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Background/Objective: Farmers conduct numerous tasks with potential for endotoxin exposure. As a first step to characterize endotoxin exposure for farmers in the Biomarkers of Exposure and Effect in Agriculture (BEEA) Study, we used published data to estimate task‐specific endotoxin concentrations. Methods: We extracted published data on task‐specific, personal, inhalable endotoxin concentrations for agricultural tasks queried in the study questionnaire. The data, usually abstracted as summary measures, were evaluated using meta‐regression models that weighted each geometric mean (GM, natural‐log transformed) by the inverse of its within‐study variance to obtain task‐specific predicted GMs. Results: We extracted 90 endotoxin summary statistics from 26 studies for 9 animal‐related tasks, 30 summary statistics from 6 studies for 3 crop‐related tasks, and 10 summary statistics from 5 studies for 4 stored grain‐related tasks. Work in poultry and swine confinement facilities, grinding feed, veterinarian services, and cleaning grain bins had predicted GMs > 1000 EU/m3. In contrast, harvesting or hauling grain and other crop‐related tasks had predicted GMs below 100 EU/m3. Significance: These task‐specific endotoxin GMs demonstrated exposure variability across common agricultural tasks. These estimates will be used in conjunction with questionnaire responses on task duration to quantitatively estimate endotoxin exposure for study participants, described in a companion paper. [ABSTRACT FROM AUTHOR]

Objectives: The inhaled endotoxin is considered as a causative factor in the process of acute bronchial obstruction, which can be measured by a decrease in forced expiratory volume in 1 s (FEV1). The aim of this study was to assess endotoxin exposure among sewage treatment plant workers (STPW) and its effect on across-shift changes in respiratory airflow. Material and Methods: A group of 78 STPW from a large sewage treatment plant was studied. Inhalable dust for endotoxin assessment was collected using personal aerosol samplers. Endotoxin was assayed with the kinetic, chromogenic Limulus amebocyte lysate test. Across-shift spirometric measurements were performed on Mondays, after 2-days absence from work, with the use of portable spirometer. The forced vital capacity (FVC), and FEV1 parameters were analyzed. Multifactor regression modeling was performed to determine parameters significantly associated with endotoxin exposure. Results: The concentration of inhalable dust and endotoxin ranged from 0.01–1.38 mg/m3 and 0.68–214 endotoxin units per cubic meter of air (EU/m3), respectively. Endotoxins were characterized with the skewed distribution (arithmetic mean (AM) = 38.8 EU/m3, geometric mean (GM) = 15.4 EU/m3, geometric standard deviation (GSD) = 4.21). Through the use of multifactor analysis, which excluded the main confounders (inhalable dust and smoking habit) it was found that, despite low levels of endotoxin, it had significant impact on the observed across-shift decline in FEV1 (p = 0.044). For this parameter, the regression slope was additionally calculated (r = –0.017, p = 0.071). Conclusions: Relatively low levels of endotoxin among sewage treatment plant workers may cause small, but significant across-shift declines in FEV1. The observed relationship was independent of organic dust concentrations and smoking habit. The respiratory protection should be provided for STPW.

The anti-inflammatory mechanisms of low-fat dairy product consumption are largely unknown. The objective of this study was to determine whether low-fat yogurt reduces biomarkers of chronic inflammation and endotoxin exposure in women. Premenopausal women (BMI 18·5–27 and 30–40 kg/m2) were randomised to consume 339 g of low-fat yogurt (yogurt non-obese (YN); yogurt obese (YO)) or 324 g of soya pudding (control non-obese; control obese (CO)) daily for 9 weeks (n 30/group). Fasting blood samples were analysed for IL-6, TNF-α/soluble TNF II (sTNF-RII), high-sensitivity C-reactive protein, 2-arachidonoyl glycerol, anandamide, monocyte gene expression, soluble CD14 (sCD14), lipopolysaccharide (LPS), LPS binding protein (LBP), IgM endotoxin-core antibody (IgM EndoCAb), and zonulin. BMI, waist circumference and blood pressure were also determined. After 9-week yogurt consumption, YO and YN had decreased TNF-α/sTNFR-RII. Yogurt consumption increased plasma IgM EndoCAb regardless of obesity status. sCD14 was not affected by diet, but LBP/sCD14 was lowered by yogurt consumption in both YN and YO. Yogurt intervention increased plasma 2-arachidonoylglycerol in YO but not YN. YO peripheral blood mononuclear cells expression of NF-κB inhibitor α and transforming growth factor β1 increased relative to CO at 9 weeks. Other biomarkers were unchanged by diet. CO and YO gained approximately 0·9 kg in body weight. YO had 3·6 % lower diastolic blood pressure at week 3. Low-fat yogurt for 9 weeks reduced biomarkers of chronic inflammation and endotoxin exposure in premenopausal women compared with a non-dairy control food. This trial was registered as NCT01686204. [ABSTRACT FROM PUBLISHER]

Indoor and outdoor endotoxin in PM 2.5 was measured for the very first time in Santiago, Chile, in spring 2012. Average endotoxin concentrations were 0.099 and 0.094 [EU/m 3 ] for indoor (N = 44) and outdoor (N = 41) samples, respectively; the indoor–outdoor correlation (log-transformed concentrations) was low: R = − 0.06, 95% CI: (− 0.35 to 0.24), likely owing to outdoor spatial variability. A linear regression model explained 68% of variability in outdoor endotoxins, using as predictors elemental carbon (a proxy of traffic emissions), chlorine (a tracer of marine air masses reaching the city) and relative humidity (a modulator of surface emissions of dust, vegetation and garbage debris). In this study, for the first time a potential source contribution function (PSCF) was applied to outdoor endotoxin measurements. Wind trajectory analysis identified upwind agricultural sources as contributors to the short-term, outdoor endotoxin variability. Our results confirm an association between combustion particles from traffic and outdoor endotoxin concentrations. For indoor endotoxins, a predictive model was developed but it only explained 44% of endotoxin variability; the significant predictors were tracers of indoor PM 2.5 dust (Si, Ca), number of external windows and number of hours with internal doors open. Results suggest that short-term indoor endotoxin variability may be driven by household dust/garbage production and handling. This would explain the modest predictive performance of published models that use answers to household surveys as predictors. One feasible alternative is to increase the sampling period so that household features would arise as significant predictors of long-term airborne endotoxin levels. [ABSTRACT FROM AUTHOR]

Objectives: The inhaled endotoxin is considered as a causative factor in the process of acute bronchial obstruction, which can be measured by a decrease in forced expiratory volume in 1 s (FEV1). The aim of this study was to assess endotoxin exposure among sewage treatment plant workers (STPW) and its effect on across-shift changes in respiratory airflow. Material and Methods: A group of 78 STPW from a large sewage treatment plant was studied. Inhalable dust for endotoxin assessment was collected using personal aerosol samplers. Endotoxin was assayed with the kinetic, chromogenic Limulus amebocyte lysate test. Across-shift spirometric measurements were performed on Mondays, after 2-days absence from work, with the use of portable spirometer. The forced vital capacity (FVC), and FEV1 parameters were analyzed. Multifactor regression modeling was performed to determine parameters significantly associated with endotoxin exposure. Results: The concentration of inhalable dust and endotoxin ranged from 0.01-1.38 mg/m³ and 0.68-214 endotoxin units per cubic meter of air (EU/m³), respectively. Endotoxins were characterized with the skewed distribution (arithmetic mean (AM) = 38.8 EU/m³, geometric mean (GM) = 15.4 EU/m³, geometric standard deviation (GSD) = 4.21). Through the use of multifactor analysis, which excluded the main confounders (inhalable dust and smoking habit) it was found that, despite low levels of endotoxin, it had significant impact on the observed across-shift decline in FEV1 (p = 0.044). For this parameter, the regression slope was additionally calculated (r = -0.017, p = 0.071). Conclusions: Relatively low levels of endotoxin among sewage treatment plant workers may cause small, but significant across-shift declines in FEV1. The observed relationship was independent of organic dust concentrations and smoking habit. The respiratory protection should be provided for STPW. [ABSTRACT FROM AUTHOR]

Cotton dusts contain agents, namely endotoxins, which can cause chronic inflammatory responses in the airways and the lung. We have hypothesized that the adverse effects of cotton dusts result from airborne endotoxin levels. The population studied comprised two groups: those who worked in the carding departments (opening, blowing, carding, drawing and roving) (n = 231) and those who worked in the weaving departments (n = 186). Cotton dust levels were monitored gravimetrically using Millipore polyvinylchloride filters and vertical elutriators with a 15 µm mass median aerodynamic diameter cut-off size. The amount of airbone endotoxin was determined using the Limulus amoebocyte lysate technique. Questionnaire administration and pulmonary function testing were carried out on each worker before entering the workshop after a 36 h rest period. Function tests were repeated at the end of the shift. In the carding department, workers were measured for airway reactivity. A test of bronchial reactivity was performed with graded doses of inhaled methacoline according the method described by Cockcroft et al. Time-weighted averages of cotton dust levels were highest in the carding departments (0.19-1.3 mg/m³) than in the weaving departments (0.11-0.58 mg/m³). The endotoxin levels in the carding departments varied between 2.5 and 58 ng/m³; endotoxin was not found in the weaving departments. The workers in the carding areas presented a higher frequency of respiratory symptoms (28.3%) than those in the weaving areas (12.7%). A relationship was found between decreases in FEV1 and airborne endotoxin levels, but not for dusts. The average reaction to methacoline was related to the amount of airborne endotoxin. The results support the hypothesis of a dose-response relationship between endotoxin levels in cotton dust and chronic lung impairment in cotton workers and the presence of increased bronchial reactivity in workers in the cotton industry. [ABSTRACT FROM AUTHOR]