نتایج جستجو برای: increasing ozone exposures
تعداد نتایج: 540322 فیلتر نتایج به سال:
Tropospheric ozone is the major oxidizing component in photochemical smog and is one of the most pervasive problems to human health of the criteria air pollutants for which the National Ambient Air Quality Standards have been designated by the Clean Air Act. Although many adverse health effects of ozone exposure have been documented in both humans and laboratory animals, controversy surrounds t...
The sea urchin, Sterechinus neumayeri, has a circumpolar distribution and is an abundant species in benthic communities of the Antarctic. Reproduction occurs during austral spring, when ozone concentrations over the past 25 years have been reduced by 50% or more, potentially exposing the planktonic embryos and larvae to elevated levels of UVB. During spring of 1996, cultures of S. neumayeri emb...
BACKGROUND The discrepancy between functional and inflammatory airway response to ozone has been reported in normal subjects, but few data are available for stable asthmatics regularly treated with inhaled corticosteroids. METHODS Twenty-three well controlled, regularly treated, mild-to-moderate asthmatic patients underwent two sequential randomised exposures to either filtered air or ozone (...
Effects of canopy ozone (O(3)) exposure and signatures of genetic structure using isozyme markers associated with O(3) tolerance were analyzed in approximately 20-, approximately 80-, and >200-yr-old ponderosa (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.) in Sequoia National Park, California. For both species, the number of alleles and genotypes per loci was ...
BACKGROUND Evidence is compelling for a positive correlation between climate change, urbanisation and prevalence of allergic sensitisation and diseases. The reason for this association is not clear to date. Some data point to a pro-allergenic effect of anthropogenic factors on susceptible individuals. OBJECTIVES To evaluate the impact of urbanisation and climate change on pollen allergenicity...
The occurrence of Cryptosporidium in raw waters and bromate formation during ozonation of bromide-containing waters leads to a difficult optimisation of ozonation processes. On the one hand inactivation of Cryptosporidium requires high ozone exposures, on the other hand under these conditions bromate formation is favored. In order to overcome this problem we need information about (i) the oxida...
The effects on heart rate variability (HRV) and arterial stiffness from exposure to ambient particulate matter and ozone have not been studied simultaneously. The aim of this study was to analyze these effects with refined exposure estimates from personal measurements of ozone and size-resolved particulate matter mass concentrations. The authors recruited 17 mail carriers in a panel study in Ta...
Background and Objective: The human environment is very sensitive and fragile. In recent years the rate of pollutants has been increasing. Ahvaz city (located in South-West of Iran) with a population of 1,000,000 persons is one of the seven polluted Iranian metropolises. So, the aim of current study was to estimate the number of respiratory and cardiovascular deaths related to ozone expos...
We assess the roles of long-lived greenhouse gases and ozone depletion in driving meridional surface pressure gradients in the southern extratropics; these gradients are a defining feature of the Southern Annular Mode. Stratospheric ozone depletion is thought to have caused a strengthening of this mode during summer, with increasing long-lived greenhouse gases playing a secondary role. Using a ...
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