaks of insect pests in rice crops in Asia in the 1970s and 80s.In addition, prolonged exposure to pesticides was associated with chronic and acute health problems among rural residents (Pingali & Roger, 1995).Use of broadspectrum insecticides in agriculture has even been linked to mosquito vectors of malaria developing resistance to insecticides used in malaria control programs (Diabate et al.,

The present report is based on data from the 2010 EFSA Report on pesticide residues in food, the Norwegian monitoring programmes 2007-2012 and data from peer reviewed literature and governmental agencies. It is a challenge to perform quantitative estimates and comparative studies of residue levels due to large variation in the measured levels, and the large number of different pesticides present in the samples. Thus, the focus is on the frequency of observed contaminations in relation to regulatory limits and to present examples to illustrate the variation in residue values and number of detected substances. 
 Pesticide residues in conventional and organic products:
 Of the 12,168 samples (plant- and animal products) in the 2010 EU-coordinated programme, 1.6% exceeded the respective maximum residue level (MRL) values, and 47.7% had measurable residues above the limit of quantification (LOQ), but below or at the MRL. Of the 1168 samples analysed in Norway in 2012 (from both imported and domestic products), 1.9% exceeded MRL and 53% contained measurable pesticide residues. Direct comparison of these values is however not possible, since they contain different types of food samples, and are analysed for a different number of pesticides.
 When organic and conventional samples from fruit, vegetables and other plant products in the 2010 EU-coordinated programme were compared, 4.2% of the conventional and 1.0% of the organic samples exceeded the MRL values, while 43.2% of the conventional and 10.8% of the organic samples had measurable residues below or at the MRL value. Most of the pesticide residues detected in organic samples are not permitted for use in organic farming. 
 Of the 624 organic samples analysed in Norway 2007 - 2012, 0.2% (one sample) had residues exceeding MRL, while measurable residues were detected in 1.8% of the samples (11 samples).
 Conventional products were often found to contain different pesticides while most organic samples were found to contain few or only one type of pesticide. 
 Lack of data on pesticide residue levels of organic samples in the EU-coordinated programme, and few Norwegian samples do not allow for a quantitative comparison of pesticide residue levels in organic and conventional samples. Comparative estimation of pesticide residues faces a number of challenges and uncertainties. However, it seems unquestionable based on available data that organic plant products contain fewer and substantially lower amounts of pesticide residues than conventional products.
 Health risk associated with pesticide residues:
 The general level of pesticide residues in both conventional and organic food is low, and well below what is likely to result in adverse health effects. This conclusion is based on the comparison of estimated dietary exposure with toxicological reference values i.e. acceptable daily intake (ADI) for chronic effects, and acute reference dose (ARfD) for acute effects. The finding of pesticide residues that exceeds established regulatory limits in a minority of tested samples is not considered to represent a health risk.
 When dietary exposure that was estimated in six different food commodities in the 2010 EUcoordinated programme was compared with their relevant reference values, EFSA concluded that for 79 of 18243 conventionally grown fruit and vegetable samples, a short-term acute consumer health risk could not be excluded. The conclusion was based on the exceeding of ARfD. None of these 79 samples were organic. It is important to also consider that the exceeding of the acute reference value only occurred in 0.4% of the samples and that the scenario used for acute intake assessment is conservative, suggesting that the toxicological implications are limited. This is also reflected in the chronic exposure assessment, where none of the samples were found to exceed the toxicological reference value ADI. 
 Dietary exposure assessments on the basis of Norwegian samples of apples, tomatoes, carrots, strawberries and lettuce did not show an exceeding of any toxicological reference value. 
 Combined exposure and cumulative risk assessment of pesticide residues:
 No generally accepted methodology is at present established for cumulative risk assessment of combined exposure to pesticide residues. Available data suggest however that combined exposure is not likely to result in increased human health risk.

A survey was developed and distributed to the Massachusetts cranberry grower community in 1999 to identify biological, educational, social and political barriers to the adoption of available integrated pest management (IPM) practices. The response rate for the 450 growers who received the survey was 54%. Approximately 80% of respondents claimed to practice IPM frequently and 16% identified themselves as occasional practitioners. Most growers practiced IPM because they agreed with IPM philosophy (80%) and believed it had environmental benefits (73%). Ninety-two percent agreed that more IPM-related research and education programs would encourage them to adopt practices they are not currently using. A significant percentage of respondents used multiple IPM component practices, with practices involving monitoring and detection of pests along with judicious use of pesticides being most common. Factor analysis was used to condense 104 potential responses to 22 factors, which were then used as predictors with six demographic variables (IPM adoption, education level, age, experience, farm size and work status). Demographic factors influenced a grower's tendency to incorporate IPM into routine farm activities. Full-time, highly experienced growers in charge of large operations tended frequently to use more IPM practices than less experienced growers who worked part-time and managed smaller farms. A large proportion of respondents agreed that IPM can reduce pesticide residues in food (92%) and the environment (96%), and can help to preserve beneficial insects (96%). Although many growers held the perception that IPM can pose measurable economic risk (and subsequently act as a barrier to adoption), growers appeared to feel less strongly about the economic benefits than potential environmental ones.

Pesticides are widely used in agricultural production to prevent or control pests, diseases, weeds, and other plant pathogens in an effort to reduce or eliminate yield losses and maintain high product quality. Although pesticides are developed through very strict regulation processes to function with reasonable certainty and minimal impact on human health and the environment, serious concerns have been raised about health risks resulting from occupational exposure and from residues in food and drinking water. Occupational exposure to pesticides often occurs in the case of agricultural workers in open fields and greenhouses, workers in the pesticide industry, and exterminators of house pests. Exposure of the general population to pesticides occurs primarily through eating food and drinking water contaminated with pesticide residues, whereas substantial exposure can also occur in or around the home. Regarding the adverse effects on the environment (water, soil and air contamination from leaching, runoff, and spray drift, as well as the detrimental effects on wildlife, fish, plants, and other non-target organisms), many of these effects depend on the toxicity of the pesticide, the measures taken during its application, the dosage applied, the adsorption on soil colloids, the weather conditions prevailing after application, and how long the pesticide persists in the environment. Therefore, the risk assessment of the impact of pesticides either on human health or on the environment is not an easy and particularly accurate process because of differences in the periods and levels of exposure, the types of pesticides used (regarding toxicity and persistence), and the environmental characteristics of the areas where pesticides are usually applied. Also, the number of the criteria used and the method of their implementation to assess the adverse effects of pesticides on human health could affect risk assessment and would possibly affect the characterization of the already approved pesticides and the approval of the new compounds in the near future. Thus, new tools or techniques with greater reliability than those already existing are needed to predict the potential hazards of pesticides and thus contribute to reduction of the adverse effects on human health and the environment. On the other hand, the implementation of alternative cropping systems that are less dependent on pesticides, the development of new pesticides with novel modes of action and improved safety profiles, and the improvement of the already used pesticide formulations towards safer formulations (e.g., microcapsule suspensions) could reduce the adverse effects of farming and particularly the toxic effects of pesticides. In addition, the use of appropriate and well-maintained spraying equipment along with taking all precautions that are required in all stages of pesticide handling could minimize human exposure to pesticides and their potential adverse effects on the environment.

Chapter 10 - Fungicide and pesticide fallout on aquatic fungi

Pesticides are one of the major inputs used for increasing agricultural productivity of crops. The pesticide residues, left to variable extent in the food materials after harvesting, are beyond the control of consumer and have deleterious effect on human health. The presence of pesticide residues is a major bottleneck in the international trade of food commodities. The localization of pesticides in foods varies with the nature of pesticide molecule, type and portion of food material and environmental factors. The food crops treated with pesticides invariably contain unpredictable amount of these chemicals, therefore, it becomes imperative to find out some alternatives for decontamination of foods. The washing with water or soaking in solutions of salt and some chemicals e.g. chlorine, chlorine dioxide, hydrogen peroxide, ozone, acetic acid, hydroxy peracetic acid, iprodione and detergents are reported to be highly effective in reducing the level of pesticides. Preparatory steps like peeling, trimming etc. remove the residues from outer portions. Various thermal processing treatments like pasteurization, blanching, boiling, cooking, steaming, canning, scrambling etc. have been found valuable in degradation of various pesticides depending upon the type of pesticide and length of treatment. Preservation techniques like drying or dehydration and concentration increase the pesticide content many folds due to concentration effect. Many other techniques like refining, fermentation and curing have been reported to affect the pesticide level in foods to varied extent. Milling, baking, wine making, malting and brewing resulted in lowering of pesticide residue level in the end products. Post harvest treatments and cold storage have also been found effective. Many of the decontamination techniques bring down the concentration of pesticides below MRL. However, the diminution effect depends upon the initial concentration at the time of harvest, substrate/food and type of pesticide. There is diversified information available in literature on the effect of preparation, processing and subsequent handling and storage of foods on pesticide residues which has been compiled in this article.

The use of synthetic pesticides among vegetable producers in urban and peri- urban Cotonou, Benin, has been increasing to the extent that certain insect pests have developed resistance to the pesticides. This paper assesses the impact of the farmer field school approach in an integrated pest management (IPM) project that aimed to increase IPM knowledge, adaptation/adoption of IPM options, and appropriate application of pesticides and awareness of related health hazards among vegetable producers in Cotonou. A sample of 54 semi-structured interviews was conducted with the vegetable producers, and a double difference model was used to compare the knowledge and practices before and after the project. The project led to increased knowledge about IPM, which was to some extent adapted into the participants' production systems, although no significant difference was noted for the type of synthetic pesticides used. The producers do adapt their practices when new technologies and practices emerge, but not always in ways that are environmentally sound or healthy.

Under the Food Sanitation Law, standards for the production and specifications of food ingredients for distribution may be established. Food that does not meet these standards is prohibited from being distributed. For pesticide residues in food, maximum residue limits (MRLs) are set for each pesticide and food type. Even pesticides without specific MRLs must comply with a uniform limit of 0.01 ppm. Thus, the positive list system controls pesticide residues in food in Japan. The MRLs for the pesticides were established based on current international agreements and concepts, and are calculated from crop residue trials for registered usage methods where maximum residue concentrations are expected. MRLs are determined if the dietary intake, when draft MRLs are adopted, does not exceed the acceptable daily intake (ADI) and acute reference dose (ARfD) as evaluated by the Food Safety Commission. The residue definition for MRL setting may be selected from the pesticide components themselves but also their metabolites and degradates, determined by considering the feasibility of analytical methods. Exposure to pesticides via food is estimated using monitoring data from quarantine stations and local governments, as well as market basket surveys. Currently, this exposure level is considered tolerable.

Pesticide residue in food has been investigated since the growing demand of food safe. The determination of pesticides residues in food is becomes an essential requirement for consumers, producers, and authorities responsible for food quality control. Pesticides can poison humans through the mouth, skin, and breathing. Often unwittingly these toxic chemicals enter a person’s body without causing sudden pain and causing chronic poisoning. This study aimed to investigate the impact of pesticides residue to health problems from meta-synthesize, sourced from the Scopus and Sinta indexed articles and obtained 12 indexed articles that were used as references. Meta-synthesize result showed that there are some type of pesticide who used by farmers such as chlorphenapir, emamctin benzoate, abamectin, chlorpyrifos, mankozeb, chlorotalonil, and propineb. Continous use of pesticides can cause such as fatigue, excessive saliva, hard breathing, frequent urination, blurred vision, dizzinesss, and fingerpain. At the end, pesticides residue is adverse effect on human health problems.

The safety of food has significant impact on human health hence the increasing concern on safe food consumption. One of the recent issues that have globally attracted the concern of consumers is the presence of pesticide residues in food. These residual chemicals are persistent organic contaminants that have serious lethal effect on human health when exposed beyond certain levels. The fears of the envisaged increased in the global population has further increased the use of pesticides due to concern for food productivity and security. The present paper examines the presence of pesticide residues in food, their sources and strategies for reducing the concentrations of these toxic chemicals. Attempt is also made in reviewing the Risk Assessment of Pesticide Residue in Food.

Food, water, and worker protection regulations have driven availability, and loss, of pesticides for use in pest management programs. In response, public-supported research and extension projects have targeted investigation and demonstration of reduced-risk integrated pest management (IPM) techniques. But these new techniques often result in higher financial burden to the grower, which is counter to the IPM principle that economic competitiveness is critical to have IPM adopted. As authorized by the 2002 Farm Bill and administered by the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS), conservation programs exist for delivering public-supported financial incentives to growers to increase environmental stewardship on lands in production. NRCS conservation programs are described, and the case for providing financial incentives to growers for implementing IPM is presented. We also explored the opportunity and challenge to use one key program, the Environmental Quality Incentives Program (EQIP), to aid grower adoption of IPM. The EQIP fund distribution to growers from 1997 to 2002 during the last Farm Bill cycle totaled approximately 1.05 billion dollars with a portion of funds supporting an NRCS-designed pest management practice. The average percentage of allocation of EQIP funds to this pest management practice among states was 0.77 +/- 0.009% (mean +/- SD). Using Michigan as an example, vegetable and fruit grower recognition of the program's use to implement IPM was modest (25% of growers surveyed), and their recognition of its use in aiding implementation of IPM was improved after educational efforts (74%). Proposals designed to enhance program usefulness in implementing IPM were delivered through the NRCS advisory process in Michigan. Modifications for using the NRCS pest management practice to address resource concerns were adopted, incentive rates for pest management were adjusted, and an expanded incentive structure for IPM technique adoption was tabled for future consideration. The case is strong for using public-supported financial incentives offered by the EQIP to aid grower adoption of IPM as a means to address resource concerns, but current use of the EQIP for this purpose is modest to meager. With appropriate program adjustments and increased grower awareness, USDA NRCS conservation programs, and the EQIP in particular, may provide an important opportunity for growers to increase their use of IPM as a resource conservation and farm management tool.