PM10 describes inhalable particles, with diameters that are generally 10 micrometers and smaller. This indicator measures the annual average PM10 concentration. Small particulate matter can lodge in the lungs and cause or aggravate the effects of asthma, lung diseases, and heart disease. Elevated concentrations of PM10 can reduce regional visibility and are associated with increased regional haze. The primary sources of PM10 in the Tahoe Basin are motor vehicle emissions, paved and unpaved road dust, wood smoke, wildfire smoke, and construction dust. PM10 is monitored by TRPA and partners at three sites around the Basin. 


Annual average PM10 in the Tahoe Region.

Evaluation Map

The location of air quality monitoring stations in the Lake Tahoe Basin. PM10 is monitored by TRPA and partners at three sites around the Basin.

2019 Evaluation

Considerably Better Than Target
Moderate Improvement
View Evaluation

Applicable Standard

AQ10: Maintain Particulate Matter10 at or below annual arithmetic average of 20µg/m3 in the portion of the Region within California, and maintain Particulate Matter10 at or below annual arithmetic average of 50µg/m3 in the portion of the Region within Nevada. Particulate Matter10 measurements shall be made using gravimetric or beta attenuation methods or any equivalent procedure which can be shown to provide equivalent results at or near the level of air quality standard.

Key Points

  • Average levels of particulate matter have decreased over time, especially on the South Shore. 
  • Reductions in particulate matter on the South Shore can mostly be attributed to reductions in local sources such as increased street sweeping and improving the efficiency of residential wood burning stoves.
  • Particulate matter concentrations at DL Bliss show more steady levels over time. Because particulate matter at DL Bliss comes more from regional sources rather than local sources, regional sources of particulate matter do not appear to be dropping as much as local sources.

Delivering and Measuring Success

EIP Indicators

  • Miles of Street Sweeping

    Since 2009 EIP partners have swept more than 61,000 miles of roadways within the Tahoe Basin reducing fine sediment particles from roadways entering the air and water.

  • Non-Compliant Wood Stoves Removed or Retrofitted

    This EIP performance measure tracks removal of polluting wood stoves to reduce local air pollution for human and ecosystem health.

Example EIP Projects

Monitoring Programs