The American Lung Association recently published their annual report regarding the air quality in the United States. The current report utilizes data from 2011, 2012 and 2013 to grade the
Ozone and Particle pollution levels in the different counties and metropolitans nationwide.
Ozone levels – Grade C
24 hour particle pollution – Grade C
Annual particle pollution - Pass
Compared to last year’s report (for the years 2010-2012) there were fewer high ozone days and the same amount of 24-hour particle pollution days (see below the color classification and explanation regarding the grading system).
Ozone:
Year of report
2014
2015
Orange days Red days Purple days Weighted
Average
10
6
0
0
0
0
3.3
2.0
24-hour particle pollution:
Year of report
2014
2015
Orange days Red days Purple days Weighted
Average
4 0 0 1.3
4 0 0 1.3
Overall score
F
C
Overall score
C
C
In Contra Costa:
Since 1996: there were 8.8 fewer high Ozone days per year in this report
Since 2000: there were 13 fewer high 24-hour particle pollution days per year in this report

In order to grade the measured levels the American Lung Association (ALA) used a weighted average calculation. Every day was classified and assigned a color according to the pollutant level:
Good Moderate
Unhealthy for sensitive populations
Unhealthy
Very
Unhealthy
While the number of orange days received a factor of 1, red days received a factor of 1.5 and purple days a factor of 2. In other words the least healthy days were more influential for the final result.
The number of days in each category was multiplied by its factor and summed to a total. The total was then divided by 3 (since the data was collected for a 3-year period).
Last, the weighted average was classified into grades A, B, C, D or F.
 The State of the Air 2015 shows that progress in improving the nation’s air quality was mixed. Many cities experienced strong improvement and many others suffered worse episodes of unhealthy air.

Since the Clean Air Act in 1970, the air has gotten cleaner while the population, the economy, energy use and miles driven increased greatly. As the economy continues to grow after the recession, overall air emissions that create the six most widespread pollutants continue to drop.

The best progress came in the continued reduction of year-round particle pollution in the eastern half of the nation .

Many cities had a record number of days with high short-term particle pollution , particularly in the West, where continuing drought and heat may have increased the dust, grass fires and wildfires, while burning wood as a heat source appears to contribute to the problem in many smaller cities.

Fresno-Madera (CA) remained the most polluted metropolitan area for both yearround and short-term particle pollution, as it was in the 2014 report

Los Angeles remains as the metropolitan area with the worst ozone pollution, as it has for all but one of the 16 reports.

Of the 25 most polluted cities by Ozone levels 7 are in California (Los Angeles-Long
Beach, Visalia-Porterville-Hanford, Bakersfield, Fresno-Madera, Sacramento-
Roseville, Modesto-Merced, El Centro)

Of the 25 most polluted cities by 24-hour particle levels 7 are in California (Fresno-
Madera, Bakersfield, Visalia-Porterville-Hanford, Modesto-Merced, Los Angeles-Long
Beach, San Jose-San Francisco-Oakland, Sacramento-Roseville)


Of the 25 cleanest cities for year round particle pollution 1 is in California (Salinas)

Children and teens

People age 65 and older

People with asthma, chronic bronchitis, or emphysema

People with cardiovascular disease or diabetes

People with low incomes
Ozone (O
3
) is a gas molecule composed of 3 atoms of oxygen. The ozone layer found high in the upper atmosphere (the stratosphere) shields us from much of the sun’s ultraviolet radiation.
However, at ground level where we can breathe it (in the troposphere), it may cause serious health problems. Ozone is created from nitrogen oxides (NOx), hydrocarbons also called volatile organic compounds (VOCs) and carbon monoxide (CO).
When these gases come in contact with sunlight, they react and form ozone. The average daily Ozone level per month (averaged for years 2008-2013):
0,04
0,035
0,03
0,025
PPM 0,02
0,015
0,01
0,005
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Particle pollution (also called particulate matter or PM) is the term for a mixture of solid particles and liquid droplets found in the air. Coarse particles are between 2.5-10 micrometer and fine particles are smaller than 2.5 micrometer (PM2.5). This is a diverse group of particles that arise from various sources. The small particles can get deep into the lungs and cause health problems.

The report presents data regarding PM2.5. The average daily PM2.5 level per month (averaged for years 2008-2013):
PM2.5 Contra Costa 2008-2013
18
16
14
12
µg/m³
10
8
6
4
2
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Drive less, use less electricity, avoid burning of wood or trash, support clean school buses and community plans to reduce air pollution. Speak up for healthy air protection.
For the complete State of the Air report and results by state or zip code: http://www.stateoftheair.org/
For more information on what can be done: http://www.stateoftheair.org/2015/key-findings/what-needs-to-be-done.html
To find out more about the health risks from Ozone and Particle pollution: http://www.stateoftheair.org/2015/health-risks/
To learn more about the six common air pollutants: http://www.stateoftheair.org/2015/health-risks/
For a summary of the clean air act by the Environmental Protection Agency: http://www2.epa.gov/laws-regulations/summary-clean-air-act
To find data about the air quality in California: http://www.arb.ca.gov/aqmis2/aqdselect.php