Project Summary Here we propose the development and implementation of a community-based air monitoring program for small towns, cities and regions around the world. AQEarth will be a synthesis of the best aspects of Denver?s Love My Air Program, funded by the Bloomberg Mayor?s Challenge, and AQTreks, a K-12 educational outreach program developed by 2B Technologies under a NIH/NIEHS SBIR Phase I and II project. AQEarth will empower communities to explore air pollution in their own neighborhoods and identify those sources that contribute most to their personal exposures. Communities participating in the AQEarth program will make use of three technologies developed successfully in three different SBIR projects ? two from NIH and one from NSF. The Personal Air Monitor (PAM) allows students and other community members to measure the air pollutants CO, CO2 and particulate matter (PM1, PM2.5) along sidewalks, inside their homes, schools and workplaces and inside vehicles like cars and buses. A Mobile Air Pollution Sensors (MAPS) monitor will be developed here to upgrade our current CarTopper for measurements of five Criteria Air Pollutions ? CO, PM2.5, O3, NO2, SO2 ? along with CO2, the primary tracer of combustion and the most significant greenhouse gas. Accurate low-cost, sensor-based measurements of NO2 and SO2 will be made possible by the novel use of ozone generated by UV light as an internal standard to reduce sensitivity drift (an innovation likely to be patentable) and the use of a zeroing scrubber to cancel baseline drift. MAPS will enable mapping of these air pollutants throughout a city with high spatial resolution using a combination of community vehicles such as parents? cars, buses, trams and city service vehicles. The third SBIR-developed technology that makes mobile measurements using low-cost sensors possible is AQSync, a fixed- base monitoring station containing highly accurate miniaturized instruments. The AQSync will serve both as a walk-by or drive-by reference station for maintaining the calibrations of the low-cost mobile sensors of the PAM and MAPS and as a long-term monitoring station for determining the diurnal, day-to-day and seasonal variations of air pollutants at that location. The AQEarth program will be deployed in three U.S. cities (Ft. Collins; CO, Anchorage, AL; Atlanta, GA), one tribal area (Navajo Nation, NM), and one international city (Mexico City) over a period of three years. This will allow us to gain experience with cities having a wide range of climates, a tribal jurisdiction, a community where environmental justice advocates will participate (Atlanta) and an international city. The program will be continuously improved as we gain experience with cities/tribes with widely different challenges. The AQEarth is a collaborative project with TD Environmental Systems, LLC, a leader in applications of air quality sensors, and the Denver Department of Public Health and Environment, where the highly successful Love My Air program was developed. The final deliverable will be a replicable community-based program for air pollution measurements coupled with education about air quality and its health effects and discovery of actionable knowledge that can be used to reduce exposure to air pollutants and improve human health.