The substantial springtime loss in ozone amount in the lower Antarctic polar stratosphere has prompted extensive studies of ozone depletion over the last two decades (World Meteorological Organization (WMO) 1992, 1995, 1999). Due to the important role ozone plays in absorbing harmful ultraviolet radiation, the ozone decline in mid-latitudes and dramatic ozone depletion over Antarctica may have ...

The unicellular algae Chlorella sorokiniana was used as a model system to investigate the interaction of ozone with plant cell membranes. Ozone induces K(+) leakage from Chlorella sorokiniana similar to the electrolytic loss observed from many higher plants under stressful conditions. The kinetics of this leakage indicate that ozone initially interacts reversibly (within sec) with sites on memb...

Data from four continuous ozone and weather monitoring sites operated by the National Park Service in Sierra Nevada, California, are used to develop an ozone forecasting model and to estimate the contribution of wildland fires on ambient ozone levels. The analyses of weather and ozone data pointed to the transport of ozone precursors from the Central Valley as an important source of pollution i...

[1] Observations from satellites and balloons suggest that ozone abundances have decreased in the tropical lower stratosphere since the late 1970s, but this long-term change is occurring in a region of large interannual variability. Three different ozone databases provide regression fits to the ozone observations, and are available for use in model studies of the influence of ozone changes on s...

The nose may help protect the lower respiratory tract from the effects of ambient ozone by scrubbing ozone from inspired air. Reductions in both nasal resistance and nitric oxide production with exercise may influence the efficiency of ozone uptake in the nose. Nasal ozone uptake was measured in 10 healthy volunteers before and after 15 min of moderate bicycle exercise. Ozone (0.2 parts/million...

Asthmatics appear to be more susceptible to the effects of air pollutants than nonasthmatics. The present studies were undertaken to examine the effects of exposing asthmatics to ozone concentrations that occur in the environment. Seventeen well-documented male and female asthmatics have been exposed for 2 hr in an environmental chamber to 0.25 ppm of ozone on one occasion (ozone) and to air on...

We compare the efficacy of intratesticular ozone therapy with intraperitoneal ozone therapy in an experimental rat model. For this purpose, 24 rats were divided into four groups including sham-operated, torsion/detorsion, torsion/detorsion plus intraperitoneal ozone (O-IP), and torsion/detorsion plus intratesticular ozone (O-IT). The O-IP ozone group received a 4 mg kg-1 intraperitoneal injecti...

The oxidation of organic and inorganic compounds during ozonation can occur via ozone or OH radicals or a combination thereof. The oxidation pathway is determined by the ratio of ozone and OH radical concentrations and the corresponding kinetics. A huge database with several hundred rate constants for ozone and a few thousand rate constants for OH radicals is available. Ozone is an electrophile...

The mechanism of ozone-mediated plant injury is not known but has been postulated to involve oxygen free radicals. Hydroxyl free radicals react with DNA causing formation of many products, one of which is 8-hydroxyguanine. By using high performance liquid chromatography with electrochemical detection, the 8-hydroxy-2'-deoxyguanosine (8-OHdG) content of a DNA enzymatic digest can be sensitively ...

We investigate the extent to which quantities that are based on total column ozone are applicable as measures of ozone loss in the polar vortices. Such quantities have been used frequently in ozone assessments by the World Meteorological Organization (WMO) and also to assess the performance of chemistry-climate models. The most commonly considered quantities are March and October mean column oz...