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Background: Endotoxin has been reported to be associated with chronic bronchitis or emphysema (CBE) at high occupational exposures. However, whether levels found in domestic environments have similar effects is unknown. Objectives: We aimed to study the association between house dust endotoxin and CBE in a sample representative of the U.S. population. Methods: We analyzed data from 3,393 participants [greater than or equal to] 20 y old from the National Health and Nutrition Examination Survey (NHANES) 2005-2006. House dust from bedding and from bedroom floors was analyzed for endotoxin content. NHANES participants received questionnaires and underwent examination as well as extensive laboratory testing. Logistic regression was used to examine the association of endotoxin levels with CBE diagnosis and symptoms, adjusting for covariates. The survey design and weights were applied so that estimates were nationally representative and so that statistical inferences were made appropriately. Results: The median endotoxin concentration in house dust was 14.61EU/mg dust, and CBE was reported by 8.2% of participants. In the adjusted analysis, one unit (EU/mg) increase in [log.sub.10]-transformed endotoxin concentrations was associated with a 27% increase in the odds of CBE diagnosis [OR = 1.27 (95% CI: 1.00, 1.61)] and a 78% increase in the odds of chronic bronchitis symptoms (defined as cough and phlegm for [greater than or equal to] 3 mo in a year for [greater than or equal to] 2 y) [OR = 1.78 (95% CI: 1.01, 3.12)]. Sensitization to inhalant allergens (p = 0.001) modified the relationship between endotoxin and CBE diagnosis, with stronger associations observed in sensitized participants [OR = 2.46 (95% CI: 1.72, 3.50) for a unit increase in [log.sub.10]-endotoxin]. Conclusions: In a population-based sample of U.S. adults, endotoxin levels in homes were associated with a self- reported history of CBE diagnosis and chronic bronchitis symptoms, with stronger associations among people sensitized to inhalant allergens. https://doi.org/10.1289/EHP2452, Introduction Chronic bronchitis is a common condition that affects 10 million Americans (American Lung Association 2014; Kim et al. 2015). The condition is characterized by airway inflammation and airway remodeling [...]

BACKGROUND: The peripheral leukocyte count is a biomarker of inflammation and is associated with human all-cause mortality. Although causes of acute leukocytosis are well-described, chronic environmental determinants of leukocyte number are less well understood. OBJECTIVES: We investigated the relationship between house dust endotoxin concentration and peripheral leukocyte counts in human subjects. METHODS: The endotoxin-leukocyte relationship was evaluated by linear regression in the National Health and Nutrition Examination Survey (NHANES) 2005-2006 (n = 6,254) and the Agricultural Lung Health Study (ALHS; n = 1,708). In the ALHS, we tested for a gene [Toll-like Receptor 4 (TLR4), encoding the endotoxin receptor]-by-environment interaction in the endotoxin-leukocyte relationship using regression models with an interaction term. RESULTS: There is a statistically significant, positive association between endotoxin concentration and total leukocyte number [estimated change, 0.186 x [10.sup.3]/[micro]L (95% CI: 0.070, 0.301 x [10.sup.3]/[micro]L) per 10- fold change in endotoxin; p = 0.004) in the NHANES. Similar positive associations were found for monocytes, lymphocytes, and neutrophils. Stratified analyses revealed possible effect modification by asthma and chronic obstructive pulmonary disease. We observed similar associations in the ALHS. For total leukocytes, there was suggestive evidence in the ALHS of a gene-by-environment interaction for minor allele carrier status at the TLR4 haplotype defined by rs4986790 and rs4986791 (interaction p = 0.15). CONCLUSIONS: This is, to our knowledge, the first report of an association between house dust endotoxin and leukocyte count in a national survey. The finding was replicated in a farming population. Peripheral leukocyte count may be influenced by residential endotoxin exposure in diverse settings. https://doi.org/10.1289/EHP661, Introduction Leukocytes are effectors and biomarkers of inflammation. The total count of white blood cells (WBCs) in the circulation is associated with coronary, cancer, and all-cause mortality in human subjects [...]

Objective: To report implementation strategies and outcomes of an evidence-based asthma counseling intervention. The Head-off Environmental Asthma in Louisiana (HEAL) intervention integrated asthma counseling (AC) capacity and addressed challenges facing children with asthma in post-disaster New Orleans.Methods: The HEAL intervention enrolled 182 children (4–12 years) with moderate-to-severe persistent asthma. Recruitment occurred from schools in the Greater New Orleans area for one year. Participants received home environmental assessments and tailored asthma counseling sessions during the study period based on the National Cooperative Inner City Asthma Study and the Inner City Asthma Study. Primary (i.e., asthma symptoms) and secondary outcomes (i.e., healthcare utilization) were captured. During the study, changes were made to meet the demands of a post-hurricane and resource-poor environment which included changes to staffing, training, AC tools, and AC sessions.Results: After study changes were made, the AC visit rate increased by 92.3%. Significant improvements were observed across several adherence measures (e.g., running out of medications (p= 0.009), financial/insurance problems for appointments (p= 0.006), worried about medication side-effects (p= 0.01), felt medications did not work (p< 0.001)). Additionally, an increasing number of AC visits was modestly associated with a greater reduction in symptoms (test-for-trendp= 0.059).Conclusion: By adapting to the needs of the study population and setting, investigators successfully implemented a counseling intervention that improved participant behaviors and clinical outcomes. The strategies for implementing the AC intervention may serve as a guide for managing asthma and other chronic conditions in resource-poor settings. [ABSTRACT FROM AUTHOR]

Background: Dust mite allergens can induce allergic sensitization and exacerbate asthma symptoms. Although dust mite reduction and control strategies exist, few asthmatics employ them.Objectives: We examined whether an in-home test kit, which quantifies dust mite allergen levels, resulted in behavioral changes in implementation and maintenance of mite reduction strategies and helped reduce allergen levels in homes of dust mite-sensitive children.Methods: We enrolled 60 households of children aged 5–15 with parent-reported dust mite allergy into a randomized controlled trial. Intervention homes (N = 30) received educational material about reducing dust mites and test kits at 1, 2, 5 and 8 months. Control homes (N = 30) received only educational material. At baseline, 6 and 12 months, study staff visited all homes, collected dust samples from three locations and obtained information about parents’ mite reduction behaviors by questionnaire. Allergen concentrations (Der f 2/Der p2) in dust were assessed by immunoassays. After adjusting for visit and location, allergen concentrations in intervention and control homes were compared using mixed effects model analysis.Results: In the intervention homes, allergen concentrations in the child’s bedroom and living room floors were significantly reduced over time compared to control homes. Although not all location-specific differences in allergen concentrations were statistically significant, combining data across locations, there was a differential reduction in allergen concentrations in the intervention group versus the control group (p = 0.02).Conclusion: The use of in-home test kits along with education may beneficially influence behaviors and attitudes toward dust mite reduction strategies and help reduce residential dust mite allergen levels. [ABSTRACT FROM PUBLISHER]

Background Bedroom allergen exposures contribute to allergic disease morbidity because people spend considerable time in bedrooms, where they come into close contact with allergen reservoirs. Objective We investigated participant and housing characteristics, including sociodemographic, regional, and climatic factors, associated with bedroom allergen exposures in a nationally representative sample of the US population. Methods Data were obtained from National Health and Nutrition Examination Survey 2005-2006. Information on participant and housing characteristics was collected by using questionnaires and environmental assessments. Concentrations of 8 indoor allergens (Alt a 1, Bla g 1, Can f 1, Fel d 1, Der f 1, Der p 1, Mus m 1, and Rat n 1) in dust vacuumed from nearly 7000 bedrooms were measured by using immunoassays. Exposure levels were classified as increased based on percentile (75th/90th) cutoffs. We estimated the burden of exposure to multiple allergens and used multivariable logistic regression to identify independent predictors for each allergen and household allergen burden. Results Almost all participants (>99%) had at least 1 and 74.2% had 3 to 6 allergens detected. More than two thirds of participants (72.9%) had at least 1 allergen and 18.2% had 3 or more allergens exceeding increased levels. Although exposure variability showed significant racial/ethnic and regional differences, high exposure burden to multiple allergens was most consistently associated with the presence of pets and pests, living in mobile homes/trailers and older and rental homes, and living in nonmetropolitan areas. Conclusions Exposure to multiple allergens is common. Despite highly variable exposures, bedroom allergen burden is strongly associated with the presence of pets and pests. [ABSTRACT FROM AUTHOR]

Rationale Although endotoxin is a recognized cause of environmental lung disease, how its relationship with respiratory outcomes varies with climate is unknown. Objective To examine the endotoxin predictors as well as endotoxin association with asthma, wheeze, and sensitization to inhalant allergens in various US climate regions. Methods We analyzed data on 6963 participants in the National Health and Nutrition Examination Survey. Endotoxin measurements of house dust from bedroom floor and bedding were performed at the University of Iowa . Linear and logistic regression analyses were used to identify endotoxin predictors and assess endotoxin association with health outcomes. Results The overall median house dust endotoxin was 16.2 EU/mg; it was higher in mixed-dry/hot-dry regions (19.7 EU/mg) and lower in mixed-humid/marine areas (14.8 EU/mg). Endotoxin predictors and endotoxin association with health outcomes significantly differed across climate regions. In subarctic/very cold/cold regions, log 10 -endotoxin was significantly associated with higher prevalence of wheeze outcomes (OR:1.48, 95% CI:1.19–1.85 for any wheeze, OR:1.48, 95% CI:1.22–1.80 for exercise-induced wheeze, OR:1.50, 95% CI:1.13–1.98 for prescription medication for wheeze, and OR:1.95, 95% CI:1.50–2.54 for doctor/ER visit for wheeze). In hot-humid regions, log 10 -endotoxin was positively associated with any wheeze (OR:1.66, 95% CI:1.04–2.65) and current asthma (OR:1.56, 95% CI:1.11–2.18), but negatively with sensitization to any inhalant allergens (OR:0.83, 95% CI:0.74–0.92). Conclusion Endotoxin predictors and endotoxin association with asthma and wheeze differ across U.S. climate regions. Endotoxin is associated positively with wheeze or asthma in cold and hot-humid regions, but negatively with sensitization to inhalant allergens in hot-humid climates. [ABSTRACT FROM AUTHOR]