Peak concentrations were observed for both PM 2.5 and NO 2 when conditions were dominated by coastal-originated winds. During this deployment 1 h average concentrations of PM 2.5 and NO 2 ranged between 0.3 to 33.6 µg/m 3 and 1.3 to 50.6 ppb, respectively. The more » CSAMs were constructed by combining low-cost particulate matter size fraction 2.5 micron (PM 2.5) and nitrogen dioxide (NO 2) sensors and distributed across eight locations with four collocated weather stations to measure local meteorological parameters. Here we present results from the deployment of the EPA developed Citizen Science Air Monitor (CSAM) used to conduct approximately five months (October 2016–February 2017) of intensive AQ monitoring in an area of Puerto Rico (Tallaboa-Encarnación, Peñuelas) with little historical data on pollutant spatial variability. The emergence of low-cost (<$2500) sensors have allowed a wide range of stakeholders to better understand local AQ conditions. Environmental Protection Agency (EPA) is involved in the discovery, evaluation, and application of low-cost air quality (AQ) sensors to support citizen scientists by directly engaging with them in the pursuit of community-based interests. for Science and Education (ORISE), Oak Ridge, TN (United States) Sponsoring Org.: USDOE Office of Science (SC) OSTI Identifier: 1628712 Grant/Contract Number: SC0014664 Resource Type: Journal Article: Accepted Manuscript Journal Name: Atmospheric Measurement Techniques (Online) Additional Journal Information: Journal Volume: 11 Journal Issue: 8 Journal ID: ISSN 1867-8548 Publisher: European Geosciences Union Country of Publication: United States Language: English Subject: 54 ENVIRONMENTAL SCIENCES Meteorology & Atmospheric = , Publication Date: Mon Jan 01 00:00: Research Org.: Oak Ridge Inst. Jacobs Technology, Inc., Research Triangle Park, NC (United States).US Environmental Protection Agency (EPA), Boston, MA (United States).State of Colorado Department of Public Health and Environment (CDPHE), Denver, CO (United States).US Environmental Protection Agency (EPA), Atlanta, GA (United States).US Environmental Protection Agency (EPA), Denver, CO (United States).US Environmental Protection Agency (EPA), Research Triangle Park, NC (United States).for Science and Education (ORISE), Oak Ridge, TN (United States) US Environmental Protection Agency (EPA), Research Triangle Park, NC (United States). These results imply that continued fieldtesting is necessary to understand emerging air sensing technology. EPA and others, which could be due to different geographic location,meteorology, and aerosol properties. This study showeddifferent results for sensor performance than previous studies performed bythe U.S. Some sensors showed a change in response to laboratoryaudits/testing from before the sampling campaign to afterwards, such asAeroqual, where the O3 response slope changed from about 1.2 to 0.6.Some PM sensors measured wind-direction and time-of-day trends similar tothose measured more » by reference monitors, while others did not. The sensors displayed a range ofcorrelations with reference instruments, from poor to very high (e.g.,hourly-average PM Pearson correlations with reference measurements variedfrom 0.01 to 0.86). Most sensors showed high data completeness when dataloggers were functioning properly. Sensors were evaluated for theirdata completeness, correlation with reference monitors, and ability toreproduce trends in pollution data, such as daily concentration values andwind-direction patterns. A suite of particulatematter (PM), ozone (O3), and nitrogen dioxide (NO2) sensors weredeployed in triplicate and were collocated with federal equivalent method(FEM) monitors at an urban regulatory site. A seven-month,systematic field evaluation of low-cost air pollution sensors was performedin Denver, Colorado, over 2015–2016 the location was chosen to evaluate thesensors in a high-altitude, cool, and dry climate. This emergingtechnology motivates the assessment under real-world conditions, includingvarying pollution levels and environmental conditions. Air pollution sensors are quickly proliferating for use in a wide variety ofapplications, with a low price point that supports use in high-densitynetworks, citizen science, and individual consumer use.

Airbeam sensor