Longitudinal Renal Function Degradation Among Florida Agricultural Workers.

OBJECTIVE: This longitudinal study evaluated renal function and acute kidney injury (AKI) over time in U.S. agricultural workers. METHODS: We followed Florida agricultural workers from January 2020 to August 2022, collecting blood and urine pre- and post-workday during 5 visits. RESULTS: Pre-workday eGFR function in all participants was lower in summers but relatively consistent over time. In participants who worked almost exclusively in fernery operations (piece-rate compensation), we observed a high incidence of post-workday AKI in 2020 (21%) that increased to 43% by the end of the study. In comparison, 11% of nursery workers (hourly compensation) had AKI, and this rate was fairly stable. CONCLUSION: AKI risk over time differs according to the type of agricultural work. Piece rate workers who are incentivized to forgo rest breaks and hydration to earn higher wages demonstrate steadily increasing rates of AKI.

Retention of Agricultural Workers Participating in a Renal Longitudinal Study.

OBJECTIVES: The relationship between heat stress, chronic kidney diseases and acute kidney injury has been documented in cross-sectional studies with agricultural workers. However, only a few international studies have assessed renal function in agricultural workers longitudinally. Our research study, Occupational Heat Exposure and Renal Dysfunction (OHEaRD) is the first longitudinal study in the U.S. that monitored renal function in agricultural workers five times over the course of 32-months. The main objectives of this study were to evaluate the rate of retention and identify predictors associated with retention in a longitudinal study with agricultural workers. METHODS: In January 2020, we enrolled 119 Florida agricultural workers to observe on 5 workdays over 32 months. Retention was defined by the number of follow-up visits that a participant attended, the consistency of visit attendance, and attendance at the last visit. Participants were provided hemoglobin A1C, lipid panel, creatinine measurement, glomerular filtration rate (eGFR), blood pressure, and body mass index results and an incentive gift card were handed out to participants at each visit. RESULTS: Four enrollees did not participate on any workday, thus analysis concentrated on the remaining 115 participants. The majority of participants (64%) completed the 32-month study, 78% completed at least 4 visits, and 55% completed all 5 visits. The statistically significant predictors of higher retention among this study were being older in age (p=0.02), Mexican nationality (p=0.004), working in ferneries (p=0.009), more years working in agriculture (p=0.02), and higher total cholesterol (p=0.02). Appreciation for the health tests was associated with greater participation at the final visit (p=0.01). CONCLUSION: Retention in longitudinal studies is crucial to better understand kidney disease among agricultural workers, an understudied population. Participants reported valuing the access to health results, indicating that implementing point-of-care health screenings and providing the health results to each participant is a good retention strategy. There was some evidence that a participant living with or being related to a fellow co-participant could impact retention as they either showed up or missed visits together, suggesting recruiting from the same household may reduce retention.

The impact of heat exposures on biomarkers of AKI and plasma metabolome among agricultural and non-agricultural workers.

BACKGROUND: Agricultural workers are consistently exposed to elevated heat exposures and vulnerable to acute kidney injury. The underlying pathophysiology and detailed molecular mechanisms of AKI among agricultural workers, and the disproportionate burden of HRI and heat stress exposure are not well understood, especially at the level of cellular metabolism. OBJECTIVE: The aim of this study was to examine the impact of heat exposures on renal biomarkers and on the human metabolome via untargeted high-resolution metabolomics among agricultural and non-agricultural workers. METHODS: Blood and urine samples were collected pre- and post-work shift from 63 agricultural workers and 27 non- agricultural workers. We evaluated pre- and post-work shift renal biomarkers and completed untargeted metabolomics using high-resolution mass spectrometry with liquid chromatography. Metabolome-wide association studies (MWAS) models identified the metabolic features differentially expressed between agricultural workers and non-agricultural workers. RESULTS: Median values of pre-shift creatinine and osteopontin (p < 0.05) were higher for agricultural workers than non-agricultural workers. Metabolic pathway enrichment analyses revealed 27 diverse pathways differed between agricultural workers and non-agricultural workers (p < 0.05) including TCA cycle and urea cycle, carbohydrate metabolism, histidine metabolism and evidence for altered microbiome shikimate pathway. CONCLUSION: This is the first investigation on the metabolic pathways that are affected among agricultural workers who are exposed to heat compared to non-heat exposed workers. This study shows extensive responses of central metabolic systems to heat exposures that impact human health.

A Pilot Study Examining the Use of Ultrasound to Measure Intravascular Volume Status in Agricultural Workers in a Field-Based Research Setting.

OBJECTIVE: The aim of this pilot study was to explore if internal jugular vein (IJV) ultrasound studies on agricultural workers in a field-based research setting could assess volume status during a hydration intervention. METHODS: We performed pre- and post-work shift IJV ultrasound images on 30 agricultural workers. The IJV collapsibility index values were <39% (euvolemic) or ≥39% (hypovolemic). RESULTS: Of the water group, 13% (2/15) had an IJV collapsibility index ≥39%, and this increased to 19% (3/16) by the end of the work shifts. The electrolyte group did not have any workers start the work shift with an IJV collapsibility index ≥39%; however, at the postshift assessment, 15% (2/13) were hypovolemic. CONCLUSION: Internal jugular vein ultrasounds may have the potential to be a useful tool to determine volume status in field-based research settings. Further investigation is needed to confirm these findings.

Retrospective Assessment of Human-Chemical Interactions in Health-Disparity Populations: A Process Evaluation of Life History Calendars.

Life-history calendars (LHCs) can produce retrospective data regarding numerous events, exposures, and sequences that have occurred across participants' lifespans. In this mixed-quantitative-and-qualitative-methods study, processes of LHC administration were evaluated in two populations experiencing health disparities: foreign-born agricultural workers (n = 41) and Indigenous people who used injection drugs (IPWIDS) (n = 40). LHC administrator and participant perspectives were elicited during follow-up survey activities. In both agricultural workers and IPWIDs, over half of participants reported that the LHC made it easier to remember things about the past, and participant age was associated with cumulative experience in different domains of interest. Qualitative findings suggested that data-collector training and the development of concise interview guides are critical for improving LHC data quality. Participants described ethical themes, including utilitarian, cathartic, and reflective aspects, of LHC participation. Future iterations of the LHC may benefit from providing free-form and open-ended spaces for participants to reflect on the LHC activity following LHC administration.

Hydration Interventions Among Agricultural Workers: A Pilot Study.

OBJECTIVE: To estimate the impact of hydration interventions on postworkday hydration status and incidence of acute kidney injury (AKI). METHODS: Thirty agricultural workers were first monitored on a workday without any interventions. On the intervention workday, the same workers were randomized to one of two groups: 169 ounces (oz) (5 L) of plain water (n = 16) or 169 oz (5L) of water with electrolytes (n = 14). RESULTS: No participants in the electrolyte group had an estimate glomerular filtration rate (eGFR) at the end of the workday of less than 90 mL/min/1.73 m2 or met the criteria for AKI in comparison to the water group (eGFR < 90: 15%; AKI: 23%) or the control group (eGFR < 90: 28%; AKI: 18%). CONCLUSION: The study showed that drinking water with electrolytes may lower the risk for development of AKI among agricultural workers.

Soft Wireless Bioelectronics Designed for Real-Time, Continuous Health Monitoring of Farmworkers.

Hotter summers caused by global warming and increased workload and duration are endangering the health of farmworkers, a high-risk population for heat-related illness (HRI), and deaths. Although prior studies using wearable sensors show the feasibility of employing field-collected data for HRI monitoring, existing devices still have limitations, such as data loss from motion artifacts, device discomfort from rigid electronics, difficulties with administering ingestible sensors, and low temporal resolution. Here, this paper introduces a wireless, wearable bioelectronic system with functionalities for continuous monitoring of skin temperature, electrocardiograms (ECG), heart rates (HR), and activities, configured in a single integrated package. Advanced nanomanufacturing based on laser machining allows rapid device fabrication and direct incorporation of sensors with a highly breathable substrate, allowing for managing excessive sweating and multimodal stresses. To validate the device's performance in agricultural settings, the device is applied to multiple farmworkers at various operations, including fernery, nursery, and crop. The accurate data recording, including high-fidelity ECG (signal-to-noise ratio: >20 dB), accurate HR (r = 0.89, r2 = 0.65 in linear correlation), and reliable temperature/activity, confirms the device's capability for multiparameter health monitoring of farmworkers.

The Health Status of Hispanic Agricultural Workers in Georgia and Florida.

To examine the health status of Hispanic agricultural workers in Florida and Georgia. Health data from agricultural workers in the Farm Worker Family Health Program (June 2019) and research studies in Florida (May 2015 and May 2019) were examined. Data from 728 agricultural workers were collected through sociodemographic questionnaire and clinical data. In the Florida sample, 83% were overweight or obese, 70% elevated blood pressure, 60% met the definition of prediabetes. In Georgia, 64% were overweight or obese and 67% had elevated blood pressure. Weak correlations were observed between BMI and systolic blood pressure (unadjusted r = 0.20), diastolic blood pressure (unadjusted r = 0.19), and glucose (unadjusted r = 0.14). Adjusting for age and gender did not show statistically significant correlation between BMI and systolic and diastolic blood pressure or glucose. While BMI has been shown to be strongly associated with high blood pressure and impaired glucose, we found a weak correlation among agricultural workers. Given the common and high use of pesticides and elevated rates of hypertension, impaired glucose, and adiposity in agricultural workers, the public health impact of this relationship may require and lead to occupational reform that protects the health of agricultural workers. Future studies should assess occupational and environmental factors and lifestyle differences between agricultural workers and the general population to better understand these discrepancies in health status.

Characterization of Lifetime Agrichemical Exposure Sequences Relative to International Migration in Foreign Born Latinx Agricultural Workers Living in South Florida.

There is a limited understanding of how toxic exposures to agrichemicals vary relative to international migration over the life course. A life history calendar (LHC) was piloted to explore sequences of agrichemical exposure relative to international migration. LHCs were administered to 41 foreign born individuals from Mexico and Central America who had agricultural work experience during their lifetime and who were living in South Florida. Social sequence analysis was used to explore occupation-by-agrichemical events relative to migration. A three-cluster solution was used to classify low, moderate, and high lifetime exposure sequences. The odds of any perceived effects of agrichemicals on the body increased with time prior to migration in the moderate and high exposure sequence clusters and continued to increase 20% with each year following migration in the moderate exposure cluster. Workers with high lifetime agrichemical exposures prior to migrating internationally showed lower likelihoods of a perceived effect on the body following migration despite continued exposure. Further research on instrument validity is warranted.

COVID-19 and Agricultural Workers: A Descriptive Study.

Agricultural workers, designated as "essential" at the start of the COVID-19 pandemic, work in harsh labor conditions, and now have the added challenge of continuing to work during the COVID-19 pandemic. The aim of this study was to assess agricultural workers' COVID-19 related history, employer-based safety measures, individual preventive practices, and COVID-19 vaccination uptake. A questionnaire study was conducted among agricultural workers in Central Florida about COVID-19 during the month of June 2020 and again in July 2021. Among 92 agricultural workers in June 2020, 47% were obese; 11% had had a COVID-19 nasal test; 87% were able to social distance at work and 34% reported employer provided face masks; 15% reported not willing to get the COVID-19 vaccine and 25% were unsure. 40% could self-isolate if they contracted COVID-19. In a follow-up visit in July 2021, 53% of participants reported receiving a COVID-19 vaccine. Agricultural workers are particularly vulnerable to COVID-19 due to existing health risk factors and lack of essential protective resources. Occupational health protections social safety net programs are urgently needed to prevent infections in vulnerable workers, and reduce community spread, and increase COVID-19 vaccination rates.

Comparative Effectiveness of Training Alternatives for the EPA's Worker Protection Standard Regulation Among Immigrant Latino Farmworkers.

OBJECTIVES: To determine the comparative effectiveness of two EPA-approved WPS training strategies. METHODS: Farmworkers in GA and FL blinded to content before training (N = 339) were randomly assigned to either a video training (n = 121) or a culturally tailored, facilitator-led training (n = 136), or an attention-placebo training focused on heat-related illness (n = 82). Data were obtained immediately before and after training and 3 months after training. RESULTS: Both active interventions increased pesticide knowledge. At the 3-month follow-up, participants in the EPA video lost acquired knowledge. Those in the facilitator-led group retained acquired knowledge and showed greater pesticide safety behavior. CONCLUSIONS: Standardized training through video improves short-term knowledge, but it is not retained and unable to support desired behavior to reduce pesticide exposure among farmworkers. A culturally tailored, facilitator-led training is more effective in achieving the spirit of the WPS regulation.

Inflammation-Related Factors Identified as Biomarkers of Dehydration and Subsequent Acute Kidney Injury in Agricultural Workers.

Globally, there is increasing recognition that agricultural workers are at risk for chronic kidney disease of unknown etiology (CKDu). Recurrent heat exposure, physical exertion, dehydration, muscle damage, and inflammation are hypothesized to contribute to the development of CKDu, but the relative importance of these processes and the interactions among them remain unclear. Moreover, there is a need to identify biomarkers that could distinguish individuals who are at greatest risk for kidney damage to target preventative interventions for CKDu. In this study, we evaluated dehydration and markers of inflammation, muscle damage, and renal function in agricultural workers at a non-workday baseline assessment. Urine specific gravity and kidney function were measured before and after work shifts on three subsequent days, and heat index, core body temperature, and heart rate were monitored during the work shifts. A combination of direct comparisons and machine learning algorithms revealed that reduced levels of uromodulin and sodium in urine and increased levels of interleukin-6 and C-reactive protein in serum were indicative of dehydration at baseline, and that dehydration, high body mass index, reduced urine uromodulin, and increased serum interleukin-6, C-reactive protein, and lipopolysaccharide-binding protein at baseline were predictive of acute kidney injury on subsequent workdays. Our findings suggest a method for identifying agricultural workers at greatest risk for kidney injury and reveal potential mechanisms responsible for this process, including pathways overlapping in dehydration and kidney injury. These results will guide future studies confirming these mechanisms and introducing interventions to protect kidney health in this vulnerable population.

Cooling Interventions Among Agricultural Workers: Qualitative Field-Based Study.

INTRODUCTION: Agricultural workers perform intense labor outside in direct sunlight and in humid environmental conditions exposing them to a high risk of heat-related illness (HRI). To implement effective cooling interventions in occupational settings, it is important to consider workers' perceptions. To date, an analysis of agricultural workers' experience and perception of cooling devices used in the field while working has not been published. METHODS: Qualitatively data from 61 agricultural workers provided details of their perceptions and experiences with cooling interventions. RESULTS: The participants in the bandana group reported the bandana was practical to use at work and did not interfere with their work routine. Cooling vest group participants agreed that the vest was effective at cooling them, but the practicality of using the vest at work was met with mixed reviews. CONCLUSION: The findings of this qualitative study support and extend existing research regarding personal cooling and heat prevention research interventions with vulnerable occupational groups. Personal cooling gear was well received and utilized by the agricultural workers. Sustainable heat prevention studies and governmental protection strategies for occupational heat stress are urgently needed to reduce the risk of heat-related morbidity, mortality, and projected climate change health impacts on outdoor workers.

Cooling Interventions Among Agricultural Workers: A Pilot Study.

BACKGROUND: Adverse health effects among agricultural workers due to chronic heat exposure have been characterized in the literature as not only due to high ambient temperatures but also due to intensive manual labor in hot and humid conditions. The aim of this study was to use biomonitoring equipment to examine the effectiveness of selected cooling devices at preventing agricultural workers from exceeding the core body temperature threshold of 38.0°C (Tc38) and attenuating heat-related illness symptoms. METHODS: A convenience sample of 84 agricultural workers in Florida was randomized to one of four groups: (a) no intervention, clothing as usual; (b) cooling bandana; (c) cooling vest; and (d) both the cooling bandana and cooling vest. Biomonitoring equipment worn by the participants included core body temperature monitor and an accelerometer to capture physical activity. FINDINGS: A total of 78 agricultural workers completed one intervention workday trial. Compared with the control group, the bandana group had lower odds of exceeding Tc38 (odds ratio [OR] = 0.7, 90% confidence interval [CI] = [0.2, 3.2]) and the vest group had higher odds of exceeding Tc38 (OR = 1.8, 90% CI = [0.4, 7.9]). The simultaneous use of cooling vest and bandana showed an effect little different from the control group (OR = 1.3, 90% CI = [0.3, 5.6]). CONCLUSION/APPLICATION TO PRACTICE: This is the first field-based study to examine cooling intervention among agricultural workers in the United States using biomonitoring equipment. This study found that using a bandana while working in a hot agricultural environment has the potential to be protective against exceeding the recommended Tc38 threshold.

Cooling intervention studies among outdoor occupational groups: A review of the literature.

BACKGROUND: The purpose of this systematic review is to examine cooling intervention research in outdoor occupations, evaluate the effectiveness of such interventions, and offer recommendations for future studies. This review focuses on outdoor occupational studies conducted at worksites or simulated occupational tasks in climatic chambers. METHODS: This systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. PubMed, Embase, and Web of Science were searched to identify original research on intervention studies published in peer-reviewed journals that aimed at reducing heat stress or heat-related illness from January 2000 to August 2020. RESULTS: A systematic search yielded a total of 1042 articles, of which 21 met the inclusion criteria. Occupations with cooling intervention studies included agriculture (n = 5), construction (n = 5), industrial workers (n = 4), and firefighters (n = 7). The studies focused on multiple types of cooling interventions cooling gear (vest, bandanas, cooling shirts, or head-cooling gel pack), enhanced heat dissipation clothing, forearm or lower body immersion in cold water, water dousing, ingestion of a crushed ice slush drink, electrolyte liquid hydration, and modified Occupational Safety and Health Administration recommendations of drinking water and resting in the shade. CONCLUSION: Current evidence indicates that using multiple cooling gears along with rest cycles may be the most effective method to reduce heat-related illness. Occupational heat-related illnesses and death may be mitigated by targeted cooling intervention and workplace controls among workers of vulnerable occupational groups and industries.