Mood disorders hospitalizations, suicide attempts, and suicide mortality among agricultural workers and residents in an area with intensive use of pesticides in Brazil

Depression in Brazilian farmers: prevalence and associated factors

BACKGROUND

The unique characteristics of rural areas and agricultural work can contribute to the genesis of diseases, including mental disorders such as depression.

AIMS

To estimate the prevalence of and factors associated with depression symptoms in Brazilian farmers.

METHODS

A cross-sectional epidemiological study involving 784 farmers of the state of Espírito Santo/Brazil was carried out. Depression was identified using the Mini-International Neuropsychiatric Interview. Hierarchical logistic regression was used to assess the associated factors.

RESULTS

The prevalence of depression symptoms among farmers was 16.8% (n = 132). Of those experiencing symptoms, 6.1% (n = 48) we're currently experiencing a depressive episode, and 10.7% (n = 84) a recurrent depressive episodes. The associated factors were: female gender (OR 1.63; 95% CI 1.04-2.54), not owning the land (OR 1.79; 95% CI 1.11-2.89), professional dissatisfaction (OR 1.99; 95% CI 1.18-3.35), previous pesticide poisoning (OR 2.87; 95% CI 1.45-5.67), complex multimorbidity (OR 1.95; 95% CI 1.15-3.31) and occurrence of previous depressive episodes (OR 9.83; 95% CI 4.39-21.99).

CONCLUSIONS

A high prevalence of depression symptoms was identified among rural workers. Sociodemographic, occupational, clinical, and professional dissatisfaction factors were associated with a higher risk of depression symptoms in this population.

Epidemiological profile, temporal analysis, and future projections of suicide cases in rural cities in the extreme south of Brazil

The present study aimed to verify the time series (2000-2017) of death rates by suicide and its associated factors in 4 municipalities in the extreme south of Brazil. Data were obtained through the analysis of medical reports and police report bulletins at the Instituto Médico Legal, in the city of Rio Grande. The suicide rate in the Rio Grande region varied from 4 to 11 suicides per 100,000 inhabitants and it is estimated that by 2030 this rate could reach 16.5 suicides per 100,000 inhabitants. The rural cities of Santa Vitória do Palmar and Chuí present even higher suicide averages when compared to Rio Grande, the most populous city of the four. The death rate from suicide increased gradually in the period analyzed, with the prevalence rising among the youngest and the elderly population. A more comprehensive understanding of the influences of environmental issues on suicidal decisions constitutes an important action that needs to be taken, both because of regional vulnerabilities and the target population identified. Evidence indicates that knowledge of factors affecting individuals residing in this Brazilian region where increased suicide rates are recorded needs to be recognized as a priority.

Hexaconazole exposure disrupt acetylcholinesterase, leading to mental illness

Hexaconazole is widely used in agricultural work, and it has been observed that it has potential to disrupt endocrine function and it has also capacity of bioaccumulation. In this study, we examined how the hexaconazole disrupts the usual balance of acetylcholinesterase. It has been already reported that heavy pesticide exposures may be a reason for several mental illnesses because these pesticides may disrupt normal balance of acetylcholinesterase. In this paper, we have done a complete molecular and dynamics analysis to understand the behavior of hexaconazole with acetylcholinesterase so that its toxicological aspect may be explored. Our findings revealed that hexaconazole has potency to interact with acetylcholinesterase in a stable manner. The binding energy of hexaconazole was found to be -7.95 kcal/mol. However, chlorpyrifos, known inhibitors of acetylcholinesterase, has binding energy of -7.17 kcal/mol. With respect to stability analysis, hexaconazole has similar stability like chlorpyrifos. Root-mean-square deviation, root-mean-square fluctuation, radius of gyration, hydrogen bonding, and solvent accessible surface area were similar to chlorpyrifos. In addition, density functional theory computations analysis reveals that hexaconazole is energetically stable like chlorpyrifos, which is necessary for establishing a stable ligand-protein complex. The result of this complete molecular analysis reveals that hexaconazole may disrupt the acetylcholinesterase balance, which leads to mental illness.

Could pesticide exposure be implicated in the high incidence rates of depression, anxiety and suicide in farmers? A systematic review

Pesticide exposure and poisoning may rise the risk of mental health problems and suicidal tendencies. To explore the potential connection between chronic occupational exposure to pesticides and depression, anxiety, and suicide-related outcomes in farmers, a systematic review was performed. Systematic review protocol is available in PROSPERO registration number CRD42022316285. A total of fifty-seven studies met inclusion criteria: twenty-nine on depression or other mental disorders, twelve on suicide (two of them on both depression and suicide), and fourteen on pesticide poisoning or self-poisoning and death. Among the fifty-seven selected studies, eighteen were conducted in Asia, seventeen in North America, fourteen in South America, seven in European Union, one in Africa, and one in Australia/Oceania. Selected studies demonstrated an increased prevalence of depressive disorders in farmworkers exposed to pesticides as well as an increased self-reported prevalence of depression in this population. Moreover, previous pesticide poisoning increased the risk estimates for depression or other mental disorders as compared with chronic pesticide exposure. Severe pesticide poisoning and multiple poisoning showed increased risks of depressive symptoms compared with milder cases. In addition, financial difficulties and poor health were positively correlated with depression. Among studies on suicide, nine of them found that suicide rates increased in areas devoted to agriculture with intensive pesticide consumption. Moreover, studies demonstrate a higher suicide risk among farmers. The present review suggests more attention to the farmer's mental health and more detailed studies on occupational exposure to the mixture of these compounds.

Acute Kidney Failure among Brazilian Agricultural Workers: A Death-Certificate Case-Control Study

Recent evidence suggests that pesticides may play a role in chronic kidney disease. However, little is known about associations with acute kidney failure (AKF). We investigated trends in AKF and pesticide expenditures and associations with agricultural work in two Brazilian regions with intense use of pesticides, in the south and midwest. Using death certificate data, we investigated trends in AKF mortality (1980–2014). We used joinpoint regression to calculate annual percent changes in AKF mortality rates by urban/rural status and, in rural municipalities, by tertiles of per capita pesticide expenditures. We then compared AKF mortality in farmers and population controls from 2006 to 2014 using logistic regression to estimate odds ratios and 95% confidence intervals adjusted by age, sex, region, education, and race. AKF mortality increased in both regions regardless of urban/rural status; trends were steeper from the mid-1990s to 2000s, and in rural municipalities, they were higher by tertiles of pesticide expenditures. Agricultural workers were more likely to die from AKF than from other causes, especially at younger ages, among females, and in the southern municipalities. We observed increasing AKF mortality in rural areas with greater pesticide expenditures and an association of AKF mortality with agricultural work, especially among younger workers.

Interactions of agricultural pesticide use near home during pregnancy and adverse childhood experiences on adolescent neurobehavioral development in the CHAMACOS study

BACKGROUND

Studies have documented independent adverse associations between prenatal and early-life exposure to environmental chemicals and social adversity with child neurodevelopment; however, few have considered these exposures jointly. The objective of this analysis is to examine whether associations of pesticide mixtures and adolescent neurobehavioral development are modified by early-life adversity in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort.

METHODS

We used linear mixed effects Bayesian Hierarchical Models (BHM) to examine the joint effect of applications of 11 agricultural pesticides within 1 km of maternal homes during pregnancy and youth-reported Adverse Childhood Experiences (ACEs) with maternal and youth-reported internalizing behaviors, hyperactivity, and attention problems assessed via the Behavior Assessment for Children (BASC) (mean = 50, standard deviation = 10) at ages 16 and 18 years (n = 458).

RESULTS

The median (25th-75th percentiles) of ACEs was 1 (0-3); 72.3% of participants had low ACEs (0-2 events) and 27.7% had ACEs (3+ events). Overall, there was little evidence of modification of exposure-outcome associations by ACEs. A two-fold increase in malathion use was associated with increased internalizing behaviors among those with high ACEs from both maternal- (β = 1.9; 95% Credible Interval (CrI): 0.2, 3.7 for high ACEs vs. β = -0.1; 95% CrI: 1.2, 0.9 for low ACEs) and youth-report (β = 2.1; 95% CrI: 0.4, 3.8 for high ACEs vs. β = 0.2; 95% CrI: 0.8, 1.2 for low ACEs). Applications of malathion and dimethoate were also associated with higher youth-reported hyperactivity and/or inattention among those with high ACEs.

CONCLUSION

We observed little evidence of effect modification of agricultural pesticide use near the home during pregnancy and adolescent behavioral problems by child ACEs. Future studies should examine critical windows of susceptibility of exposure to chemical and non-chemical stressors and should consider biomarker-based exposure assessment methods.

Unemployment and suicide among the Brazilian population in the crisis of capitalism

The current crisis of capitalism has multiple economic, financial, social, environmental, cultural and political facets. In Brazil, the severity of the crisis is no different, resulting from the exhaustion of the neo-developmentalist model and its inability to resist global crisis. This study compares suicide mortality rates (MR) among employed and unemployed persons in Brazil prior to and during the economic crisis using death records from the period 2011 to 2016. The findings show that in the period 2011 to 2016 the suicide MR fell from 2.66/100,000 to 2.46 among unemployed persons and increased from 5.52/100,000 to 6.89/100,000 in employed persons. Suicide is a complex, multi-causal phenomenon determined by a diverse range of social factors, including strategies that increase worker exploitation. Indeed, being employed can have a greater negative impact on the mental health of workers than being unemployed.

Self-reported psychological distress and self-perceived health in residents living near pesticide-treated agricultural land: a cross-sectional study in The Netherlands

OBJECTIVES

There is rising concern regarding possible health effects from exposure to pesticides in residents living near agricultural land. Some studies indicated increased risks of reporting symptoms of anxiety and depression among agricultural workers but less is known about the mental and perceived health of rural residents. We aimed to study possible associations between self-reported psychological distress (SPD) and self-perceived health (SPH) in residents near pesticide-treated agricultural land.

METHODS

Using the Public Health Monitor national survey from 2012, we selected 216 932 participants who lived in rural and semi-urban areas of the Netherlands and changed addresses at most once in the period 2009-2012. Psychological distress (PD) was assessed via the Kessler Psychological Distress scale (K10) and participants were asked to assess their own health. We estimated the area of specific crop groups cultivated within buffers of 50 m, 100 m, 250 m and 500 m around each individual's residence for the period 2009-2012. Association between these exposure proxies and the outcomes was investigated using logistic regression, adjusting for individual, lifestyle and area-level confounders.

RESULTS

Overall, results showed statistically non-significant OR across all buffer sizes for both SPD and SPH, except for the association between SPH and 'all crops' (total area of all considered crop groups) with OR (95% CI) ranging from 0.77 (0.63 to 0.93) in 50 m to 1.00 (1.00 to 1.00) in 500 m. We observed that most ORs were below unity for SPH.

CONCLUSIONS

This study provides no evidence that residential proximity to pesticide treated-crops is associated with PD or poorer perceived health.

Exposure to pesticides or agroecological practices: suicidal ideation among peasant farmers in Brazil's semi-arid region

Health risks faced by peasant farmers may vary depending on the type of agriculture they practice. This study examined the association between suicide ideation and exposure to pesticides by comparing two groups of peasant farmers of both sexes living in the semi-arid region of the north of Minas Gerais, Brazil: exposed to pesticides and adopting agroecological practices without the use of pesticides. Group participants were selected using convenience sampling and data was collected using a previously validated questionnaire administered through face-to-face interviews. Bivariate analysis was performed, followed by logistic regression. A total of 547 peasant farmers were interviewed (311 in the group exposed to pesticides and 236 in the group adopting agroecological practices). Respondents from the group exposed to pesticides were more likely to report suicidal ideation (OR=2.30; 95%CI 1.16-4.56), harmful alcohol consumption (OR=2.30; 95%CI 1.18-4.48), and lifetime acute pesticide poisoning (OR=8.58; 95%CI 2.98-24.72). The findings suggest that agricultural practices that lead to chronic pesticide exposure are associated with a greater likelihood of suicide ideation, regardless of previous episodes of acute pesticide poisoning or harmful alcohol consumption.

Suicidality among South Brazilian tobacco growers

OBJECTIVE

To assess prevalence of suicidal ideation and suicide attempt among South Brazilian tobacco growers and to analyze the associated factors related to the suicidal ideation.

METHODS

A cross-sectional study was conducted in 2011 with a random sample of 2469 tobacco growers in São Lourenço do Sul/RS. Suicidal ideation was characterized by the question "Has the thought of ending your life been on your mind?". Suicide attempt was assessed by the question "Have you ever tried to kill yourself?". Investigation of factors associated with suicidal ideation was done by means of Poisson regression.

RESULTS

Prevalence of suicidal ideation and suicide attempt was 2.5 % and 1.2 % respectively. In the adjusted analysis, suicidal ideation was associated with being female, older age, moderate participation in religious activities and difficulty in paying debts. Those who worked in activities that required inadequate postures (hunched over or other forced positions), as well as farmers who performed 6-9 pesticide-related tasks demonstrated greater risk of suicidal ideation. Regarding health conditions, medical diagnosis of asthma, chronic low back pain, number of lifetime green tobacco sickness episodes and lifetime pesticide poisoning were positively associated with suicidal ideation.

CONCLUSION

Suicidal thoughts and attempts are relevant mental health problems among tobacco growers. Reducing pesticide use, as well as exposure to nicotine and improving socio-economic conditions, can reduce suicidal ideation and improve the mental health of exposed workers.

Associations of acetylcholinesterase inhibition between pesticide spray seasons with depression and anxiety symptoms in adolescents, and the role of sex and adrenal hormones on gender moderation

BACKGROUND

Cholinesterase inhibitor pesticides, especially organophosphates, are endocrine disruptors and a few existing studies have linked self-reports of exposure with increased depression and anxiety. Some evidence suggests that associations may be stronger in women, but the mechanism of this gender difference is unclear. We assessed whether acetylcholinesterase (AChE) inhibition between 2 time points (reflecting greater cholinesterase inhibitor exposure) during different agricultural seasons in the year was associated with anxiety/depression symptoms.

METHODS

We examined 300 adolescents (ages 11-17y, 51% female) living near agricultural settings in Ecuador (ESPINA study) twice in 2016: April and July-October. We assessed AChE activity (finger stick), estradiol, testosterone, dehydroepiandrosterone, cortisol (saliva) and anxiety and depression scales (CDI-2 and MASC-2).

RESULTS

The mean (SD) depression and anxiety scores were 52.8 (9.3) and 58.1 (9.6), respectively. The median (25th, 75th percentile) AChE change (July-October vs April) was -3.94% (-10.45%, 5.13%). For every 10% decrease in AChE activity, there was a 0.96 unit (95%CI: 0.01, 1.90) increase in depression symptoms and an OR of elevated depression score of 1.67 (1.04, 2.66). These associations were stronger in girls (OR=2.72 [1.23, 6.00]) than boys (1.18 [0.59, 2.37]). Adjustment for cortisol, testosterone and dehydroepiandrosterone reduced gender differences by 18-62%. No associations were observed with anxiety.

DISCUSSION

Inhibition of AChE activity at 2 points in time during different pesticide spray periods was associated with greater depression symptoms, affecting girls more than boys. Gender differences may be partly explained by endocrine disruption. These findings suggest that AChE inhibition may transiently affect the mood of adolescents.

Multi-biomarker responses to pesticides in an agricultural population from Central Brazil

We evaluated farmworkers exposed to pesticides and individuals with no history of occupational exposure to pesticides. It was performed the comet assay to evaluate DNA damage. The immunophenotyping of TCD4⁺ lymphocyte subpopulations in peripheral blood was performed by flow cytometry. The single nucleotide polymorphisms (SNPs) in PON1, XRCC1, IL6, IL6R, TNF-α, and MIR137 genes were evaluated by real-time PCR. The exposed group was composed mostly by males (69.44%), with direct exposure to pesticides (56%) and with an average age range of 46 ± 13.89 years, being that 58.3% of farmworkers directly exposed to pesticides and reported the full use of personal protective equipment (PPE). DNA damage was greater in the exposed group (p < 0.05), reinforced by the use of PPE to denote a lower degree of DNA damage (p = 0.002). In this context, in the exposed group, we demonstrated that the use of PPE, age, gender and intoxication events were the variables that most contributed to increase DNA damage (p < 0.0001). Besides, the exposed group showed a significant increase in the subpopulations of T lymphocytes CD3⁺CD4⁺ (p < 0.05) and CD3⁺CD4⁺CD25⁺ (p < 0.0001) and a significant decrease in CD3⁺CD4⁺CD25^-FOXP3⁺ (p < 0.05). SNPs in the TNF-α (rs361525) gene presented a difference in the genotype distribution between the groups (p = 0.002). The genotype distribution of TNF-α (rs361525) was also positively correlated with the DNA damage of the exposed group (r = 0.19; p = 0.01), demonstrating a higher risk of DNA damage in the farmworkers presenting the A mutated allele. Our findings demonstrate that pesticides can exert various deleterious effects on human health by damaging the DNA as well as by influencing the immune system in the case of both direct or indirect exposure and these issues are associated to age, gender, intoxication and the nonuse of PPE.

Synthetic Pesticides and Health in Vulnerable Populations: Agricultural Workers

PURPOSE OF REVIEW

This review aims to summarize epidemiological literature published between May 15, 2018, and May 14, 2019, that examines the relationship between exposure to synthetic pesticides and health of agricultural workers.

RECENT FINDINGS

Current research suggests that exposure to synthetic pesticides may be associated with adverse health outcomes. Agricultural workers represent a potentially vulnerable population, due to a combination of unique social and cultural risk factors as well as exposure to hazards inherent in agricultural work. Pesticide exposure among agricultural workers has been linked to certain cancers, DNA damage, oxidative stress, neurological disorders, and respiratory, metabolic, and thyroid effects. This review describes literature suggesting that agricultural workers exposed to synthetic pesticides are at an increased risk of certain cancers and neurological disorders. Recent research on respiratory effects is sparse, and more research is warranted regarding DNA damage, oxidative stress, metabolic outcomes, and thyroid effects.

Self-poisoning with pesticides in Jiangsu Province, China: a cross-sectional study on 24,602 subjects

BACKGROUND

With an estimated > 800,000 suicide-related deaths and potentially several attempts for each death in the world. The purpose of this study was to determine the epidemiological characteristics of self-poisoning with pesticides within the Jiangsu province in China.

METHODS

Suicide rate was calculated the Routine Surveillance System by Jiangsu Provincial Center for Disease Control and Prevention, stratified by gender, age and region, combined with socioeconomic and agriculture-related factors to investigate trends in suicide over the study period. A logistic regression model was used to investigate the associations between pesticide types and pesticide-related deaths.

RESULTS

In recent years, Jiangsu Province has witnessed a decrease in pesticide self-poisoning cases and consequent deaths. Among all suicides by deliberate ingestion of pesticides, the proportion of cases were mainly in the age 40, accounting for 3.43% of all cases with pesticide suicide. The proportion of suicide due to pesticide poisoning in females was markedly higher than that in males (p < 0.001). Suicide using organophosphate and carbamate insecticides was most common, with 10,303 reported cases accounting for 42.02% of all suicides.

CONCLUSIONS

For national responses to be effective, the characteristics of pesticide suicides should be comprehensively investigated for the formulation of corresponding prevention strategies. At present, more pesticide suicide prevention policies for the elderly people and women should be implemented, and stronger pesticide management policies should be implemented for rural areas.

Factors Associated with Depressive Symptoms Among Rural Residents from Remote Areas

This study aimed to investigate the risk factors for depressive symptoms among rural residents in Brazil. A representative sample of two hundred eighty-eight volunteers aged from 18 to 65 years was included and determining factors for high BDI-II score were investigated through a multivariate logistic model. Sadness, loss of pleasure, crying, worthlessness and loss of interest in sex are more likely to be observed in females, and risk factors to this high depression score among rural residents were shown to be: female gender, tobacco use, pesticide application, poor self-perceived health and presence of chronic disease. These data contribute to the knowledge of factors determining depressive symptoms among rural residents and may help to expand health policies to improve quality of rural life on these communities and others with similar characteristics.

Mortality from suicide among agricultural, fishery, forestry and hunting workers in Italy and the contribution of work-related factors

OBJECTIVES

Excess risk of suicide has been reported among workers in agriculture, fishery, forestry and hunting (AFFH). However, there is still uncertainty in the quantification of the risk and in the contribution of work-related factors. We aimed to quantify the suicide mortality risk among these workers in Italy.

METHODS

We carried out a historical cohort study based on record linkage between the 2011 Italian census and the mortality archives for years 2012-2017. The mortality rate ratio (MRR) was used as a measure of risk. MRR was estimated through quasi-Poisson regression models using workers in other sectors as reference category. Models were adjusted for age, citizenship, marital status, area of residence, education, employment status and hours worked per week.

RESULTS

The cohort included 1 004 655 workers employed in the AFFH sector and 15 269 181 workers in other sectors. During the 6-year follow-up, 559 deaths from suicide (500 men and 59 women) occurred among AFFH workers and 5917 (4935 men and 982 women) among workers in other sectors. The MRR for suicide was 1.36 (95% CI 1.19 to 1.55) among men and 1.18 (95% CI 0.87 to 1.60) among women. The excess risk was remarkably high for casual and fixed-term contract workers (3.01, 95% CI 1.50 to 6.04).

CONCLUSIONS

Male workers in AFFH are at high risk of suicide mortality, and casual and fixed-term contract workers are at exceedingly high risk. Our study also suggests a higher risk among single, highly educated and long-hours workers. Female workers in AFFH do not have an appreciably increased risk.

A Scoping Review of Non-Occupational Exposures to Environmental Pollutants and Adult Depression, Anxiety, and Suicide

PURPOSE OF REVIEW

Despite a call for better understanding of the role of environmental pollutant influences on mental health and the tremendous public health burden of mental health, this issue receives far less attention than many other effects of pollutants. Here we summarize the body of literature on non-occupational environmental pollutant exposures and adult depression, anxiety, and suicide-in PubMed, Embase, Web of Science, and PsychINFO through the end of year 2018.

RECENT FINDINGS

One hundred twelve articles met our criteria for further review. Of these, we found 88 articles on depression, 33 on anxiety, and 22 on suicide (31 articles covered multiple outcomes). The earliest article was published in 1976, and the most frequent exposure of interest was air pollution (n = 33), followed by secondhand smoke (n = 20), metals (n = 18), noise (n = 17), and pesticides (n = 10). Other exposures studied less frequently included radiation, magnetic fields, persistent organic pollutants (POPs), volatile organic compounds, solvents, and reactive sulfur compounds. The current literature, although limited, clearly suggests many kinds of environmental exposures may be risk factors for depression, anxiety, and suicide. For several pollutants, important limitations exist with many of the studies. Gaps in the body of research include a need for more longitudinal, life-course studies, studies that can measure cumulative exposures as well as shorter-term exposures, studies that reduce the possibility of reverse causation, and mechanistic studies focused on neurotoxic exposures.

Associations of acetylcholinesterase activity with depression and anxiety symptoms among adolescents growing up near pesticide spray sites

BACKGROUND

The cholinergic system has an important role in mood regulation. Cholinesterase inhibitor pesticides (e.g. organophosphates) appear to increase depression and anxiety symptoms in the few existing animal and human studies. Human studies have not described such associations using biomarkers of exposure and studies among children are needed.

METHODS

We studied 529 adolescents (ages 11-17y) in agricultural communities in the Ecuadorian Andes (ESPINA study). Acetylcholinesterase (AChE) activity was measured in a finger-stick sample. Anxiety and depression symptoms were assessed using the CDI-2 and MASC-2 (greater scores reflect greater internalizing symptoms). Models adjusted for age, gender, hemoglobin, income among others.

RESULTS

The median age was 14.38y and 51% were female. The mean (SD) of the following parameters were: AChE 3.7 U/mL (0.55), depression T-score 53.0 (9.4) and anxiety T-score: 57.6 (9.8). Lower AChE activity (reflecting greater cholinesterase inhibitor exposure) was associated with higher depression symptoms (difference per SD decrease of AChE [β [95% CI:]]: 1.09 [0.02, 2.16]), was stronger among girls (β = 1.61) than boys (β = 0.69), and among younger (<14.38y, β = 1.61) vs. older children (β = 0.57). The associations were strongest among girls <14.38y (β = 3.30 [0.54, 6.05], OR for elevated symptoms per SD decrease in AChE = 2.58 [1.26, 5.27]). No associations were observed with anxiety scores. Analyses of AChE change between 2008 and 2016 concurred with these findings.

DISCUSSION

We observed associations between a biomarker of pesticide exposure and children's depression symptoms. Lower AChE activity may create risk for depression in teenagers, particularly among girls during early adolescence.

A Pest to Mental Health? Exploring the Link between Exposure to Agrichemicals in Farmers and Mental Health

The current literature acknowledges that occupational exposures can adversely affect mental health. This review seeks to elucidate the current understanding of the effect of agrichemical exposure on mental health in the agricultural sector, including low-dose, chronic pesticide exposure. This scoping review adopted a snowballing and saturation approach. The review highlights inconsistencies in linking poor mental health and pesticide use. While some studies specifically showed that both high- and low-dose pesticide exposure were associated with poor mental health, consistent and rigorous research methods are lacking. The review also proposes terms to delineate exposure types described in the literature. The review outcomes direct efforts to protect the health, wellbeing and safety of farming communities across the globe.

Pesticide exposure, tobacco use, poor self-perceived health and presence of chronic disease are determinants of depressive symptoms among coffee growers from Southeast Brazil

The lifestyle and other factors associated with the appearance of several health conditions that affect quality of life in rural zone is an issue that has been increasingly explored. Brazil is the largest coffee-producing nation in the world and has been a considerable consumer of pesticides since 2008. The aim of the present study was to investigate factors that could be contributing to the appearance of depressive symptoms in rural workers. Two hundred twenty male volunteers from nine cities in Southeast Brazil completed the Beck Depression Inventory-II (BDI-II) questionnaire about depressive symptoms and provided other information about socio-demographic characteristics and additional confounding factors. The adjusted multivariate logistic analysis demonstrated that pesticide exposure, tobacco use, poor self-perceived health and the presence of chronic disease contribute as risk factors for the appearance of depressive symptoms at a level above ups and downs considered normal in the BDI-II. This survey contributes to the search for solutions to improve quality of life and mental health in the rural living to the extent that social determinants of depression are being investigated.

Anxiety and depression following cumulative low-level exposure to organophosphate pesticides

Previous research suggests that individuals with a prior history of pesticide poisoning are at increased risk of psychiatric disorder (Freire and Koifman, 2013), but findings regarding the impact of cumulative low-level exposure are inconsistent. The aim of the current study was to investigate whether sheep farmers with a history of low-level exposure to organophosphate pesticides (1) report a higher level of psychological distress on subjective symptom questionnaires, compared to unexposed controls (2) also meet internationally agreed diagnostic criteria for a psychiatric disorder more often than unexposed controls. 127sheep farmers were evaluated and compared to 78 unexposed controls, matched in terms of gender, education, level of intelligence, working status and area of residence. Both self-report measures and structured clinical interviews were used to assess mental health. The exposed cohort reported significantly higher rates of anxiety and depression when self-report questionnaires were used to evaluate mood, even when stressful life events, demographic and physical health factors were taken into account. However, when diagnostic interviews were used to assess mood, this pattern only held true for anxiety.

Arbuscular mycorrhizal fungi are an alternative to the application of chemical fertilizer in the production of the medicinal and aromatic plant Coriandrum sativum L

The widespread use of agrochemicals is detrimental to the environment and may exert harmful effects on human health. The consumer demand for organic food plants has been increasing. There is thus a rising need for alternatives to agrochemicals that can foster sustainable plant production. The aim of this study was to evaluate the potential use of an arbuscular mycorrhizal (AM) fungus as an alternative to application of chemical fertilizer for improving growth performance of the medicinal and aromatic plant Coriandrum sativum. Plants were inoculated with the AM fungus Rhizophagus irregularis BEG163 and/or supplemented with a commercial chemical fertilizer (Plant Marvel, Nutriculture Bent Special) in agricultural soil. Plant growth, nutrition, and development of AM fungus were assessed. Plants inoculated with R. irregularis and those supplemented with chemical fertilizer displayed significantly improved growth performances when compared with controls. There were no significant differences in total fresh weight between plants inoculated with R. irregularis or those supplemented with chemical fertilizer. Leaf chlorophyll a + b (82%), shoot nitrogen (44%), phosphorus (254%), and potassium (27%) concentrations increased in plants inoculated with R. irregularis compared to controls. Application of chemical fertilizer inhibited root mycorrhizal colonization and the length of the extraradical mycelium of R. irregularis. Inoculation with R. irregularis was equally or more efficient than application of chemical fertilizer in promoting growth and nutrition of C. sativum. AM fungi may thus contribute to improve biologically based production of food plants and reduce the dependence on agrochemicals in agriculture.

Seed coating with arbuscular mycorrhizal fungi as an ecotechnologicalapproach for sustainable agricultural production of common wheat (Triticum aestivum L.)

The exploitation of arbuscular mycorrhizal (AM) fungi has become of great interest in agriculture due to their potential roles in reducing the need for agrochemicals, while improving plant growth and nutrition. Nevertheless, the application of AM fungi by dispersing inocula in granular form to open agricultural fields is not feasible because nontargeted spreading of inocula over large surface areas results in high cost per plant. Seed coating has the potential to significantly reduce the amount of inoculum needed, resulting in cost reduction and increased efficiency. The aim of this study was to assess whether seed coating with AM fungal inoculum is a feasible delivery system for production of common wheat (Triticum aestivum L.). Wheat seeds were coated with inoculum of Rhizophagus irregularis BEG140 and grown under different fertilization conditions: (1) none, (2) partial, or (3) complete. Data indicated that mycorrhizal inoculation via seed coating significantly increased the dry weight of shoot and seed spikes of wheat associated with reduced fertilization. Assessment of nutritional status of wheat showed that plants inoculated with R. irregularis via seed coating displayed enhanced stem concentrations of potassium (K), sulfur (S), and zinc (Zn). There were no significant differences in root colonization between plants conventionally inoculated with R. irregularis in soil and those inoculated via seed coating. Seed coating with AM fungi may be as effective as conventional soil inoculation and may contribute to reduce the utilization of chemical fertilizers. The application of AM via seed coating is proposed as an ecotechnological approach for sustainable agricultural wheat production.

Occupational exposure to pesticides, nicotine and minor psychiatric disorders among tobacco farmers in southern Brazil

INTRODUCTION

Exposure to pesticides has been associated with psychiatric problems among farm workers, although there is still controversy as to chemical types, intensity and forms of exposure that represent risk factors for neuropsychological problems. Furthermore, tobacco workers are exposed to dermal absorption of nicotine, although its effect on mental health has not yet been studied.

OBJECTIVES

To identify the prevalence of minor psychiatric disorders (MPD) among tobacco farmers and associated factors, paying special attention to pesticide and nicotine exposure.

METHODS

This is a cross-sectional study with a representative sample of tobacco growers, characterizing economic indicators of the farms, socio-demographic factors, lifestyle habits and occupational exposures. Multivariate analysis was performed using a hierarchical Poisson regression model.

RESULTS

A total of 2400 tobacco farmers were assessed and MPD prevalence was 12%. MPD was higher among women (PR 1.4), workers aged 40 or over, tenants/employees (PR 1.8) and those who reported having difficulty in paying debts (PR 2.0). Low socioeconomic status was inversely associated with MPD prevalence. Tasks involving dermal exposure to pesticides showed risk varying between 35% and 71%, whereas tobacco growers on farms using organophosphates had 50% more risk of MPD than those not exposed to this kind of pesticide. The number of pesticide poisoning and green tobacco sickness episodes showed linear association with MPD.

CONCLUSIONS

The study reinforces the evidence of the association between pesticide poisoning and mental health disorders. It also points to increased risk of MPD from low socioeconomic status, dermal pesticide exposure as well as from exposure to organophosphates. Furthermore, the study reveals intense nicotine exposure as a risk for tobacco farmers' mental health.

Suicide mortality among agricultural workers in a region with intensive tobacco farming and use of pesticides in Brazil

OBJECTIVE

To investigate whether suicide risk among agricultural workers is higher in regions with heavier pesticide use and/or presence of tobacco farming.

METHODS

Suicide mortality data were gathered from residents of the Brazilian state of Alagoas. Agricultural census data were used to arrange and classify Alagoas cities into distribution groups on the basis of variables concerning pesticide use and/or tobacco farming. Mortality odds ratio calculations were then used to compare suicide risk among agricultural and nonagricultural workers in different groups.

RESULTS

Suicide risk was higher among agricultural workers than among nonagricultural workers, elevated in regions that used more pesticides, and greatest in regions that produced more tobacco.

CONCLUSIONS

This is one of the first studies of its kind to suggest that combined effects of pesticide and tobacco exposure may be linked to higher suicide risk among agricultural workers.

Suicidal ideation and occupational pesticide exposure among male farmers

BACKGROUND

The occupation of farming has been reported to be associated with a high suicide rate, and suicidal ideation is an important risk factor for suicide. The objective of this study was to explore the association between occupational pesticide exposure or poisoning history and suicidal ideation among male farmers in South Korea.

METHODS

Through a nationwide sampling survey, a total of 1958 male farmers were interviewed in 2011 in South Korea. Detailed occupational pesticide exposure and pesticide poisoning information were obtained from face-to-face interviews. Suicidal ideation was defined as whether they had thought of harming themselves or trying to take their own lives over the preceding year. Logistic regression analyses were conducted to examine the effect of pesticide poisoning on suicidal ideation.

RESULTS

Among all farmers, 4.7% (n=92) reported suicidal ideation in 2010. After controlling for potential confounders, lifetime hospitalization due to pesticide poisoning showed a 2.48-fold increase in risk (95% CI: 1.26, 4.91). Those with multiple poisonings showed more significant associations with suicidal ideation (OR=2.33 for once, OR=3.02 for more than once). Moderate- or severe-symptom severity of acute pesticide poisoning cases (OR=2.23; 95% CI: 1.21-4.11) also showed increased risks of suicidal ideation than the milder classes did. However, no significant association was identified with cumulative lifetime pesticide application and suicidal ideation.

CONCLUSIONS

Our findings suggest that risk of suicidal ideation is related to occupational pesticide poisoning among male farmers.

Pesticide exposure and self-reported incident depression among wives in the Agricultural Health Study

BACKGROUND

Depression in women is a public health problem. Studies have reported positive associations between pesticides and depression, but few studies were prospective or presented results for women separately.

OBJECTIVES

We evaluated associations between pesticide exposure and incident depression among farmers' wives in the Agricultural Health Study, a prospective cohort study in Iowa and North Carolina.

METHODS

We used data on 16,893 wives who did not report physician-diagnosed depression at enrollment (1993-1997) and who completed a follow-up telephone interview (2005-2010). Among these wives, 1054 reported physician diagnoses of depression at follow-up. We collected information on potential confounders and on ever use of any pesticide, 11 functional and chemical classes of pesticides, and 50 specific pesticides by wives and their husbands via self-administered questionnaires at enrollment. We used inverse probability weighting to adjust for potential confounders and to account for possible selection bias induced by the death or loss of 10,639 wives during follow-up. We used log-binomial regression models to estimate risk ratios and 95% confidence intervals.

RESULTS

After weighting for age at enrollment, state of residence, education level, diabetes diagnosis, and drop out, wives' incident depression was positively associated with diagnosed pesticide poisoning, but was not associated with ever using any pesticide. Use of individual pesticides or functional or chemical classes of pesticides was generally not associated with wives' depression. Among wives who never used pesticides, husbands' ever use of individual pesticides or functional or chemical classes of pesticides was generally not associated with wives' incident depression.

CONCLUSIONS

Our study adds further evidence that high level pesticide exposure, such as pesticide poisoning, is associated with increased risk of depression and sets a lower bound on the level of exposure related to depression, thereby providing reassurance that the moderate levels of pesticide exposure experienced by farmers' wives likely do not increase risk.