Using a combination of ozonesonde data and numerical simulations of the Chemical Lagrangian Model of the Stratosphere (CLaMS), the trend of tropospheric ozone (O3) during 2002–2010 over Beijing was investigated. Tropospheric ozone over Beijing shows a winter minimum and a broad summer maximum with a clear positive trend in the maximum summer ozone concentration over the last decade. The observe...

ozone is an important chemical constituent of the atmosphere, and stratosphere it protects the earth surface from harmful uv radiations, such that it is known as “good ozone” while, in the lower troposphere it is a highly oxidizing pollutant and known as “bad ozone”. it is also a greenhoure gas that can affect the climate. hence, the study of spatial and temporal variations of ozone is importan...

The factors involved in evaluations of effects of volatile organic compound (VOC) and oxides of nitrogen emissions from motor vehicles on ground-level ozone are reviewed. The chemical basis for ozone formation, the computer models and chemical mechanisms used for predicting ozone impacts, and methods for quantifying differences among VOCs in their ozone impacts, are discussed. It is recommended...

Ascorbic acid (Asc) is the most abundant antioxidant in plants and serves as a major contributor to the cell redox state. Exposure to environmental ozone can cause significant damage to plants by imposing conditions of oxidative stress. We examined whether increasing the level of Asc through enhanced Asc recycling would limit the deleterious effects of environmental oxidative stress. Plants ove...

Annual field surveys were conducted from 1999–2004 within the Seney National Wildlife Refuge in northern Michigan to determine if ambient ozone levels at this remote location were great enough to injure refuge vegetation. Ozone injury was observed on sensitive bioindicator plants during each survey year; however, the incidence (percentage) of plants exhibiting symptoms was low and varied among ...

the structural and energetic characteristics of o3–h2o complexes have been investigated by means of b3lyp, mp2, mp4(sdtq), ccsd(t) and qcisd(t) methods in conjunction with the aug-cc-pvdz and aug-cc-pvtz basis sets. six conformers were found for the o3–h2o complex. two different intermolecular interactions were expected to participate in the formation of complexes, namely conventional o∙∙∙h hyd...

objective(s): this study aims to determine the effects of ozone therapy on restoring impaired nrf2 activation to ameliorate chronic tubulointerstitial injury in rats with adenine-induced ckd. materials and methods: sprague–dawley rats were fed with 0.75% adenine-containing diet to induce ckd and chronic tubulointerstitial injury. ozone therapy was administered by rectal insufflation. after 4 we...

BACKGROUND The adverse respiratory effects of ground-level ozone are well established. Ozone is the air pollutant most consistently projected to increase under future climate change. PURPOSE To project future pediatric asthma emergency department visits associated with ground-level ozone changes, comparing 1990s to 2020s. METHODS This study assessed future numbers of asthma emergency depart...

STUDY OBJECTIVES Although links between meteorological conditions and spontaneous pneumothorax (SP) have been proposed, the reports are controversial. In this study ozone levels, which are known to have some adverse effects on lung tissues, were investigated as a potential triggering factor of SP. At present there is not sufficient information about the effects of ozone on SP. METHODS Of a to...

Ozone concentration and ecosystem scale fluxes were measured continuously from June 1999 to June 2000 above a ponderosa pine plantation at Blodgett Forest, an Ameriflux site located B75 km northeast of Sacramento, CA (1300m). The ponderosa pine trees were most active during the summer but maintained a low level of activity during the fall, winter, and spring. Cumulative ozone flux for the year ...