Ageing and disease risk factors: A new paleoepidemiological methodology for understanding disease in the past

OBJECTIVES

To outline a methodology that enables the reconstruction of age-related disease risk in past societies.

MATERIALS

Modern epidemiological evidence considering risk factors for age-related disease is combined with contextual information about an archaeological society of interest.

METHODS

Data gathered is used to create a qualitative population-specific risk model for the disease of interest. To provide a case study, a risk model is constructed for Chronic Obstructive Pulmonary Disease (COPD) in the Eastern English Bronze Age.

RESULTS

This enables the first rigorous approach to reconstructing age-related disease risk in the past. A risk model shows a high degree of COPD risk in the Eastern English Bronze Age, with a major contribution from indoor airborne pollution and agricultural practices.

SIGNIFICANCE

This represents a significant new approach in human paleopathology, facilitating understanding of the occurrence of a wide variety of diseases in the past, without the need for well-preserved skeletons of identified elderly individuals.

LIMITATIONS

The risk models generated are, of necessity, qualitative rather than quantitative, since we are unable to calculate the size of risk factors in the past with certainty.

SUGGESTIONS FOR FURTHER RESEARCH

The methodology could be applied to a wide variety of diseases and for many past societies.

Respiratory Diseases Associated With Organic Dust Exposure

Organic dusts are complex bioaerosol mixtures comprised of dust and par ticulate matter of organic origin. These include components from bacteria, fungi, pollen, and viruses to fragments of animals and plants commonplace to several environmental/occupational settings encompassing agriculture/farming, grain processing, waste/recycling, textile, cotton, woodworking, bird breeding, and more. Organic dust exposures are linked to development of chronic bronchitis, chronic obstructive pulmonary disease, asthma, asthma-like syndrome, byssinosis, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis. Risk factors of disease development include cumulative dust exposure, smoking, atopy, timing/duration, and nutritional factors. The immunopathogenesis predominantly involves Toll-like receptor signaling cascade, T-helper 1/T-helper 17 lymphocyte responses, neutrophil influx, and potentiation of manifestations associated with allergy. The true prevalence of airway disease directly attributed to organic dust, especially in a workplace setting, remains challenging. Diagnostic confirmation can be difficult and complicated by hesitancy from workers to seek medical care, driven by fears of potential labor-related consequence. Clinical respiratory and systemic presentations coupled with allergy testing, lung function patterns of obstructive versus restrictive disease, and radiological characteristics are typically utilized to delineate these various organic dust-associated respiratory diseases. Prevention, risk reduction, and management primarily focus on reducing exposure to the offending dust, managing symptoms, and preventing disease progression.

Club Cells-A Guardian against Occupational Hazards

Club cells have a distinct role in the epithelial repair and defense mechanisms of the lung. After exposure to environmental pollutants, during chronic exposure, the secretion of club cells secretory protein (CCSP) decreases. Exposure to occupational hazards certainly has a role in a large number of interstitial lung diseases. According to the American Thoracic Society and the European Respiratory Society, around 40% of the all interstitial lung disease is attributed to occupational hazards. Some of them are very well characterized (pneumoconiosis, hypersensitivity pneumonitis), whereas others are consequences of acute exposure (e.g., paraquat) or persistent exposure (e.g., isocyanate). The category of vapors, gases, dusts, and fumes (VGDF) has been proven to produce subclinical modifications. The inflammation and altered repair process resulting from the exposure to occupational respiratory hazards create vicious loops of cooperation between epithelial cells, mesenchymal cells, innate defense mechanisms, and immune cells. The secretions of club cells modulate the communication between macrophages, epithelial cells, and fibroblasts mitigating the inflammation and/or reducing the fibrotic process. In this review, we describe the mechanisms by which club cells contribute to the development of interstitial lung diseases and the potential role for club cells as biomarkers for occupational-related fibrosis.

A Cross-Sectional Study of Farmer Health and Wellbeing in Norway: The HUNT Study (2017-2019)

OBJECTIVES

Obtain a broad impression of the health and wellbeing of working farmers in a representative population.

METHODS

A cross-sectional study using data from a large, general population-based survey, The HUNT Study, Norway (HUNT survey 4, 2017-2019, response rate 54%). The study included 24,313 occupationally active participants aged 19 to 76 years, including 1,188 farmers. Prevalences are estimated for outcomes covering musculoskeletal, respiratory, and mental health as well as general health and life satisfaction, with adjustment for worker age and sex. The estimates for farmers are compared to skilled white collar workers and skilled manual workers.

RESULTS

Farmers had a higher estimated prevalence of poor overall health (prevalence ratio [PR] 1.56 [95%CI 1.34,1.82]), chronically impaired mobility (PR 1.83 [1.53, 2.20]), long-standing musculoskeletal pain or stiffness (PR 1.29 [1.21, 1.37]), work-related respiratory attack (PR 4.32 [3.67, 5.08]), depression symptoms (PR 1.30 [1.04, 1.61]) and symptoms of psychological distress (PR 1.23 [1.04, 1.47]) than skilled white collar workers. The estimated prevalence of poor overall health (PR 1.19 [1.00, 1.41]) and work-related respiratory attacks (PR 1.44 [1.24, 1.67]) was also higher for farmers than skilled manual workers, after adjustment for age and sex. Farmers had greater odds of rating themselves less satisfied with life in general than skilled white collar workers (adjusted OR 1.17 [1.04, 1.31]).

CONCLUSIONS

These results are consistent with previous research and add evidence that farm work is associated with high prevalences of a broad range of adverse health outcomes. The associations with chronically impaired mobility, long-standing musculoskeletal pain, and poor self-rated health were strong. The adjusted PRs for work-related respiratory attacks relative to both comparison groups were particularly high. More research is needed to identify and evaluate interventions that can improve farmer health.

Rurality as a Risk Factor for Pulmonary Health Disparities

Rural populations experience significant pulmonary health disparities compared with urban populations. Patients in rural communities experience health determinants including high smoking prevalence, worse nutrition, lower educational attainment, specific occupational exposures, decreased health-care access, as well as unique cultural and political drivers of health. This article describes social determinants of pulmonary health relevant in rural communities, describes examples of existing pulmonary disparities in rural populations, and highlights health policies with potential to mitigate disparities.

The association of forced expiratory volume in one second with occupational exposures in a longitudinal study of adults in a rural community in Iowa

PURPOSE

The Keokuk County Rural Health Study (KCRHS) is a longitudinal population-based study conducted in rural Iowa. A prior analysis of enrollment data identified an association of airflow obstruction with occupational exposures only among cigarette smokers. The current study used spirometry data from all three rounds to investigate whether level of forced expiratory volume in one second (FEV1) and longitudinal change in FEV1 were associated with occupational vapor-gas, dust, and fumes (VGDF) exposures, and whether these associations were modified by smoking.

METHODS

This study sample comprised 1071 adult KCRHS participants with longitudinal data. A job-exposure matrix (JEM) was applied to participants' lifetime work histories to assign exposures to occupational VGDF. Mixed regression models of pre-bronchodilator FEV1 (millimeters, ml) were fit to test for associations with occupational exposures while adjusting for potential confounders.

RESULTS

Mineral dust had the most consistent association with change in FEV1, including ever/never ( - 6.3 ml/year) and nearly every level of duration, intensity, and cumulative exposure. Because 92% of participants with mineral dust also had organic dust exposure, the results for mineral dust may be due to a combination of the two. An association of FEV1 level with fumes was observed for high intensity ( - 91.4 ml) among all participants, and limited to cigarette smokers with results of  - 104.6 ml ever/never exposed,  - 170.3 ml high duration, and  - 172.4 ml high cumulative.

CONCLUSION

The current findings suggest that mineral dust, possibly in combination with organic dust, and fumes exposure, especially among cigarette smokers, were risk factors for adverse FEV1 results.

Microwave Gas Sensors Based on Electrodeposited Polypyrrole-Nickel Phthalocyanine Hybrid Films

Previous studies have shown that the incorporation of sulfonated metallophthalocyanines into sensitive sensor materials can improve electron transfer and thus species detection. Herein, we propose a simple and easy alternative to the use of generally expensive sulfonated phthalocyanines by electropolymerizing polypyrrole together with nickel phthalocyanine in the presence of an anionic surfactant. The addition of the surfactant not only helps the incorporation of the water-insoluble pigment into the polypyrrole film, but the obtained structure has increased hydrophobicity, which is a key property for developing efficient gas sensors with low sensitivity to water. The obtained results show the effectiveness of the materials tested for the detection of ammonia in the range of 100 to 400 ppm. It is shown by comparing the microwave sensor responses that the film without nickel phthalocyanine (hydrophilic) produces greater variations than the film with nickel phthalocyanine (hydrophobic). These results are consistent with the expected results since the hydrophobic film is not very sensitive to residual ambient water and therefore does not interfere with the microwave response. However, although this excess response is usually a handicap, as it is a source of drift, in these experiments the microwave response shows great stability in both cases.

Pectin alleviates the pulmonary inflammatory response induced by PM2.5 from a pig house by modulating intestinal microbiota

This study aimed to investigate whether dietary fiber pectin can alleviate PM_2.5-induced pulmonary inflammation and the potential mechanism. PM_2.5 samples were collected from a nursery pig house. The mice were divided into three groups: the control group, PM_2.5 group and PM_2.5 + pectin group. The mice in the PM_2.5 group were intratracheally instilled with PM_2.5 suspension twice a week for four consecutive weeks, and those in the PM_2.5 + pectin group were subject to the same PM_2.5 exposure, but fed with a basal diet supplemented with 5% pectin. The results showed that body weight and feed intake were not different among the treatments (p > 0.05). However, supplementation with pectin relieved PM_2.5-induced pulmonary inflammation, presenting as slightly restored lung morphology, decreased mRNA expression levels of IL-1β, IL-6 and IL-17 in the lung, decreased MPO content in bronchoalveolar lavage fluid (BLAF), and even decreased protein levels of IL-1β and IL-6 in the serum (p < 0.05). Dietary pectin altered the composition of the intestinal microbiota, increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes/Bacteroidetes. At the genus level, short-chain fatty acid (SCFA)-producing bacteria, such as Bacteroides, Anaerotruncus, Prevotella 2, Parabacteroides, Ruminococcus 2 and Butyricimonas, were enriched in the PM_2.5 +pectin group. Accordingly, dietary pectin increased the concentrations of SCFAs, including acetate, propionate, butyrate and valerate, in mice. In conclusion, dietary fermentable fiber pectin can relieve PM_2.5-induced pulmonary inflammation via alteration of intestinal microbiota composition and SCFA production. This study provides a new insight into reducing the health risk associated with PM_2.5 exposure.

Lessons from Dairy Farmers for Occupational Allergy and Respiratory Disease

PURPOSE OF REVIEW

Exposure to bioaerosols at dairies has long been associated with allergy, respiratory disease, and decreases in lung function. Recent advancements in exposure assessments have aided our understanding on the size distribution and composition of these bioaerosols, but investigations focusing solely on exposures may overlook important intrinsic factors impacting worker's susceptibility to disease.

RECENT FINDINGS

In our review, we discuss the most recent studies examining the exposures and genetic factors that contribute to occupational disease in dairy work. We also review more recent concerns in livestock work associated with zoonotic pathogens, antimicrobial resistant genes, and the role of the human microbiome. The studies highlighted in this review demonstrate the need for further research to better understand bioaerosol exposure-response relationships in the context of extrinsic and intrinsic factors, antibiotic-resistant genes, viral pathogens, and the human microbiome to help inform effective interventions that improve respiratory health among dairy farmers.

Airway Symptoms among Farmers in Central Norway. A Comparative Study of Risks. The HUNT Study

OBJECTIVES

The objective of this study was to compare the risk of developing respiratory symptoms in farmers and other occupational groups over a period of 11 to 23 years.

METHODS

The study includes data from questionnaires and interviews in HUNT1-3 in The Trøndelag Health study (HUNT). In all three surveys, farmers can be identified. Two control groups are used. Control group 1 consists of all HUNT participants who are not farmers or fishermen. Control group 2 consists of occupational groups who presumably have low exposure to dust, chemicals or gases, but similar educational status as farmers. The data are analysed in SPSS 25 (IBM, Armonk NY), with use of frequency analyses and multiple binary logistic regressions.

RESULTS

Our main finding is that healthy farmers have increased risk of developing respiratory symptoms as wheezing or breathlessness over a period of 11 and 23 years. This increased risk is statistically significant after 11 years of follow-up (HUNT1 to HUNT2), and also after 23 years (HUNT1 to HUNT3). Corresponding results regarding wheezing and breathlessness are found for healthy farmers in HUNT2 after 12 years of follow-up in HUNT3. In a subgroup analysis, we find a highly significant difference in both wheezing and shortness of breath when at work, in believing that the symptoms are caused by work, and in having to change jobs or quit because of breathing problems.

CONCLUSION

Farmers have more respiratory symptoms than controls, and the main symptom is attacks of wheezing or breathlessness. Preventive measures such as ventilation and respiratory protection should be implemented on the farm.

Low level exposure to hydrogen sulfide: a review of emissions, community exposure, health effects, and exposure guidelines

Hydrogen sulfide (H2S) is a toxic gas that is well-known for its acute health risks in occupational settings, but less is known about effects of chronic and low-level exposures. This critical review investigates toxicological and experimental studies, exposure sources, standards, and epidemiological studies pertaining to chronic exposure to H2S from both natural and anthropogenic sources. H2S releases, while poorly documented, appear to have increased in recent years from oil and gas and possibly other facilities. Chronic exposures below 10 ppm have long been associated with odor aversion, ocular, nasal, respiratory and neurological effects. However, exposure to much lower levels, below 0.03 ppm (30 ppb), has been associated with increased prevalence of neurological effects, and increments below 0.001 ppm (1 ppb) in H2S concentrations have been associated with ocular, nasal, and respiratory effects. Many of the studies in the epidemiological literature are limited by exposure measurement error, co-pollutant exposures and potential confounding, small sample size, and concerns of representativeness, and studies have yet to consider vulnerable populations. Long-term community-based studies are needed to confirm the low concentration findings and to refine exposure guidelines. Revised guidelines that incorporate both short- and long-term limits are needed to protect communities, especially sensitive populations living near H2S sources.

Agricultural dust derived bacterial extracellular vesicle mediated inflammation is attenuated by DHA

Dietary long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) and their pro-resolving metabolites are protective against atherosclerotic disease, and ameliorate systemic inflammatory conditions including lupus erythematosus, psoriasis, and bronchial asthma. Organic bioaerosol inhalation is a common and injurious hazard associated with agricultural occupations such as work in swine concentrated animal feeding operations (CAFOs) and is known to increase the risk for developing respiratory conditions such as asthma and COPD. Nearly all cells secrete membrane-bound vesicles (extracellular vesicles, EVs) that have the capacity to transmit protein, nucleic acid, and lipid signaling mediators between cells. Using a polymer-based isolation technique (ExoQuick, PEG) followed by ultracentrifugation, EVs were isolated from CAFO dust extracts, and were quantified and partially characterized. Here, we investigated the role of the n-3 PUFA docosahexaenoic acid (DHA) as a component of n-6 to n-3 PUFA mixtures used to recapitulate physiologically relevant dietary ratios in the resolution of inflammatory injury caused by exposure to EVs carried by agricultural organic dust in vitro. Primary human bronchial epithelial cells, fibroblasts and monocyte-derived macrophages were exposed to EVs isolated from swine CAFO dust. Cells were treated with mixtures of n-6 and n-3 PUFA during recovery from the EV-induced injury. CAFO dust extract (DE) was found to contain EVs that contributed significantly to the overall consequences of exposure to complete DE. DHA-rich PUFA ratios inhibited DE-derived EV-induced proinflammatory cytokine release dose-dependently. DHA-rich PUFA ratios also reversed the damaging effects of EVs on recellularization of lung matrix scaffolds, accelerated wound healing, and stimulated the release of pro-resolution mediators. These results underscore the importance of n-3 PUFA as anti-inflammatory compounds during recovery from EV-laden environmental dust exposure in the context of cellular responses in vitro, warranting future translational studies.

An assessment of occupational exposure to bioaerosols in automated versus manual waste sorting plants

Occupational exposure during waste sorting is associated with several health outcomes. This study obtained knowledge about the impact of work in fully automated waste sorting plants (AWSP; n = 3) vs manual waste sorting plants (MWSP; n = 3) on personal exposure (n = 71) to bioaerosols and exposure-related health effects. Personal full-shift air samples were collected using various filter-based active sampling devices that were placed in the workers' breathing zone. Personal exposure to inhalable and thoracic dust, endotoxin and microorganisms varied considerably between and within types of waste sorting plants (WSP). Workers at AWSP were on average exposed to 0.34 mg/m³ inhalable dust, 0.15 mg/m³ thoracic dust, and 51 EU/m³ endotoxins (geometric mean (GM) levels), whereas GM exposure levels at MWSP were 0.66 mg/m³ for inhalable dust, 0.44 mg/m³ for thoracic dust, and 32 EU/m³ for endotoxins. Exposure to submicronic fungal fragments did not differ between types of plants and ranged from levels below the detection limit (limit of detection, LOD) to levels in the order of 10⁶ fragments/m³. Higher levels of fungal fragments and fungal spores were found at AWSP compared to MWSP with a GM of 2.1 × 10⁵ spores/m³and with a GM of 1.2 × 10⁵ spores/m³, respectively. Actinobacterial spores were found in samples from AWSP only, with exposure levels ranging from 1.9 × 10⁴ to 1.1 × 10⁷ spores/m³. Exposure to microbial DNA varied within and between WSP and was on average in the order of 10⁴ copies/m³ for fungi and 10⁵ copies/m³ for bacteria. Health symptoms, such as sneezing, congested nose and runny nose were significantly more common among exposed workers compared to the unexposed control group.

Health check-ups for the French under-consuming agricultural population: A pilot evaluation of the Instants santé MSA program

BACKGROUND

The social protection scheme in charge of farmers and agricultural employees (MSA) in France has developed a two-step health promotion program with a nurse appointment followed by a consultation with a doctor of the participant's choosing to reach its under-consuming beneficiaries and enroll them back into a care pathway. Our objective was to carry out a pilot evaluation of this program.

METHODS

The evaluation was carried out on the population invited during the second semester of 2017 using data from the program's service providers (date of invitation, of nurse appointment…), regional MSA bodies (consultation voucher), and reimbursement data (other care consumption). Participation rates were calculated overall and by participant characteristics. Medical needs were identified during the nurse appointment and new care pathways were assessed using reimbursement data. Multivariable regression models identified factors associated with participation.

RESULTS

2366 beneficiaries were included in the analysis. 1559 (65.89%) were men and mean age was 52.41 (standard deviation = 14.86). 409 (17.29%) attended the nurse appointment. There was a significant increase in participation with age, in farmers vs. employees (odds ratio = 1.905, 95% confidence interval = 1.393-2.604), and in people living in the most disadvantaged areas (odds ratio = 1.579, 95% confidence interval=1.079-2.312). Participation to the consultation following the nurse appointment was high (62.35%-73.11%). 87.53% of participants had at least one medical need, and new care pathways were more frequent among those who had attended the nurse appointment (55.50% vs. 34.80%, p < 0.0001).

CONCLUSIONS

This pilot evaluation shows promising results which need to be confirmed with a national evaluation of the program and longer-term evidence.

Ever and cumulative occupational exposure and lung function decline in longitudinal population-based studies: a systematic review and meta-analysis

OBJECTIVES

Adverse occupational exposures can accelerate age-related lung function decline. Some longitudinal population-based studies have investigated this association. This study aims to examine this association using findings reported by longitudinal population-based studies.

METHODS

Ovid Medline, PubMed, Embase, and Web of Science were searched using keywords and text words related to occupational exposures and lung function and 12 longitudinal population-based studies were identified using predefined inclusion criteria. The quality of the studies was assessed using the Newcastle-Ottawa Scale. Lung function decline was defined as annual loss of forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) or the ratio (FEV₁/FVC). Fixed and random-effects meta-analyses were conducted to calculate pooled estimates for ever and cumulative exposures. Heterogeneity was assessed using the I² test, and publication bias was evaluated using funnel plots.

RESULTS

Ever exposures to gases/fumes, vapours, gases, dusts, fumes (VGDF) and aromatic solvents were significantly associated with FEV₁ decline in meta-analyses. Cumulative exposures for these three occupational agents observed a similar trend of FEV₁ decline. Ever exposures to fungicides and cumulative exposures to biological dust, fungicides and insecticides were associated with FEV₁ decline in fixed-effect models only. No statistically significant association was observed between mineral dust, herbicides and metals and FEV₁ decline in meta-analyses.

CONCLUSION

Pooled estimates from the longitudinal population-based studies have provided evidence that occupational exposures are associated with FEV₁ decline. Specific exposure control and respiratory health surveillance are required to protect the lung health of the workers.

Preliminary investigation of a hypertonic saline nasal rinse as a hygienic intervention in dairy workers

Livestock workers experience an increased burden of bioaerosol-induced respiratory disease including a high prevalence of rhinosinusitis. Dairy operations generate bioaerosols spanning the inhalable size fraction (0-100 μm) containing bacterial constituents such as endotoxin. Particles with an aerodynamic diameter between 10 and 100 μm are known to deposit in the nasopharyngeal region and likely affect the upper respiratory tract. We evaluated the effectiveness of a hypertonic saline nasal lavage in reducing inflammatory responses in dairy workers from a high-volume dairy operation. Inhalable personal breathing zone samples and pre-/post-shift nasal lavage samples from each participant over five consecutive days were collected. The treatment group (n = 5) received hypertonic saline while the control group (n = 5) received normotonic saline. Personal breathing zone samples were analyzed for particulate concentrations and endotoxin using gravimetric and enzymatic methods, respectively. Pro- and anti-inflammatory cytokines (i.e., IL-8, IL-10, and TNF-α) were measured from nasal lavage samples using a multiplex assay. Inhalable dust concentrations ranged from 0.15 to 1.9 mg/m3. Concentrations of both pro- and anti-inflammatory cytokines, specifically IL-6, IL-8, and IL-10, were significantly higher in the treatment group compared to the control group (p < 0.02, p < 0.04, and p < 0.01, respectively). Further analysis of IL-10 anti-inflammatory indicates a positive association between hypertonic saline administration and IL-10 production. This pilot study demonstrates that hypertonic saline nasal lavages were successful in upregulating anti-inflammatory cytokines to support larger interventional studies.

Prevalence and risk factors of asthma in dairy farmers: Ancillary analysis of AIRBAg

BACKGROUND

Prolonged occupational agricultural exposure is associated with an increase in asthma diagnosis. This study aimed to identify the prevalence and risk factors for asthma in dairy farmers.

METHODS

AIRBAg was a cross-sectional study including 1203 representative dairy farmers. They completed a self-administered questionnaire and underwent a health respiratory check-up. Referral to a pulmonologist was made for any participant with wheezing, dyspnoea, chronic bronchitis, a chronic cough or a FEV₁/FEV₆ ratio<80%. They underwent further examinations such as spirometry with a reversibility test. Controls (non-asthmatic dairy farmers and non-farm employees) were matched to each asthma case for sex and age (±5 years). The odds ratios (OR) between asthma and different risk factors were estimated using conditional multivariate logistic regression models.

RESULTS

Active asthma was diagnosed in 107 (8.9%) farmers. Compared with control dairy farmers, there was a positive association with family history of allergy (OR = 8.68; 95% CI [4.26-17.69]), personal history of eczema (OR = 3.39; 95% CI [1.61-7.13]), hay manipulation (OR = 5.36, 95% CI [1.59-18.01]), and a negative association with farm area (OR = 0.92; 95% CI [0.85-0.99]) and handling treated seeds (OR = 0.47; 95% CI [0.23-0.95]). Compared with control non-farm employees, there was a positive association between asthma and family history of allergy (OR = 95.82, 95% CI [12.55-731.47]).

CONCLUSIONS

The prevalence of active asthma in dairy farmers was somewhat higher than the rate observed in the general population but may be controlled by reducing exposure to airborne organic contaminants through occupational adaptions on farms.

Prevalence and Characteristics of Chronic Obstructive Pulmonary Disease in Dairy Farmers

Objective: To assess the prevalence and characteristics of chronic obstructive pulmonary disease (COPD) in dairy farmers, and evaluate the role of job exposure and smoking as predictors for respiratory health impairment. Methods: A cross-sectional study was performed, including 83 dairy farmers (mean age: 52.6±8.7 years; mean exposure duration: 23.7±7.6 years) and 80 office workers as a control group (mean age: 52.7±8.2 years) matched for age, smoking habits, and socioeconomic status. Methods for evaluation of study participants included a questionnaire on respiratory symptoms in the last 12 months, baseline spirometry and bronchodilator reversibility testing, and diagnostic criteria for COPD. Results: The mean post-bronchodilator values of spirometric parameters are significantly lower in subjects among EG with negative bronchodilator test compared to those in CG, while the mean post-bronchodilator values of spirometric parameters are lower in dairy farmers with negative BD tests exposed more than 20 years compared to those with exposure less than 20 years, being statistically significant for FEV1/FVC%, MEF25, MEF50 and MEF75. The COPD prevalence is non-significantly higher in dairy farmers compared to controls, and is significantly associated with age over 40 years in dairy farmers (P=0.035). The risk for COPD development in dairy farmers is about 36 fold higher in subjects exposed more than 20 years (OR = 36.00 (1.21-37.77) CI 95%) compared to those with exposure duration less than 20 years, and is about 6 fold higher in dairy farmers who are current smokers (OR = 6.12 (0.95-37.77) CI 95%). COPD is significantly associated with smoking duration among smokers in both groups, while combined effect of smoking, smoking duration, and number of cigarettes smoked daily has a significant impact on COPD development in dairy farmers. According to the GOLD classification, depending on the degree of airflow limitation, mild and moderate types of COPD are detected in dairy farmers, and only mild type in controls, showing no significant difference between the two groups. Conclusion: The study findings recognized the role of farming exposure, and smoking as well, as predictors for respiratory health impairment, and furthermore confirmed their potential to be a predictive factor in the COPD development. These facts should be helpful in detection of critical points for action, indicate the need of adverse occupational exposures reduction through adequate preventive measures and regular health examinations, implementation of relevant engineering controls, smoking cessation programs, and complete and efficient respiratory health assessment.

The association of chronic bronchitis and airflow obstruction with lifetime and current farm activities in a sample of rural adults in Iowa

OBJECTIVE

Farmers have an increased risk for chronic bronchitis and airflow obstruction. The objective of this study was to investigate the association of these health outcomes with farm activities.

METHODS

We evaluated the Keokuk County Rural Health Study (KCRHS) enrollment data for farm activities and the two health outcomes chronic bronchitis based on self-reported symptoms and airflow obstruction based on spirometry. We used logistic regression to model the health outcomes, yielding an odds ratio (OR) and 95% confidence interval (95% CI) for farm activities while adjusting for potential confounders and other risk factors.

RESULTS

Of the 1234 farmers, 104 (8.4%) had chronic bronchitis, 75 (6.1%) fulfilled the criteria for airflow obstruction, and the two outcomes overlapped by 18 participants. Chronic bronchitis without airflow obstruction (n = 86) had a statistically significant association with crop storage insecticides (OR 3.1, 95% CI 1.6, 6.1) and a low number of years (≤ 3) worked with turkeys (OR 3.3, 95% CI 1.2, 9.4). The latter result should be interpreted with caution because it is based on a small number of cases (n = 5). Airflow obstruction with or without chronic bronchitis (n = 75) was significantly associated with ever working in a hog or chicken confinement setting (OR 2.2, 95% CI 1.0, 4.5).

CONCLUSIONS

These results suggest that work with crop storage insecticides or turkeys may increase the risk for chronic bronchitis and work in hog or chicken confinement may increase the risk for airflow obstruction.

Influence of Childhood Exposure to a Farming Environment on Age at Asthma Diagnosis in a Population-Based Study

Purpose

Asthma is a heterogeneous disease, and factors associated with different asthma phenotypes are poorly understood. Given the higher prevalence of farming exposure and late diagnosis of asthma in more rural Western Finland as compared with the capital of Helsinki, we investigated the relationship between childhood farming environment and age at asthma diagnosis.

Methods

A cross-sectional population-based study was carried out with subjects aged 20–69 years in Western Finland. The response rate was 52.5%. We included 3864 participants, 416 of whom had physician-diagnosed asthma at a known age and with data on the childhood environment. The main finding was confirmed in a similar sample from Helsinki. Participants were classified as follows with respect to asthma diagnosis: early diagnosis (0–11 years), intermediate diagnosis (12–39 years), and late diagnosis (40–69 years).

Results

The prevalence of asthma was similar both without and with childhood exposure to a farming environment (11.7% vs 11.3%). Allergic rhinitis, family history of asthma, ex-smoker, occupational exposure, and BMI ≥ 30 kg/m² were associated with a higher likelihood of asthma. Childhood exposure to a farming environment did not increase the odds of having asthma (aOR, 1.10; 95% CI, 0.87–1.40). It did increase the odds of late diagnosis (aOR, 2.30; 95% CI, 1.12–4.69), but the odds were lower for early (aOR, 0.49; 95% CI, 0.30–0.80) and intermediate diagnosis of asthma (aOR, 0.75; 95% CI, 0.47–1.18).

Conclusion

Odds were lower for early diagnosis of asthma and higher for late diagnosis of asthma in a childhood farming environment. This suggests a new hypothesis concerning the etiology of asthma when it is diagnosed late.

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Bioaerosol Exposure and in vitro Activation of Toll-like Receptors in a Norwegian Waste Sorting Plant

Background

The global shift toward greener societies demands new technologies and work operations in the waste-management sector. However, progressive industrial methods do not necessarily consider workers’ health. This study characterized workers' exposure to bioaerosols and investigated the bioaerosols’ potential to engage the immune system in vitro.

Methods

Full shift personal aerosol sampling was conducted over three consecutive days. Dust load was analyzed by gravimetry, fungal and actinobacterial spores were analyzed by scanning electron microscopy, and endotoxin by limulus amebocyte lysate (LAL) assay. In vitro exposure of HEK cells to airborne dust samples was used to investigate the potential of inducing an inflammatory reaction.

Results

The total dust exposure level exceeded the recommended occupational exposure limit (OEL) of 5.0 mg/m³ in 3 out of 15 samples. The inhalable endotoxin level exceeded the recommended exposure level by a 7-fold, whereas the fungal spore level exceeded the recommended exposure level by an 11-fold. Actinobacterial spores were identified in 8 out of 14 samples. In vitro experiments revealed significant TLR2 activation in 9 out of 14 samples vs. significant TLR4 activation in all samples.

Conclusion

The present study showed that the dust samples contained potentially health-impairing endotoxin, fungi, and actinobacterial levels. Furthermore, the sampled dust contained microbial components capable of inducing TLR activation and thus have the potential to evoke an inflammatory response in exposed individuals.

Exposure to Bioaerosols During Fish Processing on Board Norwegian Fishing Trawlers

OBJECTIVES

The main objective was to gain more knowledge on exposure to bioaerosols in the processing area on board fishing trawlers.

METHODS

Exposure sampling was carried out during the work shifts when processing fish in the processing area on board five deep-sea fishing trawlers (trawlers 1-5). Exposure samples were collected from 64 fishermen breathing zone and from stationary sampling stations on board five deep-sea fishing trawlers (1-5). Trawlers 2, 3, and 4 were old ships, not originally built for on board processing of the catch. Trawlers 1 and 5 were relatively new and built to accommodate processing machineries. On trawlers 1-4 round fish was produced; the head and entrails were removed before the fishes were frozen in blocks. Trawler 5 had the most extensive processing, producing fish fillets. Samples were analysed for total protein, trypsin activity, parvalbumin, and endotoxin. One side analysis of variance and Kruskal-Wallis H test were used to compare levels of exposure on the different trawlers.

RESULTS

Personal exposure to total protein were higher on the three oldest trawlers (2, 3, and 4) compared with the two new trawlers (1 and 5). Highest activity of trypsin was detected on the four trawlers producing round fish (1-4). Parvalbumin was detected in 58% of samples from the fillet-trawler (5) compared with 13% of samples from the four trawlers producing round fish. The highest level of endotoxin was detected when using high-pressure water during cleaning machines and floors in the processing area.

CONCLUSIONS

Fishermen in the processing area on board Norwegian trawlers are exposed to airborne bioaerosols as proteins, trypsin, fish allergen parvalbumin, and endotoxin. Levels varied between trawlers and type of production.

Inflammatory and immunological profile in COPD secondary to organic dust exposure

Inflammatory response in patients with COPD secondary to organic dust exposure (OD-COPD) is poorly understood. We therefore aimed to characterize inflammatory and immune profile from peripheral blood mononuclear cells (PBMC) in a group of patients with mild-to-moderate COPD secondary to organic dust exposure (OD-COPD), tobacco smoking (T-COPD), or both. We compared T, B and NK cells distribution and inflammatory (TNF-α, Il-1β, IL-6), type 1 (IFN-γ), type 2 (IL-4, IL-13) and type 3 (IL-17) immunity related cytokines at baseline, and after stimulation with LPS, flagellin and CD3/CD28 beads in all COPD groups. OD-COPD displayed significantly lower NK cells and CD8+ T cells compared with controls. After flagellin stimulation, T-COPD had significantly lower IL-13 levels than OD-COPD and controls (p < 0.05) whereas IFN-γ tended to be lower in OD-COPD. All COPD groups displayed higher IL-1β and IL-17 than controls after CD3/CD28 stimulation. Inflammatory responses in OD-COPD were different from T-COPD. OD-COPD displayed higher levels of type 2 immunity related cytokines.

Does Chronic Obstructive Pulmonary Disease Affect Workers' Health?

During recent decades, the elevation of workers' health has become the utmost point of concern since it is considered among the primary indicators of economies. The economies, especially the emerging ones, are primarily focusing on every indicator to uplift their businesses. Along with the other aspects, it is also required to assess the impact of Chronic Obstructive Pulmonary Disease (COPD) on workers' health conditions in small- and medium-scale enterprises (SMEs). With this aim, we are presenting a detailed analysis to reveal useful insights regarding the COPD-workers' health nexus. The sample set of 1,008 workers is working in various SMEs in Beijing and Tianjin from September, 2020. The findings infer that a rise in COPD concerning wages will uplift the worker health problems due to COPD affecting worker health. Whereas, the working condition and tools, smoking years, and health safety training have a statistically adverse effect on workers' health concerning wages. The outcomes in terms of insights would be useful for planning future perspectives.

IL-10 producing B cells regulated 1,3-β-glucan induced Th responses in coordinated with Treg

Repeated exposure to fungi-contaminated dust can lead to multiple adverse effects on the lung, such as hypersensitivity pneumonitis, granuloma even irreversible fibrosis. 1,3-β-glucan, a major cell wall component of fungi, is considered as its exposure biomarker. Existing studies showed that a series of Th responses were involved in 1,3-β-glucan induced hypersensitivity pneumonitis, in which macrophages, Treg, and IL-10 producing B cells were reported to participate. The reciprocal interaction among those critical immune cells in 1,3-β-glucan induced inflammation was not investigated yet. To clarify the regulatory mechanism of IL-10 producing B cells on Th and Treg, the current study set up a primary cell co-culture system. The anti-CD22 antibody was injected intraperitoneally to generate IL-10 producing B cells deficiency mouse model. Cells were isolated and purified from C57BL∖6 mice in different groups. Flow cytometry was used to check the phenotype of different cell subtypes. CBA assay and real-time PCR were used to examine the levels of multiple cytokines. Our results indicated that IL-10 producing B cells could modulate the 1,3-β-glucan induced inflammatory response. The modulation of IL-10 producing B cells on Th response after 1,3-β-glucan treatment was cell contact independent. What's more, the modulation pattern of IL-10 producing B cells might be impaired without Treg response. IL-10-producing B cells regulated 1,3-β-glucan induced Th responses in co-ordination with Treg cells.

Distribution characteristics of bioaerosols inside pig houses and the respiratory tract of pigs

Particulate matter (PM) is a carrier of many substances. Microorganisms are vital constituents contained in PM, and their varieties and concentrations are closely connected to human health and animal production. This study aimed to investigate the distribution characteristics of bioaerosols inside a pig house and in the respiratory tract of pigs. Environmental indices inside a nursery pig house were monitored in winter, including temperature, relative humidity, total suspended particulate (TSP), PM₁₀, PM_2.5, NH₃, CO₂, CO and NO. The concentrations of airborne culturable bacteria, fungi and Escherichia coli were detected. Then, 16S rRNA sequencing technology was applied to identify different-sized bioaerosols and bacteria in the respiratory tract of piglets. The results showed that the concentration of airborne culturable bacteria inside the pig house was significantly higher than that outside, and no significant difference was found among culturable fungi and Escherichia coli. The 16S rRNA results showed that the bacterial aerosols presented high similarity to the bacteria in the respiratory tract of piglets. The airborne bacterial aerosols within the size range of 1.1-3.3 µm showed high similarity to the bacteria in the lower respiratory tract (bronchus and lung) of piglets. In addition, four potential pathogenic bacterial genera (Escherichia-Shigella, Streptococcus, Acinetobacter, Pseudomonas) were identified both in the bacterial aerosols and the respiratory tract of piglets. These results will provide a significant scientific basis for exploring the potential risk of aerosols from animal houses to human and animal health.

Precarious Essential Work, Immigrant Dairy Farmworkers, and Occupational Health Experiences in Vermont

Migrant dairy workers in Vermont face a wide range of occupational and health hazards at work. This research examines the environmental risks, occupational health hazards, and health outcomes experienced by migrant dairy farm workers in Vermont. This research draws on a triangulation of sources including analysis of data—surveys and interviews with migrant dairy farmworkers gathered by the organization Migrant Justice since 2015 as well as relevant key informant interviews with community organizations across the state to characterize the occupational health experiences of migrant dairy workers in Vermont. Our results show that Vermont migrant dairy farmworkers received poor health and safety training and lacked sufficient protective gear. Over three quarters of the respondents reported experiencing harm from chemical and biological risks. Close to half the survey respondents reported headaches, itchy eyes and cough; a quarter reported breathing difficulties; three fourths reported being hurt by animal-related risks. These exposures and existing health concerns are avoidable. Migrant workers require better social representation and advocates to negotiate better work-related protection and training, access to health services, and social welfare to ensure their health and safety.

Production of composted recycled manure solids from a Canadian dairy farm: Impact on microbial air quality in experimental conditions

Recycled manure solids (RMS) produced in dairy farms from fresh manure need to be sanitized before using them as bedding material. However, the impact on air quality of composting RMS remains unknown. Four RMS composting methods were tested during a 10-day aging of piles in experimental chambers: static windrow (SW), turned windrow (TW), SW following drum composting for 24 h (DC24) or SW following drum composting for 72 h (DC72). Air samples were collected using a SASS®3100 Dry Air Sampler on days 0 (pilling of the RMS), 5, and 10. Bacteria (16S rRNA genes), Penicillium/Aspergillus, A fumigatus, and 11 human pathogenic bacteria (e.g. Klebsiella pneumonia) were quantified by qPCR while endotoxins and dust particles were, respectively, measured by LAL assays and with a DustTrak^TM DRX Aerosol Monitor. On day 0, RMS produced by SW and TW yielded the lowest concentrations of airborne bacteria, while DC24 resulted in the lowest levels of Penicillium/Aspergillus and dust particles. SW method led on day 5 to the lowest concentration of bacteria and Penicillium/Aspergillus, and DC24 and DC72 to the lowest concentration of airborne dust. On day 10, SW and TW piles were associated with the lowest levels of Penicillium/Aspergillus and dust particles. A significant difference was observed between concentration of airborne bacteria, Penicillium/Aspergillus and endotoxins before and during the turnover of TW piles. None of the studied human pathogens was detected in the air samples. Results of the present study suggest that SW and TW are the most promising methods for the production of composted RMS with respect to microbial air quality. However, the experimental chambers do not accurately represent commercial dairy barns and further research on these composting methods is necessary. Finally, the study highlights that bedding material and its management may be determinant factors for air quality in dairy barns.Implications: The research evaluated the impact on microbial air quality of composting recycled manure solids (RMS) produced from fresh cow manure. RMS need to be composted or sanitized before using them as bedding material for animals. The impact on animal health of RMS still needs to be confirmed, while the effect on air quality and the health of dairy farmers is unknown. In the present study, microbial air quality associated with four RMS composting methods was investigated. Data revealed that two methods resulted in lower aerosolization of dust particles, endotoxins, molds, and bacteria.

Nutritional Factors in Occupational Lung Disease

PURPOSE OF REVIEW

Lung diseases such as asthma and COPD are major public health issues and related to occupational exposures. While therapies to limit the development and progression of these diseases are limited, nutrition interventions could offer potential alternatives to mediate the inflammation associated with these diseases. This is a narrative review of the current state of relevant nutrients on inflammation and respiratory outcomes associated with occupational exposures.

RECENT FINDINGS

Relevant nutrients that have been investigated in recent years include omega-3 polyunsaturated fatty acids, zinc, vitamin D, dairy products, and antioxidants. These nutrients have demonstrated the potential to prevent or modify the adverse outcomes associated with occupational exposures, primarily in preclinical studies. Current therapies for respiratory consequences associated with occupational exposures are limited; therefore, addressing strategies for reducing inflammation is important in improving quality of life and limiting health care costs. More human studies are warranted to determine the effectiveness of nutrition as an intervention.

The Scientific Basis for Occupational Exposure Limits for Hydrogen Sulphide-A Critical Commentary

OBJECTIVES

Occupational exposure limits for hydrogen sulphide (H₂S) vary considerably; three expert group reports, published from 2006 to 2010, each recommend different limits. Some jurisdictions are considering substantial reductions.

METHODS

This review assesses the scientific evidence used in these recommendations and presents a new systematic review of human studies from 2006-20, identifying 33 studies.

RESULTS

The three major reports all give most weight to two sets of studies: of physiological effects in human volunteers, and of effects in the nasal passages of rats and mice. The human studies were done in one laboratory over 20 years ago and give inconsistent results. The breathing style and nasal anatomy of rats and mice would make them more sensitive than humans to inhaled agents. Each expert group applied different uncertainly factors. From these reports and the further literature review, no clear evidence of detrimental health effects from chronic occupational exposures specific to H₂S was found. Detailed studies of individuals in communities with natural sources in New Zealand have shown no detrimental effects. Studies in Iceland and Italy show some associations; these and various other small studies need verification.

CONCLUSIONS

The scientific justification for lowering occupational exposure limits is very limited. There is no clear evidence, based on currently available studies, that lower limits will protect the health of workers further than will the current exposure limits used in most countries. Further review and assessment of relevant evidence is justified before exposure limits are set.

Contemporary perspectives in COPD: Patient burden, the role of gender and trajectories of multimorbidity

An individual's experience of COPD is determined by many factors in addition to the pathological features of chronic bronchitis and emphysema and the symptoms that derive directly from them. Multimorbidity is the norm rather than the exception, so most people with COPD are living with a range of other medical problems which can decrease overall quality of life. COPD is caused by the inhalation of noxious particles or gases, in particular tobacco smoke, but also by early life disadvantage impairing lung development and by occupations where inhaled exposures are common (e.g. industrial, farming and cleaning work). Wealthy people are therefore relatively protected from developing COPD and people who do develop the condition may have reduced resources to cope. COPD is also no longer a condition that predominantly affects men. The prevalence of COPD among women has equalled that of men since 2008 in many high-income countries, due to increased exposure to tobacco, and in low-income countries due to biomass fuels. COPD is one of the leading causes of death in women in the USA, and death rates attributed to COPD in women in some countries are predicted to overtake those of men in the next decade. Many factors contribute to this phenomenon, but in addition to socioeconomic and occupational factors, there is increasing evidence of a higher susceptibility of females to smoking and pollutants. Quality of life is also more significantly impaired in women. Although most medications (bronchodilators and inhaled corticosteroids) used to treat COPD demonstrate similar trends for exacerbation prevention and lung function improvement in men and women, this is an understudied area and clinical trials frequently have a preponderance of males. A better understanding of gender-based predictors of efficacy of all therapeutic interventions is crucial for comprehensive patient care. There is an urgent need to recognize the increasing burden of COPD in women and to facilitate global improvements in disease prevention and management in this specific population. Many individuals with COPD follow a trajectory of both lung function decline and also multimorbidity. Unfavourable lung function trajectories throughout life have implications for later development of other chronic diseases. An enhanced understanding of the temporal associations underlying the development of coexisting diseases is a crucial first step in unravelling potential common disease pathways. Lessons can be learned from exploring disease trajectories of other NCD as well as multimorbidity development. Further research will be essential to explain how early life risk factors commonly influence trajectories of COPD and other diseases, how different diseases develop in relation to each other in a temporal way and how this ultimately leads to different multimorbidity patterns in COPD. This review integrates new knowledge and ideas pertaining to three broad themes (i) the overall burden of disease in COPD, (ii) an unappreciated high burden in women and (iii) the contrast of COPD trajectories and different multimorbidity patterns with trajectories of other NCD. The underlying pathology of COPD is largely irreversible, but many factors noted in the review are potentially amenable to intervention. Health and social care systems need to ensure that effective treatment is accessible to all people with the condition. Preventive strategies and treatments that alter the course of disease are crucial, particularly for patients with COPD as one of many problems.

Assessment of airborne endotoxin in sandstorm dust and indoor environments using a novel passive sampling device in Al Zulfi city, Saudi Arabia - Establishing threshold exposure levels

The impact of sandstorm dust events affects local air quality and public health. These issues are becoming of greater concern in Saudi Arabia. There is a significant lack of research on airborne endotoxin exposure and analysis in the Middle East countries and no coherent body of research exists focusing on sandstorm dust in worldwide. In this study, we used a novel design of an aluminum foil plate (AFP) electrostatic dust cloth (EDC) for the passive air sampling of sandstorm dust. A total of 38 sandstorm dust samples were collected during sandstorm episodes occurring between January and April 2020 in both indoor (7 days, n = 20) and outdoor environments (24 h, n = 18). After exposure, and following an extraction procedure, bacterial endotoxin levels were measured using the Limulus Amoebocyte Lysate (LAL) gel clot method. The study highlights that the airborne endotoxin level observed was between 10 and 200 EU/m² in both indoor and outdoor environments, during a sandstorm event. Agricultural activities and farmhouses observed higher airborne endotoxin levels. In general, increased endotoxin levels were related to the severity of the sandstorms. Given that the observed values were high as per existing guidelines for respiratory health, we recommend the setting an occupational airborne exposure limit for bacterial endotoxin. This is the first report and further studies across various sandstorm-hit regions will need to be undertaken, together with various sampling methods, in order to assess for seasonal and geographic trends.

Indoor Microbial Exposures and Chronic Lung Disease: From Microbial Toxins to the Microbiome

Effects of environmental microbial exposures on human health have long been of interest. Microbes were historically assumed to be harmful, but data have suggested that microbial exposures can modulate the immune system. We focus on the effects of indoor environmental microbial exposure on chronic lung diseases. We found contradictory data in bacterial studies using endotoxin as a surrogate for bacterial exposure. Contradictory data also exist in studies of fungal exposure. Many factors may modulate the effect of environmental microbial exposures on lung health, including coexposures. Future studies need to clarify which method of assessing environmental microbial exposures is most relevant.

Mesothelioma in Agriculture in Lombardy, Italy: An Unrecognized Risk

Cohort studies showed consistently low risks for malignant mesothelioma (MM) among agricultural workers, however the investigated exposures did not include asbestos. Our aim is to describe sources of asbestos exposure of MM in agriculture. Twenty-six MM cases in agricultural or seed trades workers were identified through the MM registry of the Lombardy region, Italy in 2000–2016. Asbestos exposures were investigated through a standardized questionnaire. The most frequent exposure circumstances were recycled jute bags previously containing asbestos (11 cases) and maintenance and repair of asbestos roofs (12 subjects). Three subjects performed maintenance and repair of tractor asbestos brakes and two used asbestos filters for wine production. Our data suggest asbestos exposure opportunities in the agricultural setting, underlining the need to look for this exposure in subjects affected with mesothelioma.

Incident chronic obstructive pulmonary disease associated with occupation, industry, and workplace exposures in the Health and Retirement Study

BACKGROUND

Chronic health effects from accumulated occupational exposures manifest as the workforce ages. The Health and Retirement Study (HRS), a panel survey of U.S. adults nearing/in retirement, allows assessment of associations among industry and occupation (I/O), workplace exposures, and incident chronic obstructive pulmonary disease (COPD).

METHODS

The study population comprised respondents from the 1992 HRS cohort employed in 1972 or later and not diagnosed with COPD as of initial interview. We examined associations with incident COPD through 2016 and: (1) broad and selected detailed I/O, (2) workplace exposures, and (3) exposures within I/O. Given the cohort's baseline age (50-62), we calculated subhazard ratios (SHRs) for COPD accounting for competing risk of death.

RESULTS

SHRs for COPD were significantly elevated for several industries: mining; blast furnaces, steelworks, rolling and finishing mills; groceries and related products; and automotive repair shops. Occupations with significantly elevated SHRs were maids and housemen; farmworkers; vehicle/mobile equipment mechanics and repair workers; material moving equipment operators; and nonconstruction laborers. Significantly elevated COPD SHRs were observed for specific I/O-exposure pairs: blast furnace/steelworks/rolling/finishing mills and asbestos; automotive repair shops and aerosol paints; farmworkers and pesticide exposures; and both material moving equipment operators and nonconstruction laborers exposed to dust and ash.

CONCLUSIONS

Certain jobs and occupational exposures are associated with increased risk for developing COPD in late preretirement and during retirement. Given the disability and economic costs of COPD, these findings support focusing exposure prevention and medical monitoring resources on groups of workers at increased risk.

Ammonia exposure causes lung injuries and disturbs pulmonary circadian clock gene network in a pig study

Ammonia toxicity to respiratory system in pig faming is of particular concern, but the molecular mechanism remains still unclear. The present study was devoted to assess the impacts of the ammonia exposure on the lung tissues based on a pig study using 80 ppm ammonia exposing to piglets for different days. The histology analysis revealed ammonia exposure induced lung injury and inflammatory response, as indicated by epithelial-mesenchymal transition (EMT), significant thickening of alveolar septa, infiltration of inflammatory cells and excessive mucus production. The transcriptome analysis revealed many more up-regulated genes in exposure groups when compared with the control group, and these genes were significantly enriched in the GO term of extracellular exosome, proteolysis, and regulation of circadian rhythm. The study discovered the induction of seven genes (CRY2, CIART, CREM, NR1D1, NR1D2, PER1 and PER3) that encode repressors of circadian clock. One gene (ARNTL) that encodes activator of circadian clock was down-regulated after ammonia exposure. The results of this study suggest that ammonia exposure disturbed the pulmonary circadian clock gene expression, which may establish new evidence for further understanding the toxicity of ammonia to lungs.

Never-smokers with occupational COPD have better exercise capacities and ventilatory efficiency than matched smokers with COPD

Chronic obstructive pulmonary disease (COPD) in never-smokers exposed to organic dusts is still poorly characterized. Therapeutic strategies in COPD are only evaluated in smoking-related COPD. Understanding how never-smokers with COPD behave during exercise is an important prerequisite for optimal management. The objective of this study was to compare physiological parameters measured during exercise between never-smokers with COPD exposed to organic dusts and patients with smoking-related COPD matched for age, sex, and severity of airway obstruction. Healthy control subjects were also studied. Dyspnea (Borg scale), exercise tolerance, and ventilatory constraints were assessed during incremental cycle cardiopulmonary exercise testing in COPD patients at mild to moderate stages [22 exposed to organic dusts: postbronchodilator forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) z score -2.44 ± 0.72 and FEV₁ z score -1.45 ± 0.78; 22 with smoking-related COPD: FEV₁/FVC z score -2.45 ± 0.61 and FEV₁ z score -1.43 ± 0.69] and 44 healthy control subjects (including 22 never-smokers). Despite the occurrence of similar significant dynamic hyperinflation, never-smoker COPD patients exposed to organic dusts had lower dyspnea ratings than those with smoking-related COPD. They also had better ventilatory efficiency, higher peak oxygen consumption and peak power output than smoking-related COPD patients, all these parameters being similar to control subjects. Differences in exercise capacity between the two COPD groups were mainly driven by better ventilatory efficiency stemming from preserved diffusion capacity. Never-smokers exposed to organic dusts with mild to moderate COPD have better exercise capacities, better ventilatory efficiency, and better diffusion capacity than matched patients with smoking-related COPD.NEW & NOTEWORTHY It is unknown whether or not never-smokers with chronic obstructive pulmonary disease (COPD) behave like their smoking counterparts during exercise. This is the first study showing that never-smokers with mild to moderate COPD [defined by a postbronchodilator forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) < lower limit of normal] have preserved exercise capacities. They also have lower exertional dyspnea than patients with smoking-related COPD. This suggests that the two COPD groups should not be managed in the same way.

Uterine Cancer Mortality in White and African American Females in Southeastern North Carolina

The residents of southeastern North Carolina (NC) are exposed to multiple socioeconomic and environmental risk factors and have higher mortality rates for a number of diseases. Uterine cancer mortality is known to vary dramatically by race, so we analyzed uterine cancer mortality in populations defined by zip codes in this area to investigate the contributions of various environmental risk factors to race-specific disease patterns. Methods. Zip code specific mortality and hospital admissions for uterine cancer from 2007 to 2013 were analyzed using the NC State Center for Health Statistics data and the Inpatient Database of the Healthcare Cost and Utilization Project datafiles, respectively. Results were adjusted for age, income, education, health insurance coverage, prevalence of current smokers, and density of primary care providers. Results. Uterine cancer mortality rates were generally higher in African American (32.5/100,000, 95% CI = 18.9–46.1) compared to White (19.6/100,000, 95% CI = 12.3–26.9) females. Odds ratios (ORs) of uterine cancer death were higher in White females (OR = 2.27, p < 0.0001) residing within zip codes with hog concentrated animal feeding operations (CAFOs) (hog density >215 hogs/km²) than in White females residing in non-CAFO communities. African American females living near CAFOs had less pronounced increase of uterine cancer death (OR = 1.08, p=0.7657). Conclusion. White females living in adjacent to hog CAFOs areas of southeastern NC have lower rates of mortality from uterine cancer than African American females, but they have higher odds of death compared to their counterparts living in other NC areas. African American females living near CAFOs also have modest increases from their high baseline mortality. While the observed associations do not prove a causation, improving access to screening and medical care is important to mitigate this health issues in southeastern NC.

Prevalence and Risk Factors of Chronic Obstructive Pulmonary Disease Among Agriculturists in a Rural Community, Central Thailand

Purpose

The present study aimed to determine the prevalence and risk factors of chronic obstructive pulmonary disease (COPD) among agriculturists in a remote rural community in central Thailand.

Methods

A cross-sectional study was conducted in January 2020. Face-to-face interviews were conducted using standardized questionnaires to determine demographic characteristics and risk behaviors. COPD was defined by the spirometric criterion for airflow limitation constituting a postbronchodilator fixed ratio of FEV1/FVC <0.70 following the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines 2019. Multivariable logistic regression analysis was used to determine the risk factors for COPD, and the magnitude of association was presented as adjusted odds ratio (AOR) with 95% confidence interval (95% CI).

Results

A total of 546 agriculturists were enrolled in the study. The overall prevalence of COPD was 5.5% (95% CI: 3.6–7.4). The prevalence of COPD among males was 8.0% (95% CI: 4.7–11.3), and 3.2% (95% CI: 1.1–5.2) among females. The risk factors of COPD included age ≥60 years old (AOR 2.7, 95% CI: 1.1–7.0), higher intensity of smoking (AOR 1.1, 95% CI: 1.0–1.1), swine farm worker (AOR 4.1, 95% CI: 1.7–10.3), cattle farm worker (AOR 3.3, 95% CI: 1.4–8.2) and home cooking (AOR 2.7, 95% CI: 0.8–9.7).

Conclusion

Our data emphasized that COPD was one of the significant health problems among agriculturists in a rural community. Agricultural jobs such as animal farmers and behavioral factors such as smoking were associated with COPD. Effective public health interventions, especially, modifying risk behaviors, should be promoted in remote rural areas to prevent the disease and reduce its morbidity and mortality.

The Association of Dietary Macronutrients with Lung Function in Healthy Adults Using the Ansan-Ansung Cohort Study

This study is aimed to examine the association between macronutrient intake and lung function in healthy adults (n = 5880) using the Ansan-Ansung cohort study. To identify the index of lung function, we used the percentage difference of predicted Forced Expiratory Volume (%FEV_{1_diff}) between baseline and follow-up. Based on the median %FEV_{1_diff}, subjects were classified by two groups as “decreased vs. unchanged/improved”. The dietary macronutrients were estimated and validated using the food-frequency questionnaire. Multiple logistic regression models were used to evaluate the association after adjusting for confounders. Advanced analysis examined the association after stratifying by age and obesity. The average of %FEV₁ is 114.1 and 112.5 at baseline and follow-up, respectively. The positive association of protein and fiber intake with lung function was observed in men. Low fat and high carbohydrate intake decreased the lung function in women only. After stratification by age, the association of protein, fat, and carbohydrate intake with lung function was observed in young men and old women only. Otherwise, the association of protein and fiber with lung function was influenced by abdominal obesity. In conclusion, the lung function was positively associated with high protein and fat intake, but was negatively associated with high carbohydrate intake, which could be influenced by age and obesity.

Characterization of chronic obstructive pulmonary disease in dairy farmers

BACKGROUND

Although farming is often considered a risk factor for COPD, data regarding the burden and characteristics of COPD in dairy farmers are sparse and conflicting.

OBJECTIVES

To characterize COPD in dairy farmers.

METHODS

4788 subjects entered two parallel COPD screening programs, one in agricultural workers and one in general practice from 2011 to 2015. Subjects with COPD were invited to participate in the characterization phase of the study. Those who accepted were included in two subgroups: dairy farmers with COPD (DF-COPD) (n = 101) and non-farmers with COPD (NF-COPD) (n = 85). Patients with COPD were frequency-matched with subjects with normal spirometry for age, sex and tobacco smoking (pack-years and status) (DF-controls n = 98, NF-controls n = 89). All subjects from these four groups underwent lung function and exercise testing, questionnaires and blood analysis.

RESULTS

The frequency of COPD in dairy farmers was 8.0% using the GOLD criterion and 6.2% using the lower limit of normal criterion and was similar in non-farming subjects (7.3% and 5.2%, respectively) although dairy farmers had lower tobacco consumption (screening phase). DF-COPD had better pulmonary function, exercise capacity and quality of life, fewer symptoms and comorbidities than NF-COPD, and higher levels of some Th2 biomarkers (MCP-2, periostin) (characterization phase). In farmers, COPD was not related to occupational exposure factors, supporting the role of host factors.

CONCLUSION

COPD secondary to organic dust exposure (dairy farming) appears less severe and associated with fewer comorbidities than COPD secondary to tobacco smoking.

A High Docosahexaenoic Acid Diet Alters the Lung Inflammatory Response to Acute Dust Exposure

Agricultural workers are at risk for the development of acute and chronic lung diseases due to their exposure to organic agricultural dusts. A diet intervention using the omega-3 fatty acid docosahexaenoic acid (DHA) has been shown to be an effective therapeutic approach for alleviating a dust-induced inflammatory response. We thus hypothesized a high-DHA diet would alter the dust-induced inflammatory response through the increased production of specialized pro-resolving mediators (SPMs). Mice were pre-treated with a DHA-rich diet 4 weeks before being intranasally challenged with a single dose of an extract made from dust collected from a concentrated swine feeding operation (HDE). This omega-3-fatty-acid-rich diet led to reduced arachidonic acid levels in the blood, enhanced macrophage recruitment, and increased the production of the DHA-derived SPM Resolvin D1 (RvD1) in the lung following HDE exposure. An assessment of transcript-level changes in the immune response demonstrated significant differences in immune pathway activation and alterations of numerous macrophage-associated genes among HDE-challenged mice fed a high DHA diet. Our data indicate that consuming a DHA-rich diet leads to the enhanced production of SPMs during an acute inflammatory challenge to dust, supporting a role for dietary DHA supplementation as a potential therapeutic strategy for reducing dust-induced lung inflammation.

Respiratory diseases and allergy in farmers working with livestock: a EAACI position paper

Farmers constitute a large professional group worldwide. In developed countries farms tend to become larger, with a concentration of farm operations. Animal farming has been associated with negative respiratory effects such as work-related asthma and rhinitis. However, being born and raised or working on a farm reduces the risk of atopic asthma and rhinitis later in life. A risk of chronic bronchitis and bronchial obstruction/COPD has been reported in confinement buildings and livestock farmers. This position paper reviews the literature linking exposure information to intensive animal farming and the risk of work-related respiratory diseases and focuses on prevention. Animal farming is associated with exposure to organic dust containing allergens and microbial matter including alive microorganisms and viruses, endotoxins and other factors like irritant gases such as ammonia and disinfectants. These exposures have been identified as specific agents/risk factors of asthma, rhinitis, chronic bronchitis, COPD and reduced FEV₁. Published studies on dust and endotoxin exposure in livestock farmers do not show a downward trend in exposure over the last 30 years, suggesting that the workforce in these industries is still overexposed and at risk of developing respiratory disease. In cases of occupational asthma and rhinitis, avoidance of further exposure to causal agents is recommended, but it may not be obtainable in agriculture, mainly due to socio-economic considerations. Hence, there is an urgent need for focus on farming exposure in order to protect farmers and others at work in these and related industries from developing respiratory diseases and allergy.

Respiratory Disorders Resulting From Exposure to Low Concentrations of Ammonia: A 5-Year Historical Cohort Study

OBJECTIVE

This study aimed to investigate respiratory disorders associated with exposure to low concentrations of ammonia.

METHOD

This cohort study was conducted on 122 industrial workers. Data gathering were based on the officially registered data, the NMAM 6016 and the American Thoracic Society and European Respiratory Society protocols.

RESULTS

The prevalence rate of respiratory disorders significantly increased in the exposure group over 5 years (P < 0.05). The frequencies of these symptoms in the exposure group were significantly higher than non-exposure group (P < 0.05). Respiratory functions were decrease significantly in the exposure group and were lower than non-exposure group (P < 0.05). Exposure and the amount of exposure to ammonia had a significant relationship with respiratory disorders and respiratory functions (P < 0.05).

CONCLUSION

Exposure to ammonia lower than threshold limit value (TLV), can act as a risk factor of respiratory disorders.