A Narrative Review of Occupational Air Pollution and Respiratory Health in Farmworkers

Respiratory health and chronic disease risks in residents of agricultural areas in Chiang Mai, Northern Thailand

Respiratory health and chronic disease risks are prevalent concerns in agricultural communities in Northern Thailand, prompting an assessment of these issues among residents in Chiang Mai. A cross-sectional study involving 145 participants was conducted in San Pa Tong District from October to December 2023, utilizing structured questionnaires and spirometry tests to evaluate lung function and chronic health disease risk. The study found that education and income significantly impacted lung function, with better FVC% and FEV1/FVC% predicted values observed in those with primary education and lower income. Lower DM risk was associated with better lung function (P =  0.023). Logistic regression showed a significant increase in lung function impairment among participants with high to very high DM risk (aOR 9.06, p < 0.05). High CV and COPD risk levels also correlated with lung function impairment, though not all results were statistically significant. The results emphasize the intricate interplay between socioeconomic factors, chronic disease risks, and lung function, advocating for public health interventions that holistically address population respiratory and metabolic health.

Urban air pollution and chronic respiratory diseases in adults: insights from a cross-sectional study

Objectives

Air pollution poses a substantial public health risk, especially in urban environments characterized by elevated levels of pollutants such as fine particulate matter (PM2.5) and nitrogen dioxide (NO2). These pollutants negatively impact respiratory health, contributing to chronic respiratory conditions and reduced lung function. This study investigated the association between air pollution exposure and respiratory health outcomes, including the prevalence of chronic respiratory conditions and pulmonary function, in an urban population. Additionally, the study sought to identify demographic subgroups that are unprotected from the ill effects of air pollution.

Methods

A cross-sectional study included a total of 1,300 adult participants recruited from outpatient pulmonary and general medicine clinics. Air pollution exposure was assessed based on residential proximity to major traffic routes and ambient levels of PM2.5 and NO2 obtained from the Riyadh air quality monitoring network. Lung function was measured using spirometry, and data on chronic respiratory conditions were collected through self-reports and medical record reviews. Multivariable logistic regression and linear regression models were used to analyze the association between air pollution exposure and respiratory outcomes, adjusting for confounders such as age, gender, smoking Status, socioeconomic Status, physical activity, and occupational exposures.

Results

Higher air pollution level exposures were significantly associated with an increased prevalence of chronic respiratory conditions (adjusted OR for high exposure: 2.45, 95% CI: 1.70-3.55, p < 0.001) and a reduction in lung function, as indicated by declines in FEV1 and FVC (adjusted FEV1 coefficient for high exposure: -0.45, 95% CI: -0.58 to -0.32, p < 0.001). Subgroup analyses revealed that older adults, males, and current smokers were particularly susceptible to the adverse effects of air pollution. Sensitivity analyses confirmed the robustness of these findings across different analytical scenarios.

Conclusion

The study demonstrated a clear and significant association between higher air pollution level exposures and an increased risk of chronic respiratory conditions and reduced lung function. These findings highlight the need for specific interventions to decrease air pollution exposure, particularly in vulnerable urban populations, to mitigate the burden of respiratory diseases.

Leveraging Administrative Health Databases to Address Health Challenges in Farming Populations: Scoping Review and Bibliometric Analysis (1975-2024)

BACKGROUND

Although agricultural health has gained importance, to date, much of the existing research relies on traditional epidemiological approaches that often face limitations related to sample size, geographic scope, temporal coverage, and the range of health events examined. To address these challenges, a complementary approach involves leveraging and reusing data beyond its original purpose. Administrative health databases (AHDs) are increasingly reused in population-based research and digital public health, especially for populations such as farmers, who face distinct environmental risks.

OBJECTIVE

We aimed to explore the reuse of AHDs in addressing health issues within farming populations by summarizing the current landscape of AHD-based research and identifying key areas of interest, research gaps, and unmet needs.

METHODS

We conducted a scoping review and bibliometric analysis using PubMed and Web of Science. Building upon previous reviews of AHD-based public health research, we conducted a comprehensive literature search using 72 terms related to the farming population and AHDs. To identify research hot spots, directions, and gaps, we used keyword frequency, co-occurrence, and thematic mapping. We also explored the bibliometric profile of the farming exposome by mapping keyword co-occurrences between environmental factors and health outcomes.

RESULTS

Between 1975 and April 2024, 296 publications across 118 journals, predominantly from high-income countries, were identified. Nearly one-third of these publications were associated with well-established cohorts, such as Agriculture and Cancer and Agricultural Health Study. The most frequently used AHDs included disease registers (158/296, 53.4%), electronic health records (124/296, 41.9%), insurance claims (106/296, 35.8%), population registers (95/296, 32.1%), and hospital discharge databases (41/296, 13.9%). Fifty (16.9%) of 296 studies involved >1 million participants. Although a broad range of exposure proxies were used, most studies (254/296, 85.8%) relied on broad proxies, which failed to capture the specifics of farming tasks. Research on the farming exposome remains underexplored, with a predominant focus on the specific external exposome, particularly pesticide exposure. A limited range of health events have been examined, primarily cancer, mortality, and injuries.

CONCLUSIONS

The increasing use of AHDs holds major potential to advance public health research within farming populations. However, substantial research gaps persist, particularly in low-income regions and among underrepresented farming subgroups, such as women, children, and contingent workers. Emerging issues, including exposure to per- and polyfluoroalkyl substances, biological agents, microbiome, microplastics, and climate change, warrant further research. Major gaps also persist in understanding various health conditions, including cardiovascular, reproductive, ocular, sleep-related, age-related, and autoimmune diseases. Addressing these overlooked areas is essential for comprehending the health risks faced by farming communities and guiding public health policies. Within this context, promoting AHD-based research, in conjunction with other digital data sources (eg, mobile health, social health data, and wearables) and artificial intelligence approaches, represents a promising avenue for future exploration.

The Adverse Health Effects of Air Pollution from Sugarcane Burning: A Scoping Review of Observational and Experimental Evidence

BACKGROUND

Sugarcane burning is an agricultural practice that is implemented to increase sugar yields. However, sugarcane burning produces air pollutants associated with adverse health outcomes. This review summarizes the current knowledge of the defined exposures and health effects associated with sugarcane burning and identifies research gaps.

METHODS

A scoping review was conducted using PubMed, Scopus, and Web-of-Science to identify peer-reviewed literature on health and exposure investigations associated with air pollution from burning sugarcane. Studies were eligible if they included both an air pollution measurement and a health outcome assessment in human workers and surrounding communities or animal studies associated with sugarcane burning.

RESULTS

A total of 24 studies passed our inclusion criteria, including 19 observational and five experimental studies. All observational studies were conducted in Brazil or the United States with the majority focused on respiratory (65%, 15/24), cardiovascular (13% 3/24), and renal (13%, 3/24) health outcomes. The most frequently assessed air pollutants were particulate matter [with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 ) and with aerodynamic diameter ≤ 10 μ m (PM 10 )] and total suspended particulates (TSP). Of the observational studies, 42% (8/19) were prospective cohorts, and 58% (11/19) employed an ecological design and applied variable exposure assessment methods. The experimental studies all used rodent models with varied exposure routes and pollutants.

DISCUSSION

This review supports a well-documented link between air pollution from sugarcane burning and adverse health effects in workers and neighboring communities with respiratory, renal, and cardiovascular health effects; however, several knowledge gaps were identified, including the need for expansion of studies geographically, application of more advanced exposure science to characterize and quantify sugarcane emission components, probing of emerging health effects (i.e., kidney disease) and associated biomarkers, and evaluation of vulnerable populations that neighbor sugarcane operations. Furthermore, pairing exposure measurements and health assessments in the same study would increase our knowledge and better inform policies to improve the health of workers and communities impacted by sugarcane burning. https://doi.org/10.1289/EHP14456.

Zinc Protects against Swine Barn Dust-Induced Cilia Slowing

Agricultural workers exposed to organic dust from swine concentrated animal feeding operations (CAFOs) have increased chances of contracting chronic lung disease. Mucociliary clearance represents a first line of defense against inhaled dusts, but organic dust extracts (ODEs) from swine barns cause cilia slowing, leading to decreased bacterial clearance and increased lung inflammation. Because nutritional zinc deficiency is associated with chronic lung disease, we examined the role of zinc supplementation in ODE-mediated cilia slowing. Ciliated mouse tracheal epithelial cells were pretreated with 0-10 µg/mL ZinProTM for 1 h, followed by treatment with 5% ODE for 24 h. Cilia beat frequency (CBF) and protein kinase C epsilon (PKCε) activity were assayed. ODE treatment resulted in cilia slowing after 24 h, which was reversed with 0.5 and 1.0 µg/mL ZinPro pre-treatment. No zinc protection was observed at 50 ng/mL, and ciliated cells detached at high concentrations (100 µg/mL). ZinPro alone produced no changes in the baseline CBF and showed no toxicity to the cells at concentrations of up to 10 µg/mL. Pre-treatment with ZinPro inhibited ODE-stimulated PKCε activation in a dose-dependent manner. Based on ZinPro's superior cell permeability compared to zinc salts, it may be therapeutically more effective at reversing ODE-mediated cilia slowing through a PKCε pathway. These data demonstrate that zinc supplementation may support the mucociliary transport apparatus in the protection of CAFO workers against dust-mediated chronic lung disease.

The role of liver enzymes in the association between ozone exposure and diabetes risk: a cross-sectional study of Zhuang adults in China

Background: Growing evidence has demonstrated the role of ambient air pollutants in driving diabetes incidence. However, epidemiological evidence linking ozone (O3) exposure to diabetes risk has been scarcely studied in Zhuang adults in China. We aimed to investigate the associations of long-term exposure to O3 with diabetes prevalence and fasting plasma glucose (FPG) and estimate the mediating role of liver enzymes in Zhuang adults. Methods: We recruited 13 843 ethnic minority adults during 2018-2019 based on a cross-sectional study covering nine districts/counties in Guangxi. Generalized linear mixed models were implemented to estimate the relationships between O3 exposure and diabetes prevalence and FPG. Mediation effect models were constructed to investigate the roles of liver enzymes in the associations of O3 exposure with diabetes prevalence and FPG. Subgroup analyses were conducted to identify potential effect modifications. Results: Long-term exposure to O3 was positively associated with diabetes prevalence and FPG levels in Zhuang adults, with an excess risk of 7.32% (95% confidence interval [CI]: 2.56%, 12.30%) and an increase of 0.047 mmol L-1 (95% CI: 0.032, 0.063) for diabetes prevalence and FPG levels, respectively, for each interquartile range (IQR, 1.18 μg m-3) increment in O3 concentrations. Alanine aminotransferase (ALT) significantly mediated 8.10% and 29.89% of the associations of O3 with FPG and diabetes prevalence, respectively, and the corresponding mediation proportions of alkaline phosphatase (ALP) were 8.48% and 30.00%. Greater adverse effects were observed in females, obese subjects, people with a low education level, rural residents, non-clean fuel users, and people with a history of stroke and hypertension in the associations of O3 exposure with diabetes prevalence and/or FPG levels (all P values for interaction < 0.05). Conclusion: Long-term exposure to O3 is related to an increased risk of diabetes, which is partially mediated by liver enzymes in Chinese Zhuang adults. Promoting clean air policies and reducing exposure to environmental pollutants should be a priority for public health policies geared toward preventing diabetes.

Occupational respiratory disorders in Iran: a review of prevalence and inducers

The link between occupational respiratory diseases (ORD) and exposure to harmful factors that are present in the workplace has been well shown. Factors such as physical activity, age and duration of occupational exposure playing important roles in ORD severity, should be identified in the workplace, their effects on workers health should be studied, and ultimately, exposure to them must be minimized. We carried out a literature review by searching PubMed, Scopus, and Web of Science databases to retrieve studies published from 1999 until the end of April 2023 reporting the prevalence and inducers of ORD in Iran. In Iranian workers, several ORD such as interstitial lung disease, silicosis, occupational asthma, pulmonary inflammatory diseases, chronic obstructive pulmonary diseases, and lung cancers have been reported. It was indicated that ORD mainly occur due to repeated and prolonged exposure to noxious agents in the workplace. We also extracted the prevalence of ORD in different regions of Iran from the retrieved reports. Based on our literature review, the prevalence of ORD among Iranian workers highlights the importance of regular assessment of the risk of exposure to noxious agents in the workplace to develop measures for preventing potential adverse effects.

The growing impact of air quality on lung-related illness: a narrative review

Background and Objective

Poor air quality can be harmful to human well-being. There are a variety of respiratory disorders associated with toxins present within the atmosphere, such as bronchitis and asthma, which eventually lead to heart or lung complications over time. Fine particles like particulate matter 2.5 (PM2.5) accumulate in the small airways of the lung. These irritants can cause epigenetic modifications in gene regulation, leading to changes responsible for both benign and malignant lung diseases. In this review we will discuss known associations between environmental factors and pulmonary complications, consider preventative measures and offer further areas for future investigation. This review presents a summary of the literature outlining the current work done on air quality and its effects on lung-related illnesses. We discuss regional differences in air quality and consider the causes, such as manufacturing, traffic density, increase in fuel usage and natural events. We further explore disparities based on geography, race, and other social determinants.

Methods

A comprehensive literature review was performed using keywords related to air quality, pollution and lung disease within the PubMed database as well as MEDLINE and Google Scholar.

Key Content and Findings

The Clean Air Act of 1970 marked an essential transition for air quality improvement. The legislation led to decreased emissions and control measures to address atmosphere contamination. Despite these actions, poor atmospheric conditions still persist today and have become an ongoing issue. These poor conditions affect individuals living in metropolitan areas more significantly than suburban or rural areas. Pollution from industrial operations and transportation vehicles have led to increased emission outputs recently. Climate change further aggravates air quality problems by raising pollutant and allergen concentrations. The detrimental consequences of poor air quality include increased incidence of disease processes like asthma, chronic obstructive pulmonary disease (COPD) and lung cancer. To keep up with the well-being of people globally, it is important that actions be taken to battle contamination in the climate so its impact on public health can be limited.

Conclusions

Poor air quality and recent worsening of industrial emissions have had a negative impact on lung-related illnesses. Future mitigation strategies should be taken to reduce pollution and treat diseases earlier in their course. Some of these strategies include more reliance on alternative energy sources, creation of mass transit systems and increased rates of recycling.

The differential impact of air pollutants on acute urticaria and chronic urticaria: a time series analysis

Several studies have revealed a relationship between short-term exposure to air pollution and the exacerbation of certain skin conditions. This study was developed to expand on these findings by exploring the potential association between exposure to air pollutants including particulate matter, sulfur dioxide, and ozone and the incidence of acute and chronic urticaria in Shenyang, China, from 2016 to 2018. Exposure-response relationships between daily mean concentrations of these airborne pollutants and visits to outpatient dermatological clinics for acute urticaria and chronic urticaria were evaluated via a time series analysis approach using a generalized additive model. This analysis revealed that a 10 μg/m³ increase in daily mean O₃_8h concentrations was associated with a 0.36% (95% CI, 0.31-0.41%), 0.35% (95% CI, 0.30-0.40%), and 0.34% (95% CI, 0.29-0.39%) increase in the number of outpatient visits for acute urticaria on that day (lag0), lagging day 1 (lag1), and lagging day 2 (lag2), respectively. O3 levels also had a similar but weaker effect on the frequency of patients seeking outpatient care for chronic urticaria. These analyses also revealed that estimated 0.47% (95% CI, 0.41-0.52%) and 0.46% (95% CI, 0.40-0.51%) increases in dermatological outpatient acute urticaria visits were observed for every 10μg/m3 rise in O3_8h concentrations on cumulative lagging days (lag01 and lag02). Increases in particulate matter (PM_2.5, PM₁₀) levels had a similar cumulative effect on patients with chronic urticaria. In summary, these results suggest that short-term O₃, PM_2.5, and PM₁₀ exposure can increase the risk of acute urticaria and chronic urticaria.

Influence of COVID-19 on the poultry production and environment

Although chickens are not susceptible to SARS-CoV-2, several coronavirus disease outbreaks have been described concerning poultry processing facilities in different countries. The COVID-19 pandemic and the developed strain caused 2nd, 3rd, and recent Indian strain waves of epidemics that have led to unexpected consequences, such as forced reductions in demands for some industries, transportation systems, employment, and businesses due to public confinement. Besides, poultry processing plants' conditions exacerbate the risks due to the proximity on the line, cold, and humidity. Most workers do not have access to paid sick time or adequate health care, and because of the low wages, they have limited reserves to enable them to leave steady employment. In addition, workers in meat and poultry slaughterhouses may be infected through respiratory droplets in the air and/or from touching dirty surfaces or objects such as workstations, break room tables, or tools. Egg prices have increased dramatically during the lockdown as consumers have started to change their behaviors and habits. The COVID pandemic might also substantially impact the international poultry trade over the next several months. This review will focus on the effect of COVID-19 on poultry production, environmental sustainability, and earth systems from different process points of view.