![]() ![]() Follow live air pollution data for South Lake Tahoe at the top of this page and on the IQAir air pollution app to know when smoke in South Lake Tahoe has reached unhealthy levels. PM2.5 pollution can remain suspended in the air for hours or even days, and is easily transported by wind. In air pollution terms, black carbon and other microscopic particulates are grouped together as PM2.5, which is fine airborne matter measuring 2.5 micrograms or smaller. Black carbon, or soot, is most of what we see and describe as smoke. South Lake Tahoe smoke usually comes from wildfires burning in the late summer and early fall, or from domestic wood burning in the winter. During temperature inversions, South Lake Tahoe’s PM2.5 pollution accumulates until conditions change. ![]() ![]() The warm air layer acts like a lid, preventing the cooler air from dispersing in the atmosphere. Temperature inversions occur when snow coverage creates a ground-level air layer colder than the air layer above it. These seasonal PM2.5 pollution swings occur as a result of increased emissions from wood burning, building heating, and car idling as well as pollution-trapping weather events known as temperature inversions. In 2019, South Lake Tahoe’s most polluted months for PM2.5 were January, October, and December respectively. In South Lake Tahoe, PM2.5 pollution is significantly higher in the winter months than in the summer months. On average, 11.3 days in this greater region are deemed as unhealthy PM2.5 days, landing the region 11 th for worst 24-hour particle pollution in the US out of 217 surveyed metropolitan areas. While data from the same 2016 to 2018 monitoring period in El Dorado County lacked sufficient data availability for 24-hour PM2.5, the greater Sacramento-Roseville area in California serves as a rough indicator. Carson city air pollution and Roseville air pollution are often culpable for affecting South Lake Tahoe’s own air quality, as they experience much hotter temperatures and higher ozone levels as a result. South Lake Tahoe’s warm, dry summers with little precipitation allow ozone to accumulate and be transported by wind from nearby cities. 1 The greater Sacramento and Roseville area, which includes South Lake Tahoe, ranked 5th nationally for highest number of ozone days out of 228 surveyed metropolitan areas. Counties that average more than the allowable 3.2 unhealthy pollution days for each pollutant are considered “non-attainment” regions.įrom 2016 to 2018, El Dorado County averaged 40.2 unhealthy ozone days a year, more than 12 times the federal target. The US EPA defines “good” air quality as air that poses little to no risk to health.ĭespite such an optimistic annual average, short-term pollution spikes have caused South Lake Tahoe’s El Dorado County to fail to meet federal targets for 24-hour ozone and PM2.5 pollution.įederal targets for short-term pollution spikes are based on a weighted 3-year average. In 2019, South Lake Tahoe averaged an annual AQI score of 21, meeting the “good” category threshold. ![]() The highest individual AQI value dictates the overall AQI score, and the pollutant at the riskiest level becomes the “main pollutant.” Usually fine particulate matter (PM2.5) and ozone are the main pollutants responsible for determining overall AQI for their pervasiveness and high risk to human health. AQI values are calculated by weighting six criteria pollutants for their risk to health in a formula. The US Environmental Protection Agency (EPA) created the air quality index (AQI) scale to serve as a means for conveying a location’s overall air quality. Sunlight and heat are required to force the reaction, however, and as a result, ozone only tends to accumulate in the hotter summer months. Ozone is formed in the atmosphere from primary pollutants that exist at relatively constant levels. Summers, on the other hand, tend to have low particle pollution but high ozone. Winters typically experience high particle pollution counts as a result of increased wood burning, building heating, and temperature inversions. Its highland climate features cold winters with regular snowfall and warm arid summers. How is the air quality in South Lake Tahoe, CA today?Īir quality in South Lake Tahoe varies in composition and severity depending on the season. ![]()
0 Comments
Leave a Reply. |