Agricultural pesticide use in developing countries: health effects and research needs

Structural Features of Carbon Dots and Their Agricultural Potential

Carbon dots (CDs) have drawn attention due to their enticing physical, chemical, and surface properties. Besides, good conductivity, low toxicity, environmental friendliness, simple synthetic routes, and comparable optical properties are advantageous features of CDs. Further, recently, CDs have been explored for biological systems, including plants. Among biological systems, only plants form the basis for sustainability and life on Earth. In this Review, we reviewed suitable properties and applications of CDs, such as promoting the growth of agricultural plants, disease resistance, stress tolerance, and target transportation. Summing up the available studies, we believe that the applications of CDs are yet to be explored significantly for innovation and technology-based agriculture.

Patterns, Clinical Outcome, and Factors Associated with Poisoning Outcomes among Poisoned Patients in Northwest Ethiopia

Introduction

Poison is a substance that can hurt or cause dysfunction in the body due to its chemical action. Poisoning related to pesticides used in agriculture is a major public health issue in developing countries. However, there is a limited epidemiological data on poisoning in Ethiopia.

Objective

The aim of this study was to determine poisoning patterns, clinical outcome, and factors associated with poisoned patients in Northwest Ethiopia.

Methods

A cross-sectional study was conducted in July 2021 to include data of 1 year period. Data of all poisoned patients were collected using a standardized checklist from the registration book and patient medical records. The association between variables and outcomes was analyzed using a multivariable logistic regression model. A p-value of < 0.05 was considered to declare a statistically significant association.

Result

Over one-third of the poisoning cases (35.9%) were seen in the spring, according to a survey of 315 patient medical data. The majority of patients were in the age group of 21-30 years (44.1%). The most common form of poison consumed was organophosphate (OP), which accounts for 61.3% of all visits, and the least common was food poisoning, which accounts for 1.9%. About 82.5% of poisoning cases survived, while the remaining 17.5% were died. Time of arrival to the hospital ≥1 h (adjusted odds ratio (AOR) = 7.02; 95% confidence interval (CI): 1.16, 11.40), lack of oxygen support (AOR = 6.64; 95% CI: 3.56-6.78), and lack of adrenaline/dopamine medication (AOR = 3.57; 95% CI: 1.17-5.78) were all substantially linked with death of poisoned cases.

Conclusions

Three-fourth of poisoning cases survived, while the remaining one-fourth died. Ingestion of OPs is the most prevalent type of poisoning, and most cases are intentional. Delayed arrival ≥1 h, lack of oxygen support, and adrenaline/dopamine treatment were all linked to death. On-time arrival, oxygen assistance, and adrenaline/dopamine treatment in a healthcare setting are all recommended.

Features of fatal pesticide ingestion in South Australia

Pesticides are used to kill, repel or control any animal or plant species which are considered pests, but have also been associated with intentional and unintentional human fatalities. A rapid increase in pesticide suicides was observed during 'The Green Revolution' after pesticides were introduced into low- and middle-income rural households without appropriate guidelines for safe use and storage. While national pesticide bans have contributed to a significant decrease in pesticide-related suicides, such cases still comprise a large proportion of all suicides around the world. The aim of the current study was to provide a profile of pesticide suicides in a high-income country as a point of comparison against studies from low- and middle-income countries. Statistical analyses were performed using R (version 4.2.3). Over the 20-year study period, there were a low, yet consistent number of pesticide suicides which were most common among males over the age of 40. Paraquat and methomyl pesticides collectively contributed to almost half (48.8%) of all fatalities. Consistent with the literature, such cases often occurred with little premeditation in response to an acute emotional crisis. While interpretation of autopsy findings was mostly limited, there were some pesticides that demonstrated findings consisted with previously reported characteristics (e.g., gastroesophageal erosions with paraquat). Given the high proportion of cases where paraquat and methomyl pesticides were implicated, it may be appropriate to review the availability and accessibility of such compounds to reduce the occurrence of pesticide suicides in South Australia and potentially the wider Australian population.

Identification and characterization of Brevibacillus halotolerans B-4359: a potential antagonistic bacterium against red pepper anthracnose in Korea

Our study aimed to identify potential biocontrol agents (BCAs) against major phytopathogens under in vitro conditions by screening the Freshwater Bioresources Culture Collection (FBCC), Korea. Of the identified 856 strains, only 65 exhibited antagonistic activity, among which only one representative isolation, Brevibacillus halotolerans B-4359 was selected based on its in vitro antagonistic activity and enzyme production. Cell-free culture filtrate (CF) and volatile organic compounds (VOCs) of B-4359 were shown to be effective against the mycelial growth of Colletotrichum acutatum. Notably, B-4359 was found to promote spore germination in C. acutatum instead of exhibiting a suppressive effect when the bacterial suspension was mixed with the spore suspension of C. acutatum. However, B-4359 showed an excellent biological control effect on the anthracnose of red pepper fruits. Compared to other treatments and untreated control, B-4359 played a more effective role in controlling anthracnose disease under field conditions. The strain was identified as B. halotolerans using BIOLOG and 16S rDNA sequencing analyses. The genetic mechanism underlying the biocontrol traits of B-4359 was characterized using the whole-genome sequence of B-4359, which was closely compared with related strains. The whole-genome sequence of B-4359 consisted of 5,761,776 bp with a GC content of 41.0%, including 5,118 coding sequences, 117 tRNA, and 36 rRNA genes. The genomic analysis identified 23 putative secondary metabolite biosynthetic gene clusters. Our results provide a deep understanding of B-4359 as an effective biocontrol agent against red pepper anthracnose for sustainable agriculture.

Determination of histopathological effects and myoglobin, periostin gene-protein expression levels in Danio rerio muscle tissue after acaricide yoksorrun-5EC (hexythiazox) application

Although pesticides are essential agrochemicals to annihilate harmful organisms in agriculture, their uncontrolled use has become an important threat to environmental health. Exposure to pesticides can affect many biological systems including immune system, endocrine system, and nervous system. However, the potential side effects of pesticides to skeletal muscle system remain unclear. Present study has focused on the evaluation of this issue by using an acaricide, yoksorrun-5EC (hexythiazox), in an aquatic model organism, Danio rerio. The histological analyses revealed that increased concentrations of the acaricide cause degradation of skeletal muscle along with increased necrosis and atrophy in myocytes, intercellular edema, and increased infiltrations between perimysium sheaths of muscle fibers. The effects of acaricide on myoglobin and periostin, which are associated with oxygen transport and muscle regeneration, respectively, were investigated at the gene and protein levels. RT-PCR results suggested that high concentration yoksorrun-5EC (hexythiazox) can induce myoglobin and periostin genes. Similar results were also obtained in the protein levels of these genes by western blotting analysis. These results suggested that yoksorrun-5EC (hexythiazox)-dependent disruption of skeletal muscle architecture is closely associated with the expression levels of myoglobin and periostin genes in Danio rerio model.

Education and Socio-economic status are key factors influencing use of insecticides and malaria knowledge in rural farmers in Southern Côte d'Ivoire

BACKGROUND

Insecticides play a key role in rural farming; however, their over- or misuse has been linked with a negative impact on malaria vector control policies. This study was conducted amongst agricultural communities in Southern Côte d'Ivoire to identify which insecticides are used by local farmers and how it relates to the perception of farmers on malaria. Understanding the use of insecticides may help in designing awareness programme on mosquito control and pesticides management.

METHODS

A questionnaire was administered to 1399 farming households across ten villages. Farmers were interviewed on their education, farming practices (e.g. crops cultivated, insecticides use), perception of malaria, and the different domestic strategies of mosquito control they use. Based on some pre-defined household assets, the socioeconomic status (SES) of each household was estimated. Statistical associations were calculated between different variables, showing significant risk factors.

RESULTS

The educational level of farmers was significantly associated with their SES (p < 0.0001). Most of the householders (88.82%) identified mosquitoes as the principal cause of malaria, with good knowledge of malaria resulting as positively related to high educational level (OR = 2.04; 95%CI: 1.35, 3.10). The use of indoor chemical compounds was strongly associated to the SES of the households, their education level, their use of ITNs and insecticide in agricultural (p < 0.0001). Indoor application of pyrethroid insecticides was found to be widespread among farmers as well as the use of such insecticide for crops protection.

CONCLUSION

Our study shows that the education level remains the key factor influencing the use of insecticides by farmers and their awareness of malaria control. We suggest that better communication tailored to education level and including SES, controlled availability and access to chemical products, should be considered when designing campaigns on use of pesticides and vector borne disease control for local communities.

Environmental monitoring and potential health risk assessment from Pymetrozine exposure among communities in typical rice-growing areas of China

Pymetrozine is one of the most commonly used insecticides in China. This study was conducted to analyse Pymetrozine's potential exposures through various environmental routes beyond the treatment areas. The aim was to estimate the potential health risk for communities due to non-dietary exposures to Pymetrozine in soil and paddy water. Data on registration of pesticides in China, government reports, questionnaires, interviews and literature reviews as well as toxicological health investigations were evaluated to determine the hazard and dose-response characteristics of Pymetrozine. These were based on the US EPA exposure and human health risk assessment methods and exposure data from soil and paddy water samples collected between 10 and 20 m around the resident's location. The exposure doses from dermal contact through soil and paddy water were estimated. The potential cancer risk from the following exposure routes was evaluated: ingestion through soil; dermal contact exposure through soil; dermal contact exposure through paddy water. The potential total cancer risk for residents was estimated to be less than 1 × 10^-6. These were relatively low and within the acceptable risk levels. The potential hazard quotient (HQ) from acute and lifetime exposure by dermal contact through paddy water and soil and acute and lifetime exposure by soil ingestion for residents was less than 1, indicating an acceptable risk level. This study suggested that there were negligible cancer risk and non-cancer risks based on ingestion and dermal contact routes of exposure to residents.

Exposure Routes and Health Risks Associated with Pesticide Application

Pesticides play an important role in agricultural development. However, pesticide application can result in both acute and chronic human toxicities, and the adverse effects of pesticides on the environment and human health remain a serious problem. There is therefore a need to discuss the application methods for pesticides, the routes of pesticide exposure, and the health risks posed by pesticide application. The health problems related to pesticide application and exposure in developing countries are of particular concern. The purpose of this paper is to provide scientific information for policymakers in order to allow the development of proper pesticide application technics and methods to minimize pesticide exposure and the adverse health effects on both applicators and communities. Studies indicate that there are four main pesticide application methods, including hydraulic spraying, backpack spraying, basal trunk spraying, and aerial spraying. Pesticide application methods are mainly selected by considering the habits of target pests, the characteristics of target sites, and the properties of pesticides. Humans are directly exposed to pesticides in occupational, agricultural, and household activities and are indirectly exposed to pesticides via environmental media, including air, water, soil, and food. Human exposure to pesticides occurs mainly through dermal, oral, and respiratory routes. People who are directly and/or indirectly exposed to pesticides may contract acute toxicity effects and chronic diseases. Although no segment of the general population is completely protected against exposure to pesticides and their potentially serious health effects, a disproportionate burden is shouldered by people in developing countries. Both deterministic and probabilistic human health risk assessments have their advantages and disadvantages and both types of methods should be comprehensively implemented in research on exposure and human health risk assessment. Equipment for appropriate pesticide application is important for application efficiency to minimize the loss of spray solution as well as reduce pesticide residuals in the environment and adverse human health effects due to over-spraying and residues. Policymakers should implement various useful measures, such as integrated pest management (IPM) laws that prohibit the use of pesticides with high risks and the development of a national implementation plan (NIP) to reduce the adverse effects of pesticides on the environment and on human health.

Identification and Characterization of Bacillus tequilensis GYUN-300: An Antagonistic Bacterium Against Red Pepper Anthracnose Caused by Colletotrichum acutatum in Korea

Anthracnose is a fungal disease caused by Colletotrichum species and has detrimental effects on many crops, including red pepper. This study used Bacillus tequilensis GYUN-300 (GYUN-300), which exhibit antagonistic activity against the fungal pathogen, Colletotrichum acutatum. This pathogen causes anthracnose that manifests primarily as a fruit rot in red pepper. There have been little efforts to identify antagonistic bacteria from mushrooms; this strain of bacteria was identified as B. tequilensis using BIOLOG and 16S rDNA sequencing analysis. The genetic mechanism underpinning the biocontrol traits of GYUN-300 was characterized using the complete genome sequence of GYUN-300, which was closely compared to related strains. GYUN-300 inhibited mycelial growth and spore germination of C. acutatum under in vitro conditions. Important antagonistic traits, such as siderophore production, solubilization of insoluble phosphate, and production of lytic enzymes (cellulase, protease, and amylase), were observed in GYUN-300, These trains promoted growth in terms of seed germination and vigorous seedling growth compared to the non-treated control. When red pepper fruits were treated with GYUN-300, the preventive and curative effects were 66.6 and 38.3% effective, respectively, in wounded red pepper fruits; there was no difference between the preventive and curative effects in non-wounded red pepper fruits. Furthermore, GYUN-300 was resistant to several commercial fungicides, indicating that GYUN-300 bacterial cells may also be used synergistically with chemical fungicides to increase biocontrol efficiency. Based on in vitro results, GYUN-300 played a role to control anthracnose disease effectively in field conditions when compared to other treatments and non-treated controls. The results from this study provide a better understanding of the GYUN-300 strain as an effective biocontrol agent against red pepper anthracnose; this form of biocontrol provides an environment-friendly alternative to chemical fungicides.

Does aquatic sediment pollution result in contaminated food sources?

The sediment pollution of the aquatic environment by waste due to anthropogenic activity is of an increasing concern. The contaminants coming from the aquatic environment can enter the aquatic food chain and accumulate in the tissues of fish and shellfish used for human consumption. The aim of this study was to sum up the current level of knowledge concerning the pollution of aquatic sediments and its transfer to aquatic foods as well as to indicate whether such contamination has the potential to affect the health and welfare of aquatic organisms as well as the quality and safety of the species intended for human consumption. Based on the results of scientific studies, the European Food Safety Authority, and the Rapid Alert System for Food and Feed, contamination of fish and seafood occurs predominantly through their diet and the levels of bioaccumulative contaminants are higher in fish which rank higher in the food chain. Contamination of aquatic habitats can not only significantly affect behavior, development, and welfare of aquatic organisms, but it can also affect the safety of fish and seafood for human consumption.

What agro-input dealers know, sell and say to smallholder farmers about pesticides: a mystery shopping and KAP analysis in Uganda

BACKGROUND

Pesticides can have negative effects on human and environmental health, especially when not handled as intended. In many countries, agro-input dealers sell pesticides to smallholder farmers and are supposed to provide recommendations on application and handling. This study investigates the role of agro-input dealers in transmitting safety information from chemical manufacturers to smallholder farmers, assesses the safety of their shops, what products they sell, and how agro-input dealers abide by laws and recommendations on best practices for preventing pesticide risk situations.

METHODS

Applying a mixed-methods approach, we studied agro-input dealers in Central and Western Uganda. Structured questionnaires were applied to understand agro-input dealers' knowledge, attitude and practices on pesticides (n = 402). Shop layout (n = 392) and sales interaction (n = 236) were assessed through observations. Actual behavior of agro-input dealers when selling pesticides was revealed through mystery shopping with local farmers buying pesticides (n = 94).

RESULTS

While 97.0% of agro-input dealers considered advising customers their responsibility, only 26.6% of mystery shoppers received any advice from agro-input dealers when buying pesticides. 53.2% of products purchased were officially recommended. Sales interactions focused mainly on product choice and price. Agro-input dealers showed limited understanding of labels and active ingredients. Moreover, 25.0% of shops were selling repackaged products, while 10.5% sold unmarked or unlabeled products. 90.1% of shops were lacking safety equipment. Pesticides of World Health Organization toxicity class I and II were sold most frequently. Awareness of health effects seemed to be high, although agro-input dealers showed incomplete hygiene practices and were lacking infrastructure. One reason for these findings might be that only 55.7% of agro-input dealers held a certificate of competency on safe handling of pesticides and even fewer (5.7%) were able to provide a government-approved up-to-date license.

CONCLUSION

The combination of interviews, mystery shopping and observations proved to be useful, allowing the comparison of stated and actual behavior. While agro-input dealers want to sell pesticides and provide the corresponding risk advice, their customers might receive neither the appropriate product nor sufficient advice on proper handling. In light of the expected increase in pesticide use, affordable, accessible and repeated pesticide training and shop inspections are indispensable.

Small-scale Farmer Pesticide Knowledge and Practice and Impacts on the Environment and Human Health in Ethiopia

BACKGROUND

Inappropriate use and application of pesticides in Ethiopia pose a major threat to the health of farmers and the environment.

OBJECTIVE

The present study aimed to assess the level of knowledge, attitudes, and practices of small-scale vegetable farmers towards the use of pesticides in Ethiopia along the Lake Ziway watershed.

METHODS

This was a cross-sectional study involving a total of 210 farmers randomly selected during a period of pesticide application from a purposively selected village located in the immediate vicinity of Lake Ziway, Ethiopia. Data were generated through structured in-depth interviews and on-site observations on farms. A Chi-square test was applied to evaluate whether the collected data and their probable associations were significant.

RESULTS

World Health Organization (WHO) class II pesticides (moderately toxic) were the most frequently used pesticides in the study area. There was no reported use of WHO classes 1a and 1b and banned or restricted pesticides such as dichlorodiphenyltrichloroethane (DDT) and endosulfan. Most (92%) farmers reported indiscriminately disposing of empty containers in the field, while 86.7% applied the leftover pesticides to other crops. More than 90% of small-scale farmers did not use any personal protective equipment (PPE) when handling pesticides. About 95% of farmers had poor knowledge regarding pesticides. A significant association (p < 0.001) was observed between the knowledge of farmers and their practices related to pesticides.

CONCLUSIONS

Generally, the knowledge of small-scale farmers on pesticides was poor. Moreover, the inappropriate disposal of pesticides and pesticide containers poses a risk to the environment. The findings of the present study underline the need to train farmers concerning the safe and proper use of pesticides to mitigate hazards to human health and the environment.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

The study was granted an exemption from requiring ethics approval from the Hawassa University College of Natural and Computational Science, Research and Review Committee.

COMPETING INTERESTS

The authors declare no competing financial interests.

Agricultural land-uses consistently exacerbate infectious disease risks in Southeast Asia

Agriculture has been implicated as a potential driver of human infectious diseases. However, the generality of disease-agriculture relationships has not been systematically assessed, hindering efforts to incorporate human health considerations into land-use and development policies. Here we perform a meta-analysis with 34 eligible studies and show that people who live or work in agricultural land in Southeast Asia are on average 1.74 (CI 1.47-2.07) times as likely to be infected with a pathogen than those unexposed. Effect sizes are greatest for exposure to oil palm, rubber, and non-poultry based livestock farming and for hookworm (OR 2.42, CI 1.56-3.75), malaria (OR 2.00, CI 1.46-2.73), scrub typhus (OR 2.37, CI 1.41-3.96) and spotted fever group diseases (OR 3.91, CI 2.61-5.85). In contrast, no change in infection risk is detected for faecal-oral route diseases. Although responses vary by land-use and disease types, results suggest that agricultural land-uses exacerbate many infectious diseases in Southeast Asia.

How many premature deaths from pesticide suicide have occurred since the agricultural Green Revolution?

Introduction: The agricultural Green Revolution in the 1950s and 60s is thought to have averted many deaths from famine. However, it also introduced highly hazardous pesticides such as parathion and endrin into poor rural communities that were totally unequipped to store or use them safely. Pesticide self-poisoning rapidly became one of the two most common global means of suicide. Thus far, no attempt has been made to enumerate the total number of deaths that have occurred subsequent to the Green Revolution.Objective: To calculate plausible estimates for the total global number of pesticide suicides that have occurred since 1960.Methods: We performed a literature review on Medline and Embase databases to July 2019 to find papers that reported national or global numbers of pesticide suicides. We restricted our search to papers published in English. We used the search terms: pesticide) OR insecticide) OR paraquat) OR organophosphate) OR organophosphorus) OR agrochemical) AND suicide) OR "") OR deliberate) AND poison in all fields. These searches identified 2,144 papers; a further 8 citations were added through the searching of reference lists and our own paper collections. 2,136 papers were excluded as they contained no data on pesticide suicide, or were case reports, case series, or related to specific socio-demographic groups, or were non-human studies. This left 16 papers giving country specific or global pesticide suicide data.Long-term national trend in pesticide suicides: We found studies from one low- and middle-income country (Sri Lanka) that recorded long-term trends in suicide throughout the Green Revolution. These data showed a steady increase in suicides from 1960 to the early 1970s, with a more rapid increase from 1979 to 1984. The number of suicides plateaued until 1995, when they started a steady almost linear decrease that has continued at least until 2015. We used the Sri Lankan epidemiology as a model of the incidence of pesticide suicides in other low- and middle-income countries. Data from Bangladesh suggested that the decrease might have started in 2002.Estimating global numbers since 1960: Starting from a conservative estimate of zero deaths in 1960, the best estimate of the total global burden of pesticide suicides from 1960 to 2018 is 14,272,105 or 14,936,000 (depending on whether a fall in incidence began in 1995 or 2002), with a plausible range of 9,859,667 to 17,303,333 deaths. These are likely underestimates because suicide is illegal in many countries, and most pesticide suicides occur in poor rural areas without effective death registration systems.Conclusions: Pesticide self-poisoning has been a major clinical and public health problem in rural Asia for decades, while being long ignored. Most pesticide suicides are relatively impulsive with little planning: in the absence of highly hazardous pesticides, many people would have survived their suicidal impulse, gone on to find support amongst family, community, and health services, and lived a full life. Pesticide suicides must therefore be considered a category 4 occupation condition following Schilling's classification - if they had not been brought into rural communities for agricultural use, pesticide suicides would not have occurred. Preventing these deaths should be a global public health priority.

Is the World Health Organization predicted exposure assessment model for space spraying of insecticides applicable to agricultural farmers?

Agricultural farmers in developing countries are at high risk of pesticide exposure and adverse effects because of unsafe practices and inappropriate legislation. Biological monitoring is considered a useful tool for pesticide exposure assessment; however, its use is limited in developing countries due to a lack of techniques and resources such as laboratory analysis, trained staff and budgets. This study examines whether the World Health Organization predicted exposure assessment model (WHO-PEAM) is a suitable alternative tool for assessing insecticide exposure among agricultural farmers. WHO-PEAM was used to predict daily doses (PDD) of chlorpyrifos for a group of Vietnamese rice farmers using a set of exposure parameters obtained from a questionnaire survey of participant famers during a field study. These results were compared to absorbed daily doses (ADD) of chlorpyrifos for the farmers measured using a biological monitoring program, in which 24-h urine samples were collected and analysed for the chlorpyrifos metabolite, 3,5,6-trichloro-2-pyridinol (TCP) using LC/MS. Validation of the model results was tested using the Wilcoxon signed-rank test (WSR) and two-way mixed-model intraclass correlation coefficient (ICC). The mean of total ADD was 20 μg/kg/day while that of total PDD was 22 μg/kg/day. The WSR test revealed no statistically significant difference in the average values of ADD_T and PDD_T. ICC indicated substantial agreement for both single and average measures between ADD_T and PDD_T (ICC, 0.62 and 0.77, respectively). The results demonstrate that a refined WHO-PEAM model can be readily used as a field method, without biological monitoring, to evaluate chlorpyrifos exposure among agricultural farmers in Vietnam and similar developing countries.

Oxidative stress and pesticide disease: a challenge for toxicology

Introducción. En los últimos decenios, la síntesis de compuestos químicos ha producido un alto número de sustancias utilizadas para proteger los cultivos y las cosechas de las plagas. La mayoría de pesticidas han sido usados en grandes cantidades para fines agrícolas y la exposición tóxica a estos compuestos es un problema de gran envergadura para la toxicología, pues tiene impacto en la salud pública por su importante morbilidad y discapacidad. Así, las intoxicaciones agudas y crónicas pueden ser comunes entre trabajadores agrícolas y población general. Estos compuestos desencadenan mecanismos moleculares relacionados con la peroxidación lipídica, donde las especies reactivas de oxigeno pueden incrementar procesos oxidativos intracelulares.Objetivo. Realizar una revisión de la literatura científica relacionada con enfermedades por estrés oxidativo producido por pesticidas.Materiales y métodos. Revisión de artículos que utilizó las palabras clave Estrés oxidativo; Pesticidas; Peroxidación de lípido; Toxicidad. Se eligieron los artículos relacionados con las enfermedades por estrés oxidativo producido por pesticidas.Resultados. Se encontró que algunas enfermedades hematológicas, neurológicas, metabólicas y genotóxicas pueden estar relacionadas con la peroxidación lipídica que producen los pesticidas.Conclusión. Se presenta una revisión de la literatura científica sobre el estrés oxidativo, la peroxidación lipídica inducida por pesticidas y las diferentes enfermedades que pueden afectar a la población en general.

A Framework for Integrating Qualitative and Quantitative Data in Knowledge, Attitude, and Practice Studies: A Case Study of Pesticide Usage in Eastern Uganda

Knowledge, attitude, and practice (KAP) studies guide the implementation of public health interventions (PHIs), and they are important tools for political persuasion. The design and implementation of PHIs assumes a linear KAP relationship, i.e., an awareness campaign results in the desirable societal behavioral change. However, there is no robust framework for testing this relationship before and after PHIs. Here, we use qualitative and quantitative data on pesticide usage to test this linear relationship, identify associated context specific factors as well as assemble a framework that could be used to guide and evaluate PHIs. We used data from a cross-sectional mixed methods study on pesticide usage. Quantitative data were collected using a structured questionnaire from 167 households representing 1,002 individuals. Qualitative data were collected from key informants and focus group discussions. Quantitative and qualitative data analysis was done in R 3.2.0 as well as qualitative thematic analysis, respectively. Our framework shows that a KAP linear relationship only existed for households with a low knowledge score, suggesting that an awareness campaign would only be effective for ~37% of the households. Context specific socioeconomic factors explain why this relationship does not hold for households with high knowledge scores. These findings are essential for developing targeted cost-effective and sustainable interventions on pesticide usage and other PHIs with context specific modifications.

Molecular detection of M. tuberculosis and M. bovis and hematological and biochemical analyses in agricultural sprayers exposed to pesticides: A cross-sectional study in Punjab, Pakistan during 2014-2016

We determined the correlation between a pesticide exposure, physical health and susceptibility toward tuberculosis along with hematological indices and liver enzymes' alterations in sprayers exposed to pesticides. Molecular detection of Mycobacterium tuberculosis and Mycobacterium bovis was detected by targeting histone-like protein (hupB) gene. The WBC (white blood cells) and RBC (red blood cells) levels of male sprayers and non-sprayers were significantly different (P<0.05). In female spray workers, the WBC and neutrophils levels were significantly different as compared with non-sprayers. Overall, in both male and female pesticide-exposed sprayers, mean values of alanine amino transferase and aspartate amino transferase were higher as compared with unexposed workers. M. Tuberculosis were detected in 15% male sprayers and 36% female sprayers while, M. bovis was detected in 5% male sprayers and 10% female sprayers. A χ²-test indicated that there existed a significant different (P<0.05) between positive and negative M. tuberculosis and M. bovis in both male/female spray workers out of total. The susceptibility of pesticide-exposed sprayers to tuberculosis and alterations in hematology and liver enzymes is crucial for health. Toxic effects of pesticides may lead to a weak immune system and increased tuberculosis susceptibility.

Pesticide Knowledge and Safety Practices among Farm Workers in Kuwait: Results of a Survey

The unsafe and indiscriminate use of pesticides in agriculture represents a major hazard to the environment and human health. The aim of this study was to assess the levels of knowledge, attitude and practices of Kuwaiti farmers regarding the safe use of pesticides. A total of 250 farmers participated in this study through in-depth interviews and observations on-farm. The majority of the farmers acknowledged that pesticides were harmful to their health (71%) and the environment (65%). However, farmers’ level of knowledge of pesticide safety is insufficient. Over 70% of the farmers did not read or follow pesticide label instructions, and 58% did not use any personal protective equipment (PPE) when handling pesticides. Educated farmers were significantly more likely to use PPE compared with famers with limited formal education (χ² = 9.89, p < 0.05). Storage of pesticides within living areas was reported by 20% of farmers. When disposing of pesticide wastes, respondents adopted unsafe practices such as discarding, incinerating, or burying empty pesticide containers on-farm, or reusing the containers. Farmers also reported disposing leftover pesticide solution or old pesticide stocks on-farm or in the sewer. A significant number (82%) of the farmers reported at least one symptom of acute pesticide poisoning. Although farmers’ knowledge of pesticide hazards was high, the reported safety measures were poor. Comprehensive intervention measures to reduce the health and environmental risks of pesticides are needed, including pesticide safety training programs for farmers, stringent enforcement of pesticide laws, and promoting integrated pest management and non-synthetic methods of pest control.

Knowledge and Practices Relating to Acute Pesticide Poisoning Among Health Care Providers in Selected Regions of Tanzania

BACKGROUND

Acute pesticide poisoning (APP) is commonly underdiagnosed in Tanzania. Studies in developing countries suggest that a lack of diagnostic skills among health care providers (HCPs) undermines surveillance for APP. This study aimed at characterizing experience and skills of Tanzanian HCPs regarding APP diagnosis and management.

METHODOLOGY

The population included HCPs responsible for managing APP in Kilimanjaro and Arusha regions (n = 91). The resulting sample included 66 respondents (response rate: 73%). The data were collected in 2005 using a standardized questionnaire.

RESULTS

Half of all respondents (50%) reported handling at least 1 APP case with 15% reporting handling more than 5 cases in the past. Reported experience of handling an APP case was marginally higher in respondents who reported ⩾4 years of work experience in the health sector compared with those with <4 years of work experience (odds ratio = 1.32; 95% confidence interval = 0.9-1.5). Most of the respondents had high knowledge of exposure routes, reporting awareness of oral (98.5%), inhalational (93.9%), and dermal (77%) routes. The study revealed low awareness of pesticide classification by chemical groups (29%) or World Health Organization hazard (0%) and weak knowledge on pesticide label instructions (55%). Organophosphates accounted for 35% of the pesticide products reported by respondents as being responsible for poisoning. Some treatment options were incorrectly reported as first aid options, and some reported first aid options were wrong or inappropriate.

CONCLUSIONS

The study revealed that HCPs in northern Tanzania lack adequate skills to diagnose and manage APP. For effective surveillance of APP, there is a need to include training on hazards, classification, diagnosis, and health effects in the training programmes for all HCPs in Tanzania.

Pesticide Practices and Suicide among Farmers of the Sundarban Region in India

Background

Deliberate self-poisoning by ingesting pesticides is a serious health problem among farmers, especially in low- and middle-income countries. Preventing these suicides is a priority for a public mental health agenda.

Objective

To examine the role of pesticide poisoning in suicide and nonfatal deliberate self-harm, and clarify awareness of risks, safe practices concerning storage and use of pesticides, and associated self-injury, both unintentional and intentional, within farmer households of the Sundarban region, India.

Methods

Retrospective record review of adult cases of deliberate self-poisoning at the Block Primary Health Centres of 13 Sundarban Blocks was performed to analyze the relative roles of various methods of self-harm and their lethality. Focus group discussions, questionnaires, and in-depth interviews were undertaken in a community study of farmer households to examine pesticide-related views and practices, with particular attention to storage, use, and health impact.

Results

Pesticide poisoning was the most common method of deliberate self-harm in both men and women. Pesticide storage in most households was unsafe and knowledge was inadequate concerning adverse effects of pesticides on health, crops, and the environment.

Conclusions

An intersectoral approach linking the interests of public health, mental health, and agriculture is well suited to serve the collective interests of all three agendas better than each in isolation. Such an approach is needed to reduce morbidity and mortality from unintentional and intentional self-injury in low-income agricultural communities like those of the Sundarban region.

Pesticide use in the U.S. and policy implications: A focus on herbicides

This article examines herbicide use in the United States, providing estimates of poundage, land surface covered, distribution, and recent trends based on federal and state figures. Herbicides are by far the most widely used class of pesticide in the US, where 556 million lbs of herbicide active ingredients (AIs) were applied in 1995. Agriculture accounts for the majority of herbicide use, totaling 461 million lbs of AIs in 1995. Over 60% of the poundage of all agricultural herbicides consist of those that are capable of disrupting the endocrine and/or reproductive systems of animals. In addition, at least 17 types of `inert ingredients,' which can equal 90% or more of a pesticide product, have been identified as having potential endocrine-disrupting effects. Atrazine is the predominant herbicide used according to poundage, with 68-73 million lbs of AIs applied in 1995. However, 2,4-D is the most widespread herbicide, covering 78 million acres for agricultural uses alone. Both of these herbicides are reported endocrine disruptors. Acetolactate synthase (ALS) inhibitors, namely the sulfonylureas and imidazolinones, are one of the fastest growing classes of herbicides. Many of these herbicides are 100 times more toxic to select plant species than their predecessors, so they can be applied at rates approximately 100 times lower. Consequently, they can affect plant species at concentration levels so low that no standard chemical protocol can detect them. Due in part to these more potent herbicides, the poundage of herbicides used in the US has decreased since the mid-1980s; however, the available data suggest that the number of treated acres has not significantly declined. A thorough assessment of potential exposure to herbicides by wildlife and humans is limited due to the inaccessibility of production and usage data.

Simultaneous determination of individual isothiocyanates in plant samples by HPLC-DAD-MS following SPE and derivatization with N-acetyl-l-cysteine

The procedure for the isothiocyanates (ITCs) determination that involves derivatization with N-acetyl-l-cysteine (NAC) and separation by HPLC was developed. Prior to derivatization, plant ITCs were isolated and purified using solid-phase extraction (SPE). The optimum conditions of derivatization are: 500μL of isopropanolic eluate obtained by SPE combined with 500μL of derivatizing reagent (0.2M NAC and 0.2M NaHCO3 in water) and reaction time of 1h at 50°C. The formed dithiocarbamates are directly analyzed by HPLC coupled with diode array detector and mass spectrometer if required. The method was validated for nine common natural ITCs. Calibration curves were linear (R(2)⩾0.991) within a wide range of concentrations and limits of detection were below 4.9nmol/mL. The recoveries were in the range of 83.3-103.7%, with relative standard deviations <5.4%. The developed method has been successfully applied to determine ITCs in broccoli, white cabbage, garden cress, radish, horseradish and papaya.

Chemical Pesticides and Human Health: The Urgent Need for a New Concept in Agriculture

The industrialization of the agricultural sector has increased the chemical burden on natural ecosystems. Pesticides are agrochemicals used in agricultural lands, public health programs, and urban green areas in order to protect plants and humans from various diseases. However, due to their known ability to cause a large number of negative health and environmental effects, their side effects can be an important environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, among them agriculture reforms and food production implementing sustainable practice evolving to food sovereignty. It is more obvious than ever that the society needs the implementation of a new agricultural concept regarding food production, which is safer for man and the environment, and to this end, steps such as the declaration of Nyéléni have been taken.

Chemical Pesticides and Human Health: The Urgent Need for a New Concept in Agriculture

The industrialization of the agricultural sector has increased the chemical burden on natural ecosystems. Pesticides are agrochemicals used in agricultural lands, public health programs, and urban green areas in order to protect plants and humans from various diseases. However, due to their known ability to cause a large number of negative health and environmental effects, their side effects can be an important environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, among them agriculture reforms and food production implementing sustainable practice evolving to food sovereignty. It is more obvious than ever that the society needs the implementation of a new agricultural concept regarding food production, which is safer for man and the environment, and to this end, steps such as the declaration of Nyéléni have been taken.

Occupational pesticide exposure and adverse health effects at the clinical, hematological and biochemical level

AIMS

Although epidemiological studies have investigated associations between occupational pesticide exposures and different adverse health outcomes, they have rarely assessed individuals at two time-points of a same crop season with different pesticide use.

MATERIAL AND METHODS

Clinical symptoms, physical examination signs, hematological and clinical chemistry parameters were measured in 189 intensive agriculture workers and 91 healthy control subjects from Almeria coastline (Southeastern Spain) to evaluate potential effects of pesticide exposure.

KEY FINDINGS

Greenhouse workers showed an increased risk of ocular and skin signs relative to controls at the period of high pesticide exposure (OR: 4.80 and 2.87, respectively); however, no differences were observed for clinical symptoms. A greater risk for ECG changes (OR: 3.35) and altered spirometry (OR: 5.02) was found at the period of low exposure. Erythrocyte acetylcholinesterase was significantly decreased in greenhouse workers relative to controls in both periods. Assessment of hematological parameters revealed increased counts of erythrocytes, leukocytes, platelets and hemoglobin in greenhouse workers relative to controls, and also in the period of high versus low pesticide exposure. Changes in clinical chemistry parameters included decreased levels of glucose, creatinine, total cholesterol, triglyceride and alkaline phosphatase in greenhouse workers relative to controls; however, these parameters were raised in the period of high versus low pesticide exposure.

SIGNIFICANCE

These findings suggest that chronic occupational exposure to pesticides of lower toxicity than former compounds under integrated production systems elicit mild toxic effects, particularly targeting the skin and eyes, as well as subtle subclinical (biochemical) changes of unknown long-term consequences.

Food sovereignty, food security and health equity: a meta-narrative mapping exercise

There has been growing policy interest in social justice issues related to both health and food. We sought to understand the state of knowledge on relationships between health equity--i.e. health inequalities that are socially produced--and food systems, where the concepts of 'food security' and 'food sovereignty' are prominent. We undertook exploratory scoping and mapping stages of a 'meta-narrative synthesis' on pathways from global food systems to health equity outcomes. The review was oriented by a conceptual framework delineating eight pathways to health (in)equity through the food system: 1--Multi-Scalar Environmental, Social Context; 2--Occupational Exposures; 3--Environmental Change; 4--Traditional Livelihoods, Cultural Continuity; 5--Intake of Contaminants; 6--Nutrition; 7--Social Determinants of Health and 8--Political, Economic and Regulatory context. The terms 'food security' and 'food sovereignty' were, respectively, paired with a series of health equity-related terms. Combinations of health equity and food security (1414 citations) greatly outnumbered pairings with food sovereignty (18 citations). Prominent crosscutting themes that were observed included climate change, biotechnology, gender, racialization, indigeneity, poverty, citizenship and HIV as well as institutional barriers to reducing health inequities in the food system. The literature indicates that food sovereignty-based approaches to health in specific contexts, such as advancing healthy school food systems, promoting soil fertility, gender equity and nutrition, and addressing structural racism, can complement the longer-term socio-political restructuring processes that health equity requires. Our conceptual model offers a useful starting point for identifying interventions with strong potential to promote health equity. A research agenda to explore project-based interventions in the food system along these pathways can support the identification of ways to strengthen both food sovereignty and health equity.

Oxidative stress biomarkers and paraoxonase 1 polymorphism frequency in farmers occupationally exposed to pesticides

Previous evidence has demonstrated that chemical classes of pesticides, including organophosphates (OP), can induce oxidative stress in exposed workers. The resulting increase in free radicals causes damage to biological macromolecules, and promotes the formation of novel compounds, including advanced glycation end products (AGE) and advanced oxidation protein products (AOPP). The present study aimed to evaluate the common genetic polymorphisms of the paraoxonase 1 (PON1) gene in a group of 55 farmers exposed to pesticides, as well as the association between these polymorphisms and serum levels of AGE and AOPP. The 192Q wild‑type (WT) allele was present at a significantly higher frequency, compared with the 192R mutated allele (0.74 and 0.26, respectively). The WT allele was predominantly represented by the homozygote 192QQ genotype (51%). The mutated 192QR heterozygotic allele was prevalent, at a frequency of 45.4%, whereas the mutated homozygotes were present at a frequency of 3.6%. A significant decrease in the levels of AGE and AOPP was observed in farmers exhibiting the homozygotic 192RR mutated genotype (14,7221 AU/ml and 0.64 nmol/ml, respectively), compared with the WT genotype (16,1400 AU/ml and 1.76 nmol/ml, respectively), and 192QR genotype (15,2312 AU/ml and 1.60 nmol/ml, respectively). Therefore, due to the high catalytic activity of PON1, the 192RR genotype provides an important genetic predictor of the toxic effects associated with OP pesticide exposure. It determines a minor risk of developing oxidative damage following pesticide exposure, and measuring the levels of AOPP may provide a novel biomarker for oxidative damage in subjects exposed to OP.

Antagonistic Activities of Bacillus spp. Strains Isolated from Tidal Flat Sediment Towards Anthracnose Pathogens Colletotrichum acutatum and C. gloeosporioides in South Korea

Anthracnose is a fungal disease caused by Colletotrichum species that is detrimental to numerous plant species. Anthracnose control with fungicides has both human health and environmental safety implications. Despite increasing public concerns, fungicide use will continue in the absence of viable alternatives. There have been relatively less efforts to search antagonistic bacteria from mudflats harboring microbial diversity. A total of 420 bacterial strains were isolated from mudflats near the western sea of South Korea. Five bacterial strains, LB01, LB14, HM03, HM17, and LB15, were characterized as having antifungal properties in the presence of C. acutatum and C. gloeosporioides. The three Bacillus atrophaeus strains, LB14, HM03, and HM17, produced large quantities of chitinase and protease enzymes, whereas the B. amyloliquefaciens strain LB01 produced protease and cellulase enzymes. Two important antagonistic traits, siderophore production and solubilization of insoluble phosphate, were observed in the three B. atrophaeus strains. Analyses of disease suppression revealed that LB14 was most effective for suppressing the incidence of anthracnose symptoms on pepper fruits. LB14 produced antagonistic compounds and suppressed conidial germination of C. acutatum and C. gloeosporioides. The results from the present study will provide a basis for developing a reliable alternative to fungicides for anthracnose control.

Children's health in Latin America: the influence of environmental exposures

BACKGROUND

Chronic diseases are increasing among children in Latin America.

OBJECTIVE AND METHODS

To examine environmental risk factors for chronic disease in Latin American children and to develop a strategic initiative for control of these exposures, the World Health Organization (WHO) including the Pan American Health Organization (PAHO), the Collegium Ramazzini, and Latin American scientists reviewed regional and relevant global data.

RESULTS

Industrial development and urbanization are proceeding rapidly in Latin America, and environmental pollution has become widespread. Environmental threats to children's health include traditional hazards such as indoor air pollution and drinking-water contamination; the newer hazards of urban air pollution; toxic chemicals such as lead, asbestos, mercury, arsenic, and pesticides; hazardous and electronic waste; and climate change. The mix of traditional and modern hazards varies greatly across and within countries reflecting industrialization, urbanization, and socioeconomic forces.

CONCLUSIONS

To control environmental threats to children's health in Latin America, WHO, including PAHO, will focus on the most highly prevalent and serious hazards-indoor and outdoor air pollution, water pollution, and toxic chemicals. Strategies for controlling these hazards include developing tracking data on regional trends in children's environmental health (CEH), building a network of Collaborating Centres, promoting biomedical research in CEH, building regional capacity, supporting development of evidence-based prevention policies, studying the economic costs of chronic diseases in children, and developing platforms for dialogue with relevant stakeholders.

Farmer and retailer knowledge and awareness of the risks from pesticide use: a case study in the Wei River catchment, China

Monitoring the educational level of farmers and retailers on pesticide use would be useful to assess the appropriateness of information for reducing or/and avoiding the risks from pesticides in rural regions. The levels of knowledge and awareness of the dangers to the environment and human health were investigated by questionnaires for farmers (209) and retailers (20) in two rural regions (Qianyang County (S1) and Chencang County (S2)) of the Wei River catchment in China where the modes of farming and the state of erosion are very different. The results showed that farmers learned the use and dangers of pesticides mainly by oral communication (p<0.01). Protective measures were inadequate; 65% (S1) and 55% (S2) of farmers never used any protective measures during spraying (p<0.05). Washing hands (>70%) was the most common mode of personal hygiene, relative to wearing masks, showering, and changing clothes, but no significant differences were observed between the selected regions. Most pesticide wastes were dumped directly onto the land or into water, suggesting that educational measures should be taken to address the potential risks from the residues in the wastes. Over 85% of farmers (S1 and S2) claimed to use illegal pesticides, but the reasons for their use varied (p<0.01). Retailers were well-informed and highly conscious of their responsibility for the safe use of pesticides, especially in S2 (p<0.01). A canonical correspondence analysis indicated that educational level and age differed between the two regions and contributed greatly to the risks from pesticide use (p<0.01). Educational programmes targeted to age groups, proper disposal of pesticide waste, and sufficient supervision from authorities should consequently be considered for improving the levels of knowledge and awareness of the dangers of pesticides to human health and environmental pollution in the Wei River catchment, China.

Pesticide use practices in rural Armenia

Pesticide use can have adverse effects on both human health and the environment. Inappropriate use of pesticides increases the health risk to those who work with or live around pesticides. Educational programs for agricultural workers on the proper use of pesticides and personal protective equipment coupled with pesticide regulations are important tools to reduce the associated health risks. The authors conducted a survey (N = 2336) on pesticide use practices in the Ararat Valley of Armenia in 2000-2006. This study was a cross-sectional design. A multistage sampling method was implemented in the selection of the study population. The authors developed a questionnaire containing 173 questions to evaluate demographic characteristics, health conditions, and details of pesticides use practices. The intensity of pesticide use was high; 82.8% of respondents used them. More than 150 brand names of pesticides were in use. Unregistered, obsolete, expired, and banned compounds were found in active use. Poor compliance with the basic rules of pesticide safety was found throughout the study population, with 21.3% using gloves and only 11% using respirators. The agricultural workers' knowledge of the toxic properties of these pesticides as well as basic hygienic norms was very low. In some instances, the number of agrichemical applications to crops, particularly cucumbers and melons, reached 40 applications during the growing season. Better protection and training of pesticide users in Armenia is needed.

Mishandling and exposure of farm workers in Qatar to organophosphate pesticides

We used a combination of subjective (questionnaire) and objective (urinary metabolites) measurements to evaluate factors that can predict the exposure of farm workers in Qatar to organophosphate pesticides and to assess whether the levels of exposure are associated with any self-reported health outcomes. The results show that pesticides were being extensively mishandled in the farms. Very few (<2%) of the farm workers knew the names of the pesticide they were using, and about one-third of the participants did not know the amount of pesticides to be applied to the crops. Nearly all (96%) of the participants had participated in mixing pesticides together before use and few (29%) used protective clothing while engaged in this operation. A significant number of participants (18%) had no knowledge that pesticides are a health hazard. At least one dialkyllphosphate (DAP) metabolite was detected in every worker. The geometric mean (GM) concentration of the dimethylalkylphosphates (DMAP) was 108 nM (range, from below the limit of detection (LOD) to 351 nM), and the GM for the diethylalkylphosphates (DEAP) was 43 nM (range, LOD-180 nM). The GM for total concentration of the metabolites (DAP) of 146 nM (maximum value estimated to be 531 nM) is below the values that have been reported for farmers in some countries, but higher than the levels in the general populations of many countries. We explored the influence of metal exposure and found consistent and negative relationships between the DAP metabolites and the concentrations of most of the trace elements in the urine of the farm workers; the negative associations were statistically significant for Cr, Mn, Fe, Ni, As, and Pb. We suspect that the negative associations are not source-dependent but may be reflective of antagonistic relationships in human metabolism of OPPs and trace metals; hence we recommend that metals should be included as co-factors in assessing the health effects of OPP exposure.

Knowledge attitude and practice of pesticide use among agricultural workers in Puducherry, South India

OBJECTIVES

To study the level of knowledge and practice related to pesticides and their adverse effects among agricultural workers.

MATERIALS AND METHODS

A cross sectional study among 100 randomly selected agricultural workers, using or ever used pesticide within last one year was conducted in Puducherry, South India. The questionnaire was adapted from WHO field surveys of 'Exposure to Pesticides Standard Protocol' and similar studies. Data were collected by face to face interview.

RESULTS

All the participants were male with mean age of 54.3 yrs. While 70% of respondents perceived pesticide spraying affects a person's health, only 40% were aware that it affects the environment. Two thirds of the respondents (62%) were aware that pesticide enters the body through nose and affects lungs. Awareness on other modes of entry was less. Majority (76%) of them was aware of training programs conducted by government agriculture department on pest management. About 42% of farmers had good knowledge regarding pesticide. Between 40% and 70% of respondents were not using any protective equipments during pesticide spraying. Around 68% of farmers indiscriminately disposed empty containers while 48% buried the leftover pesticides. Significant association (p < 0.05) was observed between knowledge of the farmers and their practices related to pesticides.

CONCLUSION

Overall awareness of agricultural workers on pesticide was inadequate. Improper disposal of pesticides and its container can produce harm to the environment. The findings of the study emphasize the need to educate agricultural workers regarding safe and adequate use of pesticides to prevent health and environmental hazards.

Adverse respiratory health and hematological alterations among agricultural workers occupationally exposed to organophosphate pesticides: a cross-sectional study in North India

BACKGROUND

Non-protective work practices followed by farm workers during spraying of pesticides lead to occupational exposure among them.

OBJECTIVE

This study is designed to explore the respiratory health and hematological profile of agricultural workers occupationally exposed to OP pesticides.

MATERIALS AND METHODS

A cross sectional study was undertaken among 166 pesticide sprayers working in mango orchards of Lucknow district in North India compared with 77 controls to assess the respiratory illness, lung functions, cholinesterase levels and hematological profile. A questionnaire based survey and clinical examination for respiratory health were conducted among study subjects. Lung function test was conducted among study subjects by using spirometer. Cholinesterase level as biomarker of OP pesticides and hematological profile of study subjects were investigated in the laboratory by following the standard protocols.

RESULTS

Overall respiratory morbidity observed among exposed subjects was 36.75%. Symptoms for respiratory illness like dry cough, productive cough, wheezing, irritation of throat and blood stained sputum were found to be significantly more (p<0.05) among pesticide sprayers than controls. Lung function parameters viz. PEFR, FEV1, %PEFR predicted, %FEV1 predicted and FEV1/FVC were found to be significantly decreased (p<0.05) among pesticide sprayers as compared to controls. Exposure wise distribution of respiratory illness and lung functions among pesticide sprayers show that the exposure duration significantly elevates (p<0.05) the respiratory problems and significantly decreases (p<0.001) lung functions among pesticide sprayers. Activities of acetylcholinesterase and butyrylcholinesterase were found to be significantly depleted (p<0.001) among pesticide sprayers as compared to controls which show the exposure of OP pesticides among them. The hematological profile viz. RBC, WBC, monocytes, neutrophils, MCV, MCH, MCHC and platelet count were significantly altered (p<0.001) in pesticide sprayers than controls.

CONCLUSION

This study shows that the unsafe occupational exposure of OP pesticides causes respiratory illness, decreased lung functions and hematological alterations among pesticide sprayers.

Oxidative stress, hematological and biochemical alterations in farmers exposed to pesticides

In this study, a cohort of farmers from the Mateur region in the North of Tunisia, were interviewed and examined for the biochemical effects of pesticides. We studied their haematological profile, lipid parameters, serum markers of nephrotoxicity and hepatotoxicity. We also evaluated the activities of Butyrylcholinesterase (BChE), Acetylcholinesterase (AChE) and thiolactonase-paroxonase (PON). Moreover, lipid peroxidation and activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were determined. The duration of pesticide use and the farmers' age were considered in the analysis. Our results revealed significant differences in some haematological parameters, in liver and kidney functions, in the lipidic status of the pesticide-exposed group. We also reported an increase in the index of incidence of cardiovascular risk in farmer populations. A significant decrease in AChE, BChE and PON levels was found among farmers. Lipid peroxidation, however, increased. The activities of SOD and CAT were remarkably elevated in farmer populations. There was a significant relation between changes in biological markers, the duration of pesticide use and the farmers' age. This study indicates that a long-term exposure to pesticides may play an important role in the development of vascular diseases via metabolic disorders of lipoproteins, lipid peroxidation and oxidative stress, inhibition of BChE and decrease in thiolactonase-PON levels.

Effect of agropesticides use on male reproductive function: a study on farmers in Djutitsa (Cameroon)

This study aimed at investigating the effect of agropesticides on male reproductive function in farmers in Djutitsa (West Cameroon). To this end, 47 farmers in Djutitsa were asked questions on their health status and pesticide use in agriculture. Thereafter, their blood samples were collected for assessment of sex hormones including serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), androstenedione, testosterone, as well as sex hormone binding globulin (SHBG). Their serum triiodothyronine (T3) and thyroxine (T4) levels were also measured. Thirty seven men not exposed to agropesticides were recruited as control group. Fifty six pesticides containing 25 active substances were currently used by farmers enrolled in our study, and most of their symptoms were related to spread/use of these chemicals. Compared to the control group, there was no significant difference in FSH, LH, SHBG, estradiol, and thyroid hormones (T3 and T4) levels. Farmers had significantly lower serum testosterone (20.93 ± 1.03 nM vs. 24.32 ± 1.32 nM; P < 0.05) and higher androstenedione level (3.83 ± 0.20 nM vs. 2.80 ± 0.15 nM; P < 0.001). Their serum free testosterone as well as bioavailable testosterone were unchanged, while estradiol/testosterone and androstenedione/testosterone ratios were significantly increased (0.45 ± 0.03% vs. 0.33 ± 0.02%; P < 0.01 and 12.26 ± 3.64 vs 19.31 ± 6.82; P < 0.001, respectively). Our results suggest that male farmers of Djutitsa (West Cameroon) are exposed to agropesticides due to improper protective tool, and this exposure may impair their reproductive function through inhibition of testosterone synthesis; probably by inhibition of testicular 17β- hydroxysteroid dehydrogenase (17HSD3) and induction of aromatase (CYP19).

Spatial distribution of diuron sorption affinity as affected by soil, terrain and management practices in an intensively managed apple orchard

We investigated how the sorption affinity of diuron (3'-(3,4-dichlorophenyl)-1,1-dimenthyl-urea), a moderately hydrophobic herbicide, is affected by soil properties, topography and management practices in an intensively managed orchard system. Soil-landscape analysis was carried out in an apple orchard which had a strong texture contrast soil and a landform with relief difference of 50 m. Diuron sorption (K(d)) affinity was successfully predicted (R(2)=0.79; p<0.001) using a mid-infrared - partial least squares model and calibrated against measured data using a conventional batch sorption technique. Soil and terrain properties explained 75% of the variance of diuron K(d) with TOC, pH(w), slope and WI as key variables. Mean diuron K(d) values were also significantly different (p<0.05) between alley and tree line and between the different management zones. Soil in the tree line generally had lower sorption capacity for diuron than soil in the alleys. Younger stands, which were found to have lower TOC than in the older stands, also had lower diuron K(d) values. In intensively managed orchards, sorption affinity of pesticides to soils was not only affected by soil properties and terrain attributes but also by management regime.

Effects of a provincial ban of two toxic organophosphorus insecticides on pesticide poisoning hospital admissions

Background.

Pesticide self-poisoning causes one third of global suicides. Sri Lanka halved its suicide rate by banning WHO Class I organophosphorus (OP) insecticides and then endosulfan. However, poisoning with Class II toxicity OPs, particularly dimethoate and fenthion, remains a problem. We aimed to determine the effect and feasibility of a ban of the two insecticides in one Sri Lankan district.

Methods.

Sale was banned in June 2003 in most of Polonnaruwa District, but not Anuradhapura District. Admissions with pesticide poisoning to the district general hospitals was prospectively recorded from 2002.

Results.

Hospital admissions for dimethoate and fenthion poisoning fell by 43% after the ban in Polonnaruwa, while increasing by 23% in Anuradhapura. The pesticide case fatality fell from 14.4% to 9.0% in Polonnaruwa (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.41–0.84) and 11.3% to 10.6% in Anuradhapura (OR 0.93, 95%CI 0.70–1.25; p = 0.051). This reduction was not sustained, with case fatality in Polonnaruwa rising to 12.1% in 2006–2007. Further data analysis indicated that the fall in case fatality had actually been due to a coincidental reduction in case fatality for pesticide poisoning overall, in particular for paraquat poisoning.

Conclusions.

We found that the insecticides could be effectively banned from agricultural practice, as shown by the fall in hospital admissions, with few negative consequences. However, the ban had only a minor effect on pesticide poisoning deaths because it was too narrow. A study assessing the agricultural and health effects of a more comprehensive ban of highly toxic pesticides is necessary to determine the balance between increased costs of agriculture and reduced health care costs and fewer deaths.

Peasant association member's knowledge, attitudes, and practices towards safe use of pesticide management

BACKGROUND

Farmers in the developing world are at risk of pesticide exposure, particularly in low-income countries with a sizable agricultural sector like Ethiopia. The present investigation provides baseline data to develop strategies for the control of pesticide exposure and the prevention of pesticide poisoning.

METHODS

A questionnaire survey of a stratified random sample of peasant farmers belonging to peasant associations was conducted.

RESULTS

Most surveyed farmers sprayed pesticides without any personal protective equipment. The majority of participants reported using empty pesticide containers for drinking and food storage. Twenty percent of farmers applied pesticides by sweeping with plant leaves in a hazardous manner.

CONCLUSIONS

Ethiopian peasant farmers appeared to have limited knowledge of the hazards of pesticides and generally did not handle pesticides in a safe manner. Active health education campaigns and appropriate training programs should be instigated to promote safe use of pesticides.

Clinical parameters and biomarkers of oxidative stress in agricultural workers who applied copper-based pesticides

Copper based-pesticides are widely used in agricultural practice throughout the world. We studied the (i) concentration of Cu and proteins involved in Cu homeostasis, (ii) plasma redox status, and (iii) biomarkers of exposure in Cu-based pesticide applicators in order to compare them with clinical biochemical tests. Thirty-one professional applicators and 32 control subjects were recruited. Oxidative stress biomarkers, ceruloplasmin (CRP), metallothioneins (MTs), copper, hematological parameters, and biochemical markers for pancreatic, hepatic and renal function were measured in plasma. Copper was increased in the exposed group compared to the control group concomitantly with TBARS, protein carbonyls, and nitrate+nitrite levels. In the exposed group, α-tocopherol and the FRAP assay were lower and LDH, transaminases, GGT, ALP, urea, creatinine, CRP and MTs were higher than in the control group. The relative leukocyte subclasses were also different between the two groups. Clinical chemistry tests did not surpass the upper reference limit. Our results suggest that the incorporation of oxidative stress biomarkers to biochemical/clinical tests should be considered for validation and included in the human health surveillance protocols.

Monitoring of plasma butyrylcholinesterase activity and hematological parameters in pesticide sprayers

To evaluate the health impact of spraying organophosphorus insecticides (OPs), 34 male sprayers in the mango belt of Malihabad, a small town located 27 km from Lucknow in North India was selected. Plasma butyryl cholinesterase (PBChE) and complete blood count were assessed among sprayers after spraying pesticides and the findings obtained were compared with those determined in a reference group (n = 18). The most common symptoms observed were burning sensation in the eyes (8.82%), itching/skin irritation (23.52%) and chest symptoms (32.35%) in the exposed workers. Plasma butyrylcholinesterase (PBChE) was significantly decreased in workers. The results indicated significant decrease in the mean value of hemoglobin, hematocrit and platelets count; however, significantly higher count of leukocytes was also observed in the exposed group (sprayers) compared to that observed in the control group (P < 0.05). Monitoring of PBChE in pesticide sprayers could be useful to predict and prevent health hazards of OPs.

Pesticide Use and Self-Reported Symptoms of Acute Pesticide Poisoning among Aquatic Farmers in Phnom Penh, Cambodia

Organophosphates and carbamates (OPs/CMs) are known for their acetylcholinesterase inhibiting character. A cross-sectional study of pesticide handling practices and self-perceived symptoms of acute pesticide poisoning was conducted using questionnaire-based interviews with 89 pesticide sprayers in Boeung Cheung Ek (BCE) Lake, Phnom Penh, Cambodia. The study showed that 50% of the pesticides used belonged to WHO class I + II and personal protection among the farmers were inadequate. A majority of the farmers (88%) had experienced symptoms of acute pesticide poisoning, and this was significantly associated with the number of hours spent spraying with OPs/CMs (OR = 1.14, CI 95%: 1.02-1.28). The higher educated farmers reduced their risk of poisoning by 55% for each extra personal protective measure they adapted (OR = 0.45, CI 95%: 0.22-0.91). These findings suggest that improving safe pesticide management practices among the farmers and enforcing the effective banning of the most toxic pesticides will considerably reduce the number of acute pesticide poisoning episodes.

Monitoring health implications of pesticide exposure in factory workers in Pakistan

The study aimed to determine the hazardous health effects of pesticides exposure in the factory workers by measuring plasma cholinesterase (PChE), pesticides residues, and renal and hepatic biochemical markers. In addition, we also assessed the knowledge, attitudes, and safety practices adopted by the industrial workers. The study was conducted in three different sizes of factories located in Lahore (large), Multan (medium), and Karachi (small) in Pakistan. Total 238 adult males consisting of 184 pesticide industrial workers (exposed group) from large-sized (67), medium-sized (61), small-sized (56) industrial formulation factories, and 54 controls (unexposed) were included in the study. All the participants were male of aged 18 to 58 years. PChE levels were estimated by Ellmann's method. Plasma pesticides residue analysis was performed by using reverse phase C-18 on high-performance liquid chromatograph and GC with NPD detector. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, urea, and gamma glutamyltransferase (GGT) were measured on Selectra E auto analyzer. Plasma and C-reactive protein was analyzed by Immulite 1000. The results revealed a significant decrease in plasma post exposure PChE levels (<30%) as compared to baseline in the workers of small (29%) and medium (8%) industrial units (p < 0.001). Plasma cypermethrin, endosulfan, imidacloprid, thiodicarb, carbofuran, and methamidophos levels were found to be higher than allowable daily intake. Serum AST, ALT, creatinine GGT, malondialdehyde, total antioxidant, and CRP were significantly raised among the workers of small and medium pesticide formulation factories as compared to large industrial unit and controls (p < 0.001). The study demonstrated that unsafe practices among small- and medium-sized pesticides industrial workers cause significant increase in pesticide exposure, oxidative stress, and derangement of hepatic and renal function.

Knowledge and practices of pesticide use among farm workers in the West Bank, Palestine: safety implications

OBJECTIVES

The objectives of this study were to assess the knowledge and practices associated with pesticide use in an agricultural community in Palestine, and to determine the prevalence of self-reported health symptoms related to pesticide exposure.

METHODS

In this cross-sectional questionnaire study, agricultural farm workers in Nablus district, Palestine, were interviewed on their knowledge and practices of pesticide use. Comparisons of knowledge and practices of pesticide use between various groups were performed using the Mann-Whitney U-test or the Kruskal-Wallis rank test of variance. The program of the Statistical Package for Social Sciences (SPSS) version 15 was used for data analysis.

RESULTS

The questionnaire was completed by 381 farm workers. The mean age ± SD of the participants was 38.8 ± 11.8 years. The majority (97.9%) of the participants were male. The mean participant scores for knowledge and safety procedures were 2.8 ± 3.2 out of 8 and 9.8 ± 2.4 out of 15, respectively. There was a significant positive correlation (r = 0.323; P < 0.001) between the knowledge and safety procedure scores. Unsafe behaviors were identified as the storage of pesticide products at home, the preparation of pesticides in the kitchen, inadequate disposal of empty pesticide containers, eating and drinking during pesticide application, and using inadequate protective clothing. The most frequent self-reported toxicity symptoms associated with pesticide use were skin rash (37.5%), headache (37%), excessive sweating (24.9%), and diarrhea (21.3%). There was a strong significant negative correlation (r = -0.83; P < 0.001) between self-reported toxicity symptoms and scores for protective measures.

CONCLUSION

The results of this study indicate that most farm workers in this district need more educational programs regarding the safety and use of pesticides. Legislation promoting the use of safer pesticides is also needed.

Reducing the incidence of acute pesticide poisoning by educating farmers on integrated pest management in South India

Sixty-five farmers reported on pesticide use and the signs and symptoms of acute pesticide poisoning when using two different plant protection strategies: in 2003 using chemical controls and in 2004 using an approach to Integrated Pest Management (IPM) based on an ecological analysis of the field conditions. Exposure to organophosphates was confirmed as a serious risk factor for occupational poisoning. The adoption of IPM reduced the use of pesticides and halved the incidence of acute pesticide poisoning. Overall, the pesticide use spectrum shifted towards lower WHO Hazard Classes. A reduction of adverse health effects was attained through a reduction in exposure to toxic pesticides and behavioural changes. Given that other strategies to reduce the rate of acute poisoning have proven ineffective, interventions aiming to minimize pesticide poisoning in India and in other developing countries with similar rural conditions should focus on restricting the use of highly toxic compounds and educating farmers on IPM.