PATS Pollutant information

DRAFT 8/2/10 - PATSAC Committee Update
PATS Pollutant Information

Every air toxic has a different story. DEQ is able to measure (monitor) some pollutants directly in the air.
Some are present at levels too low for us to measure accurately or at all. For others we may be able to
simulate (model) the amounts by computer programs. We know the health effects of some pollutants
while scientists are investigating the health effects of others. One thing we do know is that information
about air toxics is evolving and we are learning more all the time. For the air toxics listed below, this
document provides summaries of the best information DEQ has at this time. As more information is
available DEQ will provide updates.

This document contains a general description of the pollutant, human-caused sources, health effects,
the Oregon ambient benchmark concentration and whether each pollutant in Portland is above or
below the benchmark based on 2005 data. The benchmark is the concentration of an air toxic in outdoor
air that would result in an excess lifetime cancer risk level of one in a million or a non-cancer hazard
quotient of one as established by the Air Toxics Science Advisory Committee.

Each pollutant description includes a pie chart showing relative contributions from human-caused
sources for each pollutant in the Portland area. DEQ is currently updating air toxics data to project
emissions for 2017. The 2017 projections may result in changes to ...