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Background: Previous human exposure studies of traffic-related air pollutants have demonstrated adverse health effects in human populations by comparing areas of high and low traffic, but few studies have utilized microenvironmental monitoring of pollutants at multiple traffic locations while looking at a vast array of health endpoints in the same population. We evaluated inflammatory markers, heart rate variability (HRV), blood pressure, exhaled nitric oxide, and lung function in healthy participants after exposures to varying mixtures of traffic pollutants., Methods: A repeated-measures, crossover study design was used in which 23 healthy, non-smoking adults had clinical cardiopulmonary and systemic inflammatory measurements taken prior to, immediately after, and 24 hours after intermittent walking for two hours in the summer months along three diverse roadways having unique emission characteristics. Measurements of PM2.5, PM10, black carbon (BC), elemental carbon (EC), and organic carbon (OC) were collected. Mixed effect models were used to assess changes in health effects associated with these specific pollutant classes., Results: Minimal associations were observed with lung function measurements and the pollutants measured. Small decreases in BP measurements and rMSSD, and increases in IL-1β and the low frequency to high frequency ratio measured in HRV, were observed with increasing concentrations of PM2.5 EC., Conclusions: Small, acute changes in cardiovascular and inflammation-related effects of microenvironmental exposures to traffic-related air pollution were observed in a group of healthy young adults. The associations were most profound with the diesel-source EC. more...

Particulate matter (PM) varies in chemical composition and mass concentration based on location, source, and particle size. This study sought to evaluate the in vitro and in vivo toxicity of coarse (PM10-2.5) and fine (PM25) PM samples collected at 5 diverse sites within California. Coarse and fine PM samples were collected simultaneously at 2 rural and 3 urban sites within California during the summer. A human pulmonary microvascular endothelial cell line (HPMEC-ST1.6R) was exposed to PM suspensions (50 μg/mL) and analyzed for reactive oxygen species (ROS) after 5 hours of treatment. In addition, FVB/N mice were exposed by oropharyngeal aspiration to 50 μg PM, and lavage fluid was collected 24 hrs post-exposure and analyzed for total protein and %PMNs. Correlations between trace metal concentrations, endotoxin, and biological endpoints were calculated, and the effect of particle size range, locale (urban vs. rural), and location was determined. Absolute principal factor analysis was used to identify pollution sources of PM from elemental tracers of those sources. Ambient PM elicited an ROS and pro-inflammatory-related response in the cell and mouse models, respectively. These responses were dependent on particle size, locale, and location. Trace elements associated with soil and traffic markers were most strongly linked to the adverse effects in vitro and in vivo. Particle size, location, source, and composition of PM collected at 5 locations in California affected the ROS response in human pulmonary endothelial cells and the inflammatory response in mice. more...

Particulate matter (PM) varies in chemical composition and mass concentration based on location, source, and particle size. This study sought to evaluate the in vitro and in vivo toxicity of coarse (PM 10-2.5 ) and fine (PM 2.5 ) PM samples collected at 5 diverse sites within California. Coarse and fine PM samples were collected simultaneously at 2 rural and 3 urban sites within California during the summer. A human pulmonary microvascular endothelial cell line (HPMEC-ST1.6R) was exposed to PM suspensions (50 μg/mL) and analyzed for reactive oxygen species (ROS) after 5 h of treatment. In addition, FVB/N mice were exposed by oropharyngeal aspiration to 50 μg PM, and lavage fluid was collected 24 h post-exposure and analyzed for total protein and %PMNs. Correlations between trace metal concentrations, endotoxin, and biological endpoints were calculated, and the effect of particle size range, locale (urban vs. rural), and location was determined. Absolute principal factor analysis was used to identify pollution sources of PM from elemental tracers of those sources. Ambient PM elicited an ROS and pro-inflammatory-related response in the cell and mouse models, respectively. These responses were dependent on particle size, locale, and location. Trace elements associated with soil and traffic markers were most strongly linked to the adverse effects in vitro and in vivo . Particle size, location, source, and composition of PM collected at 5 locations in California affected the ROS response in human pulmonary endothelial cells and the inflammatory response in mice. [ABSTRACT FROM AUTHOR] more...

In December 2019, a new, severe coronavirus (COVID-19) appeared in Wuhan, China. Shortly after, the first COVID-19 case was confirmed in the United States. The emergence of this virus led many United States governors to enact executive orders in an effort to limit the person-to-person spread of the virus. One state that utilized such measures was New York, which contains New York City (NYC), the most populous city in the United States. Many reports have shown that due to the government-backed shutdowns, the air quality in major global cities improved. However, there has been only limited work on whether this same trend is seen throughout the United States, specifically within the densely populated NYC area. Thus, the focus of this study was to examine whether changes in air quality were observed in NYC resulting from New York State's COVID-19-associated shutdown measures. To do this, daily concentrations of fine particulate matter (PM 2.5) and nitrogen dioxide (NO 2) were obtained from 15 central monitoring stations throughout the five NYC boroughs for the first 17 weeks (January through May) of 2015–2020. Decreases in PM 2.5 (36%) and NO 2 (51%) concentrations were observed shortly after the shutdown took place; however, using a linear time lag model, when changes in these pollutant concentrations were compared to those measured during the same span of time in 2015–2019, no significant difference between the years was found. Therefore, we highlight the importance of considering temporal variability and long-term trends of pollutant concentrations when analyzing for short-term differences in air pollutant concentrations related to the COVID-19 shutdowns. Unlabelled Image • New York City, United States was heavily affected by the COVID-19 pandemic. • Linear time lag models show no difference in air quality between 2020 and 2015–2019. • Air quality trends should be considered when gauging short-term pollution changes. [ABSTRACT FROM AUTHOR] more...