Although there are no available ambient air quality monitoring data within New Rochelle, regional state monitoring data are available to characterize the Fifth Avenue area. The region 3 Air Quality Control Region (AQCR), meets the State Ambient Air Quality Standards (AAQS) for all criteria pollutants (including ozone, sulfur dioxide, nitrogen dioxide, total suspended particulates, inhalable particulates, carbon monoxide, and lead) except ozone. The report, however, notes that high ozone levels are found throughout the northeastern United States, but this a regional problem more than a local problem and NYS along with other states have developed coordinating regulatory programs to work towards bringing the region into compliance. The sulfur dioxide annual concentrations have increased about 15% each year from 1994 to 1997, but decreased slightly between 1997 and 1998.

In terms of vehicle generated air quality, the primary pollutants include nitrogen dioxide, hydrocarbons, and carbon monoxide. Air quality impacts were calculated at four different intersections (Fifth Avenue and Portman Road, Fifth Avenue and Valley Peace, Madison Avenue/New Jefferson/I-95 Ramps, and Huguenot and North Avenue). The impacts were modeled assuming neutral atmospheric stability conditions and a 1 meter per second wind speed, which is representative of worst case dispersion conditions for urban areas. Table 3.10-2 of the DEIS presents the findings of the study in detail. The report indicates that all existing air quality concentrations were well below the AAQS.