Air pollutant concentrations

About: Air pollutant concentrations is a research topic. Over the lifetime, 1652 publications have been published within this topic receiving 36138 citations.

New Jobs — Cleaner Air: Employment Effects Under Planned Changes to the EPA’s Air Pollution Rules

Abstract: In this study commissioned by Ceres, James Heintz, Heidi Garrett-Peltier, and Ben Zipperer examine the economic impacts of air pollution regulations forthcoming from the Environmental Protection Agency: the Clean Air Transport Rule governing sulfur dioxide and nitrogen oxide emissions, and the National Emissions Standards for Hazardous Air Pollutants for Utility Boilers rule, which will set limits for hazardous air pollutants. Focusing on 36 states, the study assesses the potential employment impacts of the transformation of the nation’s energy generation plants to a cleaner, more efficient fleet, through investments in pollution controls and the retirement of outdated plants.

Spatiotemporal modeling of PM2.5 oxidative potential using source impact and model fusion techniques

Abstract: Exposure to elevated levels of air pollution can lead to cardiorespiratory disease, birth defects, and cancer. However, observational air quality data are spatially and temporally sparse due to high cost of monitors, limiting the scope of epidemiologic analyses and introducing error in exposure assessments. This dissertation presents the development, evaluation, and applications of multiple mathematical and computational modeling approaches for estimating spatiotemporal trends in air pollutant concentrations where and when data is not available for use in health studies. Specifically, source apportionment techniques with multivariate regression analyses are used to estimate long-term (years 1998—2010) and large-scale (eastern US) spatiotemporal trends in a novel pollutant metric, fine particulate matter (PM2.5) oxidative potential measured with a dithiothreitol assay (OP_DTT). OP_DTT measures a particle’s ability to catalytically generate reactive oxygen species while simultaneously depleting a body’s antioxidant defenses, leading to oxidative stress and, in turn, inflammation in the respiratory tract and cardiovascular system. Results show that biomass burning and vehicle sources are significant contributors to OP_DTT and that OP_DTT exposure presents higher risk ratios for asthma/wheezing and congestive heart failure emergency department visits than PM2.5 mass. Additionally, statistical downscaling techniques and model fusion approaches are developed to simulate fine-scale spatiotemporal trends (250m resolution) in air pollutant concentrations (OP_DTT, PM2.5, carbon monoxide, and nitrogen oxides) in Atlanta, GA. These methods estimate steep spatial gradients in pollutant concentrations near roadways that monitors and regional air quality models with coarse grid resolutions do not capture. The models developed in this dissertation can estimate concentration fields of air pollutants, including the novel pollutant metric OP_DTT, at regional and local scales, making them valuable tools for current and future epidemiologic and environmental justice research.

A critical review of natural gas flares-induced secondary air pollutants

Abstract: Application of material balance analysis (in one of our previous studies) to natural gas flare in the upstream petroleum operations confirmed the emission of primary air pollutants in form of CO, CO2, NO, and NO2 from “sweet” natural gas while “sour” gas emits SO2 in addition; incomplete combustion may be an impetus for the release of volatile organic compounds (VOCs) into the atmosphere from this same source. In this article, the significance of these gaseous emissions in the formation of secondary air pollutants in the atmosphere is reviewed for the purpose of air pollution control strategy. The goal is to describe the formation mechanism, to determine the influencing factors in formation along with environmental impacts and to identify the required technological and policy control approach for an improved environmental protection.

Emissions of SO2, NOx and particulates from a pipe manufacturing plant and prediction of impact on air quality.

Abstract: Integrated pipe manufacturing industry is operation intensive and has significant air pollution potential especially when it is equipped with a captive power production facility. Emissions of SO2, NO x , and particulate matter (PM) were estimated from the stationary sources in a state-of-the-art pipe manufacturing plant in India. Major air polluting units like blast furnace, ductile iron spun pipe facility, and captive power production facility were selected for stack gas monitoring. Subsequently, ambient air quality modeling was undertaken to predict ground-level concentrations of the selected air pollutants using Industrial Source Complex (ISC 3) model. Emissions of SO2, NO x , and particulate matter from the stationary sources in selected facilities ranged from 0.02 to 16.5, 0.03 to 93.3, and 0.09 to 48.3 kg h − 1, respectively. Concentration of SO2 and NO x in stack gas of 1,180-kVA (1 KW = 1.25 kVA) diesel generator exceeded the upper safe limits prescribed by the State Pollution Control Board, while concentrations of the same from all other units were within the prescribed limits. Particulate emission was highest from the barrel grinding operation, where grinding of the manufactured pipes is undertaken for giving the final shape. Particulate emission was also high from dedusting operation where coal dust is handled. Air quality modeling indicated that maximum possible ground-level concentration of PM, SO2, and NO x were to the tune of 13, 3, and 18 μg/m3, respectively, which are within the prescribed limits for ambient air given by the Central Pollution Control Board.

Trends in Air Pollutant Concentrations and the Impact of Meteorology in Shandong Province, Coastal China, during 2013-2019

Abstract: Although weather conditions significantly affect air pollutant concentrations, few quantitative studies have been conducted on the effects of long-term and seasonal changes in meteorology on air quality. Hence, in this study, the trends in Shandong Province, China, for six criteria pollutants (viz., sulfur dioxide [SO2], carbon monoxide [CO], particulate matter [PM] with an aerodynamic diameter of < 10 µm [PM10], PM with an aerodynamic diameter of < 2.5 µm [PM2.5], nitrogen dioxide [NO2], and ozone [O3]) were analyzed for the period of 2013–2019, when overall emissions of air pollutants decreased, and the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem) was applied to evaluate the role of inter-annual and seasonal meteorological changes. Five of the six criteria pollutants exhibited a sharp drop in concentration until 2017 and a gradual decline afterward, with the maximum and minimum annual values occurring during winter and summer, respectively. In contrast, the level of O3 rose between 2013 and 2019 and displayed the opposite seasonal trend. Also, the diurnal concentrations of the first five criteria pollutants showed a typical bimodal distribution, whereas those of the O3 showed a typical unimodal distribution. Furthermore, a trimodal distribution was observed for the ratios between the diurnal PM2.5 and PM10 concentrations. Using 2013 as the baseline, the inter-annual meteorological changes accounted for only 3.4–18.6% of the decrease in the five criteria pollutants—with little effect on the O3—between 2015 and 2019, indicating that emission control measures drove the long-term improvement in air quality during these years. However, seasonal meteorological factors, which favored diffusion during summer and winter but accumulation during spring and autumn, played a larger role in the short term for all six species, especially during winter, when they reduced concentrations (excluding those of SO2 in 2019 and O3 altogether) by 6.5–31.0%.