Vital Signs: Particulate Concentrations – by sensor locations

VITAL SIGNS INDICATOR Particulate Concentrations (EN1) FULL MEASURE NAME Fine particulate matter concentrations (PM2.5) LAST UPDATED September 2016 DESCRIPTION Particulate matter concentrations refer to the amount of fine particulate matter (PM2.5) in the air we breathe. Fine particulate matter particles are very small, measuring less than 2.5 microns (μg) or 1/25 the width of a human hair – yet they pose a significant health risk. Air quality standards for particulate matter are expressed in two ways: the annual average (reflecting average concentrations during the course of a given year) and the 24-hour average (reflecting worst-case conditions in a given year). This dataset includes regional and sensor-specific concentrations, as well as metropolitan area data. DATA SOURCE Bay Area Air Quality Management District 1999-2015 Air Quality Sensor Data http://www.baaqmd.gov/about-air-quality/air-quality-summaries CONTACT INFORMATION [e-mail] METHODOLOGY NOTES (across all datasets for this indicator) Data is collected at specific sensor sites operated by the Air District that capture the concentration of fine particulate matter (PM2.5) in the air; sensor locations may change over the years and thus only minor relocations are shown as the same station in this analysis (e.g., sensor moved across the street from its prior location). Data either reflect the annual average or the 98th percentile day (worst-case conditions); some data are reported as three-year rolling averages to minimize noise associated with any given year. The worst location site may shift from year to year depending on which sensor location had the highest levels of fine particulate matter over that particular time period. The regional trend reflects the average of eight sensors that were available throughout the analysis time period, using an iterated 2-way ANOVA for interpolation in gap years.