Why is This Important?

Clean air is essential to human and environmental health.  Clean air reduces the risk of lung disease and a variety of other health problems, including asthma, cardiovascular disease, and respiratory problems in children, while air pollution increases these risks. Air pollution can also damage local ecosystems, both terrestrial and aquatic.

What is a Sustainable State?

A sustainable state is one where the air is clean and poses no threat to human health or environmental quality.

How Are We Doing?

Particulate matter
• Suspended particulate matter (PM) is associated with asthma and other respiratory ailments, contributes to haze, and harms the environment. The size of particles (<2.5 μm or <10 μm) is directly linked to their potential for causing health problems, with the smaller particles most dangerous as they can lodge deep in the lungs. As of 2008, the nine-county Bay Area does not meet the new Federal PM2.5 air quality standard, and PM pollution is a growing focus for air quality pollution management programs.
• The main source of particulate matter in the county is vehicular activity, both from internal combustion engines and dust generated from roads and brakes. Other sources
include industrial processes, dust from construction sites, and wood combustion (including wood-burning stoves).
• In 2009, there was no day when concentrations of particulate matter exceeded national standards at the Redwood City air quality monitoring station. This is the second straight year with no non-attainment days.

Ozone
Ground-level ozone is the main component of smog. It can be a trigger for asthma even at very low levels and can cause permanent lung damage after long-term exposure.
• In 2009, there was no day when ozone concentrations exceeded the state one-hour standard at the Redwood City station, the fi fth straight year with no exceedances of the ozone limit.

Emissions Inventory
The California Air Resources Board (CARB) completed an updated air emissions inventory for San Mateo County in 2008. Among the important findings:
• On-road vehicles continue to be the largest polluters in the county. Vehicles are the biggest source of nitrogen oxides and reactive organic gases (the precursors to ground-level ozone formation), as well as carbon monoxide. CARB estimates that on-road vehicles emit over 106 tons per day of carbon monoxide within the county.