Ozone (O3), a major photochemical oxidant, induces leaf injury concomitant with salicylic acid (SA) synthesis. In pathogen-infected leaves, SA is synthesized via two pathways, involving phenylalanine or isochorismate. SA biosynthesis under O3 fumigation is not well understood. When we applied 14C-labeled benzoic acid (a precursor of SA in the pathway via phenylalanine) to O3-exposed tobacco lea...

Early studies of plant response to ozone (O3) utilized concentration-based metrics, primarily by summarizing the commonly monitored hourly average data sets. Research with the O3 concentration parameter led to the recognition that both peak concentrations and cumulative effects are important when relating plant response to O3. The US and Canada currently use O3 concentration-based (exposure-bas...

Little is known about the relationship between perceptions of nutrient adequacy and biomarkers of nutrition status. This cross-sectional study of U.S. and German adults (n = 200; 18-80 years) compared dietary practices, knowledge, and beliefs of omega-3 fatty acids (O3-FA) with the omega-3 index (O3-I), an erythrocyte-based biomarker associated with cardiovascular disease (CVD) risk. More than ...

This study examines ozone (O3) predictions from the Community Multiscale Air Quality (CMAQ) model version 4.5 and discusses potential factors influencing the model results. Daily maximum 8-h average O3 levels are largely underpredicted when observed O3 levels are above 85 ppb and overpredicted when they are below 35 ppb. Using a clustering approach, model performance was examined separately for...

O3 is the major component of photochemical oxidants and gives rise to visible injuries on plant leaves. In O3-exposed plants, O2- is produced before the formation of the injury, but the role that O2- plays in plant response to 03 exposure is still unknown. To clarify its role, we observed the behavior of plants during O3 exposure after pretreatment with tiron, which is an O2- scavenger. When ti...

[1] Changes in emissions of ozone (O3) precursors affect both air quality and climate. We first examine the sensitivity of surface O3 concentrations (O3 ) and net radiative forcing of climate (RFnet) to reductions in emissions of four precursors – nitrogen oxides (NOx), non-methane volatile organic compounds, carbon monoxide, and methane (CH4). We show that long-term CH4-induced changes in O3, ...

A review of the literature reveals that ozone (O3) exposure can either suppress or enhance immune responsiveness. These disparate effects elicited by O3 exposure depend, in large part, on the experimental design used, the immune parameters examined as well as the animal species studied. Despite the apparent contradictions, a general pattern of response to O3 exposure can be recognized. Most stu...

An episodic simulation is conducted to characterize midday (12:00–17:00 CDT) ozone (O3) photochemical production and to investigate its sensitivity to emission changes of ozone precursors in the Mexico City Metropolitan Area (MCMA) during an “O3-South” meteorological episode using the Comprehensive Air Quality Model with extensions (CAMx). High Ox (O3+NO2) photochemical production rates of 10–8...

In this study, the Community Multiscale Air Quality (CMAQ) modeling system is used to simulate the ozone (O3) episodes during the Program of Regional Integrated Experiments of Air Quality over the Pearl River Delta, China, in October 2004 (PRIDE-PRD2004). The simulation suggests that O3 pollution is a regional phenomenon in the Pearl River Delta (PRD). Elevated O3 levels often occurred in the s...

Exposure to ambient ozone (O3) is associated with increased exacerbations of asthma. We sought to determine whether mast cell degranulation is induced by in vivo exposure to O3 in mice and whether mast cells play an essential role in the development of pulmonary pathophysiological alterations induced by O3. For this we exposed mast cell-deficient WBB6F1-kitW/kitW-v (kitW/kitW-v) mice and the co...