Why is DEQ Designating Portland as the First Air Toxics Geographic Area?
Compared to other areas of the state, the Portland region has the highest risk to the population from air toxics. Along with national estimates of air toxics emissions, Portland monitoring studies conducted between 1999 and 2005 helped confirm the presence of air toxics above levels that are protective of public health. Polycyclic aromatic hydrocarbons from wood and debris burning, benzene from auto exhaust and soot from diesel engines are currently the air toxics of most concern in the Portland area. DEQ also conducted a modeling study called the Portland Air Toxics Assessment (PATA), which included the influences of local topography, weather and emission patterns. This local scale model, coupled with better detail about the location of emissions, including traffic data, gave DEQ the capability to predict problem areas within the Portland region. For each pollutant, model estimates were plotted as maps that DEQ shared with community members and other stakeholders to provide more detai
