Pesticide Sprayers Research Articles

Increased Frequency of Rheumatoid Arthritis and Allergic Rhinitis among Pesticide Sprayers and Associations with Pesticide Use.

Objective: The aim of this study was to identify diseases linked with the pesticide sprayer occupation and explore possible associations with exposure history data. Methods: A cross sectional study was conducted among pesticide sprayers (n = 80) and the general population (n = 90) in Thessaly (Greece). Medical history, demographic characteristics and detailed exposure history were recorded by conducting personal interviews. Lifetime exposure indicators were calculated for several pesticide chemical subclasses. Moreover, organophosphate metabolite levels were quantified in urine samples of all participants by using gas chromatography-mass spectrometry (GC-MS). Multinomial analysis was used to determine associations between occupational pesticide exposure and diseases or disorders. Results: In the pesticide sprayers group, significantly higher frequencies for rheumatoid arthritis (RA) and allergic rhinitis were observed compared with the control group (p = 0.002 and p = 0.024 respectively). Within the pesticide sprayers group, high lifetime pesticide exposure was associated with increased risk for reporting RA (OR: 43.07 95% CI: 3.09–600.67) and allergic rhinitis (OR: 9.72 95% CI: 2.31–40.89), compared with low pesticide exposure. Exposure to organophsphate, guanidine and quinone pesticides were associated with RA while organophosphates, pyrethroids and paraquat were associated with allergic rhinitis. Despite the higher levels of certain pesticide metabolites observed among participants with rheumatoid arthritis, the differences were not statistically significant. One metabolite (diethylthiophosphate) was found to be significantly increased in allergic rhinitis cases (p = 0.037). Conclusions: The results from the current study suggest a possible association of occupational pesticide exposure with RA and allergic rhinitis that should be further investigated.

Prevalence of chromosomal aberrations in Argentinean agricultural workers

Little is known about biosecurity measures and toxic effects during pesticide application in the province of Jujuy, Argentina, particularly concerning the protective measures and mixture of pesticides used by rural workers. We carried out an observational study of agricultural workers from Jujuy (76 exposed subjects and 53 controls) to investigate the prevalence of chromosomal aberrations (CAs) in human lymphocytes as well as the activity level of acetylcholinesterase (AChE) in red blood cell erythrocytes. Whole blood samples (5mL) were collected in heparinized Vacutainer tubes for cytogenetic analysis and erythrocyte cholinesterase activity determination according to Ellman's method. Cytogenetic results showed a significant CA increase in pesticide-exposed individuals as compared with controls (4.20±0.15 vs. 1.00±0.05, respectively; p<0.001), suggesting that pesticides are clastogenic agents causing DNA damage. Erythrocyte cholinesterase activity was significantly lower in exposed individuals, evidencing the possible occurrence of perturbations in blood as well as neurotoxicity in pesticide sprayers. These results suggest the need for periodic biomonitoring of these biomarkers together with education and training of occupational workers for the safe application of potentially harmful pesticides.

Convert the fuel operating system as free energy operating system for agriculture implementation

Based on the experimentation, it is found in this project that the Solar panel provides 17V, 1A during day time between 9.30 AM to 4.30 PM. Since the pesticide sprayers are used in this duration, testing is as carried out in this time. The 12V, 8Ah battery can be charged fully in 7 hours during this time at 1.3A. Hence, this module can be operated to spray continuously 7 to 8 hour which is not possible with electrical pesticide sprayer. The model cost will not exceed Rs. 7000. Hence, the proposed model is cost effective and compatible with other models available commercially.

The Effect of Selenium Supplementation on Hemoglobin Among Farmers Working as Pesticide Sprayers

The Effect of Selenium Supplementation on Hemoglobin Among Farmers Working as Pesticide Sprayers

Pesticide exposure and subjective symptoms of cut-flower farmers.

Sales of cut-flowers depend much on the outer appearance of the flowers. They are not intended to be used as foodstuffs; thus, pesticides are used more liberally for cut flower growing than for other agricultural products. Flower production is often carried out in greenhouses; therefore, pesticide exposure seems to reach not only the person spraying the pesticides, but also the non-spraying workers as well. In 2009, a special research project on pesticide poisoning, affiliated with the Japanese Association of Rural Medicine, developed a study that focused on cut-flower farmers’ exposure to pesticide, subsequent adverse symptoms experienced, and treatment modalities to relieve pesticide-related symptoms. In this group of farmers, the pesticide sprayers were almost entirely male, while the females did not do any spraying. The organophosphate metabolite level in the urine of the males was higher than that of the females. However, in the female group, a positive relation was found between average working times in the greenhouse, and urine concentration of dialkylphosphates. In 2 males of this group, the level of dimethylphosphate was detected at 1,000 times the median level. Their butyrylcholinesterase activity levels on the day of testing had declined to 64%, 72% of their average level of the proximate 4 years, respectively. Communication with these subjects regarding pesticide exposure and methods of prevention appeared to be an effective approach for reducing symptom severity. Among soil fumigants, chloropicrin and 1,3-dichloropropene were most often used. Difficulty breathing was one of the subjective symptoms associated with chloropicrin, as well as watery eyes, coughing, and runny nose. These symptoms were effectively suppressed by the preventative practice of wearing gas masks and goggles while using soil fumigants. It would be beneficial to strongly encourage use of suitable protective gear among farmers exposed to soil fumigants.

Risk Factors of Pesticide Poisoning and Pesticide Users' Cholinesterase Levels in Cotton Production Areas: Glazoué and Savè Townships, in Central Republic of Benin.

Objective:To assess the degree of poisoning in farmers using the erythrocyte acetylcholinesterase (AChE) test before and after the exposure to pesticides in townships in central Benin (Glazoué and Savè) and to identify the associated risk factors.Methods:Using a cross-sectional study design, we recruited 264 farm pesticide sprayers, who have been working for at least 5 years. They completed a questionnaire and underwent the AChE test using the Test-mate Model 400 device (EQM Research Inc.) with a photometric sensor, based on the works of Ellman.Results:Organophosphate/pyrethroids were the most common pesticides used by at least 72.96% of the farmworkers. We observed an inhibition of AChE between pre-exposure and post-exposure (P = .002) for 60.61% of the farmworkers. Among them, 11.88% displayed more than 20% AChE inhibition.Conclusions:Pesticide poisoning is a reality, and AChE monitoring is urgently needed for farmworker surveillance.

Neurotoxicity and reproductive biomarkers in pesticide sprayers

Neurotoxicity and reproductive biomarkers in pesticide sprayers

Evaluation of clinical and hematological parameters and risk perception in pesticide sprayers

Evaluation of clinical and hematological parameters and risk perception in pesticide sprayers

Paraoxonase 1 as biomarker of exposure and susceptibility to pesticide sprayers

Paraoxonase 1 as biomarker of exposure and susceptibility to pesticide sprayers

Controlling Aedes aegypti in Cryptic Environments with Manually Carried Ultra-Low Volume and Mist Blower Pesticide Applications.

Because Aedes aegypti , a vector of dengue, chikungunya, and Zika viruses, exhibits resting and reproductive behaviors that present challenges to control them, pesticide application equipment available for vector control must be evaluated for their ability to control this species in a variety of cryptic environments. Five types of pesticide sprayers, representing 3 spray technologies (1 mister, 2 ultra-low volume [ULV] cold foggers, and 2 ULV thermal foggers), were evaluated for their ability to control adult and immature stages of Ae. aegypti in indoor and outdoor environments. Cages holding adult mosquitoes and larvae were placed in cryptic sites for indoor sprays and placed among dense vegetation for outdoor sprays. Adult and pupal mortality data were recorded following applications of a mixture of synergized pyrethrins and pyriproxyfen. We found that no single sprayer was best suited for controlling Ae. aegypti in indoor and outdoor environments, nor was one best for controlling adult and immature mosquitoes. Sprayers producing larger droplets (misters and cold foggers) were more effective in controlling immature mosquitoes indoors and outdoors. Thermal fogging was more effective in controlling adults indoors, whereas cold fogs and misters were more effective for outdoor control.

The use of the lymphocyte cytokinesis-block micronucleus assay for monitoring pesticide-exposed populations.

Pesticides are widely used around the world, and hundreds of millions of people are exposed annually in occupational and environmental settings. Numerous studies have demonstrated relationships between pesticide exposure and increased risk of cancers, neurodegenerative and neurodevelopmental disorders, respiratory diseases and diabetes. Assessment of genotoxicity of pesticides and biomonitoring their effect in exposed populations is critical for a better regulation and protection, but it can be complicated because pesticides are often used as complex mixtures. The cytokinesis-block micronucleus assay in human lymphocytes (L-CBMN) is a validated method of assessment of DNA damage induced by clastogenic and aneuploidogenic mechanisms. The goal of this review is to provide an updated summary of publications on biomonitoring studies using this assay in people exposed to pesticides in different settings, and to identify gaps in knowledge, and future directions. A literature search was conducted through MedLine/PubMed and TOXLINE electronic databases up to December 2015. A total of 55 full-text articles, related to 49 studies, excluding reviews, were selected for in depth analysis, divided by the settings where exposures occurred, such as chemical plant workers, pesticide sprayers, floriculturists, agricultural workers and non-occupationally exposed groups. Majority of studies (36 out of 49) reported positive findings with L-CBMN assay. However, most of the studies of professional applicators that used single pesticide or few compounds in the framework of specific programs did not show significant increases in MN frequency. A decreased level of pesticide-induced genotoxicity was associated with the proper use of personal protection. In contrast, subjects working in greenhouses or during intensive spraying season and having acute exposure, showed consistent increases in MN frequency. Overall, this analysis confirmed that L-CBMN is an excellent tool for pesticide biomonitoring, and can validate the effects of educational and intervention programs on reducing exposure and genetic damage.

Interrelation of Glycemic Status and Neuropsychiatric Disturbances in Farmers with Organophosphorus Pesticide Toxicity.

Background:Diverse group of agro-chemicals are indiscriminately sprayed by the farmers for pest control to enhance crop yield. About 25 million agricultural workers in the developing world suffer from at least one episode of poisoning each year, mainly by anticholinesterase- like organophosphates (OPs). Objective:The present study was aimed to establish the OP toxicity in 187 occupationally exposed pesticide sprayers of mango plantation in rural Malihabad, Lucknow, in terms of neuro-cognitive impairment, mental health status, clinical symptoms, diabetes, and hematological factors. Method:The exposed group was compared to 187 pesticides-unexposed normal healthy persons engaged in normal usual agricultural work (age, sex and education corresponding to age group of selected subject group) from Rural Malihabad, Lucknow (India). Neuro-cognitive impairment was measured using the Subjective Neurocognition Inventory and mental health status using the General Health questionnaire-28. The subjects were also tested for biochemical and enzymatic parameters. Results:The exposed farmers showed alterations in enzymatic and clinical parameters. While the rates of anxiety / insomnia and severe depression were also significantly higher in the pesticide sprayers, disorders affecting psychomotor speed, selective attention, divided attention, verbal memory, nonverbal memory, prospective memory, spatial functioning, and initiative/energy were all lower in the sprayers. Pesticide sprayers showed a number of clinical symptoms like eczema, saliva secretion, fatigue, headache, sweating, abdominal pain, nausea, superior distal muscle weakness, inferior distal muscle weakness, hand tingling and etc. which all significantly correlated with the number of working years. Conclusion:These findings suggested that farmers who work with OPs are prone to neuro-psychological disorders and diabetes.

Pesticide exposure in Sri Lanka.

Pesticides are commonly used worldwide both in agricultural and domestic settings. The benefits to society and agriculture are well documented. There are, however, dangers associated with the use of pesticides. Some pesticides, such as organophosphates (the most commonly used pesticide worldwide), kill pests through a biological pathway that may also cause harm to humans. Acute exposure to pesticides has been associated with negative health effects such as cancer, respiratory disease, Parkinson’s disease and death.1–4 People in low- and middle-income countries (LMICs), such as Sri Lanka, often experience acute exposure alongside chronic exposure due to the widespread and largely unregulated use of pesticides.5 The level of chronic pesticide exposure in LMICs is likely to be higher than in high-income countries, as a large proportion of rural families in Sri Lanka live close to agricultural fields and are not only exposed to pesticides when the fields are being sprayed (Figures 1 and ​and2)2) but also have sustained exposure through their food and drink and through air particles. In addition, villagers in rural Sri Lanka often use the irrigation canals, rivers and lakes as a free source of bathing water (Figure 3). This water source is likely to be heavily contaminated with pesticides, not only due to run-off but also as a direct consequence of the practices of pesticide sprayers (Figure 4).6 Figure 1. Pesticide spraying of banana crop using a power sprayer. No personal protection worn. Figure 2. Manual pesticide spraying of a paddy crop. No personal protection worn. Figure 3. Villagers bathing and washing clothes in the local river. Figure 4. Farmer cleaning and preparing pesticide spraying equipment using the irrigation canal. Equipment is rinsed and water taken from the canal. The success of a crop is imperative for a farmer’s livelihood in rural Sri Lanka. This need, coupled with heavy marketing of pesticides (Figure 5) has led to a nearly ubiquitous use of pesticides on crops.7 It is not clear whether this heavy use, resulting in high levels of both acute and chronic exposure, has any long-term detrimental health effects. The difficulty in assessing this arises because of challenges in the measurement of long-term pesticide exposure. Traditional biological samples, like blood and urine, are difficult to collect and only capture short-term pesticide exposure.8 Figure 5. Example of a pesticide advertisment (approximate size 1 x 2.5 m). In July 2015 a feasibility study was launched to determine whether it would be possible to measure chronic (long-term) exposure to pesticides using hair samples in rural Sri Lanka, as an alternative to blood/urine samples which are logistically difficult to manage in community settings in rural Asia. The additional benefit of hair samples is that pesticide metabolites deposit over time, and it would therefore be possible to ascertain a timeline of exposure over longer periods.9 Following a village introduction (Figure 6), fieldworkers visited households and recruited individuals to take part in the study. A hair sample (head/chest/forearm) was taken alongside self-reported information on pesticide use and exposure (Figures 7 and ​and8).8). The samples will be analysed for organophosphate metabolites using gas chromatography-mass spectrometry (Figure 9). Given that the knowledge of the long-term effects of the levels of pesticide exposure experienced in these countries is limited, there needs to be more research in this area to help inform legislation and effective community programmes for the safer use of pesticides. Figure 6. Village meeting to introduce the research project prior to home visits. Figure 7. Field staff collecting head hair sample. Figure 8. Alternative hair sample collected from men with limited or no head hair. Figure 9. An example of the analysis output (pictured on the right) from organophosphate metabolite hair analysis using a gas chromatography-mass spectrometry (pictured on the left).

Biochemical Study of Antioxidant Enzymes and Oxidative Stress among Pesticide Sprayers

Biochemical Study of Antioxidant Enzymes and Oxidative Stress among Pesticide Sprayers

The Reproductive Health and Liver Functions of Occupationally Exposed Female Pesticide Sprayers of Mango Plantations

The present study explores the effect of pesticide exposure on the reproductive health and liver function of females participating in agricultural related work. Blood samples were obtained from thirty-five (35) females (out of one hundred females of reproductive age) who were willing donors. Fifty (50) females matched for age and socio economic status was recruited as a control group to compare levels of hormones (estradiol, progesterone and follicle stimulating hormone), liver enzymes-alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Results showed that 56% of the females were illiterate with 48% representing agricultural work. Females who helped in farming operations showed a higher incidence of adverse pregnancy outcome such as abortions and stillbirths compared to non-participants. There was a significant elevation in estradiol and progesterone levels among female agricultural workers. While there was an elevation in serum liver enzymes (AST and ALT) there was a significant decrease in FSH level in females engaged in agricultural activities. The study suggests that participation of females in agricultural activities with potential exposure to pesticides endangers their reproductive health and liver functions.

8-Hydroxydeoxyguanosine (8-OHdG) levels in urinary samples of pesticide sprayers on exposure to organophosphorus pesticides

&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Background: &lt;/span&gt;&lt;/strong&gt;&lt;span lang="EN-US"&gt;Free radicals and other reactive species are constantly generated &lt;em&gt;in vivo&lt;/em&gt; and cause oxidative damage to biomolecules. DNA is probably the most biologically significant target of oxidative attack. Among numerous types of oxidative DNA damage the formation of 8-hydroxyguanosine (8-OHdG) is a sensitive biomarker of oxidative stress, an adduct formed as a result of biochemical reaction between ROS and DNA. Chronic exposure to &lt;/span&gt;Organophosphorus &lt;span lang="EN-US"&gt;(OP) pesticides is implicated in many health conditions that result from the induction of oxidative stress, including cytogenetic damage. The main objective of the study was to evaluate the biochemical levels of 8-OHdG in spot urinary samples under the exposed OP pesticide sprayers and farm workers. &lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Methods:&lt;/span&gt;&lt;/strong&gt;&lt;span lang="EN-US"&gt; In this study, 51 male pesticide sprayers and 39 farm workers in the age group of 18-47 years having exposure ranged from 3 to 15 years in duration were selected. The referents (n=31) were selected on the same criteria as well as they were never exposed to pesticides at any time. This study was conducted during the growing season (January, 2009 – September, 2010). The most commonly used OP pesticides like chlorpyriphos, Diazinon, Dimethioate, Monocrotofos etc., were used in this study. Urine samples from each participant were taken in sterile tubes and were stored at -20&lt;sup&gt;0&lt;/sup&gt;C till analysed. The concentration of 8-OHdG in samples were analyzed using ELISA.&lt;strong&gt;&lt;/strong&gt;&lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Results: &lt;/span&gt;&lt;/strong&gt;&lt;span lang="EN-US"&gt;The urinary levels of 8-OHdG were found to be significantly higher in the farm workers and pesticide sprayers in contrast to the level observed in the control group (p&amp;lt;0.05). When the data was analyzed in the exposed groups in relation to duration of exposure it was found that both the farm workers and sprayers who were exposed to OP pesticides for less than 5 years showed the maximum mean values of 8-OHdG in comparison to those exposed to for more than 10 years.&lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;&lt;span lang="EN-US"&gt;Conclusions:&lt;/span&gt;&lt;/strong&gt;&lt;span lang="EN-US"&gt; In view of this regular bio monitoring studies in target human populations are imperative necessary due to frequent changes in pesticide formulations and introduction of newer pesticides. Despite that several life style factors may influence the&lt;strong&gt; &lt;/strong&gt;urinary concentrations of 8-OHdG but still this non-invasive bio-marker 8-OHdG is preferred over other invasive techniques to evaluate the environmental and occupational exposure effect of OP pesticides on the genotoxicity of the exposed workers.&lt;/span&gt;&lt;/p&gt;

Assessment of the Health risk among agricultural workers exposed to pesticides in Deoli Block Wardha District

Title: Assessment of the Health risk among agricultural workers exposed to pesticides in Deoli Block Wardha DistrictObjectives: 1) To assess the awareness & preparation of handling pesticide and its storage by the agricultural workers. 2) To find and compare the current health status between agricultural workers exposed to pesticide and non-agricultural workers.Introduction:  Pesticides affect health of farmers. It may be simple irritation of skin and eye to more severe effects such as affecting the nervous system. Disorders which are seen more commonly are mild conditions like irritation of nose, throat, and eyes. Pesticides are used extensively throughout the world.Methodology: A Cross-sectional study was conducted in Deoli which is15 km away from Wardha. Agricultural pesticide sprayers and non Agricultural workers visiting RHTC Deoli in the Department of Community MedicineResults: Pesticide sprayers and 5(6.02%) of non agricultural workers were educated up to middle school level, 32(38.55%) of agricultural pesticide sprayers and 17(20.48%) of non agricultural workers were educated up to high school level, 6(7.22%) of agricultural pesticide sprayers and 15 (18.07%) of non agricultural workers were educated up to junior college level. Running nose 15(18.07%) in agricultural pesticide workers (agricultural pesticide sprayers) compare to 10(12.04%) non agricultural workers, burning of eyes 48(57.83%) in agricultural pesticide workers compared to 15 (18.07%) in non agricultural workers, itching of eyes 30(36.12%) in agricultural pesticide sprayers compared to 2(2.40%) in non agricultural workers, excessive sweating 20(24.09%) in agricultural pesticide sprayers compared to 10(12.04%) in non agricultural workers.

Assessment of hematological, biochemical effects and genotoxicity among pesticide sprayers in grape garden.

BackgroundMany studies revealed toxic effects of pesticides on pesticide handlers but very fewer studies have been reported among grape garden pesticide sprayers in India. The purpose of this study was to evaluate the effect of pesticides among grape garden sprayers.Methods27 pesticide sprayers in study group and 27 non sprayers in control group were recruited. Blood samples were analyzed for hematological profile, biochemical parameters and urine samples for oxidative stress, buccal mucosal cells for genotoxicity. For statistical analysis student’s t-test and Mann Whitney U test were used.ResultsWhite blood cell (WBC) count was significantly decreased; uric acid and Malondialdehyde (MDA) level was significantly increased among study group. In present study the Micronucleus (MN) assay for buccal mucosal cell showed significant number of micronucleated cells in study group.ConclusionThese results suggest that pesticide sprayers in grape garden are under risk which need to be monitored continuously in large population and further study is warranted to correlate the pesticide exposure by assessing acetylcholinesterase activity, pesticide residue analysis and their personal habits.

The influence of organophosphate and carbamate on sperm chromatin and reproductive hormones among pesticide sprayers.

This study is aimed at evaluating the association between occupational exposure to organophosphate (OP) and carbamate (CB) pesticides and semen quality as well as levels of reproductive and thyroid hormones of pesticide sprayers in Malihabad, Lucknow, Uttar Pradesh, India. Thirty-five healthy men (unexposed group) and 64 male pesticide sprayers (exposed group) were recruited for clinical evaluation of fertility status. Fresh semen samples were evaluated for sperm quality and analyzed for DNA fragmentation index (DFI) by flow cytometry. Pesticide exposure was assessed by measuring erythrocyte acetylcholinesterase and plasma butyrylcholinesterase (BuChE) with a Test-mate ChE field kit. Serum levels of total testosterone (Tt), prolactin (PRL), follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and free thyroxine (FT4) were analyzed using enzyme immunoassay kits. Evidence of pesticide exposure was found in 88.5% of sprayers and significant increments were observed in sperm DFI with significant decrease in some semen parameters. DFI was negatively correlated with BuChE, sperm concentration, morphology, and vitality in these pesticide sprayers. The levels of Tt, PRL, FT4, and TSH appeared to be normal; however, there was a tendency for increased LH and FSH levels in exposed workers. The results confirm the potential impact of chronic occupational exposure to OP and CB pesticides on male reproductive function, which may cause damage to sperm chromatin, decrease semen quality, and produce alterations in reproductive hormones, leading to adverse reproductive health outcomes.

Chronic pesticide exposure: Health effects among pesticide sprayers in Southern India.

Background:Occupational health has never been a priority for policy makers in India, despite 63% of the Indian population being in the economically productive age group.Objectives:The study was designed to find out the morbidity as a result of long-term exposure to pesticides among professional pesticide sprayers in a rural block in Tamil Nadu.Subjects and Methods:A cross-sectional study was done in Kaniyambadi block of Vellore district, Tamil Nadu, during July to October 2013. A total of 70 professional pesticide sprayers and 66 people engaged in other occupations were enrolled into the study. The participants were administered a standardized questionnaire apart from measuring pulmonary function and peripheral sensations. Venous blood samples were collected for measuring serum cholinesterase.Results:The pesticide sprayers had higher prevalence of breathlessness on activities of daily living (odds ratio [OR]: 3.14, 95% confidence interval [CI]: 1.22–8.07), chronic cough/phlegm (OR: 3.53, 95% CI: 1.09–11.46), symptoms of peripheral sensory neuropathy (OR: 6.66, 95% CI: 2.53–17.51) and recurrent abdominal pain (OR: 3.05, 95% CI: 1.03–9.01), when compared to people engaged in other occupations. Pesticide sprayers also had significantly lower mean peak expiratory low rates and poor peripheral sensations. The serum cholinesterase levels were not statistically different between the groups.Conclusion:The pesticide sprayers had a higher morbidity when compared to people engaged in other occupations, and further research is needed to find out methods to prevent the same. Serum cholinesterase may not be a good marker for quantifying exposure to pesticide among sprayers, during a spraying season.