Pesticides and atopic and nonatopic asthma among farm women in the Agricultural Health Study

Associations between agricultural use of pyrethroid insecticides and asthma: AGRICAN cohort results

RATIONALE

Following the withdrawal of organochlorines and organophosphates, pyrethroids have become the most used insecticides in both agricultural and domestic settings.

OBJECTIVES

We analyzed data from the French AGRICAN agricultural cohort to assess associations of occupational pyrethroid exposures and allergic/non-allergic asthma.

METHODS

At enrollment, asthma diagnosed by a doctor was reported by 11 815 participants (7028 classified as non-allergic and 4458 as allergic based on the presence of eczema and/or hay fever). Individual exposures to 17 pyrethroids were defined in 124 992 participants, based on a combination of the history of pesticide treatment of 11 crops (grassland, vineyard, wheat/barley, corn, field peas, potatoes, tobacco, beets, sunflower, rape, fruits) and a crop-exposure matrix.

MEASUREMENTS AND MAIN RESULTS

In men, no association was observed for any of the pyrethroids regardless of asthma phenotype. In contrast, in ever-exposed women, asthma risk was increased with use of any pyrethroid, both for allergic (+80 %) and non-allergic asthma (+40 %). Highest increases were observed for allergic asthma with fenpropathrin (OR = 2.00; 95 %CI:1.38-2.90), tralomethrin (OR = 1.81; 95 %CI:1.28-2.56), fenvalerate (OR = 1.81; 95 %CI:1.38-2.38), permethrin (OR = 1.78; 95 %CI:1.26-2.50) and deltamethrin (OR = 1.76; 95 %CI:1.35-2.29). Stratified analyses on women who reported living on a farm in early life showed stronger associations for non-allergic asthma. For women who reported early life living on vineyards associations with pyrethroids were stronger for both allergic and non-allergic asthma. Associations for women who lived on cattle farms were reduced for some pyrethroids.

CONCLUSION

Occupational pyrethroid exposure was positively associated with both allergic and non-allergic asthma in women but not in men.

Association of organophosphorus pesticides and glyphosate exposure with nasal flora and total IgE in solar greenhouse workers: A unique farmer group

Studies have shown that the presence of allergens, including insecticides, significantly increases the risk of occupational allergic diseases among solar greenhouse workers. However, no studies have investigated the relationship between organophosphorus pesticides (OPs) used by solar greenhouse workers and allergic diseases, and the role of nasal flora in this context remains unclear. Therefore, this study aimed to investigate the relationship between combined exposure to organophosphorus pesticides and glyphosate (GLY) with changes in total immunoglobulin E (IgE) levels, as well as to analyze the role of nasal flora in allergic status. We collected demographic data, urine, peripheral blood and nasal swab samples from 284 solar greenhouse workers. Six metabolites in urine were detected by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Total IgE concentration was determined by enzyme-linked immunosorbent assay (ELISA). Then, we evaluated the association between OPs and GLY with total IgE levels using logistic regression analysis. In addition, 66 participants received 16S rDNA sequencing of nasal flora, followed by community diversity and species difference analyses to identify distinct microbial communities between normal and elevated total IgE groups. A total of 284 participants were included in this study, of whom 132 (46.5%) and 152 (53.5%) were male and female, respectively. The median total IgE concentration in this population was 63.52 IU/mL, of which 89 (31.3%) belonged to the elevated total IgE group. Our results suggest that dimethylphosphorodithioate (DMDTP) was a risk factor for total IgE abnormality, and GLY was positively associated with total IgE abnormality. Additionally, 20 differential flora were identified between the elevated and normal IgE groups, of which at least seven were significantly associated with OPs, GLY and their metabolites. In conclusion, there was a positive correlation between exposure to OPs and GLY with total IgE abnormalities, as well as multiple nasal pathogenic flora.

The Health and Well-Being of Women in Farming: A Systematic Scoping Review

OBJECTIVES

Health and well-being have long been identified as key issues for investigation within agricultural communities. While myriad studies have been conducted to investigate causation, impact, outcomes and interventions among farming populations, the overall emphasis has been disproportionately weighted away from the experiences of women. This systematic scoping review determines the prevalence of topics, identifies the target populations and geographical locations of studies, outlines methodological approaches to the subject area, and summarizes the key findings and conclusions of the available literature.

METHODS

With the guidance of the Arksey and O'Malley framework for conducting a scoping review, a single database search for publications focusing on the health and well-being of women in farming (including primary farmers, members of farm households, and farmworkers), in the Global North, published between 1990 and 2023, was conducted. Data were organized, thematically coded, critically appraised and analyzed using the systematic review online tool CADIMA.

RESULTS

In total, 93 studies met the inclusion criteria for full review. The majority of studies were conducted in the United States, with the number of publications steadily increasing since the 1990s. Of studies, 68% were wholly quantitative in nature, and 23% wholly qualitative. Key findings suggest women are at particular risk from certain illnesses associated with some aspects of agricultural work and face a number of stressors (including gender-specific issues) that can lower well-being, but evidence is scarce in a number of areas. Clear gaps in research exist in relation to reproductive health, caring responsibilities, or help-seeking and support. Women primary farmer and farmworkers are particularly neglected as study cohorts.

CONCLUSION

Numbers of studies related to the health and well-being of women in farming are still relatively small in comparison with the wider body of related literature, and there exists an obvious need for further studies with a specific emphasis on particular cohorts, issues pertaining to the contemporary climate, and issues specific to women, as well as greater geographical reach. By emphasizing such research gaps, opportunities exist to improve the health and well-being situation of women in agriculture through more explicit studies with the intention of developing more effective, targeted solutions.

Respiratory and allergic outcomes among farmworkers exposed to pesticides in Costa Rica

AIM

We examined the association of exposure to a pesticide mixture with respiratory and allergic outcomes among farmworkers from Costa Rica.

METHODS

We conducted a cross-sectional study of 299 farmworkers between May and August 2016. We collected information on sociodemographic factors, pesticide use, and the presence of respiratory and allergic symptoms during the last 12 months via questionnaire. We calculated specific gravity-adjusted average concentrations of 15 pesticide biomarkers measured in urine samples collected during two visits (4-5 weeks apart). We fitted "traditional" Bayesian and Bayesian Weighted Quantile Sum (BWQS) regression models to assess the association of exposure to independent and summed pesticide mixture components with the outcomes of interest. We adjusted all models for age and smoking status.

RESULTS

In "traditional" Bayesian analyses, higher urinary concentrations of 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPY, metabolite of organophosphate insecticide diazinon) were associated with increased odds of a higher asthma symptom score [adjusted OR per two-fold increase in concentrations = 1.15; 95 % credible interval (CrI): 1.04, 1.27)], asthma symptoms or medication use (aOR = 1.37; 95 % CrI: 1.13, 1.67), and rhinitis (aOR = 1.34; 95 % CrI: 1.15, 1.56). Higher urinary concentrations of boscalid-5-hydroxy (metabolite of fungicide boscalid) were associated with increased odds of asthma symptoms or medication use (aOR = 1.24; 95 % CrI: 1.00, 1.55), whereas higher concentrations of 4-hydroxypyrimethanil (metabolite of the fungicide pyrimethanil) were associated with increased odds of eczema (aOR = 1.11; 95 % CrI: 0.99, 1.24). Several inverse associations of herbicide concentrations with respiratory and allergic outcomes were observed. In BWQS analyses, a positive association was found between exposure to the pesticide mixture and increased odds of rhinitis (aOR = 1.96; 95 % CrI: 1.14, 3.20), with IMPY being the largest contributor.

CONCLUSION

Our findings indicate that exposure to pesticides may have both independent and summed mixture effects on respiratory and allergic health among farmworkers.

Respiratory system: Highly exposed yet under-reported organ in pyrethrin and pyrethroid toxicity

Pyrethrin and pyrethroid are a relatively new class of pesticides with potent insecticidal properties. Pyrethrins are naturally occurring pesticides obtained from the Chrysanthemum cinerariaefolium flower, while pyrethroids are their synthetic derivatives. They are widely used as the insecticides of choice in agriculture, veterinary medicine, public health programs, and household activities. Pyrethrin, being a broad-spectrum insecticide kills a wide range of pests, while pyrethroids last longer in the environment owing to low susceptibility to sunlight, and greater stability and efficacy than parent molecules. Humans can be exposed through inhalation, ingestion, and dermal routes. Indoor usage of an insecticide poses a serious risk to human health, especially to women, children, and stay-at-home people. Although pyrethrin and pyrethroid are generally considered safe, sustained skin or inhalation exposure or direct contact with open wounds results in higher toxicity to mammals. There is a paucity of data on the impact of pyrethrin and pyrethroid on overall pulmonary health. The respiratory system, from the nose, nasal passages, airways, and bronchi to the pulmonary alveoli, is vulnerable to environmental contaminants such as pesticides because of its anatomical location as well as being a highly blood profused organ. Under and over-functioning of the respiratory system triggers diverse pathologies such as serious infections, allergies, asthma, metastatic malignancies, and auto-immune conditions. While the association between workplace-related pesticide exposures and respiratory diseases and symptoms is well documented, it is important to understand the adverse health impact of pyrethrin and pyrethroid on the general population for awareness and also for better regulation and implementation of the law.

Association of pesticide exposure with respiratory health outcomes and rhinitis in avocado farmworkers from Michoacán, Mexico

BACKGROUND

A growing literature suggests associations between occupational pesticide exposure and respiratory health. In this study, we aimed to examine the association of exposure to insecticides, fungicides, and herbicides, individually and as a mixture, with respiratory health outcomes and rhinitis in avocado farmworkers from Michoacán, Mexico.

MATERIAL AND METHODS

We conducted a cross-sectional study of 105 avocado farmworkers between May and August 2021. We quantified 12 insecticide, fungicide, and herbicide metabolites in urine samples collected during two study visits (8-10 weeks apart). We collected survey data on self-reported pesticide use during the 12 months prior to the baseline survey and estimated annual exposure-intensity scores (EIS) using a semi-quantitative exposure algorithm. We also assessed respiratory symptoms, including wheezing, chest tightness, wheezing after exercise, and night cough. We used generalized linear regression models to examine associations of individual urinary metabolite concentrations and annual EIS with respiratory health outcomes and rhinitis. Mixture effects were assessed using Bayesian Weighted Quantile Sum (BWQS) regression.

RESULTS

After adjusting for multiple comparisons, we observed mostly null associations of individual pesticide metabolite concentrations and annual EIS with the outcomes of interest. However, in BWQS analyses, we found evidence of a mixture association of urinary pesticide metabolites with increased odds of night cough (OR: 5.34, 95 % CrI: 1.67, 20.62). Pyrethroid metabolites 3-phenoxybenzoic acid and cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid were the main contributors to this association (43 %).

CONCLUSIONS

Our findings indicate that exposure to a mixture of pesticides, particularly pyrethroid insecticides, may be associated with night cough in avocado farmworkers.

Exposure to agricultural pesticides and wheezing among 5-12-year-old children in the Imperial Valley, CA, USA

Background

Exposure to pesticides has been linked to adverse respiratory health outcomes in children.

Methods

We leveraged the Children's Assessing Imperial Valley Respiratory Health and the Environment cohort located in the rural community of Imperial Valley near the US-Mexico border. We calculated the kilograms of total pesticides applied within 400 m of children's residential addresses for the years 2016-2020. Estimated pesticide usage near homes was categorized into three groups (none vs. low vs. high [split at the median]). All health variables (i.e., asthma status and wheezing) were derived from a parent-reported questionnaire on respiratory health. We used generalized linear models, controlling for child sex, the language of survey, health insurance, respondents' highest education, and exposure to environmental secondhand smoking, to calculate prevalence differences between none versus low and high exposure to agricultural pesticides.

Results

Approximately 62% of the 708 children (aged 5-12 years) lived within 400 m of at least one pesticide application within 12 months prior to survey administration. Exposure to pesticides within 400 m of children's residences was associated with 12-month prior wheeze. Those in the "high" exposure group had a prevalence of wheezing that was 10 (95% confidence interval: 2%, 17%) percentage points higher than among children not exposed to pesticide applications. Associations for high exposure to specific categories of pesticide applications, sulfur only, all pesticides except sulfur, chlorpyrifos, and glyphosate, also were observed with a higher prevalence of wheezing than among children not exposed to pesticide applications.

Conclusions

We observed associations between living near pesticide applications and more wheeze symptoms among children.

Short occupational exposure to glyphosate and its biomonitoring via urinary levels of glyphosate and metabolite AMPA (Amino-MethylPhosphonic acid), in Italian vineyard workers

Glyphosate, an herbicide largely used in various contexts, can have adverse effects on human health. Although it is currently the most applied pesticide worldwide, few studies evaluated the extent of human exposure via biomonitoring. To expand such information, biological monitoring of exposure to glyphosate was conducted. The study has a before-and-after design to demonstrate the immediate impact of short-term interventions. Accordingly, the urine concentrations of glyphosate and its main biodegradation product (amino-methylphosphonic acid- AMPA) were measured before and the day after the single herbicide application in 17 male winegrowers. Urine samples were analyzed by high performance liquid chromatography coupled with a triple quadrupole mass spectrometer equipped with an electrospray ionization source. Glyphosate and AMPA were not detectable in pre-application urine samples (limit of quantification for glyphosate (LOQG) was 0.1 μg/L; limit of quantification for AMPA (LOQAMPA) was 0.5 μg/L). After application, glyphosate urinary levels were above LOQG in all workers. The median, min, and max values were 2.30, 0.51, and 47.2 μg/L, respectively. The same values were found for 50 %, 5 % and 95 % percentiles. After assigning numerical values, such as one half the LOQ, to each of the non-detects, the "z" of Wilcoxon matched-pairs signed-ranks test was -3.62 (p = 0.0003), suggesting the pre-application values being significantly lower than the post-application urinary glyphosate concentration. A similar analysis was not feasible with AMPA urinary levels, which were detectable only in 3 workers, after application. 12 (71 %) workers were significantly exposed to glyphosate, but adherence to the adoption of personal protective equipment was good: 14 (82 %) workers used gloves, 13 (76 %) used overalls and 13 (76 %) facial masks. Our data show that glyphosate can be absorbed by the workers after a single application and confirms the usefulness of biomonitoring in exposed workers. Further studies are needed in larger working populations and with multiple glyphosate applications, as well as to evaluate the correlations of glyphosate urine levels with exposure questionnaire data, in order to assess the actual relevance of risk and protection factors.

Identifying pesticides of high concern for ecosystem, plant, animal, and human health: A comprehensive field study across Europe and Argentina

The widespread and excessive use of pesticides in modern agricultural practices has caused pesticide contamination of the environment, animals, and humans, with confirmed serious health consequences. This study aimed to identify the 20 most critical substances based on an analysis of detection frequency (DF) and median concentrations (MC) across environmental and biological matrices. A sampling campaign was conducted across 10 case study sites in Europe and 1 in Argentina, each encompassing conventional and organic farming systems. We analysed 209 active substances in a total of 4609 samples. All substances ranked among the 20 most critical were detected in silicon wristbands worn by humans and animals and indoor dust from both farming systems. Five of them were detected in all environmental matrices. Overall, higher values of DF and MC, including in the blood plasma of animals and humans, were recorded in samples of conventional compared to organic farms. The differences between farming systems were greater in the environmental samples and less in animal and human samples. Ten substances were detected in animal blood plasma from conventional farms and eight in animal blood plasma from organic farms. Two of those, detected in both farming systems, are classified as hazardous for mammals (acute). Five substances detected in animal blood plasma from organic farms and seven detected in animal blood plasma from conventional farms are classified as hazardous for mammals (dietary). Three substances detected in human blood plasma are classified as carcinogens. Seven of the substances detected in human blood plasma are classified as endocrine disruptors. Six substances, of which five were detected in human blood plasma, are hazardous for reproduction/development. Efforts are needed to elucidate the unknown effects of mixtures, and it is crucial that such research also considers biocides and banned substances, which constitute a baseline of contamination that adds to the effect of substances used in agriculture.

[Pesticide exposure and chronic respiratory diseases]

INTRODUCTION

Pesticides are used worldwide, mainly in agriculture as a means of controlling pests and protecting crops. That said, the entire world population is ultimately subject to pesticide exposure (consumption of fruits and vegetables, living near treated fields…), with varying degrees of toxicity involved.

STATE OF THE ART

In recent decades, epidemiological studies have contributed to the identification of chemical pesticide families with detrimental effects on human health: cognitive disorders, Parkinson's disease, prostate cancer… and impairment in respiratory functioning. Current scientific evidence points to the implication of the active substances in insecticides, herbicides and fungicides in chronic respiratory diseases, two examples being chronic obstructive pulmonary disease (COPD) in exposed workers, and asthmatic wheezing in children during prenatal or postnatal exposure.

PERSPECTIVES

The safety of individuals exposed to pesticides is of key importance in public health. Further epidemiological investigations are needed to identify the chemical families affecting certain populations.

CONCLUSIONS

The scientific literature suggests strong links between pesticide exposure and respiratory health. Whether it be environmental or occupational, pesticide exposure can lead to respiratory disorders and symptoms of varying severity.

Assessing the effectiveness of mitigating pesticide-related disease risk among pesticide-spraying drone operators in Taiwan

OBJECTIVES

The purpose of this study was to evaluate the risk of pesticide poisoning, liver and renal failure, dermatitis, respiratory problems, hypersensitivity pneumonitis, keratitis, and epilepsy among pesticide-spraying personnel and to assess the effectiveness of a new method of aerial pesticide application in reducing this risk.

METHODS

A total of 2268 pesticide spraying operators (1651 ground-based field crop operators and 617 aerial pesticide spraying drone operators) who passed the national certification examination between 2010 and 2020 in Taiwan were included. Ground-based operators served as the positive control group, while 2463 farmer controls were matched from the Farmers' Health Insurance database as the negative control group. Data from the National Health Insurance Research Database were used to track possible pesticide-related disease cases. Logistic regression was employed to calculate odds ratios and 95% confidence intervals (95% CI).

RESULTS

Drone operators had significantly reduced risks of dermatitis, asthma and chronic bronchitis compared to ground-based operators. This was observed in allergic contact dermatitis (OR = 0.40, 95% CI: 0.24-0.68), unspecified contact dermatitis (OR = 0.58, 95% CI: 0.35-0.97), asthma (OR = 0.27, 95% CI: 0.12-0.60), and chronic bronchitis (OR = 0.24, 95% CI: 0.06-0.93), after adjusting for age, sex, working areas, and licensing years. However, no significant differences were found when comparing drone operators to matching farmers.

CONCLUSIONS

Aerial pesticide spraying using drones may contribute to a decreased risk of dermatitis, asthma and chronic bronchitis, suggesting potential health benefits for operators. Further field pesticide exposure surveys are recommended to validate these findings and assess health risk indicators.

Impact of glyphosate (RoundupTM) on the composition and functionality of the gut microbiome

Glyphosate, the active ingredient in the broad-spectrum herbicide RoundupTM, has been a topic of discussion for decades due to contradictory reports of the effect of glyphosate on human health. Glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) of the shikimic pathway producing aromatic amino acids in plants, a mechanism that suggests that the herbicide would not affect humans as this pathway is not found in mammals. However, numerous studies have implicated glyphosate exposure in the manifestation of a variety of disorders in the human body. This review specifically outlines the potential effect of glyphosate exposure on the composition and functionality of the gut microbiome. Evidence has been building behind the hypothesis that the composition of each individual gut microbiota significantly impacts health. For this reason, the potential of glyphosate to inhibit the growth of beneficial microbes in the gut or alter their functionality is an important topic that warrants further consideration.

Association of urinary organophosphate metabolites with adult asthma patients: a cross-sectional population-based study

Human health is adversely affected by exposure to organophosphate (OP) pesticides. This study aims to investigate the correlation between urinary OP metabolites and the prevalence of asthma. In cross-sectional studies, data from the National Health and Nutrition Examination Survey (NHANES) projects conducted between 2003-2008, 2011-2012, and 2015-2018 were analyzed. Multiple logistic regressions and restricted cubic spline (RCS) regressions were utilized to examine the relationship between four urinary OP metabolites, namely dimethyl phosphate (DMP), diethyl phosphate (DEP), dimethyl phosphorothioate (DMTP), and diethyl phosphorothioate (DETP), and the prevalence of asthma. Additionally, quantile g-computation (QG-C) regression was employed to evaluate the association between urinary OP metabolites (both individual and combined exposures) and asthma prevalence. The results showed that a total of 9316 adults, including 1298 participants with asthma, were included in the analysis. The median age of the participants was 47.37 years, and 50.27% were female. In the comprehensive model, the third tertile of DMP and DEP exhibited a positive association with asthma prevalence compared to the first tertile (odds ratio [95% confidence interval]: 1.26 [1.01-1.57], Ptrend = 0.036; and 1.25 [1.07-1.51], Ptrend = 0.008, respectively). Moreover, a linear relationship was observed between DMP, DEP, and asthma prevalence (P for nonlinearity = 0.320 and 0.553, respectively). The QG-C regression revealed a positive association between the mixture of urinary OP metabolites and asthma prevalence (OR = 1.04 [1.01-1.07], P = 0.025), with DEP contributing the most substantial effect (weight = 0.564). Our findings suggest that exposure to OP pesticides is associated with an increased prevalence of asthma, with DEP demonstrating the strongest impact.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Dichlorodiphenyltrichloroethane for Malaria and Agricultural Uses and Its Impacts on Human Health

Pesticides are widely used in agriculture and disease control, and dichlorodiphenyltrichloroethane (DDT) is one of the most used pesticides in human history. Besides its significant contributions in pest control in agriculture, DDT was credited as having saved millions of human lives for controlling malaria and other deadly insect-transmitted diseases. Even today, the use of DDT in some countries for malaria control cannot be replaced without endangering people who live there. The recent COVID-19 pandemic has changed our lives and reminded us of the challenges in dealing with infectious diseases, especially deadly ones including malaria. However, DDT and its metabolites are stable, persist long, are found in almost every corner of the world, and their persistent effects on humans, animals, and the environment must be seriously considered. This review will focus on the history of DDT use for agriculture and malaria control, the pathways for the spread of DDT, benefits and risks of DDT use, DDT exposure to animals, humans, and the environment, and the associated human health risks. These knowledge and findings of DDT will benefit the selection and management of pesticides worldwide.

The Associations between Organophosphate Pesticides (OPs) and Respiratory Disease, Diabetes Mellitus, and Cardiovascular Disease: A Review and Meta-Analysis of Observational Studies

Although some epidemiological studies have identified the associations between exposure to organophosphate pesticides (Ops) and respiratory diseases, diabetes mellitus (DM), and cardiovascular diseases (CVDs), controversial results still exist. In this review and meta-analysis, we aimed to investigate the overall pooled effect estimates and the possible mechanisms of the relationship between OP exposure and adverse health outcomes. In this study, Web of Science, PubMed, Embase, OVID, and the Cochrane Library were systematically searched until September 2022. Nineteen observational studies that focused on the general population or occupational populations examined the associations between OP exposure and respiratory diseases, DM, and CVD were included. Based on the overall pooled results, a significantly positive association was observed between OP exposure and respiratory diseases (OR: 1.12, 95% CI: 1.06-1.19). A significant link was also observed between various individual species of OP exposure and respiratory diseases, with an OR value of 1.11 (95% CI: 1.05-1.18). In particular, there was a significant association of OPs with wheezing and asthma, with OR values of 1.19 (95% CI: 1.08-1.31) and 1.13 (95% CI: 1.05-1.22), respectively. In addition, a significant association was also observed between OP exposure and DM (OR: 1.18, 95% CI: 1.07-1.29). However, no significant association was observed between OP exposure and CVD (OR: 1.00, 95% CI: 0.94-1.05). Exposure to OPs was associated with a significantly increased risk of respiratory diseases and DM, but there was no evidence of a significant association between OP exposure and CVD. Considering the moderate strength of the results, further evidence is needed to confirm these associations.

Adhesion Molecules in Lung Inflammation from Repeated Glyphosate Exposures

Glyphosate is an active ingredient in herbicides. Exposure to glyphosate-based herbicides has been associated with respiratory dysfunctions in agricultural workers. The ability of inhaled glyphosate to induce lung inflammation is not well understood. Further, the role of adhesion molecules in glyphosate-induced lung inflammation has not been studied. We evaluated lung inflammatory responses from single and repeated glyphosate exposures. Male C57BL/6 mice were intranasally exposed to glyphosate (1 μg/40 μL) for 1 day or once daily for 5 days or 10 days. Lung tissue and bronchoalveolar lavage (BAL) fluid were collected and analyzed. Repeated exposure to glyphosate for 5 days and 10 days resulted in an increase in neutrophils in BAL fluid and higher eosinophil peroxidase levels in lungs, with leukocyte infiltration further confirmed through lung histology. Repetitive exposure to glyphosate increased IL-33 and Th2 cytokines IL-5 and IL-13. A single glyphosate treatment revealed expression for ICAM-1, VCAM-1, and vWF adhesion molecules in the perivascular region of lung sections; with repeated treatment (5 and 10 days), adhesion molecule expression was found in the perivascular, peribronchiolar, and alveolar regions of the lungs. Repetitive exposure to glyphosate induced cellular inflammation in which adhesion molecules may be important to the lung inflammatory process.

Respiratory and allergic outcomes among 5-year-old children exposed to pesticides

BACKGROUND

Little is known about the effects of pesticides on children's respiratory and allergic outcomes. We evaluated associations of prenatal and current pesticide exposures with respiratory and allergic outcomes in children from the Infants' Environmental Health Study in Costa Rica.

METHODS

Among 5-year-old children (n=303), we measured prenatal and current specific gravity-corrected urinary metabolite concentrations of insecticides (chlorpyrifos, pyrethroids), fungicides (mancozeb, pyrimethanil, thiabendazole) and 2,4-D. We collected information from caregivers on respiratory (ever doctor-diagnosed asthma and lower respiratory tract infections (LRTI), wheeze and cough during last 12 months) and allergic (nasal allergies, itchy rash, ever eczema) outcomes. We fitted separate multivariable logistic regression models for high (≥75th percentile (P75)) vs low (<P75) metabolite concentrations with respiratory and allergic outcomes. We also ran models including metabolite concentrations as continuous exposure variables.

RESULTS

Children's respiratory outcomes were common (39% cough, 20% wheeze, 12% asthma, 5% LRTI). High current pyrethroid metabolite concentrations (∑pyrethroids) were associated with wheeze (OR=2.37, 95% CI 1.28 to 4.34), itchy rash (OR=2.74, 95% CI 1.33 to 5.60), doctor-diagnosed asthma and LRTI. High current ethylene thiourea (ETU) (specific metabolite of mancozeb) was somewhat associated with LRTI (OR=2.09, 95% CI 0.68 to 6.02). We obtained similar results when modelling ∑pyrethroids and ETU as continuous variables. We saw inconsistent or null associations for other pesticide exposures and health outcomes.

CONCLUSIONS

Current pyrethroid exposure may affect children's respiratory and allergic health at 5 years of age. Current mancozeb exposure might contribute to LRTI. These findings are important as pyrethroids are broadly used in home environments and agriculture and mancozeb in agriculture.

Glyphosate differentially affects the allergic immune response across generations in mice

Exposure to environmental pollutants via food, particularly during the prenatal and early postnatal periods, has been linked to adverse effects on the immune system. Among these pollutants, the widely used pesticide glyphosate has been associated with endocrine disruption, autism, and cancer. Occupational high exposure to glyphosate has also been shown to influence immune function and exacerbate allergic asthma. However, there are no studies investigating the effect of a common low-dose glyphosate exposure on the allergic immune response - neither directly nor across generations. We therefore explored the impact of oral low-dose glyphosate exposure (0.5 and 50 mg/kg body weight/day) on airway inflammation in dams (F0) and the offspring (F1 and F2 generations) using a murine multi-generational asthma model. While exposure to 50 mg/kg glyphosate induced a mild eosinophilic infiltration in the bronchoalveolar lavage and T_H2 cytokine production in the dams, the F1 offspring developed a reduced immune response after maternal exposure to 0.5 mg/kg glyphosate. In particular, decreased lung inflammation, HDM-specific IgE levels, and asthma-relevant cytokine production were primarily observed in the female F1 offspring. However, not only the T_H2 cytokines IL-13 and IL-5 but also the T_H17 cytokine IL-17 and T_H1 cytokine IFN-γ were reduced indicating a more general immunosuppressive function. Notably, the dampened immune response was no longer observed in the female F2 generation. Furthermore, female F1 offspring showed an increased abundance of bacteria in the gut, which have been associated with probiotic-mediated reduced allergic immune responses. Our results suggest a potential immunosuppressive effect of low-dose maternal glyphosate exposure in the F1 offspring that might be mediated by an altered microbiota composition. Further studies are needed to explore if this type of immune response modulation might also be associated with impairments in immune defense upon infectious diseases or even cancer pathology.

CC16 polymorphisms in asthma, asthma subtypes, and asthma control in adults from the Agricultural Lung Health Study

BACKGROUND

The club cell secretory protein (CC16) has anti-inflammatory and antioxidant effects and is a potential early biomarker of lung damage. The CC16 single nucleotide polymorphism (SNP) rs3741240 risk allele (A) has been inconsistently linked to asthma; other tagging SNPs in the gene have not been explored. The aim was to determine whether CC16 tagging polymorphisms are associated with adult asthma, asthma subtypes or asthma control in the Agricultural Lung Health Study (ALHS).

METHODS

The ALHS is an asthma case-control study nested in the Agricultural Health Study cohort. Asthma cases were individuals with current doctor diagnosed asthma, likely undiagnosed asthma, or asthma-COPD overlap defined by questionnaire. We also examined asthma subtypes and asthma control. Five CC16 tagging SNPs were imputed to 1000 Genomes Integrated phase 1 reference panel. Logistic regression was used to estimate associations between CC16 SNPs and asthma outcomes adjusted for covariates.

RESULTS

The sample included 1120 asthma cases and 1926 controls of European ancestry, with a mean age of 63 years. The frequency of the risk genotype (AA) for rs3741240 was 12.5% (n = 382). CC16 rs3741240 was not associated with adult asthma outcomes. A tagging SNP in the CC16 gene, rs12270961 was associated with uncontrolled asthma (n = 208, ORadj= 1.4, 95% CI 1.0, 1.9; p = 0.03).

CONCLUSION

This study, the largest study to investigate associations between CC16 tagging SNPs and asthma phenotypes in adults, did not confirm an association of rs3741240 with adult asthma. A tagging SNP in CC16 suggests a potential relationship with asthma control.

Effects of glyphosate on the growth, development, and physiological functions of silkworm, Bombyx mori

Glyphosate is an herbicide widely used worldwide, but whether it is safe to nontarget organisms is controversial. In this study, the lepidopteran model insect silkworm was used to investigate the effects of glyphosate residues. The LC50 (72 h) of glyphosate on silkworm was determined to be 14875.98 mg/L, and after exposure to glyphosate at 2975.20 mg/L (a concentration comparable to that used for weed control in mulberry fields), silkworm growth was inhibited by 9.00%, total cocoon weight was lowered by 10.53%, feed digestibility was decreased by 7.56%, and the activities of alpha-amylase and trypsin were reduced by 10.41% and 21.32%, respectively. Pathological analysis revealed that glyphosate exposure led to significantly damaged midgut, along with thinner basal layer, shedding microvilli, blurred cytoplasmic membrane, and appearance of vacuoles. Exposure to glyphosate also led to accumulation of peroxides in the intestinal tissue; the messenger RNA transcription of SOD, Cu/Zn-SOD, and Mn-SOD was all significantly upregulated by glyphosate treatment for 24 h, while CAT transcription was increased at 24, 48, and 72 h. The activity of SOD was increased significantly at 24 h, while significant activity changes were observed for CAT at 72 and 96 h. These results indicated that exposure to glyphosate caused oxidative stress in the midgut of silkworm and affected the midgut's physiological function. This study provides important insights in evaluating the impact of glyphosate residues in the environment on nontarget organisms.

Current status of pesticide effects on environment, human health and it's eco-friendly management as bioremediation: A comprehensive review

Pesticides are either natural or chemically synthesized compounds that are used to control a variety of pests. These chemical compounds are used in a variety of sectors like food, forestry, agriculture and aquaculture. Pesticides shows their toxicity into the living systems. The World Health Organization (WHO) categorizes them based on their detrimental effects, emphasizing the relevance of public health. The usage can be minimized to a least level by using them sparingly with a complete grasp of their categorization, which is beneficial to both human health and the environment. In this review, we have discussed pesticides with respect to their global scenarios, such as worldwide distribution and environmental impacts. Major literature focused on potential uses of pesticides, classification according to their properties and toxicity and their adverse effect on natural system (soil and aquatic), water, plants (growth, metabolism, genotypic and phenotypic changes and impact on plants defense system), human health (genetic alteration, cancer, allergies, and asthma), and preserve food products. We have also described eco-friendly management strategies for pesticides as a green solution, including bacterial degradation, myco-remediation, phytoremediation, and microalgae-based bioremediation. The microbes, using catabolic enzymes for degradation of pesticides and clean-up from the environment. This review shows the importance of finding potent microbes, novel genes, and biotechnological applications for pesticide waste management to create a sustainable environment.

Allergic and non-allergic wheeze among farm women in the Agricultural Health Study (2005-2010)

BACKGROUND

Farms represent complex environments for respiratory exposures including hays, grains and pesticides. Little is known about the impact of these exposures on women's respiratory health. We evaluated the association of farm exposures with allergic and non-allergic wheeze among women in the Agricultural Health Study, a study of farmers and their spouses based in Iowa and North Carolina.

METHODS

We used self-reported data (2005-2010) on current use (≤12 months) of 15 pesticides (selected based on frequency of use) and occupational farm activities from 20 164 women. We defined allergic wheeze as reporting wheeze and doctor-diagnosed hay fever (7%) and non-allergic wheeze as wheeze but not hay fever (8%) in the past 12 months. Using polytomous logistic regression, we evaluated associations of wheeze subtypes with pesticides and other farm exposures (eg, raising farm animals) using no wheeze/hay fever as the referent, adjusting for age, body mass index, state, current asthma, glyphosate use and smoking.

RESULTS

Current use of any pesticide, reported by 7% of women, was associated with both allergic (OR: 1.36, 95% CI: 1.10 to 1.67) and non-allergic (OR: 1.25, 95% CI: 1.04 to 1.51) wheeze. Four pesticides were associated with at least one wheeze subtype: glyphosate, with both wheeze subtypes; diazinon and fly spray with only allergic wheeze; carbaryl with only non-allergic wheeze. Working weekly with mouldy hay was associated with allergic (OR: 1.88, 95% CI: 1.26 to 2.80) and non-allergic wheeze (OR: 1.69, 95% CI: 1.18 to 2.42).

CONCLUSION

Use of specific pesticides and certain farm activities may contribute to wheeze among farm women.

Effects of exposure to glyphosate on oxidative stress, inflammation, and lung function in maize farmers, Northern Thailand

BACKGROUND

Glyphosate is a herbicide which is commonly used in agricultural areas. However, previous studies on glyphosate exposure in farmers and their health are still scarce.

METHODS

A longitudinal pre-post study was performed among maize farmers. Information from questionnaires, urine and blood samples, and lung function were collected a day before and a day after glyphosate application in the morning. The urine samples were analyzed using liquid chromatography-tandem mass spectrometry to detect glyphosate levels. Serum samples were analyzed to detect malondialdehyde (MDA), glutathione (GHS), and C-reactive protein (CRP) levels using thiobarbituric acid, dithiobisnitrobenzoic acid, and nephelometry, respectively. Lung function performances were measured using a spirometer.

RESULTS

A total of 180 maize farmers met the study inclusion criteria. After glyphosate application, it was found that increased urinary glyphosate levels contributed to increased serum MDA (β = 0.024, 95% CI = 0.000, 0.0047) and decreased serum GHS (β = -0.022, 95% CI = -0.037, -0.007), FEV1 (β = -0.134, 95% CI = -0.168, -0.100), FEV1/FVC (β = -0.062, 95% CI = -0.082, -0.042) and PEF (β = -0.952, 95% CI = -1.169, -0.735).

CONCLUSIONS

Exposure to glyphosate during glyphosate application had significant effects on oxidative stress and lung function in maize farmers.

Glyphosate and AMPA exposure in relation to markers of biological aging in an adult population-based study

BACKGROUND/AIM

Glyphosate, a broad-spectrum herbicide, and its main metabolite aminomethylphosphonic acid (AMPA) are persistent in the environment. Studies showed associations between glyphosate or AMPA exposure and several adverse cellular processes, including metabolic alterations and oxidative stress.

OBJECTIVE

To determine the association between glyphosate and AMPA exposure and biomarkers of biological aging.

METHODS

We examined glyphosate and AMPA exposure, mtDNA content and leukocyte telomere length in 181 adults, included in the third cycle of the Flemish Environment and Health Study (FLEHSIII). DNA was isolated from leukocytes and the relative mtDNA content and telomere length were determined using qPCR. Urinary glyphosate and AMPA concentrations were measured by Gas Chromatography-Tandem Mass Spectrometry (GC-MS-MS). We used multiple linear regression models to associate mtDNA content and leukocyte telomere length with glyphosate or AMPA exposure while adjusting for confounding variables.

RESULTS

A doubling in urinary AMPA concentration was associated with 5.19% (95% CI: 0.49 to 10.11; p = 0.03) longer leukocyte telomere length, while no association was observed with urinary glyphosate concentration. No association between mtDNA content and urinary glyphosate nor AMPA levels was observed.

CONCLUSIONS

This study showed that AMPA exposure may be associated with telomere biology in adults.

Environmental exposures contribute to respiratory and allergic symptoms among women living in the banana growing regions of Costa Rica

OBJECTIVES

This research evaluates whether environmental exposures (pesticides and smoke) influence respiratory and allergic outcomes in women living in a tropical, agricultural environment.

METHODS

We used data from 266 mothers from the Infants' Environmental Health cohort study in Costa Rica. We evaluated environmental exposures in women by measuring seven pesticide and two polycyclic aromatic hydrocarbons metabolites in urine samples. We defined 'high exposure' as having a metabolite value in the top 75th percentile. We collected survey data on respiratory and allergic outcomes in mothers as well as on pesticides and other environmental exposures. Using logistic regression models adjusted for obesity, we assessed the associations of pesticide exposure with multiple outcomes (wheeze, doctor-diagnosed asthma, high (≥2) asthma score based on symptoms, rhinitis, eczema and itchy rash).

RESULTS

Current pesticide use in the home was positively associated with diagnosed asthma (OR=1.99 (95% CI=1.05 to 3.87)). High urinary levels of 5-hydroxythiabendazole (thiabendazole metabolite) and living in a neighbourhood with frequent smoke from waste burning were associated with a high asthma score (OR=1.84 (95%CI=1.05 to 3.25) and OR=2.31 (95%CI=1.11 to 5.16), respectively). Women who worked in agriculture had a significantly lower prevalence of rhinitis (0.19 (0.01 to 0.93)), but were more likely to report eczema (OR=2.54 (95%CI=1.33 to 4.89)) and an itchy rash (OR=3.17 (95%CI=1.24 to 7.73)).

CONCLUSIONS

While limited by sample size, these findings suggest that environmental exposure to both pesticides and smoke may impact respiratory and skin-related allergic outcomes in women.

Using the Matrix to bridge the epidemiology/risk assessment gap: a case study of 2,4-D

BACKGROUND

The Matrix is designed to facilitate discussions between practitioners of risk assessment and epidemiology and, in so doing, to enhance the utility of epidemiology research for public health decision-making. The Matrix is comprised of nine fundamental "asks" of epidemiology studies, focusing on the types of information valuable to the risk assessment process.

OBJECTIVE

A 2,4-dichlorophenoxyacetic acid (2,4-D) case study highlights the extent to which existing epidemiology literature includes information generally needed for risk assessments and proffers suggestions that would assist in bridging the epidemiology/risk assessment gap.

METHODS

Thirty-one publications identified in the US Environmental Protection Agency 2,4-D epidemiology review were assessed. These studies focused on associations between 2,4-D exposure and non-Hodgkin lymphoma (NHL), respiratory effects, and birth outcomes.

RESULTS

Many of the papers met one or more specific elements of the Matrix. However, from this case study, it is clear that some aspects of risk assessment, such as evaluating source-to-intake pathways, are generally not considered in epidemiology research. Others are incorporated, but infrequently (e.g. dose-response information, harmonization of exposure categories). We indicated where additional analyses or modifications to future study design could serve to improve the translation.

DISCUSSION

Interaction with risk assessors during the study design phase and using the Matrix "asks" to guide the conversations could shape research and provide the basis for requests for funds to support these additional activities. The use of the Matrix as a foundation for communication and education across disciplines could produce more impactful and consequential epidemiology research for robust risk assessments and decision-making.

Pulmonary inflammatory response from co-exposure to LPS and glyphosate

Agricultural airborne work exposures are complex in nature and workplace exposures are a risk for respiratory outcomes in workers. Endotoxin and glyphosate are two common agents in agricultural exposures. While endotoxin (lipopolysaccaride, LPS) is a potent inflammatory agent it explains only a portion of the respiratory inflammatory response. The inflammatory potential when LPS is presented with another common agricultural respiratory agent, glyphosate, is not known.

METHODS

Mice were assigned to four treatment groups: control, LPS alone, glyphosate alone, glyphosate and LPS combined. Treatments were for 1, 5 or 10 days.

RESULTS

Five days of repeated exposure to the comintation of LPS and glyphosate resulted in higher neutrophil counts, myloperoxidase, TNF-α, IL-6, KC levels, and ICAM-1 and TLR-2 expression compared to the same length of treatment to LPS or glyphosate alone. After 10-days of exposure, inflammatory responses decreased, however leukocyte infiltration persisted along with increases in IL-4.

CONCLUSIONS

Glyphosate exposure modified LPS induced lung inflammatory responses and TLR-2 may be important in the modulated inflammatory response.

The impact and toxicity of glyphosate and glyphosate-based herbicides on health and immunity

Glyphosate, or N-phosphomethyl(glycine), is an organophosphorus compound and a competitive inhibitor of the shikimate pathway that allows aromatic amino acid biosynthesis in plants and microorganisms. Its utilization in broad-spectrum herbicides, such as RoundUp®, has continued to increase since 1974; glyphosate, as well as its primary metabolite aminomethylphosphonic acid, is measured in soils, water, plants, animals and food. In humans, glyphosate is detected in blood and urine, especially in exposed workers, and is excreted within a few days. It has long been regarded as harmless in animals, but growing literature has reported health risks associated with glyphosate and glyphosate-based herbicides. In 2017, the International Agency for Research on Cancer (IARC) classified glyphosate as "probably carcinogenic" in humans. However, other national agencies did not tighten their glyphosate restrictions and even prolonged authorizations of its use. There are also discrepancies between countries' authorized levels, demonstrating an absence of a clear consensus on glyphosate to date. This review details the effects of glyphosate and glyphosate-based herbicides on fish and mammal health, focusing on the immune system. Increasing evidence shows that glyphosate and glyphosate-based herbicides exhibit cytotoxic and genotoxic effects, increase oxidative stress, disrupt the estrogen pathway, impair some cerebral functions, and allegedly correlate with some cancers. Glyphosate effects on the immune system appear to alter the complement cascade, phagocytic function, and lymphocyte responses, and increase the production of pro-inflammatory cytokines in fish. In mammals, including humans, glyphosate mainly has cytotoxic and genotoxic effects, causes inflammation, and affects lymphocyte functions and the interactions between microorganisms and the immune system. Importantly, even as many outcomes are still being debated, evidence points to a need for more studies to better decipher the risks from glyphosate and better regulation of its global utilization.

The joint effect of ambient air pollution and agricultural pesticide exposures on lung function among children with asthma

BACKGROUND

Ambient environmental pollutants have been shown to adversely affect respiratory health in susceptible populations. However, the role of simultaneous exposure to multiple diverse environmental pollutants is poorly understood.

OBJECTIVE

We applied a multidomain, multipollutant approach to assess the association between pediatric lung function measures and selected ambient air pollutants and pesticides.

METHODS

Using data from the US EPA and California Pesticide Use Registry, we reconstructed three months prior exposure to ambient air pollutants ((ozone (O₃), nitrogen dioxide (NO₂), particulate matter with a median aerodynamic diameter < 2.5 μm (PM_2.5) and <10 μm (PM₁₀)) and pesticides (organophosphates (OP), carbamates (C) and methyl bromide (MeBr)) for 153 children with mild intermittent or mild persistent asthma from the San Joaquin Valley of California, USA. We implemented Bayesian kernel machine regression (BKMR) to estimate the association between simultaneous exposures to air pollutants and pesticides and lung function measures (forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and forced expiratory flow between 25% and 75% of vital capacity (FEF_25-75)).

RESULTS

In BKMR analysis, the overall effect of mixtures (pollutants and pesticides) was associated with reduced FEV₁ and FVC, particularly when all the environmental exposures were above their 60th percentile. For example, the effect of the overall mixture at the 70th percentile (compared to the median) was a -0.12SD (-50 mL, 95% CI: -180 mL, 90 mL) change in the FEV₁ and a -0.18SD (-90 mL, 95% CI: -240 mL, 60 mL) change in the FVC. However, 95% credible intervals around all of the joint effect estimates contained the null value.

CONCLUSION

At this agricultural-urban interface, we observed results from multipollutant analyses, suggestive of adverse effects on some pediatric lung function measures following a cumulative increase in ambient air pollutants and agricultural pesticides. Given the uncertainty in effect estimates, this approach should be explored in larger studies.

Allergic Anaphylactic Risk in Farming Activities: A Systematic Review

Allergic disorders in the agriculture sector are very common among farm workers, causing many injuries and occupational diseases every year. Agricultural employees are exposed to multiple conditions and various allergenic substances, which could be related to onset of anaphylactic reactions. This systematic review highlights the main clinical manifestation, the allergens that are mostly involved and the main activities that are usually involved. This research includes articles published on the major databases (PubMed, Cochrane Library, Scopus), using a combination of keywords. The online search yielded 489 references; after selection, by the authors, 36 articles (nine reviews and 27 original articles) were analyzed. From this analysis, the main clinical problems that were diagnosed in this category were respiratory (ranging from rhinitis to asthma) and dermatological (eczema, dermatitis, hives) in nature, with a wide symptomatology (from a simple local reaction to anaphylaxis). The main activities associated with these allergic conditions are harvesting or cultivation of fruit and cereals, beekeepers and people working in greenhouses. Finally, in addition to the allergens already known, new ones have emerged, including triticale, wine, spider and biological dust. For these reasons, in the agricultural sector, research needs to be amplified, considering new sectors, new technologies and new products, and ensuring a system of prevention to reduce this risk.

Characterization of inhalable endotoxin, glucan, and dust exposures in Iowa farmers

BACKGROUND

The observed deficit of lung cancer in farmers has been partly attributed to exposure to organic dusts and endotoxins based largely on surrogate metrics. To move beyond these surrogates for etiological studies, we characterized task-based and time-weighted average (TWA) exposure to inhalable endotoxin, (1 → 3)-β-D-glucan, and dust in Iowa farmers.

METHODS

We collected 320 personal inhalable dust samples from 32 farmers during 69 sample days in 2015 and 2016. Samples were collected using Button aerosol samplers and analyzed for endotoxin using a kinetic chromogenic amebocyte lysate assay, and for (1 → 3)-β-D-glucan using a Limulus endpoint assay. We assessed relationships between bioaerosol concentrations and selected tasks and farm characteristics using linear mixed-effects models.

RESULTS

Bedding work, hog handling, and working in barn/confinement buildings, grain bins, and grain elevators were associated with higher endotoxin exposure. We found a monotonic trend between higher endotoxin concentrations and increasing number of animals. Bedding work, cleaning, and feed/grain storage work were associated with higher (1 → 3)-β-D-glucan concentrations. The median concentrations by task spanned one order of magnitude for inhalable dust and two orders of magnitude for endotoxin and (1 → 3)-β-D-glucan. Pearson correlations between endotoxin and glucan concentrations were 0.22 for TWA exposure and 0.56 for task samples.

CONCLUSIONS

This characterization of exposure factors that influence bioaerosol concentrations can support the development of refined bioaerosol exposure metrics for future etiologic analyses of cancer and other health outcomes in farmers.

Gender differences in respiratory health outcomes among farming cohorts around the globe: findings from the AGRICOH consortium

Purpose: Respiratory hazards of farming have been identified for centuries, with little focus on gender differences. We used data from the AGRICOH consortium, a collective of prospective cohorts of agricultural workers, to assess respiratory disease prevalence among adults in 18 cohorts representing over 200,000 farmers, farm workers, and their spouses from six continents.Methods: Cohorts collected data between 1992 and 2016 and ranged in size from 200 to >128,000 individuals; 44% of participants were female. Farming practices varied from subsistence farming to large-scale industrial agriculture. All cohorts provided respiratory outcome information for their cohort based on their study definitions. The majority of outcomes were based on self-report using standard respiratory questionnaires; the greatest variability in assessment methods was associated with chronic obstructive pulmonary disease (COPD).Results: For all three respiratory symptoms (cough, phlegm, and wheeze), the median prevalence in men was higher than in women, with the greatest difference for phlegm (17% vs. 10%). For asthma, women had a higher prevalence (7.8% vs 6.5%), with the difference associated with allergic asthma. The relative proportion of allergic asthma varied among cohorts. In two of eight cohorts for women and two of seven cohorts for men, allergic asthma was more common than non-allergic asthma.Conclusions: These findings indicate that respiratory outcomes are common among farmers around the world despite differences in agricultural production. As women in the general population are at higher risk of asthma, exploring gender differences in occupational studies is critical for a deeper understanding of respiratory disease among agricultural workers.

Effects of glyphosate exposure on human health: Insights from epidemiological and in vitro studies

Glyphosate (GLY) is a broad-spectrum, post-emergent, non-selective and synthetic universal herbicide, whose commercial formulations are referred to as glyphosate-based-herbicides (GBHs). These chemicals and their metabolites can be found in soil, air, water, as well as groundwater and food products. This review summarizes to summarize current in vitro and epidemiological studies investigating the effects of GLY exposure on human health. Recent human cell studies have reported several GLY and GBH toxicological effects and have contributed to a better understanding of the deleterious consequences associated with their exposure. However, these detrimental effects are dependent on the cell type, chemical composition, as well as magnitude and time of exposure, among other factors. Moreover, the deleterious effects of GLY exposure on human health were observed in epidemiological studies; however, most of these studies have not determined the GLY dosage to confirm a direct effect. While GLY toxicity is clear in human cells, epidemiological studies investigating individuals exposed to different levels of GLY have reported contradictory data. Therefore, based on currently available in vitro and epidemiological data, it is not possible to confirm the complete safety of GLY use, which will require additional comprehensive studies in animal models and humans.

The Organophosphorus Pesticide Chlorpyrifos Induces Sex-Specific Airway Hyperreactivity in Adult Rats

Occupational and environmental exposures to organophosphorus pesticides (OPs) are associated with increased incidence of asthma and other pulmonary diseases. Although the canonical mechanism of OP neurotoxicity is inhibition of acetylcholinesterase (AChE), it was previously reported that the OP chlorpyrifos (CPF) causes airway hyperreactivity (AHR) in guinea pigs at levels that do not inhibit lung or brain AChE. The guinea pig is considered to have inherently hyperresponsive airways, thus, cross-species validation is needed to confirm relevance to humans. Additionally, sex differences in asthma incidence have been demonstrated in the human population, but whether OP-induced AHR is sex-dependent has not been systematically studied in a preclinical model. In this study, 8-week old male and female Sprague Dawley rats were administered CPF at doses causing comparable AChE inhibition in whole lung homogenate (30 mg/kg in males, 7 mg/kg in females, sc) prior to assessing pulmonary mechanics in response to electrical stimulation of the vagus nerves at 24 h, 48 h, 72 h, 7 d or 14 d post-exposure in males, and 24 h or 7 d post-exposure in females. CPF significantly potentiated vagally induced airway resistance and tissue elastance at 7 d post-exposure in males, and at 24 h and 7 d post-exposure in females. These effects occurred independent of significant AChE inhibition in cerebellum, blood, trachealis, or isolated airway, suggesting that AChE independent OP-induced airway hyperreactivity is a cross-species phenomenon. These findings have significant implications for assessing the risk posed by CPF, and potentially other OPs, to human health and safety.

Pesticide use, allergic rhinitis, and asthma among US farm operators

OBJECTIVE

The objective of the study is to examine associations between use of specific pesticides and lifetime allergic rhinitis and current asthma in US primary farm operators.

METHODS

The 2011 Farm and Ranch Safety Survey data from 11,210 primary farm operators were analyzed. Pesticide use on the farm was determined using an affirmative response to the question of whether the operator ever mixed, loaded, or applied pesticides on their farm in the 12 months prior to the interview. Operators who answered "yes" were further asked about the specific trade name and formulation identifiers of the product they used and personal protective equipment (PPE) used. Data were weighted to produce national estimates. Adjusted prevalence odds ratios (PORs) were calculated using logistic regression. The referent group included operators who did not use any pesticides in the 12 months prior to the interview.

RESULTS

Of an estimated 2.1 million farm operators, 40.0% used pesticides, 30.8% had lifetime allergic rhinitis, and 5.1% had current asthma. Insecticide and herbicide use were significantly associated with lifetime allergic rhinitis and current asthma. The use of 2,4-dichlorophenoxyacetic acid (POR = 1.5; 95% CI 1.2-1.9) and carbaryl (POR = 2.3; 1.4-3.7) was significantly associated with lifetime allergic rhinitis. Of operators using pesticides, 64.9% used PPE the last time they mixed, loaded, or applied pesticides.

CONCLUSIONS

Pesticide use was associated with lifetime allergic rhinitis and current asthma among farm operators. Further studies are needed to clarify the dose-response relationship between pesticide use and adverse respiratory health effects.

Pesticides Exposure by Air in Vineyard Rural Area and Respiratory Health in Children: A pilot study

RATIONALE

Asthma, frequently associated with rhinitis, is the most common chronic disease in children, and a significant role is played by a range of environmental exposures. Among them, air pollution is of foremost concern. However, little is known about the impact of airborne pesticide exposure on children's respiratory health in rural areas. The objective of this study was to analyze the association between airborne pesticide exposure and asthma and rhinitis in children.

METHODS

In a French vineyard rural area, children (3-10 years old) from 4 selected schools were invited to participate in this study over two periods: winter, with no or low air pesticide levels, and summer when fields are frequently treated with pesticides. Two health outcomes were considered: asthma and rhinitis symptoms (ISAAC questionnaire), and peak expiratory flow (PEF). A quantitative score of symptoms was built. Exposure to pesticides was evaluated 1) by measuring 56 pesticides in the ambient outdoor air around schools in the two periods and building a cumulative exposure index, and 2) by measuring ethylenethiourea (ETU) concentrations in urine in a subsample of children (n = 96), ETU being a urine biomarker of exposure to dithiocarbamates fungicides. Next, the association between pesticide exposure and respiratory health was studied using a logistic regression model, adjusted for confounders and respiratory status at baseline.

RESULTS

281 children participated in the study (47% girls, mean age: 7.5 yrs). 25% of the children were living on a farm. 22% had experienced wheezing at least once. 15.8% had asthma diagnosed by a doctor, 12% had current asthma and 35% had allergic rhinitis. The main pesticides detected in the ambient outdoor air around schools were fungicides (89,3%; mainly folpet and dithiocarbamates) and insecticides (10.6%). No association was found between the symptom score and pesticides in the outdoor air around schools during summer, when pesticides were applied to vineyards. However, an association was found between ETU urinary concentration (>0.974 μg/g creatinine) and asthma and rhinitis symptoms (OR=3.56; IC 95% 1.04-12.12). This result could be explained by extracurricular exposure, which was not considered in our air measurements in the schools. No association was found between peak expiratory flow and exposure to pesticides in the air.

CONCLUSIONS

Children living in vineyard rural areas are at a higher risk of airborne dithiocarbamates exposure during the summer period. Despite the limited size of our sample, our results suggest possible links between some pesticide measurements and respiratory and allergic symptoms such as rhinitis.

Mechanisms of organophosphorus pesticide toxicity in the context of airway hyperreactivity and asthma

Numerous epidemiologic studies have identified an association between occupational exposures to organophosphorus pesticides (OPs) and asthma or asthmatic symptoms in adults. Emerging epidemiologic data suggest that environmentally relevant levels of OPs may also be linked to respiratory dysfunction in the general population and that in utero and/or early life exposures to environmental OPs may increase risk for childhood asthma. In support of a causal link between OPs and asthma, experimental evidence demonstrates that occupationally and environmentally relevant OP exposures induce bronchospasm and airway hyperreactivity in preclinical models. Mechanistic studies have identified blockade of autoinhibitory M2 muscarinic receptors on parasympathetic nerves that innervate airway smooth muscle as one mechanism by which OPs induce airway hyperreactivity, but significant questions remain regarding the mechanism(s) by which OPs cause neuronal M2 receptor dysfunction and, more generally, how OPs cause persistent asthma, especially after developmental exposures. The goals of this review are to 1) summarize current understanding of OPs in asthma; 2) discuss mechanisms of OP neurotoxicity and immunotoxicity that warrant consideration in the context of OP-induced airway hyperreactivity and asthma, specifically, inflammatory responses, oxidative stress, neural plasticity, and neurogenic inflammation; and 3) identify critical data gaps that need to be addressed in order to better protect adults and children against the harmful respiratory effects of low-level OP exposures.

Multiple Exposures and Coexposures to Occupational Hazards Among Agricultural Workers: A Systematic Review of Observational Studies

BACKGROUND

Workers may be exposed to various types of occupational hazards at the same time, potentially increasing the risk of adverse health outcomes. The aim of this review was to analyze the effects of multiple occupational exposures and coexposures to chemical, biomechanical, and physical hazards on adverse health outcomes among agricultural workers.

METHODS

Articles published in English between 1990 and 2015 were identified using five popular databases and two complementary sources. The quality of the included publications was assessed using the methodology developed by the Effective Public Health Practice Project assessment tool for quantitative studies.

RESULTS

Fifteen articles were included in the review. Multiple chemical exposures were significantly associated with an increased risk of respiratory diseases, cancer, and DNA and cytogenetic damage. Multiple physical exposures seemed to increase the risk of hearing loss, whereas coexposures to physical and biomechanical hazards were associated with an increased risk of musculoskeletal disorders among agricultural workers.

CONCLUSION

Few studies have explored the impact of multiple occupational exposures on the health of agricultural workers. A very limited number of studies have investigated the effect of coexposures among biomechanical, physical, and chemical hazards on occupational health, which indicates a need for further research in this area.

Occupational Exposures and Health Outcomes Among Immigrants in the USA

PURPOSE OF REVIEW

Immigrants experience higher rates of occupational injury and fatality than their native-born counterparts. This review summarizes the current data related to occupational/environmental exposures and explores potential reasons for the disparities.

RECENT FINDINGS

Immigrant workers are employed in sectors that expose them to dangerous working conditions. They experience increased risk for exposure to heat, pesticides, hazardous chemicals, and cleaning agents, as well as physical hazards such as falls. Immigrant workers are at increased risk for occupational injury and fatality due to the nature of the work they traditionally perform, a lack of enforced safety regulations, and limited access to health care or worker's compensation benefits.

The role of the indoor environment: Residential determinants of allergy, asthma and pulmonary function in children from a US-Mexico border community

The El Paso Children's Health Study examined environmental risk factors for allergy and asthma among fourth and fifth grade schoolchildren living in a major United States-Mexico border city. Complete questionnaire information was available for 5210 children, while adequate pulmonary function data were available for a subset of 1874. Herein we studied indoor environmental health risk factors for allergy and asthma. Several indoor environmental risk factors were associated with allergy and asthma. In particular, we found that ant and spider pest problems, pet dogs, fireplace heat, central air conditioning, humidifier use, and cooking with gas stoves were positively associated with both allergy and asthma prevalence. With regards to asthma severity, our analysis indicated that exposure to pet dogs increased monotonically with increasing asthma severity while the lack of any heat source and gas stove use for cooking decreased monotonically with increasing asthma severity. Lung function also decreased among children who lived in homes with reported cockroach pest problem in the past year without concurrent use of pesticides. These effects on pulmonary function were present even after excluding children with a current physician's diagnosis of asthma. Clinicians and public health professionals may need to look closely at the contribution of these indoor risk factors on pulmonary health and quality of life among susceptible populations.

[Pesticides and hypothyroidism in farmers of plantain and coffee growing areas in Quindio, Colombia]

OBJECTIVES

To establish the correlation between hypothyroidism and blood pesticide levels.

MATERIALS AND METHODS

Cross-sectional study in agricultural workers and their permanent partners in plantain and coffee producing municipalities as reference population. A representative sample was estimated and thyroid function tests were performed using ELISA Stat Fax 303/Plus reader, at a wavelength of 450 nm. Organochlorine pesticide residuality was determined, a dispersive liquid-liquid microextraction (DLLME) assisted by sonication was implemented, and a gas chromatography-micro-electron capture detector (GC-pECD) was used for the analysis.

RESULTS

819 participants, 58.7% men and 41.3% women were included; their average age was 48.1 years. Prevalence of symptomatic hypothyroidism (1.2%) and subclinical hypothyroidism (6.7%) was observed, with a higher prevalence in people older than 60 years (2.6% and 8.9%, respectively). Non-causal association was found between subclinical hypothyroidism and the organochlorine pesticides 4,4'-DDE (sig.0,006), Heptachlor (sig.0,04), and Endosulfan I (sig.0,02). Antiperoxidase (Anti TPO) antibodies ≥60 lU/ml were associated with subclinical hypothyroidism (OR 2.6).

CONCLUSIONS

The prevalence of hypothyroidism in the studied population is similar to that reported in the literature, and lower than in urban areas. In turn, the prevalence of subclinical hypothyroidism is higher and positive anti-TPO values are related to risk of progression to frank hypothyroidism, which is why follow-up is required in these patients. Three organochlorine pesticides were associated with subclinical hypothyroidism. TSH screening is recommended in people aged 40 and over, especially if they are exposed to the aforementioned agrochemicals.

Pyrethroid epidemiology: a quality-based review

Pyrethroids are commonly used around the home and in agricultural production to control insects. Human contact to one or more pyrethroid insecticides is likely. Numerous epidemiology studies have evaluated the association between health outcomes in humans and pyrethroid exposure. The purpose of this review was to identify and evaluate the quality of pyrethroid-related epidemiology studies that addressed chronic health effects, and compare findings with animal toxicology studies. We evaluated the quality of 61 studies published between 2000 and 2016 by using elements of outcome, exposure metric, exposure level, and study design. None of the 61 publications demonstrated strong quality for all elements. A few of the outcome measures were strong, particularly those relying upon medical diagnoses. Most of the pyrethroid epidemiology studies used a poor exposure metric, relying upon a single sample of pyrethroid urinary metabolites, which is subject to misclassification of past exposures. In addition, many studies were a cross-sectional design, preventing an evaluation of the temporality of the exposure-disease association. Furthermore, none of the effects observed in the epidemiological literature was concordant with toxicological effects noted in extensive testing of pyrethroids in animals. In order to provide more robust data on potential health outcomes from low dose exposure to pyrethroid insecticides, future epidemiological studies should fully characterize an adverse outcome, include exposure validation components, and quantify exposure over time.

House Dust Endotoxin Levels Are Associated with Adult Asthma in a U.S. Farming Population

RATIONALE

Endotoxin initiates a proinflammatory response from the innate immune system. Studies in children suggest that endotoxin exposure from house dust may be an important risk factor for asthma, but few studies have been conducted in adult populations.

OBJECTIVES

To investigate the association of house dust endotoxin levels with asthma and related phenotypes (wheeze, atopy, and pulmonary function) in a large U.S. farming population.

METHODS

Dust was collected from the bedrooms (n = 2,485) of participants enrolled in a case-control study of current asthma (927 cases) nested within the Agricultural Health Study. Dust endotoxin was measured by Limulus amebocyte lysate assay. Outcomes were measured by questionnaire, spirometry, and blood draw. We evaluated associations using linear and logistic regression.

MEASUREMENTS AND MAIN RESULTS

Endotoxin was significantly associated with current asthma (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.14-1.47), and this relationship was modified by early-life farm exposure (born on a farm: OR, 1.18; 95% CI, 1.02-1.37; not born on a farm: OR, 1.67; 95% CI, 1.26-2.20; Interaction P = 0.05). Significant positive associations were seen with both atopic and nonatopic asthma. Endotoxin was not related to either atopy or wheeze. Higher endotoxin was related to lower FEV₁/FVC in asthma cases only (Interaction P = 0.01). For asthma, there was suggestive evidence of a gene-by-environment interaction for the CD14 variant rs2569190 (Interaction P = 0.16) but not for the TLR4 variants rs4986790 and rs4986791.

CONCLUSIONS

House dust endotoxin was associated with current atopic and nonatopic asthma in a U.S. farming population. The degree of the association with asthma depended on early-life farm exposures. Furthermore, endotoxin was associated with lower pulmonary function in patients with asthma.

Early-life farm exposures and adult asthma and atopy in the Agricultural Lung Health Study

BACKGROUND

Previous studies, mostly from Europe, suggest that early-life farming exposures protect against childhood asthma and allergy; few data exist on asthma and allergy in adults.

OBJECTIVE

We sought to examine associations between early-life farming exposures and current asthma and atopy in an older adult US farming population.

METHODS

We analyzed data from 1746 farmers and 1555 spouses (mean age, 63) from a case-control study nested within the Agricultural Health Study. Current asthma and early-life farming exposures were assessed via questionnaires. We defined atopy based on specific IgE > 0.70 IU/mL to at least 1 of 10 allergens measured in blood. We used logistic regression, adjusted for age, sex, race, state (Iowa or North Carolina), and smoking (pack years), to estimate associations between early-life exposures and asthma (1198 cases and 2031 noncases) or atopy (578 cases and 2526 noncases).

RESULTS

Exposure to the farming environment in utero and in early childhood had little or no association with asthma but was associated with reduced odds of atopy. The strongest association was seen for having a mother who performed farm activities while pregnant (odds ratio, 0.60; 95% CI, 0.48-0.74) and remained significant in models with correlated early-life exposures including early childhood farm animal contact and raw milk consumption.

CONCLUSIONS

In a large US farming population, early-life farm exposures, particularly maternal farming activities while pregnant, were strongly associated with reduced risk of atopy in adults. These results extend previous work done primarily on childhood outcomes and suggest that protective associations of early-life farming exposures on atopy endure across the life course.

United Airway Disease Among Crop Farmers

Although there are observed relationships between agriculture and respiratory health problems, little attention has been given to relationship between lower and upper airway problems among farmers in the United States. The objective was to investigate the possible relationship between occupational risk factors and "united airway disease" among farmers in eastern North Carolina. Farmers and farm workers were selected from eastern North Carolina by using a cluster sampling method. A total of 180 farmers and farm workers completed the questionnaire. Data analyses were conducted to test associations and correlations between working conditions and symptoms. Lower airway symptom prevalence was 35%, and 66% had upper airway symptoms. Only 1% of farmers had physician-diagnosed rhinitis. Self-reported rhinitis and asthma symptoms were significantly correlated (r = .228, P = .003) among farmer/farm workers. Upper airway diseases are prevalent yet overlooked among farmer/farm workers. Early management of upper airway symptoms may prevent severe lower airway diseases, which will lead to increased productivity in the agricultural workforce.

Pesticides are Associated with Allergic and Non-Allergic Wheeze among Male Farmers

BACKGROUND

Growing evidence suggests that pesticide use may contribute to respiratory symptoms.

OBJECTIVE

We evaluated the association of currently used pesticides with allergic and non-allergic wheeze among male farmers.

METHODS

Using the 2005-2010 interview data of the Agricultural Health Study, a prospective study of farmers in North Carolina and Iowa, we evaluated the association between allergic and non-allergic wheeze and self-reported use of 78 specific pesticides, reported by ≥ 1% of the 22,134 men interviewed. We used polytomous regression models adjusted for age, BMI, state, smoking, and current asthma, as well as for days applying pesticides and days driving diesel tractors. We defined allergic wheeze as reporting both wheeze and doctor-diagnosed hay fever (n = 1,310, 6%) and non-allergic wheeze as reporting wheeze but not hay fever (n = 3,939, 18%); men without wheeze were the referent.

RESULTS

In models evaluating current use of specific pesticides, 19 pesticides were significantly associated (p < 0.05) with allergic wheeze (18 positive, 1 negative) and 21 pesticides with non-allergic wheeze (19 positive, 2 negative); 11 pesticides were associated with both. Seven pesticides (herbicides: 2,4-D and simazine; insecticides: carbaryl, dimethoate, disulfoton, and zeta-cypermethrin; and fungicide pyraclostrobin) had significantly different associations for allergic and non-allergic wheeze. In exposure-response models with up to five exposure categories, we saw evidence of an exposure-response relationship for several pesticides including the commonly used herbicides 2,4-D and glyphosate, the insecticides permethrin and carbaryl, and the rodenticide warfarin.

CONCLUSIONS

These results for farmers implicate several pesticides that are commonly used in agricultural and residential settings with adverse respiratory effects.