8/11/2023 0 Comments Downtown sacramento weatherFrom 2000 to 2015, effective regulations on vehicles have resulted in a 66% reduction of VOCs and a 62% reduction for nitrogen oxides. The largest reduction in this segment is attributable to gas-powered vehicles. Emissions for both precursor pollutants have fallen steadily in recent years despite gains in population, vehicles, and economic development. Ozone is usually formed in the atmosphere from volatile organic compounds (VOC) and oxides of nitrogen (NOx) reacting to ultraviolet radiation. While particle air pollution and overall AQI in Sacramento has remained relatively stable in recent years, actual city-wide emissions of particulate matter and ozone precursor pollutants have steadily decreased due to implementation of local, state, and federal emission control programs. This wavering record for PM2.5 levels, however, has resulted in no clear improvement trend since 2011. These fluctuations reflect an unusually severe wildfire season in 2018. Year-over-year data, for example, shows that Sacramento’s air quality rose 27.8% from 2017 to 2018, then fell 40.8% from 2018 to 2019. Sporadic and unpredictable wildfires greatly influence yearly averages, making air pollution levels more difficult to control. But since 2011, Sacramento’s progress has not been a straight line. 4 In 2007, regulations on wood burning contributed to a 41% decrease in PM2.5 levels over 4 years. Since the establishment of the Clean Air Act and more recent legislation including the 1990 amendments, air quality has drastically improved across the state of California. In order to properly protect oneself from the health effects of air pollution, refer to the top of this page for Sacramento’s forecast air quality data and real-time air quality data. 3Īir pollution data varies hourly and daily. 3 Although the city’s ranking has remained relatively consistent for the last several years, true ozone levels have actually gone down by 40% in the last 20 years.4 Still, Sacramento experiences an average of 25 high-ozone days annually, far above the recommended target of 3 days or less. Nationally, Sacramento is the fifth most ozone-polluted city according to the 2019 State of the Air report released by the American Lung Association, comparing 228 metropolitan areas. Ozone is another pollutant of concern in Sacramento. 1,2 Winter months in Sacramento also experience strong cool air inversions as a result of the city’s high-pressure system, which can contribute to sustained high air pollution levels. In 2019, particularly during November, elevated air pollution levels in Sacramento were largely attributable to wildfires, such as the Ranch fire in Tehama County that burned more than 2,500 acres, and the Kincade fire in Sonoma County that burned 77,758 acres. This is typically because of increased wood burning and heating as well as temperature inversions that prevent polluted air from dispersing. November was the most polluted month of 2019, with a monthly PM2.5 average of 21.9 μg/m3, or AQI 72, followed by December (15.9 μg/m3) and January (13.6 μg/m 3).Įlevated pollution levels in the winter are common around the world. November, December, and January experienced average ratings of “moderate” that failed to meet US EPA standards. In 2019, Sacramento averaged a PM2.5 level of 8.7 ug/m 3, thereby meeting the World Health Organization (WHO) target for annual exposure (< 10 μg/m 3). Due to the pollutant’s prevalence and relatively high health risk, it is often responsible for determining the overall air quality index (AQI). PM2.5 is one of six criteria pollutants measured by the US Environmental Protection Agency (EPA) to determine an air quality rating. Air quality in Sacramento generally averages a US AQI rating of less than 50, or “good.” The “good” air quality distinction describes air that is satisfactory and poses little to no risk to health.
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