Childhood traffic-related air pollution and adverse changes in subclinical atherosclerosis measures from childhood to adulthood.

Background: Chronic exposure to air pollutants is associated with increased risk of cardiovascular disease (CVD) among adults. However, little is known about how air pollution may affect the development of subclinical atherosclerosis in younger populations. Carotid artery intima-media thickness (CIMT) is a measure of subclinical atherosclerosis that provides insight into early CVD pathogenesis.

Near-roadway air pollution exposure and altered fatty acid oxidation among adolescents and young adults - The interplay with obesity.

Background: Air pollution exposure has been shown to increase the risk of obesity and metabolic dysfunction in animal models and human studies. However, the metabolic pathways altered by air pollution exposure are unclear, especially in adolescents and young adults who are at a critical period in the development of cardio-metabolic diseases.

Objectives: The aim of this study was to examine the associations between air pollution exposure and indices of fatty acid and amino acid metabolism.

Volcanic air pollution over the Island of Hawai'i: Emissions, dispersal, and composition. Association with respiratory symptoms and lung function in Hawai'i Island school children.

Background: Kilauea Volcano on the Island of Hawai'i has erupted continuously since 1983, releasing approximately 300-12000metrictons per day of sulfur dioxide (SO2). SO2 interacts with water vapor to produce an acidic haze known locally as "vog". The combination of wind speed and direction, inversion layer height, and local terrain lead to heterogeneous and variable distribution of vog over the island, allowing study of respiratory effects associated with chronic vog exposure.

Association of Changes in Air Quality With Bronchitic Symptoms in Children in California, 1993-2012.

Importance: Childhood bronchitic symptoms are significant public and clinical health problems that produce a substantial burden of disease. Ambient air pollutants are important determinants of bronchitis occurrence.

Objective: To determine whether improvements in ambient air quality in Southern California were associated with reductions in bronchitic symptoms in children.

Association of improved air quality with lung development in children.

Background: Air-pollution levels have been trending downward progressively over the past several decades in southern California, as a result of the implementation of air quality-control policies. We assessed whether long-term reductions in pollution were associated with improvements in respiratory health among children.

Methods: As part of the Children's Health Study, we measured lung function annually in 2120 children from three separate cohorts corresponding to three separate calendar periods: 1994-1998, 1997-2001, and 2007-2011.

Determinants of the Spatial Distributions of Elemental Carbon and Particulate Matter in Eight Southern Californian Communities.

Emerging evidence indicates that near-roadway pollution (NRP) in ambient air has adverse health effects. However, specific components of the NRP mixture responsible for these effects have not been established. A major limitation for health studies is the lack of exposure models that estimate NRP components observed in epidemiological studies over fine spatial scale of tens to hundreds of meters.

Associations of children's lung function with ambient air pollution: joint effects of regional and near-roadway pollutants.

Background: Previous studies have reported adverse effects of either regional or near-roadway air pollution (NRAP) on lung function. However, there has been little study of the joint effects of these exposures.

Objectives: To assess the joint effects of NRAP and regional pollutants on childhood lung function in the Children's Health Study.

Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease.

Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the WRF/CMAQ air-quality modeling system.

Predictors of intra-community variation in air quality.

Air quality has emerged as a key determinant of important health outcomes in children and adults. This study aims to identify factors that influence local, within-community air quality, and to build a model for traffic-related air pollution (TRP).We utilized concentrations of NO(2), NO, and total oxides of nitrogen (NO(x)), which were measured at 942 locations in 12 southern California communities.

Comparing universal kriging and land-use regression for predicting concentrations of gaseous oxides of nitrogen (NOx) for the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air).

BACKGROUND: Epidemiological studies that assess the health effects of long-term exposure to ambient air pollution are used to inform public policy. These studies rely on exposure models that use data collected from pollution monitoring sites to predict exposures at subject locations. Land use regression (LUR) and universal kriging (UK) have been suggested as potential prediction methods.

Residential traffic-related pollution exposures and exhaled nitric oxide in the children's health study.

Background: The fractional concentration of nitric oxide in exhaled air (FeNO) potentially detects airway inflammation related to air pollution exposure. Existing studies have not yet provided conclusive evidence on the association of FeNO with traffic-related pollution (TRP).

Objectives: We evaluated the association of FeNO with residential TRP exposure in a large cohort of children.

Approach to estimating participant pollutant exposures in the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air).

Most published epidemiology studies of long-term air pollution health effects have relied on central site monitoring to investigate regional-scale differences in exposure. Few cohort studies have had sufficient data to characterize localized variations in pollution, despite the fact that large gradients can exist over small spatial scales. Similarly, previous data have generally been limited to measurements of particle mass or several of the criteria gases.

In utero smoke exposure, glutathione S-transferase P1 haplotypes, and respiratory illness-related absence among schoolchildren.

Background: The GSTP1 Ile105Val variant and secondhand tobacco smoke exposure have been independently associated with acute respiratory illness; however, susceptibility to in utero and secondhand tobacco smoke has yet to be examined in relation to variation across the GSTP1 locus.

Objective: The purpose of this work was to determine whether variation across the GSTP1 locus is associated with respiratory illness-related school absences and to determine whether this relationship varies by in utero and secondhand tobacco smoke exposure.

Methods: Tobacco smoke exposure status, incident respiratory-related school absence records, and DNA samples was ascertained for 1132 Hispanic and non-Hispanic white elementary school children as part of the Children's Health Study.

Exhaled nitric oxide in a population-based study of southern California schoolchildren.

Background: Determinants of exhaled nitric oxide (FeNO) need to be understood better to maximize the value of FeNO measurement in clinical practice and research. Our aim was to identify significant predictors of FeNO in an initial cross-sectional survey of southern California schoolchildren, part of a larger longitudinal study of asthma incidence.

Methods: During one school year, we measured FeNO at 100 ml/sec flow, using a validated offline technique, in 2568 children of age 7-10 yr.

Respiratory symptoms following wildfire smoke exposure: airway size as a susceptibility factor.

Background: Associations between exposure to smoke during wildfire events and respiratory symptoms are well documented, but the role of airway size remains unclear. We conducted this analysis to assess whether small airway size modifies these relationships.

Methods: We analyzed data from 465 nonasthmatic 16- to 19-year-old participants in the Children's Health Study.

Traffic-related air pollution and asthma onset in children: a prospective cohort study with individual exposure measurement.

Background: The question of whether air pollution contributes to asthma onset remains unresolved.

Objectives: In this study, we assessed the association between asthma onset in children and traffic-related air pollution.

Methods: We selected a sample of 217 children from participants in the Southern California Children's Health Study, a prospective cohort designed to investigate associations between air pollution and respiratory health in children 10-18 years of age.

Relationships of online exhaled, offline exhaled, and ambient nitric oxide in an epidemiologic survey of schoolchildren.

Unlabelled: Field measurements of exhaled nitric oxide (FeNO) and ambient nitric oxide (NO) are useful to assess both respiratory health and short-term air pollution exposure. Online real-time measurement maximizes data quality and comparability with clinical studies, but offline delayed measurement may be more practical for large epidemiological studies. To facilitate cross-comparison in larger studies, we measured FeNO and concurrent ambient NO both online and offline in 362 children at 14 schools in 8 Southern California communities.

Glutathione S-transferase P1, maternal smoking, and asthma in children: a haplotype-based analysis.

Background: Glutathione S-transferase P1 (GSTP1) plays a role in a spectrum of respiratory diseases; however, the effects of sequence variation across the entire locus in asthma pathogenesis have yet to be determined.

Objectives: This study was designed to investigate whether sequence variations in the GSTP1 coding and promoter regions are associated with asthma and wheezing outcomes and to determine whether variants affect susceptibility to maternal smoking.

Methods: Four haplotype tagging SNPs were selected that accounted for 83% of the common haplotypic variation in GSTP1.

Microsomal epoxide hydrolase, glutathione S-transferase P1, traffic and childhood asthma.

Background: Microsomal epoxide hydrolase (EPHX1) metabolises xenobiotics including polyaromatic hydrocarbons (PAHs). Functional variants at this locus have been associated with respiratory diseases. The effects of EPHX1 variants may depend upon exposures from tobacco smoke and traffic emissions that contain PAHs as well as variants in other enzymes in the PAH metabolic pathway such as glutathione S-transferase (GST) genes.

Effect of exposure to traffic on lung development from 10 to 18 years of age: a cohort study.

Background: Whether local exposure to major roadways adversely affects lung-function growth during the period of rapid lung development that takes place between 10 and 18 years of age is unknown. This study investigated the association between residential exposure to traffic and 8-year lung-function growth.

Methods: In this prospective study, 3677 children (mean age 10 years [SD 0.

Dog ownership enhances symptomatic responses to air pollution in children with asthma.

Background: Experimental data suggest that asthma exacerbation by ambient air pollutants is enhanced by exposure to endotoxin and allergens; however, there is little supporting epidemiologic evidence.

Methods: We evaluated whether the association of exposure to air pollution with annual prevalence of chronic cough, phlegm production, or bronchitis was modified by dog and cat ownership (indicators of allergen and endotoxin exposure). The study population consisted of 475 Southern California children with asthma from a longitudinal cohort of participants in the Children's Health Study.

Regular smoking and asthma incidence in adolescents.

Rationale: Although involuntary exposure to maternal smoking during the in utero period and to secondhand smoke are associated with occurrence of childhood asthma, few studies have investigated the role of active cigarette smoking on asthma onset during adolescence.

Objectives: To determine whether regular smoking is associated with the new onset of asthma during adolescence.

Methods: We conducted a prospective cohort study among 2,609 children with no lifetime history of asthma or wheezing who were recruited from fourth- and seventh-grade classrooms and followed annually in schools in 12 southern California communities.

Effects of ambient air pollutants on asthma medication use and wheezing among fourth-grade school children from 12 Southern California communities enrolled in The Children's Health Study.

To investigate the effects of 12 monthly average air pollution levels on monthly prevalence of respiratory morbidity, the authors examined retrospective questionnaire data on 2034 4th-grade children from 12 Southern California communities that were enrolled in The Children's Health Study. Wheezing during the spring and summer months was associated with community levels of airborne particulate matter with a diameter < or = 10 microm (PM10) (odds ratio (OR) = 2.91; 95% confidence interval (CI) = 1.

Mode of delivery is associated with asthma and allergy occurrences in children.

Purpose: A growing body of evidence indicates that perinatal factors modulate immune development and thereby may affect childhood asthma risk. In this study, we examined the associations between birth by cesarean section (C-section) and atopic disease occurrence in childhood.

Methods: Subjects were born in California between 1975 and 1987 and were 8 to 17 years old during their enrollment in the Children's Health Study.