Valley has nation’s worst air: Rated serious for soot; extreme for smog

The San Joaquin Valley Air Pollution Control District in its “2015-16 Report to the Community” report relates, “As noted in the latest federal EPA’s National Air Toxics Assessment, nearly all of the potential health risk in the Valley is now associated with sources of emissions that are not within the District’s authority to control. In one example specified in EPA’s report, 35% of the risk was attributed to toxic chemicals formed in the atmosphere, 33% to mobile sources (on-road vehicles, off-road equipment, airport and railyard sources), and 31% to other sources (vegetation, fires, transport from other regions, other non-point sources). Only 1% was attributed specifically to industrial sources under District jurisdiction.”1


On page 9 of the air district’s most recent community annual report, a table is shown for the National Ambient Air Quality Standards (NAAQS) for ozone and fine particulate matter (PM 2.5). Categorized in the table are several pertinent parameters for each of the two pollutants and are profiled below.

Ozone (8-hour):

  • Standard – 75 parts per billion (set in 2008; went into effect 2012)
  • Classification – Extreme
  • Next Action – Plan of Attainment: Goes into effect July 2016
  • Date of Attainment – July 2032

PM 2.5 (24-hour; Annual):

  • Standards – 35 micrograms per cubic meter; 15 micrograms per cubic meter (set in 2006; went into effect 2009)
  • Classification – Serious
  • Next Action – Plan of Attainment: Goes into effect August 2017
  • Date of Attainment – December 2024 (including extension of 5 years)

PM 2.5 (24-hour; Annual):

  • Standards – 35 micrograms per cubic meter; 12 micrograms per cubic meter (set in 2012; went into effect 2015)
  • Classification – Moderate
  • Next Action – Request moving to “serious” reclassification October 2016
  • Date of Attainment – December 2030 (including extension of 5 years) 2

It is important to note that on Oct. 1, 2015, the U.S. Environmental Protection Agency lowered the threshold for ozone measured over 8 hours to 70 parts per billion – down from 75 ppb.

Additionally, it should be further noted that 85 percent of oxides of nitrogen (NOx) pollution in the Valley comes from mobile sources, according to the air district in its most recent community report.

On the bright side

Good news! With regard to the Valley, when it comes to toxic-air-emissions-related news and information, one can and does find a ray of sunshine every now and again. From the “2015-16 Report to the Community” report, below are listed year 2015 emissions reductions for the following pollutants (measured in tons per day):

  • Oxides of Nitrogen – 16.36
  • Volatile Organic Compounds – 46.72
  • Sulfur Oxides – 4.79
  • PM 2.5 – 15.42 of PM equivalent

Moreover, from the yearly community report for 2012-13, air district Executive Director/Air Pollution Control Officer Seyed Sadredin in the “Message from the Air Pollution Control Officer” section observed: “We have seen significant improvements in the Valley’s air quality, and clean-air strategies designed and implemented in the Valley now serve as the model for the rest of the state and the nation.”

To this fact, also in that earlier air-district document, Sadredin in that same “Message from” section added: “The progress we’ve made together over the past two decades is unmistakable: an 80 percent reduction in air pollution from Valley businesses, the cleanest winters and summers on record, the attainment of an important air-quality standard for particulate matter (PM 10), significant reductions in the number of days with unhealthy air quality, and being closer than ever to meeting tough new health standards for ozone.”

That said, it is a bit premature to declare total victory just yet as the Valley maintains its position as the country’s dirty-air hotspot on account of its propensity to corral and retain toxic air-borne contaminants. The reality is there remains a significant amount of air-cleanup work yet to do.

For more year 2015 report information, see: “2015-16 Report to the Community” here.


  1. “District Incorporates New Health Risk Assessment Guidelines for Enhanced Health Protection for Children,” San Joaquin Valley Air Pollution Control District, “2015-16 Report to the Community,” p. 7
  2. “District Forms a Public Advisory Workgroup to Guide Clean Air Strategies,” San Joaquin Valley Air Pollution Control District, “2015-16 Report to the Community,” p. 9

Department of corrections: It was originally related that PM 2.5 pollution in the Valley measured over 24 hours was rated as severe. Text and title have since been revised to reflect the correction.

– Alan Kandel

3 thoughts on “Valley has nation’s worst air: Rated serious for soot; extreme for smog”

  1. One industrial source under the District’s jurisdiction is large scale wineries. Approx. 1,500 tons of smog-forming ozone-precursor VOCs are release every year during the late-summer ozone season, yet the district requires no controls. Cost effective controls exist, but the largest wineries have successfully resisted enforcement of the Clean Air Act.

    • I am interested in learning how the approximately “1,500 tons of smog-forming ozone-precursor VOCs” are emitted per year and why this is happening (what activities or processes are responsible). I presume that this is Valley wide.

      • The process of wine fermentation releases large volumes ethanol vapor during the late-summer / early-fall crush. The top-20 large scale wineries are distributed throughout the valley, from Arvin to Lodi.

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