Childhood asthma and household exposures to nitrogen dioxide and fine particles: a triple-crossover randomized intervention trial.

Objective: Triple-crossover randomized controlled intervention trial to test whether reduced exposure to household NO or fine particles results in reduced symptoms among children with persistent asthma.

Methods: Children ( = 126) aged 5-11 years with persistent asthma living in homes with gas stoves and levels of NO 15 ppb or greater recruited in Connecticut and Massachusetts (2015-2019) participated in an intervention involving three air cleaners configured for: (1) NO reduction: particle filtration and NO scrubbing; (2) particle filtration: HEPA filter and NO scrubbing; (3) control: particle filtration and NO scrubbing. Air cleaners were randomly assigned for 5-week treatment periods using a three-arm crossover design.

A community-based evaluation of proximity to unconventional oil and gas wells, drinking water contaminants, and health symptoms in Ohio.

Over 4 million Americans live within 1.6 km of an unconventional oil and gas (UO&G) well, potentially placing them in the path of toxic releases. We evaluated relationships between residential proximity to UO&G wells and (1) water contamination and (2) health symptoms in an exploratory study.

Investigating the Impact of Maternal Residential Mobility on Identifying Critical Windows of Susceptibility to Ambient Air Pollution During Pregnancy.

Identifying periods of increased vulnerability to air pollution during pregnancy with respect to the development of adverse birth outcomes can improve understanding of possible mechanisms of disease development and provide guidelines for protection of the child. Exposure to air pollution during pregnancy is typically based on the mother's residence at delivery, potentially resulting in exposure misclassification and biasing the estimation of critical windows of pregnancy. In this study, we determined the impact of maternal residential mobility during pregnancy on defining weekly exposure to particulate matter less than or equal to 10 μm in aerodynamic diameter (PM10) and estimating windows of susceptibility to term low birth weight.

Unconventional oil and gas development and risk of childhood leukemia: Assessing the evidence.

The widespread distribution of unconventional oil and gas (UO&G) wells and other facilities in the United States potentially exposes millions of people to air and water pollutants, including known or suspected carcinogens. Childhood leukemia is a particular concern because of the disease severity, vulnerable population, and short disease latency. A comprehensive review of carcinogens and leukemogens associated with UO&G development is not available and could inform future exposure monitoring studies and human health assessments.

Indoor microbial communities: Influence on asthma severity in atopic and nonatopic children.

Background: Allergic and nonallergic asthma severity in children can be affected by microbial exposures.

Objective: We sought to examine associations between exposures to household microbes and childhood asthma severity stratified by atopic status.

Methods: Participants (n = 196) were selected from a cohort of asthmatic children in Connecticut and Massachusetts.

Household concentrations and personal exposure of PM2.5 among urban residents using different cooking fuels.

Exposure to PM2.5 is a leading environmental risk factor for many diseases and premature deaths, arousing growing public concerns. In this study, indoor and outdoor PM2.

Spatiotemporal calibration and resolution refinement of output from deterministic models.

Spatiotemporal calibration of output from deterministic models is an increasingly popular tool to more accurately and efficiently estimate the true distribution of spatial and temporal processes. Current calibration techniques have focused on a single source of data on observed measurements of the process of interest that are both temporally and spatially dense. Additionally, these methods often calibrate deterministic models available in grid-cell format with pixel sizes small enough that the centroid of the pixel closely approximates the measurement for other points within the pixel.

A systematic evaluation of chemicals in hydraulic-fracturing fluids and wastewater for reproductive and developmental toxicity.

Hydraulic-fracturing fluids and wastewater from unconventional oil and natural gas development contain hundreds of substances with the potential to contaminate drinking water. Challenges to conducting well-designed human exposure and health studies include limited information about likely etiologic agents. We systematically evaluated 1021 chemicals identified in hydraulic-fracturing fluids (n=925), wastewater (n=132), or both (n=36) for potential reproductive and developmental toxicity to triage those with potential for human health impact.

Asthma medication use during pregnancy, wheeze and estimated exposure to ambient nitrogen dioxide.

Risk of wheeze associated with ambient NO exposure is higher for pregnant asthmatics who have reduced their medication.

ESTIMATING DAILY NITROGEN DIOXIDE LEVEL: EXPLORING TRAFFIC EFFECTS.

Data used to assess acute health effects from air pollution typically have good temporal but poor spatial resolution or the opposite. A modified longitudinal model was developed that sought to improve resolution in both domains by bringing together data from three sources to estimate daily levels of nitrogen dioxide () at a geographic location. Monthly measurements at 316 sites were made available by the Study of Traffic, Air quality and Respiratory health (STAR).

Associations of PM₂.₅ constituents and sources with hospital admissions: analysis of four counties in Connecticut and Massachusetts (USA) for persons ≥ 65 years of age.

Background: Epidemiological studies have demonstrated associations between short-term exposure to PM2.5 and hospital admissions. The chemical composition of particles varies across locations and time periods.

Household levels of nitrogen dioxide and pediatric asthma severity.

Background: 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.

Household mold and dust allergens: exposure, sensitization and childhood asthma morbidity.

Background: Few studies address concurrent exposures to common household allergens, specific allergen sensitization and childhood asthma morbidity.

Objective: To identify levels of allergen exposures that trigger asthma exacerbations in sensitized individuals.

Methods: We sampled homes for common indoor allergens (fungi, dust mites (Der p 1, Der f 1), cat (Fel d 1), dog (Can f 1) and cockroach (Bla g 1)) for levels associated with respiratory responses among school-aged children with asthma (N=1233) in a month-long study.

Relationship between birth weight and exposure to airborne fine particulate potassium and titanium during gestation.

Airborne particles are linked to numerous health impacts, including adverse pregnancy outcomes. Most studies of particles examined total mass, although the chemical structure of particles varies widely. We investigated whether mother's exposure to potassium (K) and titanium (Ti) components of airborne fine particulate matter (PM(2.

Association of variants in innate immune genes with asthma and eczema.

Background: The innate immune pathway is important in the pathogenesis of asthma and eczema. However, only a few variants in these genes have been associated with either disease. We investigate the association between polymorphisms of genes in the innate immune pathway with childhood asthma and eczema.

Effects of endotoxin exposure on childhood asthma risk are modified by a genetic polymorphism in ACAA1.

Background: Polymorphisms in the endotoxin-mediated TLR4 pathway genes have been associated with asthma and atopy. We aimed to examine how genetic polymorphisms in innate immunity pathways interact with endotoxin to influence asthma risk in children.

Methods: In a previous analysis of 372 children from the Boston Home Allergens and the Connecticut Childhood Asthma studies, 7 SNPs in 6 genes (CARD15, TGFB1, LY96, ACAA1, DEFB1 and IFNG) involved in innate immune pathways were associated with asthma, and 5 SNPs in 3 genes (CD80, STAT4, IRAK2) were associated with eczema.

Effects of ambient pollen concentrations on frequency and severity of asthma symptoms among asthmatic children.

Background: Previous studies on the associations between ambient pollen exposures and daily respiratory symptoms have produced inconsistent results. We investigated these relationships in a cohort of asthmatic children using pollen exposure models to estimate individual ambient exposures.

Methods: Daily symptoms of wheeze, night symptoms, shortness of breath, chest tightness, persistent cough, and rescue medication use were recorded in a cohort of 430 children with asthma (age 4-12 years) in Connecticut, Massachusetts, and New York.

Urban land-use and respiratory symptoms in infants.

Background: Children's respiratory health has been linked to many factors, including air pollution. The impacts of urban land-use on health are not fully understood, although these relationships are of key importance given the growing populations living in urban environments.

Objectives: We investigated whether the degree of urban land-use near a family's residence is associated with severity of respiratory symptoms like wheeze among infants.

Spatial and temporal variability of fine particle composition and source types in five cities of Connecticut and Massachusetts.

To protect public health from PM(2.5) air pollution, it is critical to identify the source types of PM(2.5) mass and chemical components associated with higher risks of adverse health outcomes.

Association of maternal anemia with increased wheeze and asthma in children.

Background: Increasing interest has focused on maternal nutrition and micronutrient status during pregnancy and respiratory disease development in the offspring.

Objective: To examine the relationship between maternal anemia in pregnancy with wheeze and asthma in early childhood.

Methods: The cohort included children of women followed through pregnancy and recontacted when the child was 6 years of age to evaluate respiratory health.

Modeling effects of traffic and landscape characteristics on ambient nitrogen dioxide levels in Connecticut.

An integrated exposure model was developed that estimates nitrogen dioxide (NO(2)) concentration at residences using geographic information systems (GIS) and variables derived within residential buffers representing traffic volume and landscape characteristics including land use, population density and elevation. Multiple measurements of NO(2) taken outside of 985 residences in Connecticut were used to develop the model. A second set of 120 outdoor NO(2) measurements as well as cross-validation were used to validate the model.

Prenatal exposure to fine particulate matter and birth weight: variations by particulate constituents and sources.

Background: Exposure to fine particles (PM2.5) during pregnancy has been linked to lower birth weight; however, the chemical composition of PM2.5 varies widely.

Integrated exposure modeling: a model using GIS and GLM.

Traffic exhaust is a source of air contaminants that have adverse health effects. Quantification of traffic as an exposure variable is complicated by aerosol dispersion related to variation in layout of roads, traffic density, meteorology, and topography. A statistical model is presented that uses Geographic Information Systems (GIS) technology to incorporate variables into a generalized linear model that estimates distribution of traffic-related pollution.

Household airborne Penicillium associated with peak expiratory flow variability in asthmatic children.

Background: Exposure to airborne fungi has been associated with increased airway hyperreactivity and asthma prevalence.

Objective: To investigate the association between common indoor fungi and airway hyperreactivity measured by peak expiratory flow variability in asthmatic children.

Methods: Children 6 to 12 years of age (n = 225) with a physician diagnosis of asthma were enrolled in the study to have their peak expiratory flow recorded twice daily during a 2-week period.

Symptoms and medication use in children with asthma and traffic-related sources of fine particle pollution.

Background: Exposure to ambient fine particles [particulate matter < or = 2.5 microm diameter (PM(2.5))] is a potential factor in the exacerbation of asthma.