RATIONALE Although substantial scientific evidence suggests that chronic exposure to ambient air pollution contributes to premature mortality, uncertainties exist in the size and consistency of this association. Uncertainty may arise from inaccurate exposure assessment. OBJECTIVES To assess the associations of three types of air pollutants (fine particulate matter, ozone [O3], and nitrogen di...

Although the ground-level NO2 measurement from air quality monitoring sites is relatively accurate, it a challenge to obtain continuous spatial coverage due discrete distribution of sites. Thus, tropospheric column amount satellites with wide and temporal higher resolution has been increasingly used estimate NO2. However, most estimation methods were performed spontaneously using simple linear ...

To measure the concentration of nitrites and nitrates by chemiluminescence, we examined the efficiency of five reducing agents [V(III), Mo(VI) + Fe(II), NaI, Ti(III), and Cr(III)] to reduce nitrite (NO2-) and (or) nitrate (NO3-) to nitric oxide (NO). The effect of each reducing agent on the conversion of different amounts of NO2- and (or) NO3- (100-500 pmol, representing concentrations of 0.4 t...

We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2) concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p<0.01) higher for nonwhites tha...

The trend in stratospheric NO2 column at the NDACC (Network for the Detection of Atmospheric Composition Change) station of Jungfraujoch (46.5 N, 8.0 E) is assessed using ground-based FTIR and zenith-scattered visible sunlight SAOZ measurements over the period 1990 to 2009 as well as a composite satellite nadir data set constructed from ERS-2/GOME, ENVISAT/SCIAMACHY, and METOP-A/GOME-2 observat...

The effects of low concentrations of nitric oxide (NO) and nitrogen dioxide (NO2) on actively dividing cultures of Staphylococcus aureus, Micrococcus luteus, Micrococcus roseus, Serratia marcescens, Bacillus subtilis, Bacillus circulans, Bacillus megaterium, and Bacillus cereus were studied. Fresh cultures of each organism were incubated for 24 h at 25 degrees C on both nutrient agar and minera...

Trends in NO2 derived from a 45 year integration of a chemistry-climate model (CCM) run have been compared with ground-based NO2 measurements at Lauder (45 S) and Arrival Heights (78 S). Observed trends in NO2 at both sites exceed the modelled trends in N2O, the primary source gas for stratospheric NO2. This suggests that the processes driving the NO2 trend are not solely dictated by changes in...

Ozone Monitoring Instrument (OMI) tropospheric NO2 vertical column density data were used in conjunction with in-situ NO2 concentrations collected by permanently installed monitoring stations to infer 24 h surface-level NO2 concentrations at 0.1 (∼11 km) resolution. The region examined included rural and suburban areas, and the highly industrialised area of Windsor, Ontario, which is situated d...

The time-kinetics of NO2 induced effects on bronchial responsiveness are poorly known as most observations have been made shortly after exposure. The aim of this study was to measure nonspecific bronchial responsiveness, lung function and inflammatory markers at different times after NO2 exposure in asthmatics. Nineteen subjects with mild asthma were exposed to either purified air or 488 microg...