Physical Sciences and Mathematics Commons^™

Long-Term Spatial And Temporal Assessment Of Criteria Air Pollutants Concentration Trends In The Lower Rio Grande Valley Region Of Texas, Usa, Md Salahuddin Majumder

Theses and Dissertations

Air pollution is a substantial environmental challenge all over the world. This study investigated the long-term air pollution levels in the Lower Rio Grande Valley region, by utilizing data collected from five continuous ambient monitoring stations in two counties over 23 years, from January 2000 to December 2022, to analyze daily, monthly, and seasonal variations of different pollutants, including ground-level ozone, particulate matter, and carbon monoxide. This study also identified distinct daily and seasonal patterns for O3, PM2.5, PM10, and CO at each monitoring site, influenced by factors such as traffic emissions, temperature, solar radiation, indoor heating, and weather conditions. …

Changes Of Air Pollutants In Urban Cities During The Covid-19 Lockdown-Sri Lanka, Buddhi Pushpawela, Sherly Shelton, Gayathri Liyanage, Sanduni Jayasekara, Dimuthu Rajapaksha, Akila Jayasundara, Lesty Das Jayasuriya

Department of Earth and Atmospheric Sciences: Faculty Publications

In response to the COVID-19 pandemic in early 2020, Sri Lanka underwent a nationwide lockdown that limited motor vehicle movement, industrial operations, and human activities. This study analyzes the impact of COVID-19 lockdown on carbon monoxide (CO), ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and particulate matter (PM₁₀, PM_2.5) concentrations in two urban cities (Colombo and Kandy) in Sri Lanka, by comparison of data from the lockdown period (March to May 2020) with its analogous period of 2019 and 2021. The results showed that the percentage change of daytime …

Slides: Hydrofracking: Air Issues And Community Exposure, Debra A. Kaden

Air Quality Impacts from Oil and Gas Development (January 27)

Presenter: Debra Kaden, Ph.D., Toxicologist, ENVIRON International Corporation, discusses air concentrations of chemicals of potential health concern surrounding oil and gas development activities, as well as temporal and spatial patterns of these chemicals in the ambient environment. Such information is necessary to evaluate possible health impacts of the drilling process on air in surrounding communities.

19 slides

Anthropogenic Osmium In Rain And Snow Reveals Global-Scale Atmospheric Contamination, Cynthia Chen, Peter N. Sedwick, Mukul Sharma

Dartmouth Scholarship

Osmium is one of the rarer elements in seawater, with typical concentration of approximately 10 x 10(-15) g g(-1) (5.3 x 10(-14) mol kg(-1)). The osmium isotope composition ((187)Os/(188)Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (approximately 1.3) and mantle/cosmic dust (approximately 0.13). Here, we show that the (187)Os/(188)Os ratios measured in rain and snow collected around the world range from 0.16 to 0.48, much lower than expected (>1), but similar to the isotope composition of ores (approximately 0.2) that are processed to extract platinum and other metals to be used primarily …