Exposure to ozone (O3) is associated with adverse respiratory and cardiovascular outcomes. Alterations in circulating microRNAs (miRNAs) may contribute to the adverse vascular effects of O3 exposure through inter-cellular communication... more
Exposure to ozone (O3) is associated with adverse respiratory and cardiovascular outcomes. Alterations in circulating microRNAs (miRNAs) may contribute to the adverse vascular effects of O3 exposure through inter-cellular communication resulting in post-transcriptional regulation of messenger RNAs by miRNAs. In this study, we investigated whether O3 exposure induces alterations in circulating miRNAs that can mediate effects on downstream vascular and coagulation biomarkers. Twenty-three healthy male adults were exposed on successive days to filtered air and 300 ppb O3 for 2 h. Circulating miRNA and protein biomarkers were quantified after each exposure session. The data were subjected to mixed-effects model and mediation analyses for the statistical analyses. The results showed that the expression level of multiple circulating miRNAs (e.g., miR-19a-3p, miR-34a-5p) was significantly associated with O3 exposure. Pathway analysis showed that these miRNAs were predictive of changing lev...
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Background Rising temperatures and decreased global circulation in the upcoming decades are expected to have a detrimental impact on air quality, particularly with respect to ozone. The largest imp...
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Exposure to ambient levels of air pollution increases cardiovascular morbidity and mortality. Advanced age is among the factors associated with susceptibility to the adverse effects of air pollutio...
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Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust (DE) is a major contributor to ambient PM and gaseous emissions in... more
Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust (DE) is a major contributor to ambient PM and gaseous emissions in urban areas. This was a pilot study designed to evaluate concentration-dependent effects of short-term exposure to whole DE on the cardiovascular system in order to identify a threshold concentration that can elicit biological responses in healthy human volunteers. Six healthy middle-aged participants with glutathione-S-transferase-Mu 1 (GSTM1) null genotype underwent sequential exposures to 100 µg/m(3), 200 µg/m(3), and 300 µg/m(3) whole DE generated in real time using an idling diesel truck engine. Exposures were separated by 14 d and each was 2 h in duration. We report concentration-dependent effects of exposure to DE, with 100 µg/m(3) concentration causing minimal cardiovascular effects, while exposure to 300 µg/m(3) DE for 2 h resulted in a borderline significant reduction of baseline brachial artery diameter (3.34 ± 0.27 mm pre- versus 3.23 ± 0.25 mm post-exposure; p = 0.08). Exposure to the highest concentration of DE also resulted in increases of 5 mmHg in diastolic blood pressure as well as a decrease in indices of the frequency domain of heart rate variability (HRV). These findings demonstrate that acute exposure to relatively high concentrations of DE produces cardiovascular changes in middle-aged GSTM1 null individuals. This study therefore suggests that arterial vasoconstriction and changes in HRV are responses through which traffic-related air pollution increases the risk of adverse cardiovascular outcomes.
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On June 1st 2008 a lightning strike in the Pocosin Lakes National Wildlife refuge in Eastern North Carolina (Hyde County), initiated a fast burning wildfire (Evans Road fire). It burned for two months destroying over 40,000 acres of... more
On June 1st 2008 a lightning strike in the Pocosin Lakes National Wildlife refuge in Eastern North Carolina (Hyde County), initiated a fast burning wildfire (Evans Road fire). It burned for two months destroying over 40,000 acres of southeast shrub bog. The Pocosin ...
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We project the change in ozone-related mortality burden attributable to changes in climate between a historical (1995-2005) and near-future (2025-2035) time period while incorporating a non-linear and synergistic effect of ozone and... more
We project the change in ozone-related mortality burden attributable to changes in climate between a historical (1995-2005) and near-future (2025-2035) time period while incorporating a non-linear and synergistic effect of ozone and temperature on mortality. We simulate air quality from climate projections varying only biogenic emissions and holding anthropogenic emissions constant, thus attributing changes in ozone only to changes in climate and independent of changes in air pollutant emissions. We estimate non-linear, spatially varying, ozone-temperature risk surfaces for 94 US urban areas using observed data. Using the risk surfaces and climate projections we estimate daily mortality attributable to ozone exceeding 40 p.p.b. (moderate level) and 75 p.p.b. (US ozone NAAQS) for each time period. The average increases in city-specific median April-October ozone and temperature between time periods are 1.02 p.p.b. and 1.94 °F; however, the results varied by region. Increases in ozone...
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Sustainable fire management has eluded all industrial societies. Given the growing number and magnitude of wildfire events, prescribed fire is being increasingly promoted as the key to reducing wildfire risk. However, smoke from... more
Sustainable fire management has eluded all industrial societies. Given the growing number and magnitude of wildfire events, prescribed fire is being increasingly promoted as the key to reducing wildfire risk. However, smoke from prescribed fires can adversely affect public health. We propose that the application of air quality standards can lead to the development and adoption of sustainable fire management approaches that lower the risk of economically and ecologically damaging wildfires while improving air quality and reducing climate-forcing emissions. For example, green fire breaks at the wildland–urban interface (WUI) can resist the spread of wildfires into urban areas. These could be created through mechanical thinning of trees, and then maintained by targeted prescribed fire to create biodiverse and aesthetically pleasing landscapes. The harvested woody debris could be used for pellets and other forms of bioenergy in residential space heating and electricity generation. Colle...
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Wildfire smoke is known to exacerbate respiratory conditions; however, evidence for cardiovascular and cerebrovascular events has been inconsistent, despite biological plausibility. A population-based epidemiologic analysis was conducted... more
Wildfire smoke is known to exacerbate respiratory conditions; however, evidence for cardiovascular and cerebrovascular events has been inconsistent, despite biological plausibility. A population-based epidemiologic analysis was conducted for daily cardiovascular and cerebrovascular emergency department (ED) visits and wildfire smoke exposure in 2015 among adults in 8 California air basins. A quasi-Poisson regression model was used for zip code-level counts of ED visits, adjusting for heat index, day of week, seasonality, and population. Satellite-imaged smoke plumes were classified as light, medium, or dense based on model-estimated concentrations of fine particulate matter. Relative risk was determined for smoky days for lag days 0 to 4. Rates of ED visits by age- and sex-stratified groups were also examined. Rates of all-cause cardiovascular ED visits were elevated across all lags, with the greatest increase on dense smoke days and among those aged ≥65 years at lag 0 (relative ris...
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Identifying communities vulnerable to adverse health effects from exposure to wildfire smoke may help prepare responses, increase the resilience to smoke and improve public health outcomes during smoke days. We developed a Community... more
Identifying communities vulnerable to adverse health effects from exposure to wildfire smoke may help prepare responses, increase the resilience to smoke and improve public health outcomes during smoke days. We developed a Community Health-Vulnerability Index (CHVI) based on factors known to increase the risks of health effects from air pollution and wildfire smoke exposures. These factors included county prevalence rates for asthma in children and adults, chronic obstructive pulmonary disease, hypertension, diabetes, obesity, percent of population 65 years of age and older, and indicators of socioeconomic status including poverty, education, income and unemployment. Using air quality simulated for the period between 2008 and 2012 over the continental U.S. we also characterized the population size at risk with respect to the level and duration of exposure to fire-originated fine particulate matter (fire-PM2.5) and CHVI. We estimate that 10% of the population (30.5 million) lived in ...
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Research Interests: Chemistry, Olive Oil, Medicine, Environmental Sciences, Humans, and 15 moreFemale, Male, Fish Oil, Dietary Supplements, Endothelial dysfunction, Aged, Middle Aged, Particulate Matter, Tissue Plasminogen Activator, Vasodilation, Blood Flow Velocity, Fibrinolysis, Air Pollutants, Brachial artery, and Medical and Health Sciences
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Research Interests: Risk, Medicine, Humans, Blood Pressure, Female, and 15 moreMale, Heart rate, Aged, Middle Aged, Genotype, Adult, Particle Size, Particulate Matter, Cardiovascular Diseases, Glutathione Transferase, Air Pollutants, Aerodynamic Diameter, Metabolic Syndrome X, Pharmacology and pharmaceutical sciences, and crossover study
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Background— Recent epidemiology studies have reported associations between short-term ozone exposure and mortality. Such studies have previously reported associations between airborne particulate matter pollution and mortality, and... more
Background— Recent epidemiology studies have reported associations between short-term ozone exposure and mortality. Such studies have previously reported associations between airborne particulate matter pollution and mortality, and support for a causal relationship has come from controlled-exposure studies that describe pathophysiological mechanisms by which particulate matter could induce acute mortality. In contrast, for ozone, almost no controlled-human-exposure studies have tested whether ozone exposure can modulate the cardiovascular system. Methods and Results— Twenty-three young healthy individuals were exposed in a randomized crossover fashion to clean air and to 0.3-ppm ozone for 2 hours while intermittently exercising. Blood was obtained immediately before exposure, immediately afterward, and the next morning. Continuous Holter monitoring began immediately before exposure and continued for 24 hours. Lung function was performed immediately before and immediately after expos...
Research Interests: Medicine, Humans, Female, Male, Systemic inflammation, and 14 moreHeart rate, Young Adult, Follow-up studies, Clinical Sciences, Cardiovascular system, Ozone, Adult, Public health systems and services research, Circulation, Cross-Over Studies, Fibrinolysis, Air Pollutants, Cardiovascular medicine and haematology, and crossover study
Research Interests: Inflammation, Medicine, Humans, Female, Male, and 15 moreExercise, American, Lung, Neutrophils, Spirometry, Ozone, Adult, Vital Capacity, Time Factors, Glutathione Transferase, Reference Values, Air Pollutants, Respiratory function tests, reverse transcriptase polymerase chain reaction, and Medical and Health Sciences
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Background: Ambient PM2.5 is a ubiquitous air pollutant with established adverse health consequences. While postulated to promote a systemic inflammatory response, limited studies have demonstrated changes in serum biomarkers related to... more
Background: Ambient PM2.5 is a ubiquitous air pollutant with established adverse health consequences. While postulated to promote a systemic inflammatory response, limited studies have demonstrated changes in serum biomarkers related to PM2.5 exposure. We aim to examine associations between short-term PM2.5 exposure and commonly measured biomarkers known to be affected by inflammation among patients receiving maintenance in-center hemodialysis. Methods: We conducted a retrospective open cohort study from 1-1-2008 to 12-31-2014. Adult hemodialysis patients were identified from the United States Renal Data System and linked at the patient level to laboratory data from a large dialysis organization. Daily ambient PM2.5 was estimated on a 1 km grid and assigned to cohort patients based on the ZIP codes of dialysis clinics. Serum albumin, serum ferritin, transferrin saturation (TSAT), and serum hemoglobin were ascertained from the dialysis provider organization database. Mixed-effect mod...
Research Interests: Dialysis, Medicine, Internal Medicine, Kidney, Hemodialysis, and 4 moreHemoglobin, Cohort, Ferritin, and Biomarker
Figure S1. Percent of population "in poverty" by county (US Census Bureau 2012). Figure S2. Comparison of SFS PM2.5, satellite imagery and FRM monitor PM2.5: May 11, 2011. Figure S3. Comparison of cRR (per 10 μg/m3 rise in... more
Figure S1. Percent of population "in poverty" by county (US Census Bureau 2012). Figure S2. Comparison of SFS PM2.5, satellite imagery and FRM monitor PM2.5: May 11, 2011. Figure S3. Comparison of cRR (per 10 μg/m3 rise in wildfire PM2.5) between statistical model adjusted for county-level poverty (used in this study) and an un-adjusted (crude) statistical model. Figure S4. Percent change in ED visits and 95 % confidence intervals per 10 μg/m3 rise in wildfire PM2.5 for adults and stratified by gender. (DOCX 4293 kb)
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BackgroundWildfires are increasingly a significant source of fine particulate matter (PM2.5), which has been linked to adverse health effects and increased mortality. ESKD patients are potentially susceptible to this environmental... more
BackgroundWildfires are increasingly a significant source of fine particulate matter (PM2.5), which has been linked to adverse health effects and increased mortality. ESKD patients are potentially susceptible to this environmental stressor.MethodsWe conducted a retrospective time-series analysis of the association between daily exposure to wildfire PM2.5 and mortality in 253 counties near a major wildfire between 2008 and 2012. Using quasi-Poisson regression models, we estimated rate ratios (RRs) for all-cause mortality on the day of exposure and up to 30 days following exposure, adjusted for background PM2.5, day of week, seasonality, and heat. We stratified the analysis by causes of death (cardiac, vascular, infectious, or other) and place of death (clinical or nonclinical setting) for differential PM2.5 exposure and outcome classification.ResultsWe found 48,454 deaths matched to the 253 counties. A 10-μg/m3 increase in wildfire PM2.5 associated with a 4% increase in all-cause mor...
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Rationale: Wildfire smoke often impacts rural areas without air quality monitors, limiting assessment of health impacts. A 2008 wildfire in Pocosin Lakes National Wildlife Refuge produced massive quantities of smoke affecting eastern NC,... more
Rationale: Wildfire smoke often impacts rural areas without air quality monitors, limiting assessment of health impacts. A 2008 wildfire in Pocosin Lakes National Wildlife Refuge produced massive quantities of smoke affecting eastern NC, a rural area with limited air quality monitoring. To assess the association between smoke exposure and adverse health effects, we evaluated the rates of asthma- and other respiratory-related emergency department (ED) visits in the affected counties during and after the fire. Methods: Aerosol optical depth (AOD) from the Geostationary Operational Environmental Satellite was used to determine the location and extent of the smoke plume. Individual-level ED data, obtained from the NC Disease Event Tracking and Epidemiologic Collection Tool, included the visit date, list of chief complaints, up to 11 discharge ICD-9-CM codes, gender, age, and county of residence. We used Poisson regression to model the expected daily number of ED visits as a function of ...
Page 1. / Poster Discussion Session / Sunday, May 16/1:30 A106 BIOMASS SMOKE: ORGANIC DOES NOT MEAN LESS HARMFUL! PM-4:00 PM / Room 225-227 (Second Level), Morial Convention Center Healthy Volunteers ...
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Research Triangle Park, NHEERL, US EPA, Chapel Hill, NC, University of North Carolina School of Medicine, 7310, University of South 1 2 3 ... Carolina, Columbia, TRC, Chapel Hill, United States Environmental Protection Agency, Research... more
Research Triangle Park, NHEERL, US EPA, Chapel Hill, NC, University of North Carolina School of Medicine, 7310, University of South 1 2 3 ... Carolina, Columbia, TRC, Chapel Hill, United States Environmental Protection Agency, Research Triangle Park, NC, United States - ...
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Human exposure to wood smoke particles (WSP) impacts on human health through changes in indoor air quality, exposures from wild fires, burning of biomass and air pollution. This investigation tested the postulate that healthy volunteers... more
Human exposure to wood smoke particles (WSP) impacts on human health through changes in indoor air quality, exposures from wild fires, burning of biomass and air pollution. This investigation tested the postulate that healthy volunteers exposed to WSP would demonstrate evidence of both pulmonary and systemic inflammation. Ten volunteers were exposed to filtered air and, 3 weeks or more later, WSP. Each exposure included alternating 15 min of exercise and 15 min of rest for a total duration of 2 h. Wood smoke was generated by heating an oak log on an electric element and then delivered to the exposure chamber. Endpoints measured in the volunteers included symptoms, pulmonary function tests, measures of heart rate variability and repolarisation, blood indices and analysis of cells and fluid obtained during bronchoalveolar lavage. Mean particle mass for the 10 exposures to air and WSP was measured using the mass of particles collected on filters and found to be below the detectable limit and 485±84 μg/m(3), respectively (mean±SD). There was no change in either symptom prevalence or pulmonary function with exposure to WSP. At 20 h after wood smoke exposure, blood tests demonstrated an increased percentage of neutrophils, and bronchial and bronchoalveolar lavage revealed a neutrophilic influx. We conclude that exposure of healthy volunteers to WSP may be associated with evidence of both systemic and pulmonary inflammation.