Pesticide Use and Self-Reported Health Symptoms Among Rice Farmers in Zanzibar

Understanding determinants related to farmers' protective measures towards pesticide exposure: A systematic review

OBJECTIVE

Pesticide poisoning is the main cause of adverse effects and mortality worldwide. Protective measures can reduce the intensity of the effects of pesticides on the health of farmers. Numerous cross-sectional studies have been conducted on the determinants of performing protective measures to reduce exposure to pesticides, but there is no systematic study that comprehensively examines the impact of these factors. Therefore, the aim of this study is to identify existing studies on the determinants of effective protective measures to reduce exposure to pesticides among farmers.

METHODS

In this systematic review, studies were obtained from PubMed, Web of Science and Scopus databases using a search strategy that covered articles from the first years of database design to April 20, 2023. The inclusion and exclusion criteria were based on the PICOs criteria. The study included cross-sectional studies that measured the implementation of protective measures using objective or valid subjective tools. The data were extracted and analyzed based on several criteria and ecological levels. The Ecological Model of Health Behavior was used to classify the determinants that affect the performance of protective behaviors. The National Heart, Lung and Blood Institute (NHLBI) has developed a quality assessment tool for studies.

RESULTS

A total of 39 studies were ultimately selected for inclusion in this analysis. Many of these studies were conducted in developing countries. The most important factors that have an impact on protective measures include a variety of socio-demographic characteristics (age, gender, level of education, income, farming experience, experience of using pesticides), individual level (knowledge, attitude, risk perception, intention), interpersonal level (subjective norms), organizational level (education), and public policy level (government attention, health costs, governmental extension services). The quality of most studies was fair.

CONCLUSIONS

Research indicates that several factors influence the use of personal protective equipment and safe behaviors when handling pesticides. These include farmers' education level, knowledge, and attitudes towards safety measures. Environmental factors such as access to information, extension services, training programs, and media coverage can also help minimize exposure to pesticides.

Knowledge and practices of commercial banana farmers related to pesticide use in Chitwan district, Nepal; a cross-sectional study and meta-analyses

The exposure of farmers to pesticides due to inadequate safety measures is a concern in low-income countries in Africa and Asia. However, until now, there have been limited studies on the farmers' risk due to pesticide application to fruit crops. The knowledge of farmers' exposure related to pesticide use and their safety practices was studied among 100 banana farmers in three areas (Padampur, Jagatpur, and Thimura) of Chitwan district, Nepal. More than 75% of the farmers complained about problems related to insects. Most frequently used insecticides in the area were chlorpyrifos and cypermethrin. Ten percent (10%) of the applied pesticides were highly hazardous to humans, according to the World Health Organization hazard category, with skin rash being the most common acute symptom reported by 29% of the farmers. Banned organochlorine and organophosphate insecticides, such as endosulfan and triazophos, respectively, are still being used by farmers in the aforementioned areas. Spearman's correlation analysis revealed the lack of knowledge and safety practices among farmers leading to inadequate awareness related to the negative effects of pesticide use on human health and the environment. Therefore, government extension service can play a crucial role in improving banana farmers' knowledge of the toxic effects of pesticides as well as enforcing the Nepali language in the labeling of pesticide containers and packages.

Research on knowledge construction and analysis of pesticide exposure to children based on bibliometrics

Pesticide exposure is a major health problem that cannot be ignored, and children are particularly vulnerable and sensitive. As a result, the study of health damage in children caused by pesticide exposure has gradually developed into an important cross-disciplinary research topic. In this study, we reviewed the current state, characteristics, and trends of existing research findings and summarized them comprehensively and systematically through bibliometrics. We collected and examined a large number of studies using Citespace and Vosviewer, employing a clustering method to analyze the effects of pesticide exposure on children and to highlight the hot keywords in the research field. Through an analysis of the active time of high-frequency keywords, we found that the research field is in a hot spot, and the occurrence value of keywords was used to judge the innovation of the research results, thereby highlighting the frontier and key directions of future research in this field. We conclude that in addition to core pesticides, children, exposure, and other malaria and polychlorinated biphenyls also appear as high-frequency keywords in the research field of pesticide exposure effects on children. The core issues of concern in this field include occupational pesticide exposure and childhood leukemia, history of pesticide exposure during pregnancy and childhood leukemia, environmental factors and dietary intake and organophosphorus pesticide exposure in children, and pyrethroid pesticide exposure and neurobehavioral development in children. Future research may focus on how to control the safe use of pesticides, quantitative research on pesticide hazards, and potential effects on children's health.

Health problems in agricultural workers occupationally exposed to pesticides

Agricultural workers are susceptible to several health problems as a result of occupational exposure to toxic substances, especially pesticides. The aim of this review was to describe the health issues associated with occupational exposure to pesticides in agricultural workers. A descriptive study, in the form of an integrative literature review, was conducted based on articles retrieved from the LILACS, SciELO and PubMed databases, published between January 2015 and October 2018. The searches were conducted using the keywords "pesticides," "workers' health," "occupational exposure" and "agricultural workers." The study was guided by the following research question: what health problems do agricultural workers experience as a result of occupational exposure to pesticides? The screening process led to the selection of 35 studies performed in several countries and continents, all of which shed light on the vulnerability of agricultural workers, especially due to the misuse of personal protective equipment and lack of knowledge about the correct use of these devices. The studies investigated a variety of health issues, and most reported a positive association between these conditions, which include cancer, and the use of pesticides. Educational and preventive measures must be implemented to promote the health of rural workers. Furthermore, it is crucial that governments play an active role in these initiatives and provide alternatives to pesticides for pest control.

Occupational exposure to pesticides and health symptoms among family farmers in Brazil

OBJECTIVE:

To explore the association of occupational pesticide exposure with acute and mental health symptoms.

METHODS:

Cross-sectional survey carried out with 78 Brazilian family farmers, who were pesticide applicators and helpers conveniently selected. Symptoms and exposure data were collected by interviews, and mental health outcomes by the Self-Reporting Questionnaire. Blood samples were analyzed to assess cholinesterase levels. Exposure indicators and symptoms were compared between applicators and helpers, and Poisson regression was performed to estimate prevalence ratios.

RESULTS:

Farmers reported exposure to multiple pesticides from early ages; they worked without safety training, technical support, and full protective equipment, and they had a high prevalence of acute and mental health symptoms (e.g., headache, mucosal irritation, tachycardia, and depressive signs). Applicators had more cholinesterase changes than helpers, but less symptoms. Helpers used less personal protection and had significantly higher prevalence ratio of headache, dyspnea, wheezing, cough, poor digestion, tiredness, and feeling worthless, after adjustment.

CONCLUSIONS:

Acute and mental health symptoms were observed, both among farmers and helpers. Thus, surveillance actions must be reinforced in Brazil, technical support and safety training improved, focused on applicators and helpers, who are occupationally and environmentally exposed to pesticides. Agricultural practices of these groups with less pesticide use should receive incentive.

The global distribution of acute unintentional pesticide poisoning: estimations based on a systematic review

BACKGROUND

Human poisoning by pesticides has long been seen as a severe public health problem. As early as 1990, a task force of the World Health Organization (WHO) estimated that about one million unintentional pesticide poisonings occur annually, leading to approximately 20,000 deaths. Thirty years on there is no up-to-date picture of global pesticide poisoning despite an increase in global pesticide use. Our aim was to systematically review the prevalence of unintentional, acute pesticide poisoning (UAPP), and to estimate the annual global number of UAPP.

METHODS

We carried out a systematic review of the scientific literature published between 2006 and 2018, supplemented by mortality data from WHO. We extracted data from 157 publications and the WHO cause-of-death database, then performed country-wise synopses, and arrived at annual numbers of national UAPP. World-wide UAPP was estimated based on national figures and population data for regions defined by the Food and Agriculture Organization (FAO).

RESULTS

In total 141 countries were covered, including 58 by the 157 articles and an additional 83 by data from the WHO Mortality Database. Approximately 740,000 annual cases of UAPP were reported by the extracted publications resulting from 7446 fatalities and 733,921 non-fatal cases. On this basis, we estimate that about 385 million cases of UAPP occur annually world-wide including around 11,000 fatalities. Based on a worldwide farming population of approximately 860 million this means that about 44% of farmers are poisoned by pesticides every year. The greatest estimated number of UAPP cases is in southern Asia, followed by south-eastern Asia and east Africa with regards to non-fatal UAPP.

CONCLUSIONS

Our study updates outdated figures on world-wide UAPP. Along with other estimates, robust evidence is presented that acute pesticide poisoning is an ongoing major global public health challenge. There is a need to recognize the high burden of non-fatal UAPP, particularly on farmers and farmworkers, and that the current focus solely on fatalities hampers international efforts in risk assessment and prevention of poisoning. Implementation of the international recommendations to phase out highly hazardous pesticides by the FAO Council could significantly reduce the burden of UAPP.

Factors affecting use of personal protective equipment and pesticide safety practices: A systematic review

An evidence-based understanding of factors influencing PPE use and pesticide safety practices has the benefit of facilitating the design of interventions to minimize exposure to pesticides and the promotion of the utilization of PPE and safety practices among agricultural pesticide handlers. The aim of this study, therefore, is to review the available literature on the use of PPE in agricultural pesticide handlers in world regions, and also the factors associated with the use of PPE and pesticide safety practices in farmers and farm workers. Full-text articles published on PubMed, Scopus, and ISI databases between 1999 and 2019 were reviewed and the scientific evidence was evaluated. One hundred and twenty-one articles were eligible for inclusion in this quantitative synthesis: 110 evaluated PPE use in agricultural pesticide handlers, and 23 focused on factors affecting PPE use and pesticide safety practices. Considerable evidence was found to show that the most basic PPE worn among pesticide handlers in all world regions was a long sleeve shirt (66.1%), long sleeve trousers (71.1%), and a hat (47.3%). The lowest basic PPE worn was an apron (8.6%), goggles (24.3%), gloves (40.5%), boots (42.3%), and mask (43.2%). The PPE worn (except for an apron) was proportionally higher in farmers than in farm workers. There is considerable evidence to suggest that the significant determinants associated with PPE use and pesticide safety practices are as follows: (1) demographic factors (i.e. education/literacy level, experience of illness, income); (2) farm structure factors (i.e. farm size); (3) behavioral and psychosocial factors (i.e. contact with pesticides, perceptions, attitudes, awareness, norms and beliefs); and (4) environmental factors (i.e. information about pesticides, access to extension services, training program, and farm organization). Therefore, there is a recognizable need for a life-long education program with training to change the perception and behavior of pesticide handlers sustainably.

Environmental Health Research in Africa: Important Progress and Promising Opportunities

The World Health Organization in 2016 estimated that over 20% of the global disease burden and deaths were attributed to modifiable environmental factors. However, data clearly characterizing the impact of environmental exposures and health endpoints in African populations is limited. To describe recent progress and identify important research gaps, we reviewed literature on environmental health research in African populations over the last decade, as well as research incorporating both genomic and environmental factors. We queried PubMed for peer-reviewed research articles, reviews, or books examining environmental exposures and health outcomes in human populations in Africa. Searches utilized medical subheading (MeSH) terms for environmental exposure categories listed in the March 2018 US National Report on Human Exposure to Environmental Chemicals, which includes chemicals with worldwide distributions. Our search strategy retrieved 540 relevant publications, with studies evaluating health impacts of ambient air pollution (n=105), indoor air pollution (n = 166), heavy metals (n = 130), pesticides (n = 95), dietary mold (n = 61), indoor mold (n = 9), per- and polyfluoroalkyl substances (PFASs, n = 0), electronic waste (n = 9), environmental phenols (n = 4), flame retardants (n = 8), and phthalates (n = 3), where publications could belong to more than one exposure category. Only 23 publications characterized both environmental and genomic risk factors. Cardiovascular and respiratory health endpoints impacted by air pollution were comparable to observations in other countries. Air pollution exposures unique to Africa and some other resource limited settings were dust and specific occupational exposures. Literature describing harmful health effects of metals, pesticides, and dietary mold represented a context unique to Africa. Studies of exposures to phthalates, PFASs, phenols, and flame retardants were very limited. These results underscore the need for further focus on current and emerging environmental and chemical health risks as well as better integration of genomic and environmental factors in African research studies. Environmental exposures with distinct routes of exposure, unique co-exposures and co-morbidities, combined with the extensive genomic diversity in Africa may lead to the identification of novel mechanisms underlying complex disease and promising potential for translation to global public health.

Respiratory and non-respiratory symptoms associated with pesticide management practices among farmers in Ghana's most important vegetable hub

The data presented here are from the Offinso North District Farm Health Study (ONFAHS), a population-based cross-sectional study among vegetable farmers in Ghana. The paper addresses knowledge, pesticide handling practices, and protective measures related to pesticide use by self-reported symptoms for 310 adult farmers who completed a comprehensive questionnaire on pesticide management practices and health. In addition, an inventory was prepared using information supplied by pesticide sellers/dealers in this district. We report that cough and wheezing (but not breathlessness) are positively associated with stirring pesticide preparations with bare hands/drinking water while mixing/applying pesticides, and stirring pesticide preparations with bare hands/drinking water/smoking cigarettes while mixing/applying pesticides. There is a significant exposure-response association between the number of precautionary measures practiced while handling pesticides and cough and wheezing but not with breathlessness. We also found unsafe practices to be associated with sexual dysfunction, nervousness, and lack of concentration. The results also suggest a negative association between practice of any precautionary measure when mixing/applying pesticides and sexual dysfunction, nervousness, and lack of concentration. We found that in spite of the fact that farmers have adequate knowledge about the environment and health effects of pesticides, several unhygienic practices are in widespread use, indicating that knowledge is not necessarily always translated in action. Further action is necessary to promote the safe use of pesticides and to replace existing poor management practices among these and other farmers in Ghana.

Occurrence and distribution of pesticides in precipitation as revealed by targeted screening through GC-MS/MS

Facing the tough challenge of precise measurement of ever-increasing numbers of organic contaminants in the environment, there is an urgent need for more reliable and cost-effective methodologies. In this study, we developed and validated a screening method for analysis of over 450 pesticides in precipitation using gas chromatography with tandem mass spectrometry (GC-MS/MS) in multiple reaction monitoring (MRM) mode. Solid phase extraction (SPE) was applied to extract target analytes from precipitation. Using this targeted approach, we managed to detect 123 pesticides with maximum retention time shifts below 0.1 min (except for DEET) in 101 precipitation samples collected between October 2015 and March 2017 in Singapore. This is probably the first study to report the measurements of a wide range of pesticides in precipitation. A spectrum of insecticides, herbicides, fungicides and their synergists were detected and among them DEET, malathion and carbaryl were the most frequently detected pesticides (detection frequency: 100%, 96% & 67%). The Spearman correlations suggest that some pesticides of different subgroups had significant correlations. It is believed that these finding could shed light on the understanding of the contribution of precipitation to environmental contaminants in water cycle.

Farmers' Training on Pesticide Use Is Associated with Elevated Safety Behavior

Occupational exposure to pesticides in agricultural applications may cause acute and long-term health effects to farmers, and thus research on factors that reduce exposure is useful. However, studies on the relevance and effectiveness of training are limited. The association of previous training in the form of intensive seminars relating to pesticide use (e.g., use of spraying equipment, application parameters, use of personal protective equipment, risks to human health and the environment) with farmers’ knowledge and behavior in pesticide use was studied via the self-reporting method in a purposive sample of 82 trained and non-trained farmers. Most trained farmers showed higher levels of knowledge of pesticide use, higher levels of beliefs in pesticide hazard control, and higher levels of safety behavior than non-trained farmers. Knowledge of pesticide use and beliefs regarding pesticide hazard control were significantly correlated with safety behavior in both groups of farmers. Concerning farmers’ beliefs regarding pesticide hazard control, trained farmers were more likely to think that safety precautions work very well and less likely to feel they had little control over avoiding pesticide hazards. Overall, previous training was associated with increased levels of farmers’ knowledge of pesticides and beliefs about pesticide hazard control, was accompanied by elevated safety behavior in farmers, and thus was connected with lower occupational exposure to pesticides. Interventions that facilitate knowledge and compliance with safety behaviors should become a priority for decreasing exposure to pesticides among farmers.

Undereporting of acute pesticide poisoning in Tanzania: modelling results from two cross-sectional studies

BACKGROUND

Acute pesticide poisoning (APP) is known to cause serious injuries to end users globally but the magnitude of this problem in Tanzania is not well known. This study aimed to determine the extent and pattern of underreporting of APP in Tanzania to inform the development of a surveillance system and appropriate interventions.

METHODS

This study integrates findings from two recent Tanzanian studies. A household survey established the proportion of poisoned farmers in a typical rural area who reported to hospital for a pesticide poisoning. Only 5 of the 112 farmers who reported attending hospital due to poisonings could be traced in medical records at the facilities they claimed to have attended. The 95% confidence interval for this ratio (5/112) was used to generate a high and low boundary for the estimates. Three under-estimation factors were generated for sensitivity analysis to adjust for under-reporting. A review of health facilities in three regions of Tanzania collected prospective data on admissions for APP in 2006 to generate population-based APP incidence rates stratified by circumstances of poisoning (occupational, accidental, suicide, and unknown). Sensitivity analysis was conducted involving adjustment for high and low boundaries of the under-reporting of occupational APP and an adjustment for different scenario allocations of cases with 'unknown' circumstances to different combinations of known circumstances.

RESULTS

The study estimated the rate of occupational poisoning as ranging from 11.3-37.7 cases/million to 84.3-279.9 cases per million. The rate of all poisonings (occupational and non-occupational) ranged from 24.45-48.01 cases per million to 97.37-290.29 cases per million. Depending on the choice of scenario and under-reporting correction factor used, occupational APP could comprise from 52.2 to 96% of all APP cases.

CONCLUSION

The study confirms that data on APP in Tanzanian hospitals are poorly reported and that occupational circumstances are particularly overlooked in routine facility-based surveillance. Occupational APP needs to be taken more seriously in addressing prevention measures. A comprehensive surveillance system for APP should consider multiple data sources including community self-reporting in order to achieve better coverage.