Cancer risks in a population-based study of agricultural workers: results from the Taiwan's Farmers and Health Cohort study.

OBJECTIVE: The purpose of this study was to assess cancer risk among agricultural workers compared to the general population. METHODS: The study utilized data from Farmers' Health Insurance (FHI) in Taiwan, which enrolled agricultural workers (N=1 175 149). The enrolled workers were matched to a general population (N=1 175 149) of the same age, gender, township, and enrollment year. The study population was linked to the National Cancer Registry to identify new cancer cases between 2000 and 2018. The Cox proportional hazards model was used to estimate the hazard ratio and 95% confidence interval for outcomes. RESULTS: During the study period, 136 913 new cancers among agricultural workers were identified. The study found that male farmers had an increased cancer risk, including lymphocytic leukemia, chronic myelogenous leukemia, non-Hodgkin's lymphoma (NHL), oral cancer, lip cancer, esophagus cancer, rectum and rectosigmoid junction cancer, liver and intrahepatic bile duct cancer, lung cancer, trachea and bronchi cancer, and other non-melanoma skin cancer, even when considering the latency period. Female farmers had an elevated risk of multiple myeloma and other non-melanoma skin cancer. Moreover, only lymphoma, NHL, other lymphoid, and multiple myeloma, were both found to occur at different insurance periods. CONCLUSIONS: This study provides farmer cancer patterns and risk, adding to the evidence that farmers are at increased risk of certain types of cancer, especially for hematological cancers. As exposure varies by farm operation type, individual farmer exposure may vary widely. Further understanding of the complex relationship between occupational exposure, environmental factors, and lifestyle factors is needed.

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.

Acute Pesticide Poisoning in Tobacco Farming, According to Different Criteria.

BACKGROUND: Brazil is one of the world's largest pesticide consumers, but information on pesticide poisoning among workers is scarce. OBJECTIVE: To evaluate acute pesticide poisoning among tobacco growers, according to different criteria. METHODS: This was a two-step cross-sectional study with 492 pesticide applicators. It used a 25 question pesticide-related symptoms (PRS) questionnaire and medical diagnosis for comparison with toxicological assessment. Associations were evaluated using Poisson regression. RESULTS: 10.6% reported two or more PRS, while 8.1% reported three or more. Furthermore, 12.2% received a medical diagnosis of poisoning. According to toxicologists, possible cases accounted for 14.2% and probable cases for 4.3%. PRS increased during the period of greater exposure. Those exposed to dithiocarbamates, sulfentrazone, pyrethroids, fipronil and iprodione exhibited more PRS. The number of exposure types, multi-chemical exposure, clothes wet with pesticides and spillage on the body/clothes were associated with acute poisonings. All criteria showed sensitivity greater than 79% for probable cases but only greater than 70% for medical diagnosis when compared to possible cases, presenting substantial Kappa agreement. CONCLUSION: The prevalence of acute pesticide poisoning is much higher than officially recorded. Trained physicians can screen for pesticide poisoning. It is necessary to improve workers' education to reduce pesticide use and exposure to them.

The Prevalence of Heat-related Illnesses and Associated Factors among Rice Farmers in Vietnam.

Objective: The aim of this study was to examine the prevalence of heat-related illnesses (HRI) and their associated factors among rice farmers in Central Vietnam. Methods: A cross-sectional study was conducted using a sample of 379 farmers from August to September 2021 in Ha Tinh province on the north-central coast of Vietnam. A structured questionnaire was used to collect demographic information, farming activities, heat exposure, and health issues. Multivariable logistic regression was used to identify the factors associated with HRI. Results: At least one HRI symptom was experienced by 83.4% of farmers, and two or more HRI symptoms were experienced by 55.1% of farmers during the last harvesting season (the summer-autumn rice season, 2021). Factors significantly associated with HRI were age, having chronic diseases, type of farming tasks, the number of hours working in the heat, and water intake. Farmers working outdoors for more than 4 hours in the heat were 2.3 times [95%CI: 1.14-4.69] more likely to experience HRI than those working fewer than 2 hours. A higher risk of HRI was also associated with heavy farming tasks (OR = 2.35, [1.34-4.14]), having hypertension (OR = 3.75, [1.90-7.81]), cardiovascular diseases (OR = 2.53, [1.03-6.93]), and other chronic conditions (OR = 2.51, [1.51-4.25]). In contrast, a lower risk of HRI was found in the older group (OR = 0.44, [0.22-0.87]) and increased water intake (OR = 0.46, [0.27-0.77]). Conclusions: Hot weather is a significant occupational health risk for farmers in Vietnam. Changing the working schedule, working in shorter intervals, and remaining well-hydrated should be considered in HRI prevention strategies.

Village-integrated eye workers for prevention of corneal ulcers in Nepal (VIEW study): a cluster-randomised controlled trial.

BACKGROUND: Corneal ulcers are a common cause of blindness in low-income and middle-income countries, usually resulting from traumatic corneal abrasions during agricultural work. Antimicrobial prophylaxis of corneal abrasions can help prevent corneal ulcers, but delays in the initiation of therapy are frequent. We aimed to assess whether a community-based programme for corneal ulcer prevention would reduce the incidence of corneal ulceration. METHODS: A cluster-randomised trial was performed in village development committees (VDCs) in Nepal. VDCs in the catchment area of Bharatpur Eye Hospital, Nepal with less than 15 000 people were eligible for inclusion. We randomly assigned (1:1) VDCs to either an intervention group or a control group. In the intervention VDCs, existing female community health volunteers (FCHVs) were trained to diagnose corneal abrasions and provide a 3-day course of ophthalmic antimicrobials to their patients. In the control VDCs, FCHVs did not provide this intervention. Participants were not masked given the nature of the intervention. Both groups were followed up for 3 years for photographic evidence of corneal ulceration. The primary outcome was the incidence of corneal ulceration, determined by masked assessment of corneal photographs. The analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT01969786. FINDINGS: We assessed 112 VDCs, of which 24 were enrolled. The study was performed between Feb 4, 2014, and Oct 20, 2017. 12 VDCs were randomly assigned to the intervention group and 12 to the control group. 252 539 individuals were included in the study (130 579 in the intervention group and 121 960 in the control group). FCHVs diagnosed and provided antimicrobials for 4777 corneal abrasions. The census identified 289 corneal ulcers among 246 893 person-years in the intervention group (incidence 1·21 cases [95% CI 0·85-1·74] per 1000 person-years) and 262 corneal ulcers among 239 170 person-years in the control group (incidence 1·18 cases [0·82-1·70] per 1000 person-years; incidence rate ratio 1·03 [95% CI 0·63-1·67]; p=0·93). Medication allergy was self-reported in 0·2% of participants. INTERPRETATION: We did not detect a reduction in the incidence of corneal ulceration during the first 3 years of a community-based corneal ulcer prevention programme. Further study might be warranted in more rural areas where basic eye care facilities are not available. FUNDING: National Eye Institute.

Child Labor in Family Tobacco Farms in Southern Brazil: Occupational Exposure and Related Health Problems.

Tobacco farming is considered Hazardous Child Labor in Brazil. This study examined the work of children and adolescents in tobacco farming, characterizing the level of urinary cotinine and the occurrence of Green Tobacco Sickness (GTS), pesticide poisoning, respiratory symptoms, and musculoskeletal disorders. A cross-sectional descriptive study was conducted with a random sample of tobacco growers under 18 years old in Southern Brazil. Ninety-nine young people were interviewed at 79 family farms. The majority began working in agriculture before they were 14 and worked harvesting and tying hands of tobacco; 60% were 16 or 17 years old, and 51.5% were male. During their lifetime, 24.5% reported GTS, and 3% reported pesticide poisoning. In the previous year, 29.3% reported low back pain, 6.1% wheezing, and 16.2% coughing without having a cold. Half of the 12 young people evaluated had over 100 ng/mL of urinary cotinine. The study indicates that child laborers do various activities and present a high prevalence of health problems. Health workers should be trained to identify child laborers and their impacts on health. Full-time farm schools could provide knowledge about sustainable agricultural production, reducing the rates of age-grade mismatch, without taking young people away from rural areas.

Farmer and farm worker illnesses and deaths from COVID-19 and impacts on agricultural output.

Farmers and farm workers are critical to the secure supply of food, yet this population is potentially at high risk to acquire COVID-19. This study estimates the prevalence of COVID-19 among farmers and farmworkers in the United States by coupling county-level data on the number of farm workers relative to the general population with data on confirmed COVID-19 cases and deaths. In the 13 month period since the start of the pandemic (from March 1, 2020 to March 31, 2021), the estimated cumulative number of COVID-19 cases (deaths) was 329,031 (6,166) among agricultural producers, 170,137 (2,969) among hired agricultural workers, 202,902 (3,812) among unpaid agricultural workers, and 27,223 (459) among migrant agricultural workers. The cases amount to 9.55%, 9.31%, 9.39%, and 9.01% of all U.S. agricultural producers, hired workers, unpaid workers, and migrant workers, respectively. The COVID-19 incidence rate is significantly higher in counties with more agricultural workers; a 1% increase in the number of hired agricultural workers in a county is associated with a 0.04% increase in the number of COVID-19 cases per person and 0.07% increase in deaths per person. Although estimated new cases among farm workers exhibit similar trends to that of the general population, the correlation between the two is sometimes negative, highlighting the need to monitor this particular population that tends to live in more rural areas. Reduction in labor availability from COVID-19 is estimated to reduce U.S. agricultural output by about $309 million.

Effectiveness of interventions to promote pesticide safety and reduce pesticide exposure in agricultural health studies: A systematic review.

OBJECTIVE: There is a relationship between pesticide exposure and farmworkers' health. Well-conducted evaluations can provide an insight into how to develop and implement more effective interventions to prevent farmers and farmworkers' exposure to pesticides. This review aimed to summarize the literature on the effectiveness of interventions to promote pesticide safety and reduce pesticide exposure among farmers and farmworkers. METHODS: A comprehensive search on PubMed, Embase, ISI Web of Science, Scopus, Science Direct, Agricola, NIOSHTIC, and Agris databases was performed to identify relevant studies published from 2000 to 2019. Randomized controlled trials (RCTs) and quasi-experimental studies assessing the effectiveness of interventions on a variety of outcomes related to pesticide exposure were considered. The searches were restricted to articles written in English. The methodological quality of included reviews was appraised using the Effective Public Health Practice Project quality assessment tool (EPHPP). RESULTS: The initial search led to 47912 records, 31 studies of which including nine RCTs and twenty-two quasi-experimental studies met the criteria. The majority of the included studies focused on the educational/ behavioral approach. The studies that applied this approach were effective in improving the participants' knowledge and attitude; however, these interventions were less effective in terms of making changes in participants' behaviors and their risk of exposure to toxic pesticides. Multifaceted interventions were moderately effective in terms of improving farmers' and farmworkers' behaviors and reduction in exposure to toxic pesticides. We did not find any studies that had evaluated the effectiveness of engineering/technological, and legislation/enforcement interventions. CONCLUSIONS: Although the majority of studies were based on an educational/behavioral approach and did not assess the effect of interventions on objective measures, the results of this review highlight the significant effectiveness of educational programs and some potential key elements of these interventions. These findings may inform policymakers to develop interventions to reduce pesticide exposure among farmers and farmworkers.

Risk factors associated among respiratory health and banana farming.

Pesticides cause risks to the respiratory health of banana farming workers. To investigate the prevalence of ventilatory dysfunction in workers and characteristics of work in banana production in a region of the Ribeira Valley, Brazil. A questionnaire containing sociodemographic, work and health data was applied, as well as spirometry. The data were statistically analyzed with participants divided into two groups (presence or absence of ventilatory dysfunction). The majority were males, low schooling, mean age 39.6 years and 13.8 years of working time in banana farming. The prevalence of moderate obstructive disorder (10.0%), mild obstructive disorder (13.3%) and mild mixed disorder (3.3%) were observed. Obstructive disorders predominated, with decreased FEV1 and FEV1/FVC, in addition to being correlated with working time in banana farming. It was concluded that one-third of the workers had some type of ventilatory dysfunction and there was a relationship with work in banana farming.

Evidence on Human Exposure to Pesticides and the Occurrence of Health Hazards in the Brazilian Population: A Systematic Review.

Brazil is among the biggest pesticide consumers in the world, with its population severely exposed to tons of such substances, both because of environmental contamination and occupational use. The health consequences of pesticide exposure are well-documented, but still sparse regarding Brazilian population. This study systematically reviewed the Brazilian studies published that address the relationship between exposure to pesticides and health problems in the Brazilian population. Also, information about pesticide use in Brazil is provided. The included studies showed that exposure to pesticides has a relevant impact on the health of the Brazilian population, regardless of age and gender, and on workers in rural areas or not. Most poisoning events seem to result from the continuous use of pesticides, whether occupationally or environmentally, characterizing a public health problem. The major consequences reported in literature were damage to the central nervous system, cancer, deleterious effects on rural workers' health, intoxications, malformations, and endocrine changes. These findings point out the need to understand the impact of chronic exposure to pesticides on severely exposed people and highlight the importance of creating public policies to protect them and avoid disease occurrence.

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.

Pesticide exposure and incident thyroid cancer among male pesticide applicators in agricultural health study.

BACKGROUND: Many pesticides are known to have thyroid-disrupting properties. However, few studies have evaluated the association between specific pesticide ingredients and risk of thyroid cancer. We investigated self-reported pesticide use and incident thyroid cancer in the Agricultural Health Study (AHS), a large cohort of occupationally-exposed male pesticide applicators. METHODS: The AHS is a prospective cohort of licensed pesticide applicators in Iowa and North Carolina. At enrollment (1993-1997) and follow-up (1999-2005), participants reported use of 50 pesticides. We characterized exposure as ever use (44 pesticides with ≥5 exposed cases) and by cumulative intensity-weighted lifetime days (22 pesticides with ≥10 exposed cases), a metric that accounts for factors that influence exposure. We estimated hazard ratios (HR) and 95% confidence intervals (CI) using Cox regression for incident thyroid (n = 85 cases) cancer among male participants using follow-up through 2014/2015. RESULTS: Use of the fungicide metalaxyl (HR = 2.03, CI:1.16-3.52) and the organochlorine insecticide lindane (HR = 1.74, CI:1.06-2.84) was associated with increased risk of thyroid cancer. The herbicide chlorimuron-ethyl was inversely associated with risk when we restricted to papillary thyroid cancer, the most common subtype (HR = 0.52, CI:0.28-0.96). High use of the insecticide carbaryl (>median intensity-weighted days) was inversely associated with thyroid cancer (HR = 0.20, CI:0.08-0.53, ptrend = 0.001). CONCLUSIONS: In this large cohort study, we observed increased risk of thyroid cancer associated with use of metalaxyl and lindane, and an inverse association with carbaryl. More work is needed to understand the potential role of these chemicals in thyroid carcinogenesis.

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.

[Neck pain among tobacco farm workers in Southern Brazil]. / Dolor cervical entre agricultores que producen tabaco en el sur de Brasil.

This study aims to assess neck pain prevalence and associated factors among tobacco farm workers. This is a cross-sectional study of 2,469 tobacco farm workers in southern Brazil. An adapted version of the Nordic Questionnaire of Musculoskeletal Symptoms was used to characterize neck pain. Multivariate analysis was performed using Poisson regression, following a hierarchical theoretical model. Neck pain prevalence in the last year among the population studied was 7.4%. Worker age, tobacco smoking, tobacco bundling, use of heavy chainsaws, working at an intense or accelerated pace and green tobacco sickness were variables associated with neck pain in females. Among males, age, use of heavy chainsaws, working in a sitting position on the ground, pesticide poisoning, and green tobacco sickness were associated with the outcome. The study reinforces the importance of ergonomic and physiological workloads in the determination of neck pain. Future studies are needed to understand the role of pesticides and nicotine exposures on musculoskeletal problems. The mechanization of tobacco harvesting could reduce ergonomic and chemical exposure, thereby improving farmers' health.

Este estudio tiene como objetivo evaluar la prevalencia del dolor cervical y los factores asociados entre agricultores que producen tabaco. Se realizó un estudio transversal en el que participaron 2.469 agricultores que producen tabaco en el sur de Brasil. Para la caracterización del dolor cervical se utilizó una adaptación del cuestionario nórdico para síntomas musculoesqueléticos. El análisis multivariante se realizó mediante la regresión de Poisson, siguiendo un modelo teórico jerárquico. La prevalencia del dolor cervical en el año previo entre la población estudiada fue del 7,4%. Las variables que se asociaron con el dolor cervical entre las mujeres trabajadoras fueron la edad, el consumo de tabaco, el enfardado del tabaco, el uso de motosierras pesadas, trabajar en un ritmo intenso o acelerado y la enfermedad del tabaco verde, mientras que, entre los varones, fueron la edad, el uso de motosierras pesadas, el trabajo sentado en el suelo, la intoxicación por plaguicidas y la enfermedad del tabaco verde. El estudio refuerza la importancia de las cargas de trabajo ergonómicas y fisiológicas en la determinación del dolor cervical. Se necesitan estudios futuros para comprender el papel de la exposición a los plaguicidas y a la nicotina en los problemas musculoesqueléticos. La mecanización de la cosecha del tabaco podría reducir la exposición ergonómica y química, mejorando así la salud de los agricultores.

Evidence of nickel and other trace elements and their relationship to clinical findings in acute Mesoamerican Nephropathy: A case-control analysis.

BACKGROUND: Although there are several hypothesized etiologies of Mesoamerican Nephropathy (MeN), evidence has not yet pointed to the underlying cause. Exposure to various trace elements can cause the clinical features observed in MeN. METHODS AND FINDINGS: We measured 15 trace elements, including heavy metals, in renal case-patients (n = 18) and healthy controls (n = 36) in a MeN high-risk region of Nicaragua. Toenails clippings from study participants were analyzed using inductively coupled plasma mass spectrometry. A case-control analysis was performed, and concentrations were also analyzed over participant characteristics and clinical parameters. Nickel (Ni) concentrations were significantly higher in toenails from cases (1.554 mg/kg [0.176-42.647]) than controls (0.208 mg/kg [0.055-51.235]; p<0.001). Ni concentrations correlated positively with serum creatinine levels (p = 0.001) and negatively with eGFR (p = 0.001). Greater Ni exposure was also associated with higher leukocyte (p = 0.001) and neutrophil (p = 0.003) counts, fewer lymphocytes (p = 0.003), and lower hemoglobin (p = 0.004) and hematocrit (p = 0.011). CONCLUSIONS: Low-dose, chronic environmental exposure to Ni is a possible health risk in this setting. Ni intoxication and resulting systemic and renal effects could explain the clinical signs observed during early MeN. This study provides compelling evidence for a role of Ni in the acute renal impairment observed in this MeN high-risk population. Additional work to assess exposure levels in a larger and heterogeneous population, identify environmental sources of Ni and exposure pathways, and evaluate the link between Ni and MeN pathogenesis are urgently needed.

Faecal carriage of extended spectrum beta-lactamase (ESBL) and New Delhi metallo beta-lactamase(NDM) producing Escherichia coli between piglets and pig farmworkers.

A cross-sectional study on five organized pig farms was conducted to assess the faecal carriage of ESBL and blaNDM carbapenemase-producing E. coli in piglets and pig farmworkers. Faecal samples from piglets (n = 155) and pig farmworkers (n = 21) were processed for isolation and characterization of E. coli. A total of 124 E. coli isolates from piglets and 21 E. coli isolates pig farmworkers were recovered and screening for ESBL production showed that 44.4 % (55/124) of the isolates from piglets and 42.9 % (9/21) of the isolates from farmworkers were ESBL positive. The ESBL positive isolates from piglets and farmworkers harbored blaCTX-M and also co-harbored other beta-lactams, sulphonamide, quinolone and tetracycline resistance genes. Diarrhoeic (50%, 49/98) and crossbred piglets (52.7%, 39/74) harbored a significantly higher number of ESBL producing isolates than non-diarrhoeic (23.1 %, 6/26) and purebred piglets (32%, 16/50) (p < 0.05). Piglets and pig farmworkers harbored nine and two carbapenem-resistant isolates, respectively. Interestingly, two isolates from piglets and one isolate from farmworkers harbored the blaNDM gene. The blaNDM positive E. coli isolated from piglets and farmworkers of the same farm revealed similar antibacterial resistance patterns, resistant genes, sequence (ST-167) and plasmid type (IncX3). In India, carbapenems are not used in food animal treatment, hence carbapenem resistant E. coli in piglets possibly originated from the human contact or common environment and is of public health importance.

A Pilot Study to Assess Inhalation Exposures among Sugarcane Workers in Guatemala: Implications for Chronic Kidney Disease of Unknown Origin.

BACKGROUND: Sugarcane workers in Central America experience a heavy burden of chronic kidney disease of unknown origin. We conducted a pilot study among worker proxies in Guatemala to characterize exposures to particulate matter, silica, heavy metals, and glyphosate, as well as to examine potential nephrotoxic exposures. METHODS: Air, soil, and ash samples were collected and analyzed using scanning electron microscopy, X-ray diffraction, inductively coupled plasma mass spectrometry, and an enzyme-linked immunosorbent assay. RESULTS: The average mass concentration for particulate matter (PM)2.5 and PM100 exposures were 360 µg/m3 (range: 32 to 1500 µg/m3) and 555 µg/m3 (range: 229 to 1170 µg/m3), respectively. The elemental composition of particles was largely silicon. The amount of crystalline silica was below 5 µg, yet the percentage of total silica was ~17% by weight. Putatively, the silica was in the amorphous form. Concentrations of aluminum and calcium ranged from 2-7 µg/m3. Glyphosate was not detectable in analyzed air samples but was detectable at concentrations ranging from 81-165 ppb in soil samples. CONCLUSION: Sugarcane workers are exposed to high concentrations of particulate matter. Future studies should investigate the potential role of silica, heavy metals, and agrochemicals in the etiology of chronic kidney disease in this population.

Occupational Pesticide Use and Risk of Renal Cell Carcinoma in the Agricultural Health Study.

BACKGROUND: Agricultural work and occupational pesticide use have been associated with increased risk of renal cell carcinoma (RCC), the most common form of kidney cancer. However, few prospective studies have investigated links to specific pesticides. OBJECTIVE: We evaluated the lifetime use of individual pesticides and the incidence of RCC. METHODS: We evaluated the associations between intensity-weighted lifetime days (IWDs) of 38 pesticides and incident RCC in the Agricultural Health Study, a prospective cohort of licensed pesticide applicators in Iowa and North Carolina. Among 55,873 applicators, 308 cases were diagnosed between enrollment (1993-1997) and the end of follow-up (2014-2015). We estimated incidence rate ratios (RRs) and 95% confidence intervals (CIs) using Poisson regression, controlling for potential confounding factors, with lagged and unlagged pesticide exposures. RESULTS: There was a statistically significant increased risk of RCC among the highest users of 2,4,5-T compared with never users [unlagged RRIWD Tertile 3=2.92 (95% CI: 1.65, 5.17; ptrend=0.001)], with similar risk estimates for lagged exposure [20-y lag RRIWD Tertile 3=3.37 (95% CI: 1.83, 6.22; ptrend=0.001)]. In 20-y lagged analyses, we also found exposure-response associations with chlorpyrifos [RRIWD Quartile 4=1.68 (95% CI: 1.05, 2.70; ptrend=0.01)], chlordane [RRIWD Tertile 3=2.06 (95% CI: 1.10, 3.87; ptrend=0.02)], atrazine [RRIWD Quartile 4=1.43 (95% CI: 1.00, 2.03; ptrend=0.02)], cyanazine [RRIWD Quartile 4=1.61 (95% CI: 1.03, 2.50; ptrend=0.02)], and paraquat [RRIWD>Median=1.95 (95% CI: 1.03, 3.70; ptrend=0.04)]. CONCLUSIONS: This is, to our knowledge, the first prospective study to evaluate RCC risk in relation to various pesticides. We found evidence of associations with RCC for four herbicides (2,4,5-T, atrazine, cyanazine, and paraquat) and two insecticides (chlorpyrifos and chlordane). Our findings provide insights into specific chemicals that may influence RCC risk among pesticide applicators. Confirmation of these findings and investigations of the biologic plausibility and potential mechanisms underlying the observed associations are warranted. https://doi.org/10.1289/EHP6334.

Occurrence and characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in buffalo bulk tank milk and the farm workers in Italy.

The aim of the present study was to assess the occurrence of MRSA in buffalo dairy farms and in buffalo tank milk from Italy, and to provide information about the antimicrobial resistance profile and molecular characteristics of the isolates. We collected 75 bulk tank milk (BTM) samples from 75 farms and 24 nasal swabs from 24 farm operators. Three (4%) of the 75 BTM samples and 1 (4%) of the 24 human nasal swabs tested positive for MRSA. The milk isolates belonged to the genotypes ST1/t127/Va and ST72/t3092/V, while the human isolate was characterized as ST1/t127/IVa. All isolates were multidrug resistant but vancomycin susceptible; they carried the icaA gene but tested negative for the pvl and ses genes. ST72 is a CA-MRSA commonly found in South Korea, and this is the first report of its detection in Europe. Although we found a low prevalence of MRSA in the farms we surveyed, this study clearly demonstrates, for the first time in Europe, that MRSA can be found in dairy buffalo farms and in raw buffalo milk. Therefore, the risk of human colonization/infection with MRSA linked to the handling of raw milk or consumption of contaminated dairy products should not be ruled out.

Serological and molecular evidence of Mycobacterium bovis in dairy cattle and dairy farm workers under the intensive dairy production system in Egypt.

AIMS: We employed a combination of diagnostic tests including single cervical tuberculin test (SCT), rapid lateral-flow test (RT), TB-Feron, conventional PCR and culture to investigate the prevalence of Mycobacterium bovis infections in dairy cattle under the intensive dairy production system in Egypt. METHODS AND RESULTS: In total, 2710 dairy cows from 11 herds in six Governorates were tested by SCT and 444 (16·4%) were TB reactors. Only 65 cows responded to M. bovis antigen by RT and TB-Feron. A postmortem examination showed that 49 (75·4%) of slaughtered cows have visible lesions. Testing of 215 out 444 SCT reactor cows by culture and PCR using blood and milk samples revealed that M. bovis were more frequently identified in the blood (6·1-20·5%) than milk (2·3-5·6%) samples. Additionally, in this study, we investigated the prevalence and potential risk factors associated with M. bovis infection in dairy farm workers. Overall, 100 dairy farm workers were tested using QuantiFERON-TB Gold In-Tube test to detect Mycobacterium tuberculosis complex (MTC) and 35 (35%) were positive. In all, 23 (23%) of MTC positive were M. bovis positive using PCR. Mycobacterium bovis positive cases were associated with workers who had respiratory signs and did not wash or disinfect their hands after handling cows. CONCLUSIONS: The prevalence of M. bovis in dairy cows and dairy farm workers under the intensive dairy production system in Egypt is high. It is therefore essential to disseminate effective prevention and control measures to prevent the spread of M. bovis between dairy cows and dairy workers. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed that the use of RT or TB-Feron as an ancillary test of SCT reactor cows resulted in a significant reduction in the SCT false-positive slaughtered cows. A high prevalence of M. bovis infection among farm workers provides evidence of occupational risk in the intensive dairy production system in Egypt.