nitrogen-dioxide and Hypersensitivity

The increase in cases of asthma and allergies has become an important health issue throughout the globe. Although these ailments were not common diseases a few short decades ago, they are now affecting a large part of the population in many regions. Exposure to environmental (both outdoor and indoor) pollutants may partially account for the prevalence of such diseases. In this review, we provide a multidisciplinary review based on the most up-to-date survey of literature regarding various types of airborne pollutants and their associations with asthma-allergies. The major pollutants in this respect include both chemical (nitrogen dioxide, ozone, sulfur dioxide, particulate matter, and volatile organic compounds) and biophysical parameters (dust mites, pet allergens, and mold). The analysis was extended further to describe the development of these afflictions in the human body and the subsequent impact on health. This publication is organized to offer an overview on the current state of research regarding the significance of air pollution and its linkage with allergy and asthma.

Topics: Air Pollution; Air Pollution, Indoor; Allergens; Animals; Asthma; Environmental Exposure; Fungi; Humans; Hypersensitivity; Nitrogen Dioxide; Ozone; Particulate Matter; Pyroglyphidae; Sulfur Dioxide; Volatile Organic Compounds

This review outlines recent advances in the investigation of the chemical properties, molecular interactions and health effects of hazardous compounds in atmospheric aerosols, in particular reactive oxygen species (ROS), soot, polycyclic aromatic compounds (PACs) and allergenic proteins. Epidemiological studies show correlations between air particulate matter and adverse health effects of air pollution including allergy, asthma, cardiovascular and respiratory diseases, but the causative relations and mechanisms of interaction on the molecular level are still unclear. ROS generated by photochemical and heterogeneous reactions in the atmosphere seem to play a key role in aerosol health effects and provide a direct link between atmospheric and physiological multiphase processes. Soot and PACs can trigger formation of ROS in vivo, leading to inflammation and cellular damage. PACs as well as allergenic proteins are efficiently oxygenated and nitrated upon exposure to ozone and nitrogen dioxide, which leads to an enhancement of their toxicity and allergenicity.

Topics: Aerosols; Allergens; Asthma; Atmosphere; Cardiovascular Diseases; Epidemiologic Studies; Humans; Hypersensitivity; Nitrogen Dioxide; Ozone; Particulate Matter; Polycyclic Aromatic Hydrocarbons; Proteins; Reactive Oxygen Species; Soot

While many of the contributing cell types and mediators of allergic asthma are known, less well understood are the factors that influence the development of allergic responses that lead to the development of allergic asthma. As the first airway cell type to respond to inhaled factors, the epithelium orchestrates downstream interactions between dendritic cells (DCs) and CD4⁺ T cells that quantitatively and qualitatively dictate the degree and type of the allergic asthma phenotype, making the epithelium of critical importance for the genesis of allergies that later manifest in allergic asthma. Amongst the molecular processes of critical importance in airway epithelium is the transcription factor, nuclear factor-kappaB (NF-κB). This review will focus primarily on the genesis of pulmonary allergies and the participation of airway epithelial NF-κB activation therein, using examples from our own work on nitrogen dioxide (NO₂) exposure and genetic modulation of airway epithelial NF-κB activation. In addition, the mechanisms through which Serum Amyloid A (SAA), an NF-κB-regulated, epithelial-derived mediator, influences allergic sensitization and asthma severity will be presented. Knowledge of the molecular and cellular processes regulating allergic sensitization in the airways has the potential to provide powerful insight into the pathogenesis of allergy, as well as targets for the prevention and treatment of asthma.

Topics: Animals; Asthma; CD4-Positive T-Lymphocytes; Dendritic Cells; Epithelial Cells; Humans; Hypersensitivity; NF-kappa B; Nitrogen Dioxide; Serum Amyloid A Protein; Severity of Illness Index

Numerical research on the health effects of air pollution has been published in the last decade. Epidemiological studies have shown that children's exposure to air pollutants during fetal development and early postnatal life is associated with many types of health problems including abnormal development (low birth weight [LBW], very low birth weight [VLBW], preterm birth [PTB], intrauterine growth restriction [IUGR], congenital defects, and intrauterine and infant mortality), decreased lung growth, increased rates of respiratory tract infections, childhood asthma, behavioral problems, and neurocognitive decrements. This review focuses on the health effects of major outdoor air pollutants including particulates, carbon monoxide (CO), sulfur and nitrogen oxides (SO(2), NOx), ozone, and one common indoor air pollutant, environmental tobacco smoke (ETS). Animal data is presented that demonstrate perinatal windows of susceptibility to sidestream smoke, a surrogate for ETS, resulting in altered airway sensitivity and cell type frequency. A study of neonatal monkeys exposed to sidestream smoke during the perinatal period and/or early postnatal period that resulted in an altered balance of Th1-/Th2-cytokine secretion, skewing the immune response toward the allergy-associated Th2 cytokine phenotype, is also discussed.

Topics: Air Pollutants; Air Pollution; Air Pollution, Indoor; Allergens; Animals; Carbon Monoxide; Child; Child Development; Congenital Abnormalities; Humans; Hypersensitivity; Infant; Nitrogen Dioxide; Ozone; Respiratory Tract Diseases; Sudden Infant Death; Sulfur Dioxide; Tobacco Smoke Pollution

The environment is a major contributor to allergic disease, and great effort is being expended to identify the chemical pollutants and allergens that make a significant impact. Exposure to high levels of ozone, sulfur dioxide, nitrogen dioxide, and diesel exhaust particles is known to reduce lung function. Studies continue to delineate the role of these particles as adjuvants and carriers of allergens into the respiratory system. Current studies also show the exacerbation of allergic disease through fungal spore inhalation and continue to document the role of pollen in allergic rhinitis. Pollen also was recently associated with asthma epidemics, especially after thunderstorms. Forecasting models currently are being developed that predict the trajectories of pollen dispersal and may allow increased avoidance of dangerous outdoor conditions.

Topics: Air Pollutants; Allergens; Asthma; Forecasting; Fungi; Humans; Hypersensitivity; Nitrogen Dioxide; Ozone; Pollen; Rhinitis, Allergic, Seasonal; Risk Factors; Seasons; Spores, Fungal; Sulfur Dioxide; Vehicle Emissions

Topics: Air Pollutants; Animals; Bronchial Hyperreactivity; Cytokines; Humans; Hypersensitivity; Immunoglobulin E; Nitrogen Dioxide; Respiratory Mucosa; Sulfur Dioxide; Vehicle Emissions

Topics: Acids; Air Pollutants; Air Pollution; Animals; Asthma; Ecosystem; Environmental Monitoring; Epidemiological Monitoring; Humans; Hypersensitivity; Lung Diseases, Obstructive; Lung Neoplasms; Nitrogen Dioxide; Ozone; Prognosis; Respiratory Tract Diseases; Respiratory Tract Infections; Rhinitis; Sulfur Dioxide; Vehicle Emissions

Topics: Aerosols; Air Pollution; Animals; Asbestos; Benzopyrenes; Cricetinae; Dust; Gases; Guinea Pigs; Humans; Hypersensitivity; Injections, Subcutaneous; Iron; Lead; Lead Poisoning; Lung Neoplasms; Mice; Nitrogen Dioxide; Ozone; Rats; Research Design; Skin Absorption; Smoking; Sulfur Dioxide; Time Factors; Vehicle Emissions

Both peak flow decrements in children at summer camps and increased hospital admissions for asthma have been associated with summer "acid haze," which is composed of ozone and various acidic species. The objective of this study was to investigate the pulmonary effects of acid summer haze in a controlled laboratory setting. Twenty-eight adolescent subjects with allergic asthma, exercise-induced bronchospasm, and a positive response to a standardized methacholine challenge enrolled in the study; 22 completed the study. Each subject inhaled one of four test atmospheres by mouthpiece on two consecutive days. The order of exposure to the four test atmospheres was assigned via a random protocol: air, oxidants (0.12 parts per million [ppm]* ozone plus 0.30 ppm nitrogen dioxide), oxidants plus sulfuric acid at 70 micrograms/m3 of air, or oxidants plus 0.05 ppm nitric acid. Exposure to each of the different atmospheres was separated by at least one week. The exposures were carried out during alternating 15-minute periods of rest and moderate exercise for a total exposure period of 90 minutes per day. Pulmonary function was measured before and after exposure on both test days and again on the third day as a follow-up measurement. A postexposure methacholine challenge was performed on Day 3. Low methacholine concentrations were chosen for the postexposure challenge to avoid provoking a response. The protocol was designed to detect subtle changes in airway reactivity. The statistical significance of the pulmonary function values was tested using paired t tests. First, we compared the difference between baseline and postexposure measurements after air exposure on Day 1 with the differences between baseline and postexposure measurements after Day 1 exposure to each of the other three atmospheres. Second, we compared the difference between baseline and postexposure measurements after the Day 2 air exposure with the differences between baseline and postexposure measurements after the Day 2 exposure to each of the pollutant atmospheres. Third, we compared the difference between baseline measurements on Day 1 of each exposure atmosphere with measurements after exposure to the same atmosphere on Day 2 to detect delayed effects. No changes in any of the pulmonary function parameters were statistically significant when compared with changes after clean air exposure. Six subjects left the study because of uncomfortable symptoms associated with the exposures. These all occurred

Topics: Acid Rain; Adolescent; Adult; Aerosols; Air Pollutants; Asthma; Bronchial Hyperreactivity; Bronchial Spasm; Child; Female; Follow-Up Studies; Humans; Hypersensitivity; Lung; Male; Nitric Acid; Nitrogen Dioxide; Oxidants; Ozone; Physical Exertion; Sulfuric Acids

Air pollution is known to have an impact on respiratory health. However, the assessment of this relationship is far from complete and is rarely extended to the country level. We used drug sales data, both Over-The-Counter (OTC) and prescription drugs, to assess exhaustively the impact of air pollution on asthma and allergy at the national level in France.. The WHO Anatomical Therapeutic Chemical (ATC) classification system was used to describe the distribution of sales of drugs of class R03 (Drugs for obstructive airways diseases, overall for asthma) and R06 (Antihistamines for systemic use). We performed a Quasi-Poisson regression model with a generalized additive model (GAM) to estimate the relationship (Relative Risks and 95% Confidence Interval) between drug sales and air pollutants, that is Particulate Matter with a diameter less than 2.5 micrometers (PM. PM. Our study confirms the presence of an association between major air pollutants and the sales of drugs against asthma and allergies. Further studies on larger databases and over several years are necessary to confirm and better understand these results.

Topics: Air Pollutants; Air Pollution; Anti-Asthmatic Agents; Asthma; Commerce; Environmental Exposure; Environmental Pollutants; Humans; Hypersensitivity; Nitrogen Dioxide; Nonprescription Drugs; Prescription Drugs

Air pollution is a current major health issue. The burden of airborne pollutants and aeroallergen levels varies throughout the year, as well as their interaction and consequences. Prenatal exposure during pregnancy has been associated with adverse perinatal outcomes. The aim of this study was to evaluate the impact of air pollutants on perinatal outcomes in patients with or without respiratory allergy.. Nested case-control retrospective study on 3006 pregnant women. Correlations between concentrations of common pollutants in each trimester of pregnancy and on average during the whole pregnancy and both gestational age at delivery and birthweight were studied. Pearson's correlation coefficient and binary logistic regression were used.. In general, pollutants correlated more strongly with birthweight than with gestational age at delivery. Nine-month NO. Air pollutant concentrations, especially SO

Topics: Air Pollutants; Air Pollution; Birth Weight; Case-Control Studies; China; Female; Gestational Age; Humans; Hypersensitivity; Nitrogen Dioxide; Pregnancy; Retrospective Studies

Higher exposure to air pollution may contribute to the increased prevalence of allergic diseases in children. The study investigated the associations between the prevalence of childhood respiratory diseases and long-term exposure to NO2, SO2, PM10, especially some surrogates in schoolchildren in Hungary. We also analyzed the possible modification effects of some confounders by interaction analysis.. A total of 6771 children aged 8-9-year-old residing at their current addresses since their births with air pollution monitoring stations were selected into this analysis. Health outcomes and their possible determinants, as well as surrogates of air pollution were surveyed by using a standardized questionnaire. Long-term exposure to PM10, NO2, and SO2 was calculated at settlement level derived from daily average concentrations of pollutants. Descriptive and analytical statistical methods were applied.. NO2 levels were positively associated with respiratory allergies and asthma. Decreased risk for ragweed, any other pollen, house dust mite and animal fur allergy was detected with PM10 level. There were significant associations between respiratory allergies to ragweed, any other pollen, house dust mite, animal fur, wheeze symptoms and living or attending school nearby a factory, power station or bus station as well as living in a home with intensive noise or vibration. Gender, parental atopy, home mold and early respiratory infection were significant effect modifiers in some cases.. The results of this study indicate that respiratory health in children is adversely affected by air pollutants.

Topics: Air Pollution; Ambrosia; Asthma; Humans; Hungary; Hypersensitivity; Nitrogen Dioxide; Respiratory Sounds

Little information exists on interaction effects between air pollution and influenza vaccination on allergic respiratory diseases. We conducted a large population-based study to evaluate the interaction effects between influenza vaccination and long-term exposure to ambient air pollution on allergic respiratory diseases in children and adolescents.. A cross-sectional study was investigated during 2012-2013 in 94 schools from Seven Northeastern Cities (SNEC) in China. Questionnaires surveys were obtained from 56 137 children and adolescents aged 2-17 years. Influenza vaccination was defined as receipt of the influenza vaccine. We estimated air pollutants exposure [nitrogen dioxide (NO. We found statistically significant interactions between influenza vaccination and air pollutants on allergic respiratory diseases and related symptoms (doctor-diagnosed asthma, current wheeze, wheeze, persistent phlegm and allergic rhinitis). The adjusted ORs for doctor-diagnosed asthma, current wheeze and allergic rhinitis among the unvaccinated group per interquartile range (IQR) increase in PM. Influenza vaccination may play an important role in mitigating the detrimental effects of long-term exposure to ambient air pollution on childhood allergic respiratory diseases. Policy targeted at increasing influenza vaccination may yield co-benefits in terms of reduced allergic respiratory diseases.

Topics: Adolescent; Air Pollutants; Air Pollution; Asthma; Child; Child, Preschool; China; Cities; Cross-Sectional Studies; Environmental Exposure; Female; Humans; Hypersensitivity; Influenza, Human; Logistic Models; Male; Nitrogen Dioxide; Particulate Matter; Respiration Disorders; Respiratory Sounds; Respiratory Tract Diseases; Risk Factors; Schools; Surveys and Questionnaires; Vaccination

It's inconsistent about associations of early exposures to outdoor air pollutants with allergies and airway diseases in childhood. Here, we investigated associations of prenatal and postnatal exposures to outdoor nitrogen dioxide (NO

Topics: Air Pollutants; Air Pollution; Child; China; Female; Humans; Hypersensitivity; Nitrogen Dioxide; Particulate Matter; Pregnancy

The study investigated the associations between the prevalence of the childhood respiratory diseases and the long-term exposure to air pollution in the burdened area of Moravian-Silesian Region in the Czech Republic. The health data were collected during 2014 in 7,239 children 5, 9, 13 and 17 years of age. Exposure to PM

Topics: Adolescent; Air Pollutants; Child; Child, Preschool; Czech Republic; Environmental Exposure; Europe; Female; Humans; Hypersensitivity; Male; Models, Theoretical; Nitrogen Dioxide; Odds Ratio; Particulate Matter; Prevalence; Respiratory Tract Diseases; Vehicle Emissions

Topics: Air Pollution; Allergens; Cross-Over Studies; Double-Blind Method; Humans; Hypersensitivity; Nitrogen Dioxide; Vehicle Emissions

There has been growing global concern about air pollution due to its great risk to public health. In Japan, although industrial- and traffic-related air pollution has been decreasing, concerns about particulate matter air pollution has been growing in recent years. In this study, we examined the effects of air pollution on symptoms and the health status of healthy subjects in Japan.. Participants (n = 2887) who visited healthcare centers in Kumamoto or Niigata prefectures in February from 2010 to 2015 were asked to fill out a questionnaire, which was a self-completed booklet containing questions on the characteristics of participants, their respiratory symptoms, and questionnaires on their health status in February, May, and July. Generalized estimating equation analyses were performed to predict the factors associated with the symptoms and health status using two-week averages of air quality parameters obtained from 49 monitoring stations as independent variables.. Only allergy was associated with air quality in both areas. Prevalence of the other respiratory symptoms were correlated with air quality only in Kumamoto. The health statuses including the 'physical fitness', 'daily activities', and 'social activities' domains were related only to time spent outdoors. The 'overall health' was associated with time spent outdoors and concentrations of nitrogen dioxide and suspended particulate matters (SPM) in Kumamoto, and with temperatures and SPM in Niigata. The 'pain' score was correlated with temperature and carbon monoxide concentration only in Kumamoto. In Kumamoto, the 'quality of life (QoL)' was worse in those who spent shorter hours outdoors, were exposed to lower humidity, higher concentrations of oxidants, SPM, and PM2.5, and who experienced more Asian sand dust (ASD) events. In Niigata, a worsened 'QoL' was associated with time spent outdoors, temperature, and SPM.. The associations between air quality and the health status was found mainly in the comprehensive domain of the health status such as 'overall health' and 'QoL'. The effect of short-term exposure to larger particles, such as SPM, on health status was observed when compared to smaller particles such as PM2.5 and gaseous pollutants.

Topics: Adult; Air Pollutants; Air Pollution; Carbon Monoxide; Diagnostic Self Evaluation; Dust; Environmental Exposure; Female; Health Status; Humans; Humidity; Hypersensitivity; Japan; Male; Nitrogen Dioxide; Particulate Matter; Quality of Life; Respiratory Tract Diseases; Surveys and Questionnaires; Temperature; Time Factors

Long-term exposure to ambient air pollution can lead to adverse health effects in children; however, underlying biological mechanisms are not fully understood.. We evaluated the effect of air pollution exposure during different time periods on mRNA expression as well as circulating levels of inflammatory cytokines in children.. We measured a panel of 10 inflammatory markers in peripheral blood samples from 670 8-y-old children in the Barn/Child, Allergy, Milieu, Stockholm, Epidemiology (BAMSE) birth cohort. Outdoor concentrations of nitrogen dioxide (NO. A 10 μg/m. Our results indicate alterations in systemic inflammatory markers in 8-y-old children in relation to early-life exposure to traffic-related air pollution. https://doi.org/10.1289/EHP460.

Topics: Air Pollution; Biomarkers; Child; Cytokines; Environmental Exposure; Gene Expression; Humans; Hypersensitivity; Interleukin-10; Interleukin-6; Nitrogen Dioxide; Particulate Matter; Vehicle Emissions

Traffic-related air pollution (TRAP) exposure is associated with allergic airway diseases and reduced lung function in children, but evidence concerning adults, especially in low-pollution settings, is scarce and inconsistent.. We sought to determine whether exposure to TRAP in middle age is associated with allergic sensitization, current asthma, and reduced lung function in adults, and whether these associations are modified by variants in Glutathione S-Transferase genes.. The study sample comprised the proband 2002 laboratory study of the Tasmanian Longitudinal Health Study. Mean annual residential nitrogen dioxide (NO. Increased mean annual NO. Even relatively low TRAP exposures confer an increased risk of adverse respiratory and allergic outcomes in genetically susceptible individuals.

Topics: Adult; Air Pollutants; Air Pollution; Australia; Environmental Exposure; Female; Genetic Predisposition to Disease; Glutathione Transferase; Humans; Hypersensitivity; Lung; Male; Nitrogen Dioxide; Odds Ratio; Skin Tests; Spirometry; Vehicle Emissions

We estimated the exposure to ambient air pollutants and analyzed the associations with allergic diseases. We enrolled 177 children with atopic dermatitis (AD) and 70 asthmatic adults living in Seoul Metropolitan Area, Korea, and followed for 17months between August 2013 and December 2014. Parents or patients recorded symptom scores on a daily basis. Exposure to particulate matter with a diameter <10μm (PM

Topics: Adult; Air Pollutants; Air Pollution; Asthma; Child; Dermatitis, Atopic; Environmental Exposure; Female; Humans; Hypersensitivity; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Seoul

Nitrogen dioxide (NO2) is an environmental air pollutant and endogenously generated oxidant that contributes to the exacerbation of respiratory disease and can function as an adjuvant to allergically sensitize to an innocuous inhaled Ag. Because uric acid has been implicated as a mediator of adjuvant activity, we sought to determine whether uric acid was elevated and participated in a mouse model of NO2-promoted allergic sensitization. We found that uric acid was increased in the airways of mice exposed to NO2 and that administration of uricase inhibited the development of OVA-driven allergic airway disease subsequent to OVA challenge, as well as the generation of OVA-specific Abs. However, uricase was itself immunogenic, inducing a uricase-specific adaptive immune response that occurred even when the enzymatic activity of uricase had been inactivated. Inhibition of the OVA-specific response was not due to the capacity of uricase to inhibit the early steps of OVA uptake or processing and presentation by dendritic cells, but occurred at a later step that blocked OVA-specific CD4(+) T cell proliferation and cytokine production. Although blocking uric acid formation by allopurinol did not affect outcomes, administration of ultra-clean human serum albumin at protein concentrations equivalent to that of uricase inhibited NO2-promoted allergic airway disease. These results indicate that, although uric acid levels are elevated in the airways of NO2-exposed mice, the powerful inhibitory effect of uricase administration on allergic sensitization is mediated more through Ag-specific immune deviation than via suppression of allergic sensitization, a mechanism to be considered in the interpretation of results from other experimental systems.

Topics: Adaptive Immunity; Allergens; Allopurinol; Animals; Antigen Presentation; Asthma; Cytokines; Disease Models, Animal; Humans; Hypersensitivity; Lung; Mice; Mice, Inbred BALB C; Nitrogen Dioxide; Ovalbumin; Serum Albumin; Th2 Cells; Urate Oxidase; Uric Acid

Asthma and allergies are both major global health problems with an increasing prevalence, and environmental data implicate an influence of air pollutants on their development. The present study focuses on the influence of nitrogen dioxide (NO2) and the major allergen of the house dust mite Der p 1 on human nasal epithelial cells of nonallergic patients in vitro. Nasal epithelial mucosa samples of 11 donors were harvested during nasal air passage surgery and cultured as an air-liquid interface. Exposure to 0.1, 1 and 10 ppm NO2 or synthetic air as a control was performed for 1 h. Subsequently, the cells were exposed to Der p 1 for 24 h. The release of interleukin (IL)-6 and IL-8 was measured by ELISA, and the production of IL-6 mRNA and IL-8 mRNA was measured by RT-PCR. NO2 exposure resulted in a concentration-dependent release of IL-6, but not IL-8 release. The coexposure of 0.1 ppm NO2 and Der p 1, or 1 ppm NO2 and Der p 1 significantly increased both IL-6 and IL-8 release. Exposure to NO2, Der p 1, or their combination, did not significantly influence the production of IL-6 or IL-8 mRNA. In conclusion, NO2 increases the release of inflammatory cytokines in human nasal epithelial cells, especially in coexposure with Der p 1, as a mechanism of allergotoxicology.

Topics: Allergens; Animals; Antigens, Dermatophagoides; Arthropod Proteins; Cysteine Endopeptidases; Cytokines; Enzyme-Linked Immunosorbent Assay; Gene Expression; Humans; Hypersensitivity; Immunization; Nasal Mucosa; Nitrogen Dioxide

Nitrogen dioxide (NO2), a surrogate measure of traffic-related air pollution (TRAP), has been associated with incident childhood asthma. Timing of exposure and atopic status may be important effect modifiers. We collected cross-sectional data on asthma outcomes from Toronto school children aged 5-9years in 2006. Lifetime home, school and daycare addresses were obtained to derive birth and cumulative NO2 exposures for a nested case-control subset of 1497 children. Presence of other allergic disease (a proxy for atopy) was defined as self-report of one or more of doctor-diagnosed rhinitis, eczema, or food allergy. Generalized estimating equations were used to adjust for potential confounders, and examine hypothesized effect modifiers while accounting for clustering by school. In children with other allergic disease, birth, cumulative and 2006 NO2 were associated with lifetime asthma (OR 1.46, 95% CI 1.08-1.98; 1.37, 95% CI 1.00-1.86; and 1.60, 95% CI 1.09-2.36 respectively per interquartile range increase) and wheeze (OR 1.44, 95% CI 1.10-1.89; 1.31, 95% CI 1.02-1.67; and 1.60, 95% CI 1.16-2.21). No or weaker effects were seen in those without allergic disease, and effect modification was amplified when a more restrictive algorithm was used to define other allergic disease (at least 2 of doctor diagnosed allergic rhinitis, eczema or food allergy). The effects of modest NO2 levels on childhood asthma were modified by the presence of other allergic disease, suggesting a probable role for allergic sensitization in the pathogenesis of TRAP initiated asthma.

Topics: Air Pollution; Asthma; Canada; Child; Child, Preschool; Environmental Exposure; Female; Humans; Hypersensitivity; Male; Nitrogen Dioxide; Prevalence

In Japan, air pollution due to nitrogen oxides (NOx) and particulate matter (PM) has been gradually reduced since control measures based on the Automobile NOx/PM law were enforced beginning in 2001. The effects of decrease in air pollutants due to the control measures during the past decade on the prevalence of respiratory and allergic disorders such as asthma in children were evaluated.. Using data of 618,973 children collected in 28 regions of Japan from 1997 to 2009, we evaluated whether reductions in the concentrations of nitrogen dioxide (NO2) and suspended particulate matter (SPM) contribute to the decrease in the prevalence of asthma, wheezing, bronchitis, allergic rhinitis, and atopic dermatitis by multiple linear regression analysis, including adjustments for related factors.. The annual rates of decrease in air pollution in the PM-law-enforced areas were 2.0 and 2.5 times higher for NO2 and SPM, respectively, compared with those in the non-enforced areas. The prevalence of asthma decreased significantly at -0.073% per year in the areas in which measures based on the Automobile NOx/PM law were taken but not in area where such measures were not applied. Multiple linear regression analysis showed a reduction in the ambient air pollution was significantly associated with a reduction in the prevalence of asthma, with a rate of 0.118% [95% confidence interval (CI): 0.012-0.225] per 1 ppb for NO2, and 0.050% [95% CI: 0.020-0.080] per 1 μg/m(3) for SPM. An increase in the ambient air pollution was associated with an increase in the prevalence of atopic dermatitis of 0.390% [95% CI: 0.107-0.673] per 1 ppb for NO2, 0.141% [95% CI: 0.058-0.224] per 1 μg/m(3) for SPM. The changes in the prevalence of wheezing and allergic rhinitis were not significantly correlated with changes in air pollutant concentrations.. The enforcement of measures to control automobile emissions based on the Automobile NOx/PM law was shown to have reduced air pollution and contributed to decreases in the prevalence of respiratory and allergic disorders in 3-year-old children.

Topics: Air Pollution; Child, Preschool; Humans; Hypersensitivity; Japan; Nitrogen Dioxide; Particulate Matter; Prevalence; Respiration Disorders; Vehicle Emissions

There are fewer longitudinal studies from China on symptoms as described for the sick building syndrome (SBS). Here, we performed a two-year prospective study and investigated associations between environmental parameters such as room temperature, relative air humidity (RH), carbon dioxide (CO2), nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3), particulate matter (PM10), and health outcomes including prevalence, incidence and remission of SBS symptoms in junior high schools in Taiyuan, China. Totally 2134 pupils participated at baseline, and 1325 stayed in the same classrooms during the study period (2010-2012). The prevalence of mucosal symptoms, general symptoms and symptoms improved when away from school (school-related symptoms) was 22.7%, 20.4% and 39.2%, respectively, at baseline, and the prevalence increased during follow-up (P<0.001). At baseline, both indoor and outdoor SO2 were found positively associated with prevalence of school-related symptoms. Indoor O3 was shown to be positively associated with prevalence of skin symptoms. At follow-up, indoor PM10 was found to be positively associated with new onset of skin, mucosal and general symptoms. CO2 and RH were positively associated with new onset of mucosal, general and school-related symptoms. Outdoor SO2 was positively associated with new onset of skin symptoms, while outdoor NO2 was positively associated with new onset of skin, general and mucosal symptoms. Outdoor PM10 was found to be positively associated with new onset of skin, general and mucosal symptoms as well as school-related symptoms. In conclusion, symptoms as described for SBS were commonly found in school children in Taiyuan City, China, and increased during the two-year follow-up period. Environmental pollution, including PM10, SO2 and NO2, could increase the prevalence and incidence of SBS and decrease the remission rate. Moreover, parental asthma and allergy (heredity) and pollen or pet allergy (atopy) can be risk factors for SBS.

Topics: Adolescent; Air Pollutants; Asthma; Child; China; Cohort Studies; Environmental Monitoring; Female; Follow-Up Studies; Humans; Humidity; Hypersensitivity; Longitudinal Studies; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Prevalence; Prospective Studies; Risk Factors; Sick Building Syndrome; Sulfur Dioxide; Surveys and Questionnaires; Temperature

Allergic sensitization is a risk factor for asthma and allergic diseases. The relationship between ambient air pollution and allergic sensitization is unclear.. To investigate the relationship between ambient air pollution and allergic sensitization in a nationally representative sample of the US population.. We linked annual average concentrations of nitrogen dioxide (NO2), particulate matter ≤10 μm (PM10), particulate matter ≤2.5 μm (PM2.5), and summer concentrations of ozone (O3), to allergen-specific immunoglobulin E (IgE) data for participants in the 2005-2006 National Health and Nutrition Examination Survey (NHANES). In addition to the monitor-based air pollution estimates, we used the Community Multiscale Air Quality (CMAQ) model to increase the representation of rural participants in our sample. Logistic regression with population-based sampling weights was used to calculate adjusted prevalence odds ratios per 10 ppb increase in O3 and NO2, per 10 μg/m(3) increase in PM10, and per 5 μg/m(3) increase in PM2.5 adjusting for race, gender, age, socioeconomic status, smoking, and urban/rural status.. Using CMAQ data, increased levels of NO2 were associated with positive IgE to any (OR 1.15, 95% CI 1.04, 1.27), inhalant (OR 1.17, 95% CI 1.02, 1.33), and indoor (OR 1.16, 95% CI 1.03, 1.31) allergens. Higher PM2.5 levels were associated with positivity to indoor allergen-specific IgE (OR 1.24, 95% CI 1.13, 1.36). Effect estimates were similar using monitored data.. Increased ambient NO2 was consistently associated with increased prevalence of allergic sensitization.

Topics: Adolescent; Adult; Aged; Air Pollution; Child; Environmental Exposure; Environmental Monitoring; Female; Humans; Hypersensitivity; Immunoglobulin E; Male; Middle Aged; Nitrogen Dioxide; Nutrition Surveys; Particulate Matter; Prevalence; United States; Young Adult

Adverse respiratory effects in children with asthma are associated with exposures to nitrogen dioxide (NO2). Levels indoors can be much higher than outdoors. Primary indoor sources of NO2 are gas stoves, which are used for cooking by one-third of U.S. households. We investigated the effects of indoor NO2 exposure on asthma severity among an ethnically and economically diverse sample of children, controlling for season and indoor allergen exposure.. Children 5-10 years of age with active asthma (n = 1,342) were recruited through schools in urban and suburban Connecticut and Massachusetts (2006-2009) for a prospective, year-long study with seasonal measurements of NO2 and asthma severity. Exposure to NO2 was measured passively for four, month-long, periods with Palmes tubes. Asthma morbidity was concurrently measured by a severity score and frequency of wheeze, night symptoms, and use of rescue medication. We used adjusted, hierarchical ordered logistic regression models to examine associations between household NO2 exposure and health outcomes.. Every 5-fold increase in NO2 exposure above a threshold of 6 ppb was associated with a dose-dependent increase in risk of higher asthma severity score (odds ratio = 1.37 [95% confidence interval = 1.01-1.89]), wheeze (1.49 [1.09-2.03]), night symptoms (1.52 [1.16-2.00]), and rescue medication use (1.78 [1.33-2.38]).. Asthmatic children exposed to NO2 indoors, at levels well below the U.S. Environmental Protection Agency outdoor standard (53 ppb), are at risk for increased asthma morbidity. Risks are not confined to inner city children, but occur at NO2 concentrations common in urban and suburban homes.

Topics: Air Pollution, Indoor; Asthma; Child; Child, Preschool; Environmental Exposure; Environmental Monitoring; Family Characteristics; Female; Humans; Hypersensitivity; Logistic Models; Male; Nitrogen Dioxide; Prospective Studies; Seasons; Severity of Illness Index

Children are vulnerable to air pollution, which is known to be related to the recent increasing trend of allergic disease.. To investigate the effects of air pollution on respiratory allergic diseases in school children.. A prospective survey of parental responses to International Study of Asthma and Allergies in Childhood questionnaires, together with allergy evaluation, was conducted in 1743 school children selected from metropolitan cities and industrial areas during a 2-year period. Individual exposure to air pollution was estimated by using a geometric information system with the 5-year mean concentration of air pollutants.. A total of 1,340 children (male:female ratio, 51.4:48.6) with a mean (SD) age of 6.84 (0.51) years were included in the analysis. Each child underwent allergy evaluation at the time of enrollment and at a 2-year follow-up. After 2 years, the 12-month prevalence of wheezing was significantly decreased, whereas the lifetime prevalence of allergic rhinitis showed a significant increase. Ozone exposure was significantly associated with the 12-month prevalence of wheeze (odds ratio per 5 ppb, 1.372; 95% confidence interval, 1.016-1.852). Ozone was also associated with allergic rhinitis in children who reside in industrial areas. In addition, significant positive associations between ozone and the rate of newly developed sensitization to outdoor allergen were found (P for trend = .007).. Exposure to ozone was associated with current wheeze and allergic rhinitis. An increased rate of newly developed sensitization to outdoor allergen by ozone may explain the association.

Topics: Air Pollutants; Asthma; Carbon Monoxide; Child; Environmental Exposure; Female; Health Surveys; Humans; Hypersensitivity; Immunoglobulin E; Incidence; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Prevalence; Prospective Studies; Respiratory Sounds; Rhinitis, Allergic, Perennial; Skin Tests; Sulfur Dioxide

The objective of this study is to investigate the relationship between five air pollutants (PM(10), SO(2), NO(2), O(3), CO) measured on the daily basis, and adverse health symptoms using epidemiological surveillance data. The generalized estimated equation (GEE) model, a logistic regression analysis model, was used to estimate the effects of air pollution on children's daily health symptoms, focusing on the morbidity including both respiratory and allergic symptoms in four different cities. Analysis of the effects of each pollutant on children's respiratory and allergic symptoms demonstrated that CO affected all symptoms in all the study areas. When the concentration of SO(2) and NO(2) was elevated, upper respiratory symptoms increased significantly. In contrast, when the concentration of O(3) rose, the symptoms decreased significantly. The relationship between measured concentrations and health symptoms was site-dependent for each pollutant.

Topics: Air Pollutants; Air Pollution; Carbon Monoxide; Child; Environmental Exposure; Female; Humans; Hypersensitivity; Korea; Logistic Models; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Population Surveillance; Respiratory Tract Diseases; Sulfur Dioxide; Urban Population

Epidemiological studies that have investigated the association between air pollution and atopy have found inconsistent results. Furthermore, often exposure to outdoor air pollution has had limited quality, and more individual exposure is needed.. To investigate the relations between early and lifetime exposure to residential outdoor air pollution and allergen sensitization in 9-10-year-old children in Oslo, Norway.. Sensitization to common allergens was measured by skin prick tests (SPTs), which were performed in 2244 children who had lived in Oslo since birth. Several definitions of positive SPT were used. Information on potential confounding variables was collected by a parental questionnaire. Exposure to outdoor air pollution was assessed by the EPISODE dispersion model, which calculates hourly concentrations of nitrogen dioxide (NO2), particulate matter (PM) with aerodynamic diameter <10 microm (PM10) and <2.5 microm (PM2.5), respectively.. We found no associations between long-term air pollution exposure and sensitization to any allergen, any indoor or any pollen allergen. However, lifetime air pollution exposure was associated with sensitization to the house dust mite Dermatophagoides farinae. One interquartile increase of lifetime exposure to NO2, PM10 and PM2.5 was associated with 1.88 (adjusted odds ratio) (1.02, 3.47) [95% confidence interval (CI)], 1.61 (0.96, 2.72) and 1.46 (0.96, 2.22), respectively, for D. farinae. Lifetime exposure was also associated with sensitization to cat in a subpopulation. Both associations diminished after adjusting for a contextual socio-economic factor.. Long-term exposure to traffic-related pollutants was generally not associated with allergen sensitization in 9-10-year-old Oslo children. However, lifetime exposure was associated with sensitization to D. farinae, and with sensitization to cat in a subpopulation, which may be explained by socio-economic confounding or multiple comparisons. The air pollution levels in Oslo may be too low to reveal associations with sensitization.

Topics: Air Pollution; Allergens; Animals; Cats; Child; Dermatophagoides farinae; Environmental Exposure; Female; Humans; Hypersensitivity; Intradermal Tests; Male; Nitrogen Dioxide; Norway; Particulate Matter; Sex Factors; Surveys and Questionnaires; Urban Population

In addition to being an air pollutant, NO2 is a potent inflammatory oxidant generated endogenously by myeloperoxidase and eosinophil peroxidase. In these studies, we sought to determine the effects of NO2 exposure on mice with ongoing allergic airway disease pathology. Mice were sensitized and challenged with the antigen ovalbumin (OVA) to generate airway inflammation and subsequently exposed to 5 or 25 ppm NO2 for 3 days or 5 days followed by a 20-day recovery period. Whereas 5 ppm NO2 elicited no pathological changes, inhalation of 25 ppm NO2 alone induced acute lung injury, which peaked after 3 days and was characterized by increases in protein, LDH, and neutrophils recovered by BAL, as well as lesions within terminal bronchioles. Importantly, 25 ppm NO2 was also sufficient to cause AHR in mice, a cardinal feature of asthma. The inflammatory changes were ameliorated after 5 days of inhalation and completely resolved after 20 days of recovery after the 5-day inhalation. In contrast, in mice immunized and challenged with OVA, inhalation of 25 ppm NO2 caused a marked augmentation of eosinophilic inflammation and terminal bronchiolar lesions, which extended significantly into the alveoli. Moreover, 20 days postcessation of the 5-day 25 ppm NO2 inhalation regimen, eosinophilic and neutrophilic inflammation, pulmonary lesions, and AHR were still present in mice immunized and challenged with OVA. Collectively, these observations suggest an important role for NO2 in airway pathologies associated with asthma, both in modulation of degree and duration of inflammatory response, as well as in induction of AHR.

Topics: Animals; Bronchi; Bronchial Hyperreactivity; Dose-Response Relationship, Drug; Hypersensitivity; Mice; Mice, Inbred C57BL; Nitrogen Dioxide; Ovalbumin; Oxidants, Photochemical; Pneumonia

We investigated 10 naturally ventilated schools in Shanghai, in winter. Pupils (13-14 years) in 30 classes received a questionnaire, 1414 participated (99%). Classroom temperatures were 13-21 degrees C (mean 17 degrees C), relative air humidity was 36-82% (mean 56%). The air exchange rate was 2.9-29.4 ac/h (mean 9.1), because of window opening. Mean CO2 exceeded 1000 ppm in 45% of the classrooms. NO2 levels were 33-85 microg/m3 indoors, and 45-80 microg/m3 outdoors. Ozone were 1-9 microg/m3 indoors and 17-28 microg/m3 outdoors. In total, 8.9% had doctors' diagnosed asthma, 3.1% wheeze, 23.0% daytime breathlessness, 2.4% current asthma, and 2.3% asthma medication. Multiple logistic regression was applied. Observed indoor molds was associated with asthma attacks [odds ratio (OR) = 2.40: P < 0.05]. Indoor temperature was associated with daytime breathlessness (OR = 1.26 for 1 C; P < 0.001), and indoor CO2 with current asthma (OR = 1.18 for 100 ppm; P < 0.01) and asthma medication (OR = 1.15 for 100 ppm; P < 0.05). Indoor NO2 was associated with current asthma (OR = 1.51 for 10 microg/m3; P < 0.01) and asthma medication (OR = 1.45 for 10 microg/m3; P < 0.01). Outdoor NO2 was associated with current asthma (OR = 1.44 for 10 microg/m3; P < 0.05). Indoor and outdoor ozone was negatively associated with daytime breathlessness. In conclusion, asthma symptoms among pupils in Shanghai can be influenced by lack of ventilation and outdoor air pollution from traffic. Practical Implications Most urban schools in Asia are naturally ventilated buildings, often situated in areas with heavy ambient air pollution from industry or traffic. The classes are large, and window opening is the only way to remove indoor pollutants, but this results in increased exposure to outdoor air pollution. There is a clear need to improve the indoor environment in these schools. Building dampness and indoor mold growth should be avoided, and the concept of mechanical ventilation should be introduced. City planning aiming to situate new schools away from roads with heavy traffic should be considered.

Topics: Adolescent; Air Pollutants; Air Pollution, Indoor; Animals; Asthma; China; Dyspnea; Female; Formaldehyde; Humans; Humidity; Hypersensitivity; Male; Nitrogen Dioxide; Ozone; Respiratory Sounds; Schools; Students; Temperature; Vehicle Emissions; Ventilation

This study was conducted in order to determine the relationship between air pollution and the varying prevalence of allergic diseases in the city of Taichung and the rural town of Chu-Shan. We used questionnaires to screen children aged from 7 to 15 years in Taichung and Chu-Shan and compared the results from these 2 areas with the factors related to air pollution. The study included 11,580 children in Taichung and 2621 children in Chu-Shan. In Taichung, the prevalence of asthma was 7.0%, of allergic rhinitis 27.6% and of atopic dermatitis 3.4%. In Chu-Shan, the prevalence of asthma was 5.6%, of allergic rhinitis 21.8% and of atopic dermatitis 3.3%. We also collected data on the concentration of air pollutants in the 2 areas over a 1-year period from January to December 2001 and compared the average annual concentrations of various pollutants. Compared with Chu-Shan, Taichung had higher air concentrations of nitric oxide (NO; 11.47 +/- 4.75 vs 5.07 +/- 2.81 ppb), carbon monoxide (CO; 0.78 +/- 0.19 vs 0.59 +/- 0.12 ppm), nitrogen dioxide (NO(2); 24.99 +/- 6.8 vs 21.45 +/- 7.87 ppb) and sulfur dioxide (SO(2); 2.58 +/- 1.0 vs 2.44 +/- 0.88 ppb). Student's t test results showed that CO and NO were related significantly to the prevalence of allergic disease (p<0.005). The prevalence of both asthma and allergic rhinitis is higher in Taichung than in Chu-Shan, a finding that could be related to higher levels of some air pollutants in the urban location.

Topics: Adolescent; Air Pollution; Asthma; Carbon Monoxide; Child; Dermatitis, Atopic; Female; Humans; Hypersensitivity; Male; Nitric Oxide; Nitrogen Dioxide; Prevalence; Rhinitis, Allergic, Perennial; Risk Factors; Rural Health; Sulfur Dioxide; Taiwan; Urban Health

We sought to determine whether nitrogen dioxide (NO2) can enhance airway inflammation after allergen challenge in asthmatic subjects.. Fifteen house-dust-mite (HDM)-sensitive asthmatic subjects were exposed for 3 hours to filtered air or 0.4 ppm NO2, followed by inhalational challenge with HDM allergen. Markers of inflammation were measured in sputum at 6 hours and 26 hours after allergen challenge.. After exposure to NO2, eosinophil concentration decreased significantly in the 6-hour postallergen sputum. No significant NO2-related difference was observed for other variables.. Our results suggest that, in most asthmatic individuals, multi-hour exposure to a high ambient concentration of NO2 does not enhance the inflammatory response to subsequent inhaled allergen as assessed by cell distribution in induced sputum. Because the decrease in airway eosinophils has been reported in previous animal studies, future research should be directed toward the mechanism of this effect.

Topics: Adult; Asthma; Eosinophils; Female; Humans; Hypersensitivity; Male; Middle Aged; Nitrogen Dioxide; Pneumonia; Pyroglyphidae; Respiratory System; Surveys and Questionnaires

Gas stoves release respiratory irritants, such as nitrogen dioxide and other combustion by-products. Adults with asthma may be susceptible to the effects of gas stove exposure because of their underlying airway hyperresponsiveness, but this association has been difficult to establish.. To examine the association between gas stove use and respiratory health.. The analysis used data from the US Third National Health and Nutrition Examination Survey among 445 adults with asthma (representing 4.8 million persons with the condition).. Nearly half of the adults with asthma had a gas stove in their home (47.1%). There was no association between gas stove use and FEV1 (mean change 146 ml; 95% CI -50 to 342 ml), FVC (0 ml; 95% CI -151 to 152 ml), or FEF25%-75% (357 ml; 95% CI -7 to 722 ml). There was also no relation between gas stove use and the risk of self reported cough (OR 0.8; 95% CI 0.4 to 1.7), wheeze (OR 1.5; 95% CI 0.7 to 3.2), or other respiratory symptoms. Controlling for sociodemographic, smoking, housing, and geographic factors did not appreciably affect these results.. Among adults with asthma, there was no apparent impact of gas stove use on pulmonary function or respiratory symptoms. These results should be reassuring to adults with asthma and their health care providers.

Topics: Adolescent; Adult; Air Pollution, Indoor; Asthma; Cooking; Cross-Sectional Studies; Female; Forced Expiratory Volume; Household Articles; Humans; Hypersensitivity; Linear Models; Male; Nitrogen Dioxide; Nutrition Surveys; Respiratory Function Tests

The effect of exposure to irritant air pollutants on the development of allergic airway disease is poorly understood. This study examines the effects of the lower respiratory tract irritant, NO(2), on the outcome of ovalbumin (OVA)-induced allergic airway disease. Male and female C57Bl/6 mice were sensitized by weekly intraperitoneal (ip) OVA injections for 3 wk followed by daily 1-h OVA aerosol inhalation challenge for 3 or 10 d. Initially, mice were exposed daily for 3 d to air or 0.7 or 5 ppm NO(2) for 2 h following each OVA aerosol challenge. OVA exposure resulted in pronounced lower airway inflammation, as evidenced by a significant increase in bronchoalveolar lavage (BAL) total cellularity and eosinophil levels. BAL eosinophil levels were significantly lower in OVA-NO(2) compared to OVA-air animals. The reduction was similar at both NO(2) exposure concentrations. In a subsequent study, sensitized animals were exposed for 3 or 10 d to aerosolized OVA followed by air or 0.7 ppm NO(2). BAL eosinophils were again reduced at 3 d by OVA-NO(2) exposure compared to OVA-air mice. At 10 d the eosinophilia was virtually abolished. This reduction in OVA-induced cellular inflammation by NO(2) was confirmed by histopathological analysis. Contrary to expectations, exposure to NO(2) during the aerosol challenge to OVA dramatically diminished the outcome of allergic disease in lungs as measured by airway cellular inflammation.

Topics: Aerosols; Animals; Disease Models, Animal; Humans; Hypersensitivity; Inflammation; Inhalation Exposure; Lung Diseases; Mice; Mice, Inbred C57BL; Nitrogen Dioxide; Oxidants, Photochemical

The prevalence of asthma and allergic disease has been increasing in Hong Kong and environmental factors are thought to play a major role.. To define the distribution of common inhaled allergens and air pollutants inside residential homes in Hong Kong.. Forty randomly selected residential homes were visited and surveyed. Dust samples were collected from mattress, bedroom floor, lounge room floor and kitchen floor for assays of Der p 1, Fel d 1, and Bla g 2. Nitrogen dioxide (NO2) levels were measured by stationary samplers left in the bedroom, lounge room and kitchen over a 1-week period.. All 40 homes were apartments in high-rise buildings and the mean age of the homes was 7.6 +/- 4.8 years. Visible dampness and mould patches were present in 27.5% of homes and the main fuel for cooking was gas (97.5%). Der p 1, Fel d 1 and Bla g 2 were detectable in at least 1 niche in over 85% of homes. In particular, all dust samples from mattress and bedroom floor contained Der p 1, and over 50% had levels > or = 2 microg/g. The (geometric) mean Der p 1 level in mattress dust was 8.8 (0.3-157.8) microg/g. Fel d 1 and Bla g 2 were present in low levels throughout the homes with respective (geometric) means of 0.3 (0-3.7) microg/g and 0.1 (0-1.1) Unit/g in mattress dust. NO2 was readily detected in all niches but the highest level was in the kitchen with mean exposure of 48.7 ppb which was 1.5 times higher than that in the bedroom and lounge room.. Major allergens of mite, cat and cockroach, and NO2 are present in varying quantities in residential homes in Hong Kong. Exposure to these environmental factors could be important in the development of asthma and allergic diseases in susceptible individuals.

Topics: Air Pollution, Indoor; Allergens; Animals; Animals, Domestic; Asthma; Beds; Cockroaches; Data Collection; Dust; Environmental Exposure; Evaluation Studies as Topic; Floors and Floorcoverings; Housing; Humans; Hypersensitivity; Interior Design and Furnishings; Mites; Nitrogen Dioxide; Prevalence

Nitrogen dioxide levels were measured in 80 homes in the Latrobe Valley, Victoria, Australia, using passive samplers. Some 148 children between 7 and 14 yr of age were recruited as study participants, 53 of whom had asthma. Health outcomes for the children were studied using a respiratory questionnaire, skin prick tests, and peak flow measurements. Nitrogen dioxide concentrations were low, with an indoor median of 11.6 microgram/m3 (6.0 ppb), and a maximum of 246 microgram/m3 (128 ppb). Respiratory symptoms were more common in children exposed to a gas stove (odds ratio 2.3 [95% CI 1. 0-5.2], adjusted for parental allergy, parental asthma, and sex). Nitrogen dioxide exposure was a marginal risk factor for respiratory symptoms, with a dose-response association present (p = 0.09). Gas stove exposure was a significant risk factor for respiratory symptoms even after adjusting for nitrogen dioxide levels (odds ratio 2.2 [1.0-4.8]), suggesting an additional risk apart from the average nitrogen dioxide exposure associated with gas stove use. Atopic children tended to have a greater risk of respiratory symptoms compared with nonatopic children with exposure to gas stoves or nitrogen dioxide, but the difference was not significant.

Topics: Adolescent; Air Pollutants; Air Pollution, Indoor; Asthma; Child; Confidence Intervals; Cough; Dyspnea; Female; Fossil Fuels; Household Articles; Housing; Humans; Hypersensitivity; Male; Nitrogen Dioxide; Odds Ratio; Oxidants, Photochemical; Parents; Peak Expiratory Flow Rate; Respiration Disorders; Respiratory Sounds; Risk Factors; Sex Factors; Skin Tests; Surveys and Questionnaires

A review of the health effects of relative humidity in indoor environments suggests that relative humidity can affect the incidence of respiratory infections and allergies. Experimental studies on airborne-transmitted infectious bacteria and viruses have shown that the survival or infectivity of these organisms is minimized by exposure to relative humidities between 40 and 70%. Nine epidemiological studies examined the relationship between the number of respiratory infections or absenteeism and the relative humidity of the office, residence, or school. The incidence of absenteeism or respiratory infections was found to be lower among people working or living in environments with mid-range versus low or high relative humidities. The indoor size of allergenic mite and fungal populations is directly dependent upon the relative humidity. Mite populations are minimized when the relative humidity is below 50% and reach a maximum size at 80% relative humidity. Most species of fungi cannot grow unless the relative humidity exceeds 60%. Relative humidity also affects the rate of offgassing of formaldehyde from indoor building materials, the rate of formation of acids and salts from sulfur and nitrogen dioxide, and the rate of formation of ozone. The influence of relative humidity on the abundance of allergens, pathogens, and noxious chemicals suggests that indoor relative humidity levels should be considered as a factor of indoor air quality. The majority of adverse health effects caused by relative humidity would be minimized by maintaining indoor levels between 40 and 60%. This would require humidification during winter in areas with cold winter climates. Humidification should preferably use evaporative or steam humidifiers, as cool mist humidifiers can disseminate aerosols contaminated with allergens.

Topics: Aerosols; Allergens; Bacterial Infections; Communicable Diseases; Formaldehyde; Fungi; Humans; Humidity; Hypersensitivity; Mites; Nitrogen Dioxide; Occupational Diseases; Ozone; Respiratory Tract Infections; Skin Diseases; Sulfur Dioxide; Virus Diseases

Adult male volunteers were exposed to ozone (O3) at 0.25, 0.37, or 0.50 ppm, and to O3 in combination with nitrogen dioxide (NO2) and carbon monoxide (CO), with secondary stresses of heat, intermittent light exercise, and repeated exposure. Few important physiological changes, and only mild symptoms, were found with 0.25 ppm O3, with 0.25 ppm 03 plus 0.30 ppm NO2, or when 30 ppm CO was added to the latter mixture. With 0.37 ppm O3, more symptoms were present and some subjects developed definite decreases in pulmonary function. With 0.50 ppm O3, most subjects had symptoms and about half showed substantial pulmonary function decrement. In reactive subjects exposed on two successive days, changes were usually greater the second day, indicating that effects of successive exposures were cumulative.

Topics: Adult; Air Pollutants; Analysis of Variance; Asthma; Carbon Dioxide; Environmental Exposure; Humans; Hypersensitivity; Male; Nitrogen Dioxide; Ozone; Respiratory Function Tests; Respiratory System; Respiratory Tract Diseases; Smoking

Topics: Agricultural Workers' Diseases; Ambroxol; Dust; Farmer's Lung; Gas Poisoning; Humans; Hypersensitivity; Lung Diseases; Nitrogen; Nitrogen Dioxide; Oxygen Inhalation Therapy; Oxytetracycline; Pathology; Penicillins; Pneumonia; Radiography, Thoracic; Silo Filler's Disease; Toxicology; Tuberculin Test