Background
Organic dust is associated with Equine asthma. Ionization should reduce airborne dust levels.
Objectives
To determine the effect of ionization of air, type of bedding, and feed on the ...levels of airborne dust, endotoxin, and fungal colonies in horse stables.
Animals
24 healthy University‐owned horses occupied the stables.
Methods
A randomized controlled cross‐over study. Four units with 6 stables were equipped with an ionization installation (25 VA, 5000 Volt Direct Current). Horses were kept either on wood shavings and fed haylage (2 units), or on straw and fed dry hay (2 units). Measurements were performed with and without activated ionization, during daytime and nighttime, repeatedly over the course of a week and repeatedly during 4‐6 weeks. Statistical analysis was performed using a mixed effect model with Akaike's Information Criterion for model reduction and 95% profile (log) likelihood confidence intervals (CI).
Results
Ionization did not alter concentrations of dust, endotoxin, or fungi, fewer. In the units with straw and hay, the concentration of dust, endotoxin, and fungi (difference in logarithmic mean 1.92 (95%CI 1.71‐2.12); 2.86 (95%CI 2.59‐3.14); 1.75 (95%CI 1.13‐2.36)) were significantly higher compared to wood shavings and haylage.
Conclusions and Clinical Importance
The installation of a negative air‐ionizer in the horse stable did not reduce concentrations of dust, endotoxin, and viable fungal spores. The substantial effect of low dust bedding and feed is confirmed.
Endotoxin exposure occurs in homes and occupational environments and is known to cause adverse health effects. In order to compare results from different studies and establish standards, airborne ...endotoxin exposures should be assessed using standardized methods. Although the European Committee for Standardization (CEN) developed guidelines for endotoxin exposure assessment, these leave room for individual interpretation. The influence of methods of sampling, extraction, and analysis has never been investigated in a full experimental design. Thus, we sought to fully elucidate the importance of all facets of endotoxin assessment. Inhalable dust samples collected simultaneously were used to investigate the effects on and interactions with airborne endotoxin concentration in two working environments of filter type (glass fiber or Teflon), transport conditions (with/without desiccant), sample storage (-20 or 4°C), extraction solution (pyrogen-free water PFW or PFW plus 0.05% Tween 20), extract storage (-20 or 4°C), and assay solution (PFW or PFW plus 0.05% Tween 20). Four hundred samples were collected and randomly distributed over the 20 combinations of treatments. There were no differences found for transport conditions and storage temperature of extracts. Also, no interactions between study variables existed. Sampling on glass-fiber filters, storage of samples in the freezer, and extraction in PFW plus 0.05% Tween 20 resulted in 1.3-, 1.1-, and 2.1-fold-higher estimated endotoxin concentrations, respectively. Use of PFW plus 0.05% Tween 20 in the assay solution had an additive effect. Thus, this study investigated gaps in the CEN protocol and provides data with which to fully specify a protocol for standardization of endotoxin exposure assessment.
Odour annoyance forms the main source of environmental stress in residents living in the proximity of animal feeding operations (AFOs) and it has been associated with reduced health. This study aims ...to gain more insight into the association between AFOs in the neighbourhood, odour annoyance, other environmental stressors, and health, and incorporates health care seeking behaviour for reported symptoms.
Cross-sectional data from 753 people living in an area in the Netherlands with a high density of AFOs was evaluated. Odour and other environmental annoyances in the neighbourhood, general health and symptom reporting were obtained by questionnaire. Health care utilisation was obtained from electronic medical records of general practices. The number of pigs, poultry and cattle within a 500 m radius from homes was computed using Geographic Information System data. Mutually adjusted multiple Poisson and (ordinal) logistic regression analyses were performed.
The number of pigs, poultry and cattle was equally associated with odour annoyance. This annoyance was associated with reduced general health and increased reporting of respiratory, gastrointestinal, neurological and stress-related symptoms. Participants rarely consulted their general practitioner for reported symptoms. Environmental stressors were weakly associated.
The number of animals around the homes was associated with odour annoyance. Odour annoyance was associated with reduced health, which could be a reason for caution with the construction of new AFOs.
There is an ongoing debate on airborne transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) as a risk factor for infection. In this study, the level of SARS-CoV-2 in air and ...on surfaces of SARS-CoV-2 infected nursing home residents was assessed to gain insight in potential transmission routes. During outbreaks, air samples were collected using three different active and one passive air sampling technique in rooms of infected patients. Oropharyngeal swabs (OPS) of the residents and dry surface swabs were collected. Additionally, longitudinal passive air samples were collected during a period of 4 months in common areas of the wards. Presence of SARS-CoV-2 RNA was determined using RT-qPCR, targeting the RdRp- and E-genes. OPS, samples of two active air samplers and surface swabs with Ct-value ≤35 were tested for the presence of infectious virus by cell culture. In total, 360 air and 319 surface samples from patient rooms and common areas were collected. In rooms of 10 residents with detected SARS-CoV-2 RNA in OPS, SARS-CoV-2 RNA was detected in 93 of 184 collected environmental samples (50.5%) (lowest Ct 29.5), substantially more than in the rooms of residents with negative OPS on the day of environmental sampling (n = 2) (3.6%). SARS-CoV-2 RNA was most frequently present in the larger particle size fractions >4 μm 60% (6/10); 1-4 μm 50% (5/10); <1 μm 20% (2/10) (Fischer exact test P = 0.076). The highest proportion of RNA-positive air samples on room level was found with a filtration-based sampler 80% (8/10) and the cyclone-based sampler 70% (7/10), and impingement-based sampler 50% (5/10). SARS-CoV-2 RNA was detected in 10 out of 12 (83%) passive air samples in patient rooms. Both high-touch and low-touch surfaces contained SARS-CoV-2 genome in rooms of residents with positive OPS high 38% (21/55); low 50% (22/44). In one active air sample, infectious virus in vitro was detected. In conclusion, SARS-CoV-2 is frequently detected in air and on surfaces in the immediate surroundings of room-isolated COVID-19 patients, providing evidence of environmental contamination. The environmental contamination of SARS-CoV-2 and infectious aerosols confirm the potential for transmission via air up to several meters.
Inverse associations have been found between exposure to bio-contaminants and asthma and allergies. The aim of this study was to prospectively assess whether early exposure to bio-contaminants in ...dust is associated with asthma and allergy later in childhood among children from (sub)-urban areas. In subsets of three European birth cohorts (PIAMA: n=553; INMA: n=481; and LISAplus: n=395), endotoxin, (1,3,)-β-d-glucan and extracellular polysaccharide were measured in dust from living rooms shortly after birth. Current asthma at 6 years and 10 years of age and ever asthma up to 10 years of age were assessed by parental questionnaires. Specific IgE levels at 8 years (PIAMA) and 10 years (LISAplus) were available. Adjusted, cohort-specific logistic regression analyses were performed. Higher endotoxin concentrations were positively associated with current asthma at 6 years of age in PIAMA (adjusted OR 1.96, 95% CI 1.07-3.58), but were inversely related with ever asthma up to 10 years of age in INMA (adjusted OR 0.39, 95% CI 0.16-0.94). No associations with asthma were found for LISAplus. No associations were observed with atopic sensitisation in all cohorts. All associations with (1,3)-β-d-glucan and extracellular polysaccharide were statistically nonsignificant. The suggested immunological mechanisms of early exposure to bio-contaminants with regards to asthma and allergy might be different for children growing up in (sub)-urban environments.
ObjectiveTo test the hypotheses that current endotoxin exposure is inversely associated with allergic sensitisation and positively associated with non-allergic respiratory diseases in four ...occupationally exposed populations using a standardised analytical approach.MethodsData were pooled from four epidemiological studies including 3883 Dutch and Danish employees in veterinary medicine, agriculture and power plants using biofuel. Endotoxin exposure was estimated by quantitative job-exposure matrices specific for the study populations. Dose–response relationships between exposure, IgE-mediated sensitisation to common allergens and self-reported health symptoms were assessed using logistic regression and generalised additive modelling. Adjustments were made for study, age, sex, atopic predisposition, smoking habit and farm childhood. Heterogeneity was assessed by analysis stratified by study.ResultsCurrent endotoxin exposure was dose-dependently associated with a reduced prevalence of allergic sensitisation (ORs of 0.92, 0.81 and 0.66 for low mediate, high mediate and high exposure) and hay fever (ORs of 1.16, 0.81 and 0.58). Endotoxin exposure was a risk factor for organic dust toxic syndrome, and levels above 100 EU/m3 significantly increased the risk of chronic bronchitis (p<0.0001). Stratification by farm childhood showed no effect modification except for allergic sensitisation. Only among workers without a farm childhood, endotoxin exposure was inversely associated with allergic sensitisation. Heterogeneity was primarily present for biofuel workers.ConclusionsOccupational endotoxin exposure has a protective effect on allergic sensitisation and hay fever but increases the risk for organic dust toxic syndrome and chronic bronchitis. Endotoxin's protective effects are most clearly observed among agricultural workers.
Occupational exposure to bio-aerosols has been linked to various health effects. This review presents an overview of bio-aerosol exposure levels in veterinary practices, and investigates the ...possibility of health effects associated with bio-aerosol exposure.
A systematic literature search was carried out in PubMed. Publications were included if they provided information on bio-aerosol exposure and related health effects through veterinary practice and other professions with similar exposures, occupationally exposed to animals.
Few studies in veterinary settings showed that substantial bio-aerosol exposure levels (e.g. endotoxin and β(1→3)-glucan) were likely occur when handling farm animals and horses. Exposure levels are comparable to those levels observed in farming which have been associated with respiratory health effects. Animal specific allergen exposures have hardly been studied, but showed to be measurable in companion animal clinics and dairy barns. The Findings of the few studies available among veterinary populations, particularly those working with farm animals and horses, are indicative of an elevated risk for developing respiratory symptoms. Studies among pig farmers, exposed to similar environments as veterinarians, strongly confirm that veterinary populations are at an increased risk of developing respiratory diseases in relation to bio-aerosol exposure, in particular endotoxin. Exposure to animal allergens during veterinary practice may cause allergic inflammation, characterized by IgE-mediated reactions to animal allergens. Nonetheless, the occurrence of sensitization or allergy against animal allergens is poorly described, apart from laboratory animal allergy, especially known from exposure to rats and mice.
Veterinary populations are likely exposed to elevated levels of bio-aerosols such as endotoxins, β(1→3)-glucans, and some specific animal allergens. Exposures to these agents in animal farmers are associated with allergic and non-allergic respiratory effects, proposing similar health effects in veterinary populations.
Associations between house dust-associated β-(1,3)-glucan exposure and airway inflammatory reactions have been reported, while such exposures in early childhood have been suggested to protect against ...asthma and wheezing. Most epidemiological studies have used reservoir dust samples and an inhibition enzyme immunoassay (EIA) for β-(1,3)-glucan exposure assessment. The objective of this study was to develop inexpensive but highly sensitive enzyme immunoassays to measure airborne β-(1,3)-glucans in low-exposure environments, like homes. Specificities of available anti-β-(1,3)-glucan antibodies were defined by direct and inhibition experiments. Three suitable antibody combinations were selected for sandwich EIAs. β-(1,3)-Glucans in passive airborne dust collected with an electrostatic dust fall collector (EDC) and floor dust from seven homes were measured with the three EIAs. Floor dust samples were additionally analyzed in the inhibition EIA. The sandwich EIAs were sensitive enough for airborne glucan measurement and showed different specificities for commercial glucans, while the β-(1,3)-glucan levels in house dust samples correlated strongly. The feasibility of measuring glucans in airborne dust with the recently introduced EDC method was further investigated by selecting the most suitable of the three EIAs to measure and compare β-(1,3)-glucan levels in the EDC and in floor and actively collected airborne dust samples of the previously performed EDC validation study. The EDC β-(1,3)-glucan levels correlated moderately with β-(1,3)-glucans in actively collected airborne dust and floor dust samples, while the glucan levels in the airborne dust and floor dust samples did not correlate. The combination of the newly developed β-(1,3)-glucan sandwich EIA with EDC sampling now allows assessment in large-scale population studies of exposure to airborne β-(1,3)-glucans in homes or other low-exposure environments.
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