Occupational exposure to pesticides and symptoms of depression in agricultural workers. A systematic review.

BACKGROUND: The use of pesticides can result in harm to both the environment and human health. There is a growing concern in the field of occupational health about the impact on the mental health of agricultural workers. OBJECTIVES: The objective of this review was to systematize scientific evidence from the last ten years on the impact of occupational exposure to pesticides on the development of depression symptoms in agricultural workers. METHODS: We conducted a comprehensive search in the PubMed and Scopus databases from 2011 to September 2022. Our search included studies in English, Spanish, and Portuguese that examined the association between occupational exposure to pesticides and symptoms of depression in agricultural workers, following the guidelines recommended by the PRISMA statement and the PECO strategy (Population, Exposure, Comparison, and Outcomes). RESULTS: Among the 27 articles reviewed, 78% of them indicated a link between exposure to pesticides and the incidence of depression symptoms. The pesticides most frequently reported in the studies were organophosphates (17 studies), herbicides (12 studies), and pyrethroids (11 studies). The majority of the studies were rated as having intermediate to intermediate-high quality, with the use of standardized measures to assess both exposure and effect. CONCLUSION: The updated evidence presented in our review indicates a clear association between pesticide exposure and the development of depressive symptoms. However, more high-quality longitudinal studies are necessary to control for sociocultural variables and utilize pesticide-specific biomarkers and biomarkers of depression. Given the increased use of these chemicals and the health risks associated with depression, it is crucial to implement more stringent measures to monitor the mental health of agricultural workers regularly exposed to pesticides and to enhance surveillance of companies that apply these chemicals.

[Benefits of green spaces and physical activity for the well-being and health of people]. / Beneficios de los espacios verdes y actividad física en el bienestar y salud de las personas.

BACKGROUND: Physical environment can influence well-being, quality of life and health and population health in several ways. Exposure to green spaces improves the physical and mental health of individuals. Chile has privileged conditions for outdoor activities that could benefit millions of people. However, a small percentage of the Chilean population is exposed to green spaces in the recommended amounts to promote health. AIM: To describe the benefits of green spaces on physical and mental health and their relationship with the practice of physical activity. MATERIAL AND METHODS: Review of the scientific literature in English in the Web of Science (WoS) electronic database published between 2006-2019. RESULTS: In addition to the direct benefits of green spaces, there are synergistic effects of performing physical activities in these environments such as feelings of good health, satisfaction with life and pleasure, increased physiological relaxation, positive emotions, mental well-being, restoration of attention, decreased perceived stress and a reduction negative affections. CONCLUSIONS: This review supports strategies for improving access to green spaces in urban areas coupled with physical activity promotion in these settings. Health and urban planning stakeholders should consider these aspects in future programs.

An educational intervention on the risk perception of pesticides exposure and organophosphate metabolites urinary concentrations in rural school children in Maule Region, Chile.

BACKGROUND: Organophosphate (OP) pesticides can be hazardous to human health if not applied with appropriate precautions. There is evidence in the Maule region of Chile that rural schoolchildren are exposed to OP pesticides. OBJECTIVE: To evaluate the effectiveness of an educational intervention on OP exposure and understanding of pesticides and their hazards (risk perception) in two school communities in the Maule Region of Chile during 2016. METHOD: We conducted a quasi-experimental study about the effects on OP pesticide exposure of a community outreach and education program (COEP) administered in four 2-h sessions that's included hands-on activities among 48 schoolchildren from two rural schools. The intervention was directed to groups of parents and school-children separately, and aimed to educate them about the risks of exposure to pesticides and their effects on health. We measured 3,5,6-trichloro-2-pyridinol (TCPy), 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPY), malathion dicarboxylic acid (MDA), p-nitrophenol (PNP), specific urinary metabolites of the OP pesticides chlorpyrifos, diazinon, malathion and parathion, respectively, as well as the non-specific diethylakylphosphates (DEAPs) and dimethylalkylphosphates (DMAPs) in 192 urine samples of schoolchildren collected before and after the intervention. The risk perception of school children and their parents was also assessed through a questionnaire before and after the intervention. Generalized Estimated Equations were used to account for each child's repeated measures during four sessions, two in September 2016 (pre-intervention) and two in November 2016 (post-intervention). RESULTS: The intervention level had significant effect on the risk perception of adults and children, which increased after the intervention. However, the intervention was not associated with reduced of urinary metabolites levels, with no significant differences between the pre and post measures. The detection frequencies were 1.1% (MDA), 71.4% (TCPy), 43.3% (IMPY), 98.96% (PNP), and 100% (DEAPs and DMAPs). Higher DEAPs urine concentrations were associated with eating more fruit at school (p = 0.03), a younger age (p = 0.03), and being male (p = 0.01). DMAPs showed no associations with potential predictor variables (e.g. OPs applied at home, fruit consumption at school, among others). Higher TCPy was associated with attending a school closer to farms (p = 0.04) and living in a home closer to farm fields (p = 0.01); higher PNP was marginally associated with children younger age (p = 0.035). CONCLUSION: Environmental exposure to OP pesticides was unchanged even after behavior changes. It is possible that a longer time period is needed to observe changes in both behavior and urinary metabolites. The levels of DEP and DMP metabolites found here are above the reference population of the US, and our findings indicate exposure to a wide variety of OP pesticides. Given that individual-level interventions were not associated with lower exposures, efforts to reduce exposure must occur upstream and require stricter regulation and control of pesticide use by government agencies.

Reliability and factorial validity of a questionnaire to assess organophosphate pesticide exposure to agricultural workers in Maule, Chile.

The aim was to evaluate the reliability and validity of a questionnaire to assess organophosphate pesticide (OP) exposure in agricultural workers. We then enrolled a random sample of 114 agricultural workers from the region of Maule, Chile (mean age = 50 years [SD = 12]). An internal consistency analysis (Cronbach's alpha> 0.70) and a Varimax rotational factorial analysis were applied. The instrument had a high reliability to predict likely occupational pesticide exposures: Cronbach's alpha = 0.95, the Kaiser-Meyer-Olkin (KMO) measure was 0.90 and the Bartell sphericity test = p < 0.001. Four factors explaining 68% of the variance were extracted. The factors identified were as follows: (1) labor conditions during application of OPs; (2) use of personal protective equipment; (3) workplace conditions related to OP exposure and (4) home conditions related to OP exposure. The questionnaire has adequate metric properties to characterize likely OP exposure of agricultural workers and to explore associated working and home conditions.

Laboratory of the Neuropsychology and Cognitive Neurosciences Research Center of Universidad Católica del Maule, Chile.

The Laboratory of the Neuropsychology and Cognitive Neurosciences Research Center (CINPSI Neurocog), located in the "Technological Park" building of the Catholic University of Maule (Universidad Católica del Maule, UCM) campus in Talca, Chile, has been established as "Psychology Lab" recently in July, 2016. Our lines of work include basic and applied research. Among the basic research, we study executive functions, decision-making, and spatial cognition. In the applied field, we have studied neuropsychological and neurobehavioral effects of pesticides exposure, among other interests. One of our aims is to develop collaboration both national and internationally. It is important to mention that to date there are only few psychology laboratories and research centers in Chile involved with the fields of neuropsychology and neurosciences. Thus, this scientific effort could be a groundbreaking initiative to develop specific knowledge in this area locally and interculturally through its international collaborations.

Exposure to organophosphate (OP) pesticides and health conditions in agricultural and non-agricultural workers from Maule, Chile.

The objective was to evaluate the characteristics of exposure to OP pesticides and health status in Chilean farm workers from the Maule Region. An occupational health questionnaire was administered in 207 agricultural and non-agricultural workers. For the group of agricultural workers, we asked about specific occupational exposure history and symptoms of OP pesticide poisoning. The main health problem of the exposed group was previous OP pesticide poisoning (p < 0.001). Fifty-six percent of agricultural workers reported symptoms consistent with acute OP pesticide poisoning. The use of respiratory personal protective equipment and younger age were protective against these symptoms, and number of years of OP pesticide exposure was positively associated with reporting symptoms of poisoning. Of the pesticide applicators 47 % reported using chlorpyrifos. The regulations regarding use and application of pesticides should be strengthened, as should training and intervention with workers to improve the use of personal protective equipment.

Demographics and tenure of the Chilean urban dog population. A mathematical model.

BACKGROUND: Irresponsible dog ownership in urban areas is a public health concern with significant implications for human, animal, and environmental welfare. Factors such as abandonment, variations in adoption, insufficient supervision, emerging identification initiatives, and collective feeding impact the growth of stray dog populations and the transmission of diseases. Developing a modeling tool to understand the dynamics of canine population growth and the effect of human behavior on this phenomenon is essential. METHODS: An ordinary differential equation model was developed to depict the growth dynamics and movements of urban dog populations, distinguishing between those with owners (restricted and semi-restricted) and those without (stray and community dogs). Two equilibrium states of the system were analyzed: with and without the presence of individually owned dogs. An increase rate for the population of individually owned dogs was calculated, and a local sensitivity analysis was conducted to assess the impact of parameters on the reduction of this population. Additionally, two global sensitivity analysis methods were used to evaluate the simultaneous influence of the parameters. RESULTS: Findings indicate that system equilibrium depends on various dog categories. Although total eradication of stray and community dogs is unlikely, equilibrium levels are directly related to subpopulation growth rates, responsible ownership practices, and adoption and abandonment rates. The growth rates of the population of dogs without individual owners have a direct and proportional influence on their regulation, while adoption rates have an inverse and proportional effect. The study, through global sensitivity analysis, identifies key parameters for each dog subpopulation. For restricted dogs, environmental carrying capacity is the most variable factor; for semi-restricted dogs, awareness of responsible ownership is crucial. The abandonment of restricted dogs significantly impacts stray dog dynamics, while the transition from stray to community status is an important variable factor for community dogs. CONCLUSION: Addressing the situation of unowned dogs requires a collective effort to reduce risks associated with the spread of zoonotic diseases, environmental pollution, and biodiversity loss, thus contributing to public health and environmental conservation.

Mental health care before and during the COVID-19 pandemic in public healthcare centers of a Chilean municipality. / Atención de salud mental antes y durante la pandemia COVID-19 en centros de salud pública de una municipalidad de Chile.

Introduction: Globally, the COVID-19 pandemic has affected people's mental health care. This study aims to describe mental health care in the first semester of the COVID-19 pandemic of the year 2020 compared to the first semester of the year 2019 in the public health establishments of the commune of Chillán, Chile. Methods: A descriptive ecological study. The treated cases were analyzed in aggregate, considering the pandemic, amount of admissions, the reason for consultation, sex, and age for the years 2019 and 2020. Prevalence, percentages, and statistical analysis were evaluated using non-parametric tests. Results: The prevalence of cases due to admissions to the mental health program in primary health care remained similar between the first semester of 2019 and the first semester of 2020. Most mental health cases concentrate on mood (affective) and anxiety disorders. Statistically significant differences were observed between 2019 and 2020 in the number of mental health admissions for mental and behavioral disorders due to psychotropic substances, harmful use disorders, drug dependence, and personality disorders. Conclusions: It is a priority for Chile to increase coverage in primary mental health care. The data provided in this study show at an exploratory level that the initial situation of the pandemic could have affected access to timely care for the most vulnerable people with mental disorders.

Introducción: A nivel mundial, la pandemia por COVID-19 ha afectado la atención en salud mental de las personas. El presente estudio tiene como propósito describir la atención de salud mental en el primer semestre de la pandemia COVID-19 del año 2020, comparado con el primer semestre del año 2019 en los establecimientos de salud pública de la comuna de Chillán, Chile. Métodos: Estudio ecológico descriptivo. Se analizaron de manera agregada los casos atendidos considerando la pandemia, cantidad de ingresos, motivo de consulta, sexo y edad para los años 2019 y 2020, observando prevalencias, porcentajes y comparación estadística con pruebas no paramétricas. Resultados: La prevalencia de casos por ingresos al programa de salud mental de atención primaria en salud/especialidad se mantuvo similar entre el primer semestre del año 2019 y el primer semestre del año 2020. La mayor proporción de casos de salud mental se concentran en los trastornos de humor (afectivos) y trastornos de ansiedad. Se observaron diferencias estadísticamente significativas entre el año 2019 y 2020 en el número de atenciones por ingresos en salud mental para los trastornos mentales y del comportamiento debido a consumo sustancias psicotrópicas, trastornos por consumo perjudicial o dependencia a drogas y trastornos de personalidad. Conclusión: Es prioritario que en Chile se aumente la cobertura en la atención primaria de salud mental, los datos entregados en este estudio muestran a nivel exploratorio que la situación inicial de la pandemia pudo haber afectado el acceso a la atención oportuna de las personas más vulnerables con trastornos de salud mental.

A cross-sectional study on the quality of life and psychosocial risk of migrant workers. / Estudio transversal sobre la calidad de vida y el riesgo psicosocial de trabajadores migrantes.

Introduction: Migration figures place Chile as one of the South American countries with the highest rate of migrants. The present study estimated the relationship between sociodemographic characteristics, quality of life, and psychosocial occupational risks in migrant workers from the Maule region. Methods: Cross-sectional study with migrant workers between 18 and 60 years of age residing in the Maule region (n = 145). The applied questionnaires were: a psychosocial risk questionnaire, a health and quality of life questionnaire, and a sociodemographic questionnaire. A bivariate statistical analysis was performed using nonparametric Mann-Whitney U tests, Kruskal Wallis, Spearman correlation, and multiple linear regression models. Results: In Chile, 21% of the migrants maintained the same work activity as in their country of origin. Although the quality of life in physical and mental health is adequate, 52% have low psychological demands at work, 48.9% have low levels of active work and development skills, 57.7% have a high-risk level of compensation and self-esteem, and 65.5% have a high-risk level of double presence at work. Migrants with a higher quality of life in the physical health dimension have a lower risk of maintaining a balance between effort and reward; they worked 44 hours a week and did not work directly at Maule. Migrants with a higher quality of life in the mental health dimension have a lower risk of emotional demands, perceive greater social support in the company, and are less concerned about domestic chores. Conclusions: Migrants with lower quality of life in the physical health dimension presented less compensation at work and recognition, came to work directly in the region, and had jobs with fewer contract hours. Workers with lower quality of life in their mental health exhibited a greater risk of psychological demands at work and perceived low social support in the company; they were concerned about having to respond to domestic and salaried work.

Introducción: Las cifras migratorias sitúan a Chile como uno de los países sudamericanos con mayor número de migrantes. El presente estudio estimó la relación entre características sociodemográficas, calidad de vida y riesgos psicosociales laborales en migrantes trabajadores de la región del Maule. Métodos: Estudio transversal con trabajadores migrantes entre 18 y 60 años, residentes en la Región del Maule (n = 145). Las encuestas aplicadas fueron: Cuestionario de riesgo psicosocial, Cuestionario de salud y calidad de vida y Cuestionario sociodemográfico. Se realizó un análisis estadístico bivariado con pruebas no paramétricas de U de Mann Whitney, Kruskal Wallis, correlación de Spearman y modelos de regresión lineal múltiple. Resultados: Un 21% de los migrantes mantuvo en Chile la misma actividad laboral a la que se dedicaban en su país de origen. Si bien la calidad de vida de la salud física y mental es adecuada, 52% presenta bajas demandas psicológicas en el trabajo, 48,9% bajos niveles de trabajo activo y habilidades de desarrollo, 57,7% tiene un nivel de alto riesgo en la compensación y la autoestima, y 65,5% un nivel de alto riesgo de doble presencia en el trabajo. Los migrantes con mayor calidad de vida en la dimensión salud física presentan menor riesgo de mantener el equilibrio entre el esfuerzo y recompensa, poseen un trabajo de 44 horas a la semana y no llegaron a trabajar directamente al Maule. Los migrantes con mayor calidad de vida en la dimensión salud mental poseen menor riesgo en las demandas emocionales, perciben mayor apoyo social en la empresa y menor preocupación por las tareas domésticas. Conclusiones: Los migrantes con menor calidad de vida en la dimensión salud física, presentan menores compensaciones en el trabajo, bajo reconocimiento, llegaron directamente a trabajar a la región y poseían trabajos con menos horas de contrato. Los trabajadores con menor calidad de vida en su salud mental exhiben mayor riesgo en las exigencias psicológicas en el trabajo, perciben bajo apoyo social en la empresa y preocupación por responder al trabajo doméstico y al asalariado.

Mathematical Model of the Spread of Hantavirus Infection.

A mathematical epidemiological model incorporating the mobility of rodents and human groups among zones of less or major contact between them is presented. The hantavirus infection dynamics is expressed using a model type SEIR (Susceptible-Exposed-Infectious-Removed), which incorporates the displacement of the rodent and the human, between the urban and rural sector, the latter being subdivided in populated and non-populated. The results show the impact that rodent or human displacement may have on the propagation of hantavirus infection. Human mobility is more significant than rodents in increasing the number of hantavirus infection cases. The results found may be used as a reference by the health authorities to develop more specific campaigns on the territorial dynamics of the rodent, attend to the mobility of humans in these territories, mainly agricultural and forestry workers, and strengthen control-prevention actions in the community, to prevent future outbreaks that are fatal.

Effects of human mobility and behavior on disease transmission in a COVID-19 mathematical model.

Human interactions and perceptions about health risk are essential to understand the evolution over the course of a pandemic. We present a Susceptible-Exposed-Asymptomatic-Infectious-Recovered-Susceptible mathematical model with quarantine and social-distance-dependent transmission rates, to study COVID-19 dynamics. Human activities are split across different location settings: home, work, school, and elsewhere. Individuals move from home to the other locations at rates dependent on their epidemiological conditions and maintain a social distancing behavior, which varies with their location. We perform simulations and analyze how distinct social behaviors and restrictive measures affect the dynamic of the disease within a population. The model proposed in this study revealed that the main focus on the transmission of COVID-19 is attributed to the "home" location setting, which is understood as family gatherings including relatives and close friends. Limiting encounters at work, school and other locations will only be effective if COVID-19 restrictions occur simultaneously at all those locations and/or contact tracing or social distancing measures are effectively and strictly implemented, especially at the home setting.

Affective modulation of cognitive control: A systematic review of EEG studies.

In recent years, a growing corpus of research has been conducted utilizing a variety of behavioral and neurophysiological methodologies to investigate the relationship of emotion and cognition, yielding unique insights into fundamental concerns about the human mind and mental disease. Electroencephalography (EEG) has been utilized to investigate how emotional states alter neural markers of cognitive control. The current study is a systematic analysis of EEG research that looks at affective modulation (mood, emotion) of cognitive control and its many sub-processes (e.g., cognitive flexibility, inhibitory control, and working memory). The PRISMA standards were followed in this review, which looked at experimental designs and tasks, as well as methodological elements of EEG recording and analysis across research. A total of 35 articles were chosen for qualitative synthesis as a consequence of the search. The examination of event-related potentials (ERPs), which showed affective modulation of 19 different components, was the most common electrophysiological approach used across research. The majority of the investigations focused on N2 and P3, indicating that affective induction has a strong influence on attentional processes and response inhibition. Future research should look into different methodologies such as source location and connection metrics to better understand the brain's areas and dynamic response during affective induction activities. It is also suggested that the technical components of the report be more explicit in order to promote study comparability and replication.

Modeling of hantavirus cardiopulmonary syndrome. / Modelamiento del síndrome cardiopulmonar por hantavirus.

Introduction: Hantavirus cardiopulmonary syndrome is an infection caused by rodents of the Bunyanvirales family towards humans. This disease in Chile is considered endemic, which has a high fatality rate. At present, some studies show the contagion between people of the Andes virus, whose locality is concentrated in Argentina and Chile. Objectives: Analyze the possibility of hantavirus transmission between humans using an SEIR-type mathematical model. Methods: An SEIR (Susceptible, Exposed, Infectious and Recovered) mathematical model to express the dynamics of hantavirus disease is proposed, including the possibility of human-to-human transmission and the perception of risk. Results: The peak of human-to-human contagion decreases by about 25% after increasing peoples perception of risk by reducing the rate of resistance to changeand increasing the speed of peoples reaction. Conclusions: It is urgent to review risk communication strategies and prevention measures in the face of this possibility of massive human-tohuman infections, in addition to strengthening research and planning the development of a vaccine to protect populations exposed to this disease with a high fatality rate.

Introducción: El síndrome cardiopulmonar por hantavirus es una enfermedad causada por un virus perteneciente al orden bunyanvirales, y transmitida hacia los humanos a través de roedores. Esta enfermedad en Chile es considerada endémica, la cual tiene una alta tasa de letalidad. En la actualidad existen estudios que evidencian el contagio entre personas del virus Andes, cuya localidad se concentra en los países de Argentina y Chile. Objetivos: Analizar la posibilidad de transmisión de hantavirus entre humanos, mediante un modelo matemático tipo SEIR. Métodos: Se plantea un modelo matemático tipo SEIR (susceptible, expuesto, infeccioso y recuperado) para expresar la dinámica de la enfermedad por hantavirus, incluyendo la posibilidad de transmisión entre humanos y la percepción del riesgo. Resultados: El máximo de contagio entre humanos disminuye cerca de 25% tras aumentar la percepción de riesgo de las personas, mediante la reducción de la tasa de resistencia al cambio y aumento la velocidad de reaccionar de las personas. Conclusiones: Es urgente revisar las estrategias de comunicación de riesgo y medidas de prevención ante esta posibilidad de contagios masivos entre humanos, además de fortalecer la investigación y proyectar el desarrollo de una vacuna para proteger las poblaciones expuestas a esta enfermedad con alta tasa de letalidad.

Health Effects of Pesticide Exposure in Latin American and the Caribbean Populations: A Scoping Review.

BACKGROUND: Multiple epidemiological studies have shown that exposure to pesticides is associated with adverse health outcomes. However, the literature on pesticide-related health effects in the Latin American and the Caribbean (LAC) region, an area of intensive agricultural and residential pesticide use, is sparse. We conducted a scoping review to describe the current state of research on the health effects of pesticide exposure in LAC populations with the goal of identifying knowledge gaps and research capacity building needs. METHODS: We searched PubMed and SciELO for epidemiological studies on pesticide exposure and human health in LAC populations published between January 2007 and December 2021. We identified 233 publications from 16 countries that met our inclusion criteria and grouped them by health outcome (genotoxicity, neurobehavioral outcomes, placental outcomes and teratogenicity, cancer, thyroid function, reproductive outcomes, birth outcomes and child growth, and others). RESULTS: Most published studies were conducted in Brazil (37%, n=88) and Mexico (20%, n=46), were cross-sectional in design (72%, n=167), and focused on farmworkers (45%, n=105) or children (21%, n=48). The most frequently studied health effects included genotoxicity (24%, n=62) and neurobehavioral outcomes (21%, n=54), and organophosphate (OP) pesticides were the most frequently examined (26%, n=81). Forty-seven percent (n=112) of the studies relied only on indirect pesticide exposure assessment methods. Exposure to OP pesticides, carbamates, or to multiple pesticide classes was consistently associated with markers of genotoxicity and adverse neurobehavioral outcomes, particularly among children and farmworkers. DISCUSSION: Our scoping review provides some evidence that exposure to pesticides may adversely impact the health of LAC populations, but methodological limitations and inconsistencies undermine the strength of the conclusions. It is critical to increase capacity building, integrate research initiatives, and conduct more rigorous epidemiological studies in the region to address these limitations, better inform public health surveillance systems, and maximize the impact of research on public policies. https://doi.org/10.1289/EHP9934.

Neurobehavioral, Neuromotor, and Neurocognitive Effects in Agricultural Workers and Their Children Exposed to Pyrethroid Pesticides: A Review.

In recent years, pyrethroids have emerged as a less toxic alternative to eliminate insect pests. However, some animal studies and studies with children show that these pesticides are toxic and lead to neurobehavioral effects similar to other pesticides, such as organophosphates. The purpose of this review was to systematize the epidemiological scientific evidence about the neurobehavioral, neuromotor, and neurocognitive effects in agricultural workers and their children exposed to pyrethroid pesticides. We conducted two searches (with different terms) in PubMed and Scopus databases, including articles in Spanish and English language on the effects of occupational exposure to pyrethroid pesticides associated with neurobehavioral, neuromotor, and neurocognitive functioning of agricultural workers and their children. There were no filters by year, and the search included studies till march 2021. To develop the search, we followed the recommendations contained in the PRISMA guidelines and the PICO strategy. The results show that in 66.6% of the studies reviewed (8 of 12 studies), agricultural workers or their children occupationally exposed to pyrethroid pesticides have a higher risk of presenting difficulties in their neurocognitive, neuromotor, or neurobehavioral performance, mainly associated with attention, processing speed (linked to hand-eye coordination), and motor coordination. There are still few studies that address this issue. However, the quality of most of the research conducted (83% intermediate or high quality) confirms the risk for neurobehavioral health in agricultural workers due to occupational exposure to pyrethroids. More research is required evaluating the exposure to pyrethroids, including biomarkers and validated neurobehavioral and neuromotor tests, in addition to evaluating the effect of simultaneous exposure to other hazardous pesticides. Assuming that the use of pyrethroids is increasing considerably and faster than the scientific evidence, it is suggested as a precautionary principle to regulate, more strictly, the sale of pyrethroids and other pesticides.

[Pesticide exposure in Chile and population health: urgency for decision making]. / Exposición a plaguicidas en Chile y salud poblacional: urgencia para la toma de decisiones.

In the last 25 years, Chile has had an expanding role as an agro-export country in the global economy, with efficient rates of productivity in the region, based on the technological development of agriculture, with of large monocultures whose productivity depends on the intensive application of agrochemicals. This form of agriculture has also lacked efficient regulations and surveillance, so it is difficult to estimate the real magnitude of the exposed population and its effects on health in the short or long term. This systematic review compiles the epidemiological evidence generated from studies conducted in several regions of Chile regarding pesticide exposure and health effects. Of the total number of articles, 50% included agricultural workers, 25% children, and 25% women of childbearing age, with the greatest effects being the neurotoxic (54%), genotoxic (31%) and reproductive (15%). The evidence collected shows that in Chile the levels of exposure to pesticides in the general and occupational population are higher than international studies levels. It is urgent to protect the health of both the occupational and general population and especially children through a stricter control of the sale and use of pesticides, with comprehensive surveillance systems in environmental health and educational actions in the social and cultural context of rural communities. It is a priority to strengthen research with national relevance on health effects, and strictly restrict the use of pesticides already prohibited in developed countries due to their high level of risk to human and environmental health.

Psychometric Validation of a Questionnaire to Assess Perception and Knowledge About Exposure to Pesticides in Rural Schoolchildren of Maule, Chile.

Exposure to pesticides during infancy is associated with numerous adverse health outcomes. The assessment of knowledge and perception of pesticides exposure and risk among children has not been thoroughly studied. The aim of the study was to evaluate the reliability and validity of a questionnaire that measures the knowledge and perception of exposure to organophosphate pesticides among rural schoolchildren. The questionnaire was administered to 151 schoolchildren between 9 and 13years from four Chilean rural schools. An internal consistency analysis of the ordinal alpha coefficient and a polychoric factor analysis for categorical data were used. The results show that the ordinal alpha was 0.95. Polychoric matrices of rotated components show the 17 questions summarized pesticide knowledge in five factors extracted after promax rotation. This factorial model explains 56.3% of the variance. The questions were grouped as follows: knowledge about pesticides (Factor 1); knowledge of health effects related to pesticides exposure (Factor 2); pesticide exposure through the growing of fruits and vegetables (Factor 3); perception and action against pesticides exposure at school (Factor 4); and perception and action against pesticides exposure at home (Factor 5). The questionnaire provides a useful tool for examining pesticide exposure in agricultural regions, allowing younger community members to participate.

Levels of Polychlorinated Dibenzo-p-Dioxins/Furans (PCDD/Fs) and Dioxin-Like Polychlorinated Biphenyls (DL-PCBs) in Human Breast Milk in Chile: A Pilot Study.

Persistent organic pollutants (POPs) are organic compounds that resist biochemical degradation, moving long distances across the atmosphere before deposition occurs. Our goal was to provide up-to-date data on the levels of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in breast milk from Chilean women and to estimate the exposure of infants due to breast milk consumption. In Chile, we conducted a cross-sectional study based on methodologies proposed by the WHO, with a sample of 30 women recruited from three defined areas: 10 from the Arica Region (urban; Arica and Parinacota Region), 10 from Coltauco (rural; O'Higgins Region), and 10 from Molina (40% rural; Maule Region). High-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC/HRMS) was performed on pooled samples from each area. We calculated equivalent toxic concentrations (WHO-TEQ) based on the current WHO Toxic Equivalency Factors (TEF). The minimum and maximum values of ∑ PCDDs/Fs + DL-PCBs-TEQ were 4.317 pg TEQ/g fat in Coltauco and 6.31 pg TEQ/g fat in Arica. Molina had a total TEQ of 5.50 pg TEQ/g fat. The contribution of PCDD/Fs was approximately five-fold higher than that of DL-PCBs. The Estimated Daily Intake (EDI) of ∑ PCDDs/Fs + DL-PCBs based on the three pooled samples ranged between 6.71 and 26.28 pg TEQ/kg body weight (bw)/day, with a mean intake of 16.11 (±6.71) pg TEQ/kg bw/day in breastfed children from 0 to 24 months old. These levels were lower than those reported in international studies. Despite the fact that the observed levels were low compared to those in most industrialized countries, the detection of a variety of POPs in breast milk from Chilean women indicates the need for follow-up studies to determine whether such exposures during childhood could represent a health risk in adulthood.

Pesticide application, educational treatment and infectious respiratory diseases: A mechanistic model with two impulsive controls.

In this paper, we develop and analyze an SIS-type epidemiological-mathematical model of the interaction between pesticide use and infectious respiratory disease transmission for investigating the impact of pesticide intoxication on the spread of these types of diseases. We further investigate the role of educational treatment for appropriate pesticide use on the transmission dynamics. Two impulsive control events are proposed: pesticide use and educational treatment. From the proposed model, it was obtained that the rate of forgetfulness towards educational treatment is a determining factor for the reduction of intoxicated people, as well as for the reduction of costs associated with educational interventions. To get reduced intoxications, the population's fraction to which is necessary to apply the educational treatment depends on its individual effectiveness level and the educational treatments' forgetfulness rate. In addition, the turnover of agricultural workers plays a fundamental role in the dynamics of agrotoxic use, particularly in the application of educational treatment. For illustration, a flu-like disease with a basic reproductive number below the epidemic threshold of 1.0 is shown can acquire epidemic potential in a population at risk of pesticide exposure. Hence, our findings suggest that educational treatment targeting pesticide exposure is an effective tool to reduce the transmission rate of an infectious respiratory disease in a population exposed to the toxic substance.

[Model for a threshold of daily rate reduction of COVID-19 cases to avoid hospital collapse in Chile]. / Modelo de umbral de reducción de tasa diaria de casos COVID-19 para evitar el colapso hospitalario en Chile.

Using a mathematical model, we explore the problem of availability versus overdemand of critical hospital processes (e.g., critical beds) in the face of a steady epidemic expansion such as is occurring from the COVID-19 pandemic. In connection with the statistics of new cases per day, and the assumption of maximum quota, the dynamics associated with the variables number of hospitalized persons (critical occupants) and mortality in the system are explored. A parametric threshold condition is obtained, which involves a parameter associated with the minimum daily effort for not collapsing the system. To exemplify, we include some simulations for the case of Chile, based on a parameter of effort to be sustained with the purpose of lowering the daily infection rate.

Mediante un modelo matemático este trabajo explora la problemática de la disponibilidad versus sobredemanda de procesos críticos hospitalarias (por ejemplo, camas críticas) ante una fuerte expansión epidémica como la que está ocurriendo como consecuencia de la pandemia de COVID-19. En conexión con la estadística de nuevos casos diarios y el supuesto de cupo máximo, exploramos la dinámica asociada a las variables número de hospitalizados (ocupantes críticos) y mortalidad en el sistema. Obtenemos una condición paramétrica umbral que involucra un parámetro asociado al esfuerzo mínimo diario para el no colapso del sistema. En orden a ejemplificar, incluimos algunas simulaciones para el caso de Chile, en función de un parámetro de esfuerzo a sostener para bajar la tasa de infección diaria.