… Long-term trends are quantified using seasonal-trend … in the northeastern United States.
Prior studies of these data included … The analysis of long-term trends of the measured particle …

… vehicles will lead to even lower vehicle emissions and further improvements in air quality. We
review historical vehicle emissions and air quality trends … vehicle emissions in urban areas. …

… for seven other US metropolitan areas with populations … US cities considered here: the
long-term trend in NO x /CO enhancement ratios is driven by changes in motor vehicle emissions…

… in long-term observed trends, we aggregate all datasets to annual averages at monitoring
locations. … , potentially highlighting the influence of CO transport into urban areas. EC annual …

The northeastern United States has experienced significant emissions reductions in the last
two decades leading to a decrease in PM 2.5 , major gaseous pollutants (SO 2 , CO, NO x ) …

… using isotopic signatures, the urban-to-rural CO 2 gradient, and emissions of the valley as
a … on diel and seasonal timescales, long-term trends of CO 2 across an urban area, and the …

… This study aims to examine the long-term trends of atmospheric PAHs at the national-level in
the US, … an overall downward trend (6–9% annual reduction) in urban areas, but not in rural …

… , and recent developments in methods using high … metropolitan region. We estimated
separately the PM 2.5- attributable burden from emissions from all motor vehicle traffic in the region …

… in policies and regulations aimed at decreasing PM 2.5 concentrations in urban areas. …
results over the same period nor investigated long-term trends from mobile sources in the Midwest…

… urban area in general and whether these cities are representative of vehicle emissions
elsewhere in the US … ratios were −3%, −10%, and 11%, respectively, without significant trends. …