Airways inflammation among workers in poultry houses

Risk of hypersensitivity pneumonitis and other interstitial lung diseases following organic dust exposure

BACKGROUND

Organic dust is associated with hypersensitivity pneumonitis, and associations with other types of interstitial lung disease (ILD) have been suggested. We examined the association between occupational organic dust exposure and hypersensitivity pneumonitis and other ILDs in a cohort study.

METHODS

The study population included all residents of Denmark born in 1956 or later with at least 1 year of gainful employment since 1976. Incident cases of hypersensitivity pneumonitis and other ILDs were identified in the Danish National Patient Register 1994-2015. Job exposure matrices were used to assign individual annual levels of exposure to organic dust, endotoxin and wood dust from 1976 to 2015. We analysed exposure-response relations by different exposure metrics using a discrete-time hazard model.

RESULTS

For organic dust, we observed increasing risk with increasing cumulative exposure with incidence rate ratios (IRR) per 10 unit-years of 1.19 (95% CI 1.12 to 1.27) for hypersensitivity pneumonitis and 1.04 (95% CI 1.02 to 1.06) for other ILDs. We found increasing risk with increasing cumulative endotoxin exposure for hypersensitivity pneumonitis and other ILDs with IRRs per 5000 endotoxin units/m3-years of 1.55 (95% CI 1.38 to 1.73) and 1.09 (95% CI 1.00 to 1.19), respectively. For both exposures, risk also increased with increasing duration of exposure and recent exposure. No increased risks were observed for wood dust exposure.

CONCLUSION

Exposure-response relations were observed between organic dust and endotoxin exposure and hypersensitivity pneumonitis and other ILDs, with lower risk estimates for the latter. The findings indicate that organic dust should be considered a possible cause of any ILD.

TRIAL REGISTRATION NUMBER

j.no.: 1-16-02-196-17.

EAACI guidelines on environmental science for allergy and asthma: The impact of short-term exposure to outdoor air pollutants on asthma-related outcomes and recommendations for mitigation measures

The EAACI Guidelines on the impact of short-term exposure to outdoor pollutants on asthma-related outcomes provide recommendations for prevention, patient care and mitigation in a framework supporting rational decisions for healthcare professionals and patients to individualize and improve asthma management and for policymakers and regulators as an evidence-informed reference to help setting legally binding standards and goals for outdoor air quality at international, national and local levels. The Guideline was developed using the GRADE approach and evaluated outdoor pollutants referenced in the current Air Quality Guideline of the World Health Organization as single or mixed pollutants and outdoor pesticides. Short-term exposure to all pollutants evaluated increases the risk of asthma-related adverse outcomes, especially hospital admissions and emergency department visits (moderate certainty of evidence at specific lag days). There is limited evidence for the impact of traffic-related air pollution and outdoor pesticides exposure as well as for the interventions to reduce emissions. Due to the quality of evidence, conditional recommendations were formulated for all pollutants and for the interventions reducing outdoor air pollution. Asthma management counselled by the current EAACI guidelines can improve asthma-related outcomes but global measures for clean air are needed to achieve significant impact.

Occupational Bioaerosol Exposures Associated with Poultry Farming

This study aimed to investigate occupational exposure to particulate dust, endotoxin, and (1-3)-β-D-glucan among workers involved in various poultry farming activities. A total of 298 personal samples were collected from randomly selected individuals from exposure groups based on distinct poultry farming activities comprising broiler farms, rearing, laying, hatchery, and catching activities. Aside from the inhalable particulate dust concentration that was determined, filter extracts were also analyzed for (1-3)-β-D-glucan and endotoxin using the endpoint Glucatell® and Limulus amoebocyte lysate (LAL) assays, respectively. Data were analyzed using STATA 12 and linear regression models developed. The mean (GM) dust particulate concentration was 11.04 mg/m3 (GSD = 3.87); 2298 endotoxin units (EU/m3) (GSD = 10.56) and 149 ng/m3 for (1-3)-β-D-glucan (GSD = 4.62). A modest positive correlation was observed between log-transformed endotoxin and (1-3)-β-D-glucan concentrations (Pearson r = 0.44, p < .001), whilst a moderate negative correlation was observed for inhalable dust particulate and (1-3)-β-D-glucan (Pearson r = -0.33, p < .001). However, there was a very poor correlation between inhalable dust and endotoxin (Pearson r = -0.02, p < .001). In the regression models, exposure group based on the nature of farming activity explained 50% of the variability in dust particulate and glucan levels. For dust particulate, rearing activities were significant predictors of higher dust levels compared to hatchery work, while rearing, laying, broiler and catching activities were significant predictors of higher endotoxin or glucan levels. Furthermore, working in a small broiler was a significant determinant of elevated glucan exposures. Farms using automated laying activities had significantly higher particulate levels compared to those using manual laying activities. This study revealed that workers engaged in poultry farming activities were exposed to significantly high levels of inhalable particulate dust, endotoxin, and (1-3)-β-D-glucan concentrations, posing an increased risk for adverse respiratory health effects in these farm workers.

Acute exacerbation of chronic obstructive pulmonary disease in a slaughterhouse

We describe the case of a 52-year-old male who presented with two episodes of acute exacerbations (AE) of chronic obstructive pulmonary disease (COPD) during work, while suspending live chickens for slaughter. The patient was exposed to high levels of bioaerosols, including endotoxins and microorganisms. Endotoxins can induce bronchoconstriction and airway inflammation, and COPD patients are more vulnerable to airway infections caused by microorganisms inhaled with bioaerosols. This study suggests that a high level of bioaerosols may induce airway infections, resulting in acute exacerbations of COPD.

Intensive poultry farming: A review of the impact on the environment and human health

Poultry farming is one of the most efficient animal husbandry methods and it provides nutritional security to a significant number of the world population. Using modern intensive farming techniques, global production has reached 133.4 mil. t in 2020, with a steady growth each year. Such intensive growth methods however lead to a significant environmental footprint. Waste materials such as poultry litter and manure can pose a serious threat to environmental and human health, and need to be managed properly. Poultry production and waste by-products are linked to NH₃, N₂O and CH₄ emissions, and have an impact on global greenhouse gas emissions, as well as animal and human health. Litter and manure can contain pesticide residues, microorganisms, pathogens, pharmaceuticals (antibiotics), hormones, metals, macronutrients (at improper ratios) and other pollutants which can lead to air, soil and water contamination as well as formation of antimicrobial/multidrug resistant strains of pathogens. Dust emitted from intensive poultry production operations contains feather and skin fragments, faeces, feed particles, microorganisms and other pollutants, which can adversely impact poultry health as well as the health of farm workers and nearby inhabitants. Fastidious odours are another problem that can have an adverse impact on health and quality of life of workers and surrounding population. This study discusses the current knowledge on the impact of intensive poultry farming on environmental and human health, as well as taking a look at solutions for a sustainable future.

A cross sectional study on airborne inhalable microorganisms, endotoxin, and particles in pigeon coops - Risk assessment of exposure

Pigeon breeding is associated with symptoms of the airways. The aim of this study is to illuminate the bacteriological and toxicological characteristics of airborne dust in pigeon coops. Airborne dust was sampled in 31 urban pigeon coops with homing and fancy pigeons, and following the dust was characterized. In total 141 different bacterial species were identified using MALDI-TOF MS, and of these 11 species are classified in risk group 2. Of the cultivable bacteria, Staphylococcus equorum was present in the highest concentration. Microorganisms in the dust were able to form biofilm, and the amount correlated positively with the number of bacteria. Next generation sequencing showed 180 genera with Acinetobacter in highest reads. On average 999 ± 225 ZOTUs were observed per sample with a Shannon-Wiener biodiversity index of 6.17 ± 0.24. Of the identified species the following have previously been suggested as causative agents of extrinsic allergic alveolitis: Alcaligenes faecalis, Bacillus subtilis, Pantoea agglomerans, Sphingobacterium spiritivorum, Thermoactinomyces sp., and Streptomyces albus. Staphylococcus was present on particles with sizes between 1.1 and > 7.0 μm with a geometric mean diameter of particles on 4.7 ± 1.1 μm. Concentrations of airborne endotoxin and dust were elevated compared to references, and the geometric mean concentrations were 102 EU/m³ and 1.07 mg dust/m³, respectively. Upon exposure to the airborne dust human granulocytes produced Reactive Oxidative Species during the first 5 min, and then no further reaction was observed. The concentrations of bacteria in general, Staphylococcus spp., and endotoxin and biodiversity were associated significantly with season, temperature and/or relative humidity, but not with type or density of pigeons. The bacterial composition and biodiversity indices were not affected by type of pigeon. In conclusion, the exposure to bacteria and endotoxin in pigeon houses should not be neglected in the evaluation of causative agents of airways symptoms among pigeon breeders.

Derivation of an occupational exposure limit for β-glucans

β-Glucans are abundant bacterial, yeast, and fungal cell wall polysaccharides that have been shown to activate the immune system. Establishment of an occupational exposure limit (OEL) for β-glucan exposure is critical to the protection of worker health, as these exposures have been linked to immunosuppressive and inflammatory reactions and possibly the development of respiratory diseases. Detectable concentrations of β-glucans have been identified in common occupational inhalation exposure scenarios, such as in the agricultural and waste management sectors. However, no published exposure benchmarks for inhalation of β-glucans are available for workers or the general population. Thus, a health-based OEL for inhalation exposure of workers to β-glucans was derived based on consideration of human and non-human effect data for this class of compounds and contemporary risk assessment methods. The weight of the evidence indicated that the available data in humans showed significant methodological limitations, such as lack of a representative study size, appropriate control population, and clear dose-response relationship. Thus, an OEL of 150 ng/m³ was derived for β-glucans based on the most relevant nonclinical study. This OEL provides an input to the occupational risk assessment process, allows for comparisons to worker exposure, and can guide risk management and exposure control decisions.

Occupational risk factors in health of broiler-farm workers: A systematic review

The present study aimed to identify gaps in literature regarding occupational risks to broiler farming workers. A systematic review was performed in which inclusion criteria were workers in poultry farms. The search was done between May and June 2019 with online papers. Keywords were "poultry farmer," "poultry worker," and "poultry workers" as terms of an axis of a theoretical framework. Results indicated as predominant topics lung diseases, nasal mucosa or paranasal sinus contamination, and aflatoxicosis. The identified gaps in scientific publications are related to mitigation of occupational risks. Prevalent described risks are associated to exposure to chemicals gases, vapors and aerosols, biological hazards (micro-organisms), ergonomic risks, wrong working posture, excessive body movement and inadequate behaviors. Preventive policies about poultry farmer's health and safety needs to be adopted to reduce potentially dangerous risk factors and increase productivity.

Respiratory health disorders associated with occupational exposure to bioaerosols among workers in poultry breeding farms

Working in poultry farms revealed the exposure to chemical and biological emissions (bioaerosols) that might be related to respiratory diseases in the workers and an increased loss in lung function. The current study aimed to determine the respiratory health status among poultry farm workers and to monitor the biological and the environmental conditions at ten poultry farms in Egypt. It reported that the total dust, ammonia (NH₃), and carbon dioxide (CO₂) concentrations in the studied poultry farms did not exceed the permissible exposure limits except farm V where NH₃ was slightly exceeded the recommended levels. 35.7% of the poultry farm workers had positive nose and throat culture (bacterial and fungal). The poultry farm workers had higher prevalence of cough, wheeze, and shortness of breath with lower mean values of spirometric measurements than the controls (P < 0.05). Also, the positive culture poultry farm workers had significantly higher respiratory manifestations and lower spirometry values than negative culture ones (P < 0.05). Therefore, intervention programs for reducing the exposure are amendatory point for the health and safety of poultry farm workers.

Assessment of Respiratory Problems in Workers Associated with Intensive Poultry Facilities in Pakistan

Background

The poultry industry in Pakistan has flourished since the 1960s; however, there are scarce data regarding the impact of occupational exposure on the pulmonary health of farm workers in terms of years working in the industry. The objective of the present study was to assess the effect of poultry environment on the health of occupationally exposed poultry farmers in countries of warm climatic regions, such as Pakistan. This study will also show the effect of exposure to poultry facilities on the health of poultry farmers in the context of low-income countries with a relatively inadequate occupational exposure risk management.

Materials and methods

The lung function capacity of 79 poultry workers was measured using a spirometer. Along with spirometry, a structured questionnaire was also administrated to obtain information about age, height, weight, smokers/nonsmokers, years of working experience, and pulmonary health of farm workers. The workers who were directly involved in the care and handling of birds in these intensive facilities were considered and divided into four groups based on their years of working experience: Group I (3-10 months), Group II (1-5 years), Group III (6-10 years), and Group IV (more than 11 years). The forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio were considered to identify lung function abnormalities. Statistical analysis was carried out using independent sample t test, Chi-square test, Pearson's correlation, and linear regression.

Results

Based on the performed spirometry, 68 (86 %) of workers were found normal and healthy, whereas 11 (14 %) had a mild obstruction. Of the 11 workers with mild obstruction, the highest number with respect to the total was in Group IV (more than 11 years of working experience) followed by Group III and Group II. Most of the workers were found healthy, which seems to be because of the healthy survivor effect. For the independent sample t test, a significant difference was noticed between healthy and nonhealthy farmers, whereas Chi-square test showed a significant association with height, drugs, and working experience. Linear regression that was stratified by respiratory symptoms showed for workers with symptoms, regression models for all spirometric parameters (FVC, FEV1, and FEV1/FVC) have better predictive power or R square value than those of workers without symptoms.

Conclusion

These findings suggest that lung function capacity was directly related to years of working experience. With increasing number of working years, symptoms of various respiratory problems enhanced in the poultry workers. It should be noted that most of the poultry workers were healthy and young, the rationale being that there is a high turnover rate in this profession. The mobility in this job and our finding of 86% of the healthy workers in the present study also proposed healthy worker survivor effect.

Respiratory symptoms and lung functional impairments associated with occupational exposure to poultry house pollutants

This study aimed to assess respiratory symptoms and the pulmonary function test (PFT) in a group of poultry workers. The prevalence of respiratory symptoms was determined. Airborne concentrations of total and repairable dusts exceeded the threshold limit values. Gram-positive cocci and Cladosporium were the dominant genera of bacteria and fungi, respectively. The prevalence of respiratory symptoms was significantly higher in the exposed subjects. Mean baseline values of forced expiratory volume (FEV₁), FEV₁ to forced vital capacity (FVC) ratio (FEV₁/FVC) and peak expiratory flow (PEF) were significantly lower in the exposed group. Significant cross-shift decrements were noted in vital capacity (VC), FVC, FEV₁, PEF and FEV₁/FVC of the exposed subjects. A dominant pattern of lung function abnormality was found to be obstructive. Exposure to poultry pollutants may result in a significant increase in the prevalence of respiratory symptoms as well as both acute reversible and chronic irreversible decrements in the PFT.

COPD, airflow limitation and chronic bronchitis in farmers: a systematic review and meta-analysis

Introduction

The current definition of chronic obstructive pulmonary disease (COPD) associates persistent airflow limitation and chronic respiratory symptoms. Agricultural work has been associated with an increased risk of developing COPD, but the prevalence and definition of the disease vary greatly between studies. This meta-analysis aimed to assess the association between agricultural work and COPD using the most widely used definitions of the disease.

Methods

Inclusion criteria were: (1) design: cross-sectional or longitudinal, (2) groups: at least one group of farmers and a control group of non-farmers, (3) outcome: prevalence or unadjusted OR of COPD, airflow limitation and/or chronic bronchitis, (4) study subjects: groups of exposed subjects comprising ≥30 individuals and with a mean age ≥40 years and (5) language: English and French language, full-length, original publications in peer-reviewed journals.

Results

In total, 22 manuscripts were included in the meta-analysis. Eight studies assessed only the prevalence of airflow limitation, nine assessed only the prevalence of chronic bronchitis and four assessed the prevalence of both these parameters. Only one assessed the prevalence of COPD according to its current definition, and this study also provided the prevalence of airflow limitation. Ten studies showed a positive association between farming exposure and airflow limitation or chronic bronchitis, and 12 showed no association (OR (95% CI)=1.77 (1.50 to 2.08), p<0.001). Cattle, swine, poultry and crop farming were associated with either airflow limitation or chronic bronchitis.

Conclusion

Although some features of COPD are associated with some agricultural work, well-designed studies with appropriate diagnostic criteria should be conducted to draw strong conclusions about the relationship between COPD and farming.

Poultry rearing on perforated plastic floors and the effect on air quality, growth performance, and carcass injuries - Experiment 2: Heat stress situation

Previously, we reported the effect of rearing conditions (plastic floors and air quality) on carcass injury development of broiler chickens at thermal comfort. In this study, the same rearing conditions were tested at thermal stress. The birds were reared in 2 climatic chambers, and the experiment followed a completely randomized design with one factor, flooring material: wood shaving or perforated plastic. The birds were divided into 16 experimental pens, being 8 females and 8 males. The studied parameters were the same as the previous study (ammonia concentration, carbon dioxide, performance, carcass yield, and variability, and scores of hygiene, gait and chest, and hocks and footpad lesions). Higher ammonia (15 ppm vs. 4 ppm) and carbon dioxide (1,000 ppm vs. 850 ppm) concentration was seen at d 42 for the wood shavings floor as compared to the perforated plastic floor, respectively. Regarding gender, males had better performance than females at 42 d of age on both floor types. Males reared on wood shavings showed a higher meat production (29.049 kg/m2) than females (24.700 kg/m2). There were observed breast lesion incidences of 10.4% (score 1) in males reared on the plastic floor, as well higher incidence of hock injury and footpad dermatitis. Chickens reared on plastic flooring showed better hygiene than chickens reared on wood shavings. Our findings revealed that the use of perforated plastic flooring in a heat stress situation can improve the air quality (less CO2 and NH3 concentration) and bird cleanliness. On the other hand, chickens are more susceptible to develop lesions in the breast, hock, and footpad. We conclude that the use of plastic flooring in heat stress conditions needs more attention, since chickens are more susceptible to develop lesions on the carcass, being a source of pain, impairing bird wellbeing and causing losses in meat production.

Poultry rearing on perforated plastic floors and the effect on air quality, growth performance, and carcass injuries-Experiment 1: Thermal Comfort

The present study investigated the use of perforated plastic floors in the rearing of male and female poultry under thermal comfort conditions. The study was conducted in 2 climate chambers, in one was conventional poultry litter (wood shavings) and in the other was a perforated plastic floor. The experimental design was a completely randomized design with the factors wood shavings and plastic floor. In each chamber, the animals were divided into 16 experimental pens (8 with males and 8 with females) with a density of 12 birds/m2. The poultry rearing effect was evaluated in terms of air quality (% concentration of ammonia [NH3] and carbon dioxide [CO2]); broiler performance, e.g., weight gain (kg), feed intake (kg), feed conversion, carcass yield and parts (%), meat production (kg/m2), and viability (% of live birds at d 42); scores of hygiene and mobility; and injuries in the chest, hocks, and footpads. Treatments affected air quality, with higher concentrations of NH3 on d 42 (25 ppm vs. 2 ppm) and CO2 (1,400 ppm vs. 1,000 ppm) for wood shavings than for perforated plastic floor, respectively. Males showed a better performance (weight gain, feed intake and feed conversion) than females on d 42 in both floor types (wood shavings and plastic floor). Males reared on wood shavings showed a higher meet production (35.992 kg/m2) than females (32.257 kg/m2). On the plastic floor, males showed a better viability (100%) than females (94.05%), as well better meet production for males (38.55 kg·m-2) than females (31.64 kg/m2). There was no incidence of breast lesions in any of the studied systems. The birds reared on the plastic floor had better hygiene scores and lower hock injury rates than birds reared in the wood shavings chambers. The results of the present study show that the use of perforated plastic floors in chicken farming is an efficient method, which promotes a better-quality environment, superior production rates, and reduced incidence of injuries.

Respiratory Protection Behavior and Respiratory Indices among Poultry House Workers on Small, Family-Owned Farms in North Carolina: A Pilot Project

The aim of this pilot study was to evaluate respiratory behavior and respiratory indices of poultry workers on family-owned, poultry farms with 10 or less employees in North Carolina. A field study was conducted to collect data on participants (N = 24) using spirometry, fractional exhaled nitric oxide (Feno), and an interviewer-administered questionnaire. The majority of workers (76%) ranked respiratory protection as being important, yet 48% reported never or rarely wearing respiratory protection when working in dusty conditions. A large percent of workers reported eye (55%) and nasal (50%) irritation and dry cough (50%). On average, pulmonary lung function and Feno tests were normal among nonsmokers. In bivariate analysis, significant associations were identified between working 7 days on the farm (P = .01), with eye irritation, and working 5 or fewer years in poultry farming (P = .01). Poultry workers on family-owned farms spend a considerable amount of work time in poultry houses and report acute respiratory-related health symptoms. Administrative controls among small, family-owned poultry farms are necessary to improve and promote safety and health to its employees.

Cage Versus Noncage Laying-Hen Housings: Worker Respiratory Health

The objective of this study was to compare respiratory health of poultry workers in conventional cage, enriched cage and aviary layer housing on a single commercial facility, motivated by changing requirements for humane housing of hens. Three workers were randomly assigned daily, one to each of conventional cage, enriched cage, and aviary housing in a crossover repeated-measures design for three observation periods (for a total of 123 worker-days, eight different workers). Workers' exposure to particles were assessed (Arteaga et al. J Agromedicine. 2015;20:this issue) and spirometry, exhaled nitric oxide, respiratory symptoms, and questionnaires were conducted pre- and post-shift. Personal exposures to particles and endotoxin were significantly higher in the aviary than the other housings (Arteaga et al., 2015). The use of respiratory protection was high; the median usage was 70% of the shift. Mixed-effects multivariate regression models of respiratory cross-shift changes were marginally significant, but the aviary system consistently posted the highest decrements for forced expiratory volume in 1 and 6 seconds (FEV1 and FEV6) compared with the enriched or conventional housing. The adjusted mean difference in FEV1 aviary - enriched cage housing was -47 mL/s, 95% confidence interval (CI): (-99 to 4.9), P = .07. Similarly, for FEV6, aviary - conventional housing adjusted mean difference was -52.9 mL/6 s, 95% CI: (-108 to 2.4), P = .06. Workers adopting greater than median use of respiratory protection were less likely to exhibit negative cross-shift pulmonary function changes. Although aviary housing exposed workers to significantly higher respiratory exposures, cross-shift pulmonary function changes did not differ significantly between houses. Higher levels of mask use were protective; poultry workers should wear respiratory protection as appropriate to avoid health decrements.

Eggshells as a source for occupational exposure to airborne bacteria in hatcheries

Occupational exposure to high concentrations of airborne bacteria in poultry production is related to an increased risk of respiratory disorders. However, potential sources and formation of hatchery bioaerosols are rarely characterized. In this study, bacterial multiplication on fresh shell fragments from turkey hatching eggs under conditions present in a hatcher incubator was investigated. A 10⁵-fold amplification was observed both by colony count and total cell count gaining 4 × 10⁷ cfu/cells per gram eggshell within 30 hr of incubation. Furthermore, the bacterial community present on eggshells was analyzed by generation of 16S rRNA gene clone libraries and identification of eight isolates. RFLP analysis revealed no shift in community composition during incubation and Enterococcus faecalis and Enterococcus gallinarum were found as the predominant species on turkey eggshells, both have been classified as risk group 2 microorganisms (German TRBA 466). Since Enterococcus spp. were found as predominant species on turkey eggshells, contribution of this genus to bioaerosol formation was demonstrated. During different work activities with poult and eggshell handling concentrations of airborne enterococci up to 1.3 × 10⁴ cfu m^-3 were detected. In contrast, no enterococci were identified at a day without poult or eggshell processing. In conclusion, turkey hatching eggs carry a viable specific microflora from breeder flocks to hatcheries. After hatching of turkey poults, hatcher incubators and eggshell fragments provide appropriate conditions for excessive bacterial growth. Thus, high bacterial loads on eggshell fragments are a source of potential harmful bioaersols caused by air flows, poult activity, and handling of equipment.

High throughput genomic sequencing of bioaerosols in broiler chicken production facilities

Chronic inhalation exposure to agricultural dust promotes the development of chronic respiratory diseases among poultry workers. Poultry dust is composed of dander, chicken feed, litter bedding and microbes. However, the microbial composition and abundance has not been fully elucidated. Genomic DNA was extracted from settled dust and personal inhalable dust collected while performing litter sampling or mortality collection tasks. DNA libraries were sequenced using a paired-end sequencing-by-synthesis approach on an Illumina HiSeq 2500. Sequencing data showed that poultry dust is predominantly composed of bacteria (64-67%) with a small quantity of avian, human and feed DNA (< 2% of total reads). Staphylococcus sp. AL1, Salinicoccus carnicancri and Lactobacillus crispatus were the most abundant bacterial species in personal exposure samples of inhalable dust. Settled dust had a moderate relative abundance of these species as well as Staphylococcus lentus and Lactobacillus salivarius. There was a statistical difference between the microbial composition of aerosolized and settled dust. Unlike settled dust composition, aerosolized dust composition had little variance between samples. These data provide an extensive analysis of the microbial composition and relative abundance in personal inhalable poultry dust and settled poultry dust.

Prevalence of toxigenic Penicillium species associated with poultry house in Telangana, India

The prevalence of mycotoxigenic Penicillium species in poultry houses of Telangana, India, was studied during 4 seasons between June 2009 and May 2010. Fungi belonging to 13 genera, including Penicillium, comprising 43 species were collected using petri plates. Fourteen Penicillium species demonstrated varying degrees of mycotoxigenicity. Chemical and chromatographic analysis of the different poultry feed samples revealed 8 different mycotoxins with ochratoxin A (OTA) predominating. The mean contamination rate of OTA was 38%. OTA quantities ranged between 5.78 and 6.73 µg/kg^-1, 10.13 and 14.23 µg/kg^-1, and 12.33 and 15.20 µg/kg^-1 in starter, broiler, and layer feeds, respectively. Statistically significant positive correlation between prevalence of Penicillium species and the monsoon, autumn, and spring seasons and negative correlation between prevalence and the autumn, spring, and summer seasons were observed. These findings may serve as risk exposure indicators and contribute toward the initiation of a sustainable control program.

Antimicrobial-Resistant Escherichia coli Survived in Dust Samples for More than 20 Years

In a retrospective study, 119 sedimentation dust samples stored between five and 35 years from various barns of intensive livestock farming were evaluated for the occurrence of cultivatable Escherichia coli. Growth of E. coli occurred in 54 samples. Successful cultivation was achieved in samples from as early as 1994. The frequency of detection increased from earlier to later time periods, but the concentrations, which ranged between 3.4 × 10(2) and 1.1 × 10(5) colony-forming units per gram, did not correlate with sample age (Spearman rank correlation; p > 0.05). We hypothesize that E. coli cells survived in dust samples without cell division because of the storage conditions. Dry material (dust) with low water activities (arithmetic mean < 0.6) and storage at 4°C in the dark likely facilitated long-term survival. E. coli were isolated on MacConkey agar with and without ciprofloxacin supplementation. For 110 isolates (79 from non-supplemented media and 31 from supplemented media), we determined the E. coli phylotype and antimicrobial resistance. Six phylogenetic groups were identified. Phylogroups A and B1 predominated. Compared to group A, phylogroup B1 was significantly associated with growth on ciprofloxacin-supplemented media (chi-square test, p = 0.003). Furthermore, the antibiotic resistance profiles determined by a microdilution method revealed that isolates were phenotypically resistant to at least one antimicrobial substance and that more than 50% were resistant to a minimum of five out of 10 antibiotics tested. A linear mixed model was used to identify factors associated with the number of phenotypic resistances of individual isolates. Younger isolates and isolates from fattening poultry barns tended to be resistant to significantly more antibiotics than older isolates and those from laying-hen houses (p = 0.01 and p = 0.02, respectively). Sample origin and storage conditions may have influenced the number of antimicrobial resistances. Overall, we found that under particular conditions, dust from farm animal houses can be reservoirs for antimicrobial-resistant E. coli for at least 20 years. The survival strategies that allow E. coli to survive such long periods in environmental samples are not fully understood and could be an interesting research topic for future studies.

Automated Image Analysis for Determination of Antibody Titers Against Occupational Bacterial Antigens Using Indirect Immunofluorescence

Employees who are exposed to high concentrations of microorganisms in bioaerosols frequently suffer from respiratory disorders. However, etiology and in particular potential roles of microorganisms in pathogenesis still need to be elucidated. Thus, determination of employees' antibody titers against specific occupational microbial antigens may lead to identification of potentially harmful species. Since indirect immunofluorescence (IIF) is easy to implement, we used this technique to analyze immunoreactions in human sera. In order to address disadvantageous inter-observer variations as well as the absence of quantifiable fluorescence data in conventional titer determination by eye, we specifically developed a software tool for automated image analysis. The 'Fluorolyzer' software is able to reliably quantify fluorescence intensities of antibody-bound bacterial cells on digital images. Subsequently, fluorescence values of single cells have been used to calculate non-discrete IgG titers. We tested this approach on multiple bacterial workplace isolates and determined titers in sera from 20 volunteers. Furthermore, we compared image-based results with the conventional manual readout and found significant correlation as well as statistically confirmed reproducibility. In conclusion, we successfully employed 'Fluorolyzer' for determination of titers against various bacterial species and demonstrated its applicability as a useful tool for reliable and efficient analysis of immune response toward occupational exposure to bioaerosols.

Non-culturable bioaerosols in indoor settings: Impact on health and molecular approaches for detection

Despite their significant impact on respiratory health, bioaerosols in indoor settings remain understudied and misunderstood. Culture techniques, predominantly used for bioaerosol characterisation in the past, allow for the recovery of only a small fraction of the real airborne microbial burden in indoor settings, given the inability of several microorganisms to grow on agar plates. However, with the development of new tools to detect non-culturable environmental microorganisms, the study of bioaerosols has advanced significantly. Most importantly, these techniques have revealed a more complex bioaerosol burden that also includes non-culturable microorganisms, such as archaea and viruses. Nevertheless, air quality specialists and consultants remain reluctant to adopt these new research-developed techniques, given that there are relatively few studies found in the literature, making it difficult to find a point of comparison. Furthermore, it is unclear as to how this new non-culturable data can be used to assess the impact of bioaerosol exposure on human health. This article reviews the literature that describes the non-culturable fraction of bioaerosols, focussing on bacteria, archaea and viruses, and examines its impact on bioaerosol-related diseases. It also outlines available molecular tools for the detection and quantification of these microorganisms and states various research needs in this field.

Production of the allergenic protein Alt a 1 by Alternaria isolates from working environments

The aim of the study was to evaluate the ability of Alternaria isolates from workplaces to produce Alt a 1 allergenic protein, and to analyze whether technical materials (cellulose, compost, leather) present within the working environment stimulate or inhibit Alt a 1 production (ELISA test). Studies included identification of the isolated molds by nucleotide sequences analyzing of the ITS1/ITS2 regions, actin, calmodulin and Alt a 1 genes. It has been shown that Alternaria molds are significant part of microbiocenosis in the archive, museum, library, composting plant and tannery (14%-16% frequency in the air). The presence of the gene encoding the Alt a 1 protein has been detected for the strains: Alternaria alternata, A. lini, A. limoniasperae A. nobilis and A. tenuissima. Environmental strains produced Alt a 1 at higher concentrations (1.103-6.528 ng/mL) than a ATCC strain (0.551-0.975 ng/mL). It has been shown that the homogenization of the mycelium and the use of ultrafiltration allow a considerable increase of Alt a 1 concentration. Variations in the production of Alt a 1 protein, depend on the strain and extraction methods. These studies revealed no impact of the technical material from the workplaces on the production of Alt a 1 protein.

Removal of odorous compounds from poultry manure by microorganisms on perlite--bentonite carrier

Laboratory-scale experiments were conducted using poultry manure (PM) from a laying hen farm. Six strains of bacteria and one strain of yeast, selected on the base of the previous study, were investigated to evaluate their activity in the removal of odorous compounds from poultry manure: pure cultures of Bacillus subtilis subsp. spizizenii LOCK 0272, Bacillus megaterium LOCK 0963, Pseudomonas sp. LOCK 0961, Psychrobacter faecalis LOCK 0965, Leuconostoc mesenteroides LOCK 0964, Streptomyces violaceoruber LOCK 0967, and Candida inconspicua LOCK 0272 were suspended in water solution and applied for PM deodorization. The most active strains in the removal of volatile odorous compounds (ammonia, hydrogen sulfide, dimethylamine, trimethylamine, isobutyric acid) belonged to B. subtilis subsp. spizizenii, L. mesenteroides, C. inconspicua, and P. faecalis. In the next series of experiments, a mixed culture of all tested strains was immobilized on a mineral carrier being a mixture of perlite and bentonite (20:80 by weight). That mixed culture applied for PM deodorization was particularly active against ammonia and hydrogen sulfide, which were removed from the exhaust gas by 20.8% and 17.5%, respectively. The experiments also showed that during deodorization the microorganisms could reduce the concentrations of proteins and amino acids in PM. In particular, the mixed culture was active against cysteine and methionine, which were removed from PM by around 45% within 24 h of deodorization.

Accessing indoor fungal contamination using conventional and molecular methods in Portuguese poultries

Epidemiological studies showed increased prevalence of respiratory symptoms and adverse changes in pulmonary function parameters in poultry workers, corroborating the increased exposure to risk factors, such as fungal load and their metabolites. This study aimed to determine the occupational exposure threat due to fungal contamination caused by the toxigenic isolates belonging to the complex of the species of Aspergillus flavus and also isolates from Aspergillus fumigatus species complex. The study was carried out in seven Portuguese poultries, using cultural and molecular methodologies. For conventional/cultural methods, air, surfaces, and litter samples were collected by impaction method using the Millipore Air Sampler. For the molecular analysis, air samples were collected by impinger method using the Coriolis μ air sampler. After DNA extraction, samples were analyzed by real-time PCR using specific primers and probes for toxigenic strains of the Aspergillus flavus complex and for detection of isolates from Aspergillus fumigatus complex. Through conventional methods, and among the Aspergillus genus, different prevalences were detected regarding the presence of Aspergillus flavus and Aspergillus fumigatus species complexes, namely: 74.5 versus 1.0 % in the air samples, 24.0 versus 16.0 % in the surfaces, 0 versus 32.6 % in new litter, and 9.9 versus 15.9 % in used litter. Through molecular biology, we were able to detect the presence of aflatoxigenic strains in pavilions in which Aspergillus flavus did not grow in culture. Aspergillus fumigatus was only found in one indoor air sample by conventional methods. Using molecular methodologies, however, Aspergillus fumigatus complex was detected in seven indoor samples from three different poultry units. The characterization of fungal contamination caused by Aspergillus flavus and Aspergillus fumigatus raises the concern of occupational threat not only due to the detected fungal load but also because of the toxigenic potential of these species.

Exposure to airborne culturable microorganisms and endotoxin in two Italian poultry slaughterhouses

Even if slaughterhouses' workers handle large amounts of organic material and are potentially exposed to a wide range of biological agents, relatively little and not recent data are available. The main objective of this study was to characterize indoor concentrations of airborne bacteria, fungi, and endotoxin mod = Im (endotoxin∼Gram-negative*plant*filter) in two Italian poultry slaughterhouses. Air samples near air handling units inlets were also collected. Since there are not standardized protocols for endotoxin sampling and extraction procedures, an additional aim of the study was to compare the extraction efficiency of three different filter.. The study was also aimed at determining the correlation between concentrations of Gram-negative bacteria and endotoxin. In Plant A bacterial levels ranged from 17.5 to 2.6×10(3) CFU/m3. The highest concentrations were observed in evisceration area of chickens, between the automatic detachment of the neck and washing offal, and near birds coupling before hair-chilling. The highest mean value of Gram-negative (266.5 CFU/m3) was found near the washing offal of turkeys. In Plant B bacterial concentration ranged from 35 to 8×10(3) CFU/m3. The highest concentration. with the highest value of Gram-negative (248 CFU/m3), was found after defeathering. Fungal concentrations were overall lower than those found for bacteria (range: 0-205 CFU/m3 in Plant A and 0-146.2 CFU/m3 in Plant B). The microbial flora was dominated by Gram-negative and coagulase-negative staphylococci for bacteria and by species belonging to Cladosporium, Penicillium and Aspergillus genera for molds. The highest endotoxin concentrations were measured in washing offal for Plant A (range: 122.7-165.9 EU/m3) and after defeathering for Plant B (range: 0.83-38.85 EU/m3). In this study airborne microorganisms concentrations were lower than those found in similar occupational settings and below the occupational limits proposed by some authors. However, these microorganisms may exert adverse effects on exposed workers, in particular for those engaged in the early slaughtering stages, as evidenced by the presence of pathogenic species. The detection of pathogenic bacteria near AHU inlet may constitute a risk to public health and environmental pollution.

Monitoring total endotoxin and (1 --> 3)-beta-D-glucan at the air exhaust of concentrated animal feeding operations

Mitigation of bioaerosol emissions from concentrated animal feeding operations (CAFOs) demands knowledge of bioaerosol concentrations feeding into an end-of-pipe air treatment process. The aim of this preliminary study was to measure total endotoxin and (1 --> 3)-beta-glucan concentrations at the air exhaust of 18 commercial CAFOs and to examine their variability with animal operation type (swine farrowing, swine gestation, swine weaning, swine finishing, manure belt laying hen, and tom turkey) and season (cold, mild, and hot). The measured airborne concentrations of total endotoxin ranged from 98 to 23,157 endotoxin units (EU)/m3, and the airborne concentrations of total (1 --> 3)-beta-D-glucan ranged from 2.4 to 537.9 ng/m3. Animal operation type in this study had a significant effect on airborne concentrations of total endotoxin and (1 --> 3)-beta-D-glucan but no significant effect on their concentrations in total suspended particulate (TSP). Both endotoxin and (1 --> 3)-beta-D-glucan attained their highest airborne concentrations in visited tom turkey buildings. Comparatively, season had no significant effect on airborne concentrations of total endotoxin or (1 --> 3)-beta-D-glucan. Endotoxin and (1 --> 3)-beta-glucan concentrations in TSP dust appeared to increase as the weather became warmer, and this seasonal effect was significant in swine buildings. Elevated indoor temperatures in the hot season were considered to facilitate the growth and propagation of bacteria and fungi, thus leading to higher biocomponent concentrations in TSP.

Recovery of ammonia from poultry litter using flat gas permeable membranes

The use of flat gas-permeable membranes was investigated as components of a new process to capture and recover ammonia (NH3) in poultry houses. This process includes the passage of gaseous NH3 through a microporous hydrophobic membrane, capture with a circulating dilute acid on the other side of the membrane, and production of a concentrated ammonium (NH4) salt. Bench- and pilot-scale prototype systems using flat expanded polytetrafluoroethylene (ePTFE) membranes and a sulfuric acid solution consistently reduced headspace NH3 concentrations from 70% to 97% and recovered 88% to 100% of the NH3 volatilized from poultry litter. The potential benefits of this technology include cleaner air inside poultry houses, reduced ventilation costs, and a concentrated liquid ammonium salt that can be used as a plant nutrient solution.

Immunodetection and quantification of airborne (1-3)-β-D-glucan-carrying particles with the halogen immunoassay

Fungal cell wall components, such as (1-3)-β-D-glucan, are known to be capable of activating the innate immune system and pose a respiratory health risk in different environments. Mass-based non-viable techniques commonly used for assessment of fungal exposures could be β-D-glucan-specific, but are limited to analysis of liquid extracts. The variable solubility of different β-D-glucans may underestimate β-D-glucan exposure and long sampling times required for mass-based methods make assessing short-term exposures difficult. In this study, we evaluated the utility of the halogen immunoassay (HIA), an immunoblotting technique previously used for allergens, to immunodetect and quantify β-D-glucan-carrying particles (BGCPs). The HIA was able to detect BGCPs without background staining when β-D-glucan standards and air samples collected at a poultry house during short sampling periods were evaluated. The image analysis protocol previously developed by our group for mouse allergen allowed simultaneous immunodetection and quantification of β-D-glucan-containing particles. Our results suggest that the HIA holds promise for quantifying β-D-glucan exposures. To our knowledge, this is the first time in which the HIA was used for non-allergenic compounds of microbial or fungal origins.

Microbial exposure and respiratory dysfunction in poultry hatchery workers

Today's modern animal confinement with high stocking density of a single species has resulted in new workplaces that are rarely characterised in regard to microbial exposure. In this study we determine the personal microbial exposure by long term monitoring in a duck hatchery. Four hatchery workers were accompanied for four weeks and on every working day personal bioaerosol sampling and lung function tests were performed. Quantitative and qualitative molecular methods were used for analysing bioaerosol samples. Restriction Fragment Length Polymorphism (RFLP) analyses showed a unique microbial exposure on eclosion days. By 16S rRNA gene sequence cloning analysis we detected Staphylococcus, Acinetobacter and Enterococcus as predominant bacterial genera. Ducklings' down was identified as a medium for bacterial contamination. Furthermore on eclosion days the four workers showed a decline in lung function over their working shift causing an average FEV 1 decrease.

3-D jobs and health disparities: The health implications of Latino chicken catchers' working conditions

OBJECTIVES

This study uses qualitative data to describe the tasks performed by chicken catchers, their organization of work, and possible health and safety hazards encountered.

METHODS

Twenty-one Latino immigrant chicken catchers for North Carolina poultry-processing plants were interviewed to obtain their perceptions of the job and its hazards. Interviews were recorded and transcribed (n = 10) or detailed notes recorded (n = 11). Transcripts and notes were subjected to qualitative analysis.

RESULTS

Chicken catching takes place in a highly contaminated and hazardous work environment. The fast pace of work, low level of control over work intensity, and piece rate compensation all result in high potential for work-related injury and illness, including trauma, electrical shock, respiratory effects, musculoskeletal injuries, and drug use. Workers receive little safety or job training.

CONCLUSIONS

Chicken catching is characterized by a work environment and organization of work that promote injury and illness.

Indoor exposure to airborne endotoxin: a review of the literature on sampling and analysis methods

Assessment of exposure to airborne endotoxins has been studied for several years, especially in occupational environments, but a large number of procedures are used for sampling and analysis. This lack of standardization makes it very difficult to compare results and set internationally accepted threshold limit values (TLVs) or occupational exposure limits (OELs) for endotoxin exposure. This paper reviews the methods reported, using advanced bibliographical search techniques: 82 papers published from 2004 to the present were selected to analyze methods for the assessment of human exposure to airborne endotoxins, with particular reference to occupational settings, and to examine their performance and critical points. Only few studies have focused on the standardization of sampling and analysis methods. The European Committee for Standardization Guidelines coincide with the procedures most frequently applied, but this does not guarantee the best results in terms of recovery and reproducibility. The factor that mainly affects endotoxin measurements is the extraction method, the main concern being the presence in the samples of a fraction insoluble in aqueous media. If substantial differences in the proportions of this fraction in different environments are confirmed in the future, the contribution of insoluble endotoxins cannot be neglected.

Occupational exposure to poultry dust and effects on the respiratory system in workers

Farmers are occupationally exposed to many respiratory hazards at work and display higher rates of asthma and respiratory symptoms than other workers. Dust is one of the components present in poultry production that increases risk of adverse respiratory disease occurrence. Dust originates from poultry residues, molds, and feathers and is biologically active as it contains microorganisms. Exposure to dust is known to produce a variety of clinical responses, including asthma, chronic bronchitis, chronic airways obstructive disease (COPD), allergic alveolitis, and organic dust toxic syndrome (ODTS). A study was developed to determine particle contamination in seven poultry farms and correlate this with prevalence rate of respiratory defects and record by means of a questionnaire the presence of clinical symptoms associated with asthma and other allergy diseases by European Community Respiratory Health Survey. Poultry farm dust contamination was found to contain higher concentrations of particulate matter (PM) PM5 and PM10. Prevalence rate of obstructive pulmonary disorders was higher in individuals with longer exposure regardless of smoking status. In addition, a high prevalence for asthmatic (42.5%) and nasal (51.1%) symptoms was noted in poultry workers. Data thus show that poultry farm workers are more prone to suffer from respiratory ailments and this may be attributed to higher concentrations of PM found in the dust. Intervention programs aimed at reducing exposure to dust will ameliorate occupational working conditions and enhance the health of workers.

Respiratory health and breath condensate acidity in sawmill workers

PURPOSE

The aim of the study was to evaluate exhaled breath condensate acidity (EBC pH) as a biomarker of airway response to occupational respiratory hazards present in sawmill.

METHODS

Sixty-one sawmill workers in total (26 from Sawmill 1 and 35 from Sawmill 2) provided EBC samples at the beginning and at the end of the working week. Respiratory symptoms, lung function, bronchodilator test and atopy status were assessed. Occupational environment was checked for the levels of respiratory hazards.

RESULTS

Airborne dust concentrations were below threshold limit value. Endotoxin in Sawmill 1 and Sawmill 2, and moulds in Sawmill 1 were at the levels able to induce inflammatory response in the airways. Mould levels were 2.5 times higher in Sawmill 1 than in Sawmill 2. Compared to Sawmill 2 workers, lower spirometry values, higher prevalence of dry cough and positive bronchodilator test were found in Sawmill 1 workers. Monday EBC pH values did not differ between sawmills, but declined after one working week in Sawmill 1 workers (from 7.88 to 7.49, P = 0.012) and not in Sawmill 2 workers. Similar results were obtained when only respiratory healthy non-smokers were analysed. Monday-to-Friday change of other respiratory parameters was not observed.

CONCLUSION

The results suggest EBC pH as a biomarker of acute respiratory effects related to occupational exposure to respiratory hazards in sawmills, presumably increased mould levels. The effect was present even at subclinical level, namely in respiratory healthy subjects. The long-term health implications remain unclear and should be evaluated in a follow-up study.

Health effects of occupational exposure in a dairy food industry, with a specific assessment of exposure to airborne lactic acid bacteria

OBJECTIVE

Lactic acid bacteria (LAB) are used in food industries as probiotic agents. The aim of this study is to assess the potential health effects of airborne exposure to a mix of preblend (LAB and carbohydrate) and milk powder in workers.

METHODS

A medical questionnaire, lung function tests, and immunologic tests were carried out on 50 workers. Occupational exposure to inhalable dust and airborne LAB was measured.

RESULTS

Workers not using respiratory masks reported more symptoms of irritation than workers using protection. Workers from areas with higher levels of airborne LAB reported the most health symptoms and the immune responses of workers to LAB was higher than the immune responses of a control population.

CONCLUSIONS

Measures to reduce exposure to airborne LAB and milk powder in food industries are recommended.

Poultry processing work and respiratory health of Latino men and women in North Carolina

OBJECTIVE

To evaluate associations between poultry processing work and respiratory health among working Latino men and women in North Carolina.

METHODS

Between May 2009 and November 2010, 402 poultry processing workers and 339 workers in a comparison population completed interviewer-administered questionnaires. Of these participants, 279 poultry processing workers and 222 workers in the comparison population also completed spirometry testing to provide measurements of forced expiratory volume in 1 second and forced vital capacity.

RESULTS

Nine percent of poultry processing workers and 10% of workers in the comparison population reported current asthma. Relative to the comparison population, adjusted mean forced expiratory volume in 1 second and forced vital capacity were lower in the poultry processing population, particularly among men who reported sanitation job activities.

CONCLUSIONS

Despite the low prevalence of respiratory symptoms reported, poultry processing work may affect lung function.

Characterization of endotoxin collected on California dairies using personal and area-based sampling methods

Endotoxin, found in the cell wall of gram negative bacteria, is an important contributor to the biological activity of agriculture particulate matter (PM). We analyzed endotoxin in PM collected on 13 California dairies and from the breathing zone of 226 workers during the summer months of 2008. Two particle size fractions were measured: PM(2.5) and inhalable PM. Recombinant factor C assays were used to analyze biologically active endotoxin, while gas chromatography coupled with mass spectrometry in tandem was used to quantify total lipopolysaccharide. Biologically active endotoxin concentrations in the inhalable PM size fraction from area-based samples ranged from 11-2095 EU/m(3) and from 45-2061 EU/m(3) for personal samples. Total endotoxin in the inhalable PM size fraction ranged from 75-10,166 pmol/m(3) for area-based samples and 34-11,689 pmol/m(3) for personal samples. Area-based geometric mean concentrations for biologically active endotoxin and total endotoxin in PM(2.5) and inhalable PM size fractions were 3 EU/m(3), 149 EU/m(3), 60 pmol/m(3), and 515 pmol/m(3), respectively. Personal geometric mean concentrations in the inhalable PM size fraction were 334 EU/m(3), and 1178 pmol/m(3). Biologically active and total endotoxin concentration variation was best explained by meteorological data, wind speed, relative humidity, and dairy waste management practices. Differences in endotoxin concentration and composition were found across locations on the dairy.