Combative SLO County officials grill leading scientist in air quality

October 5, 2023

By KAREN VELIE

During a San Luis Obispo County Air Pollution Control District (APCD) board meeting last week, county Supervisor Jimmy Paulding grilled a leading scientist in air quality who successfully fielded his, at times, loaded questions.

It was a rare chance for the board to hear from Dr. Lynn Russell, one of the nation’s leading scientists in the study of airborne particulates and other aerosols. The board has regularly attempted to block the views of scientists who have questioned the APCD’s inaccurate assertions regarding the makeup of dust blowing on the Nipomo Mesa.

In 2010, the APCD claimed that toxic crystalline silica dust from off-road activity posed a health risk for people living on the Nipomo Mesa. Years later, a study of the dust determined it did not contain crystalline silica.

Since 2011, the APCD has attempted to regulate and fine State Parks for dust blowing on the dunes for a variety of reasons all related to off-road vehicle recreation at the Oceano Dunes.

For more than a decade, the APCD claimed that 100% of PM10, which refers to any airborne particle that is 10 micrometers in diameter or smaller, blowing on the Mesa was mineral dust. However, Russell conducted a study that refuted their claim and lowered that number to 14%.

After more than a decade of alleging dust on the Mesa was 100% mineral dust, the APCD’s Scientific Advisory Group ran their own smaller study, which also found a low percentage of mineral dust contained in the particulate matter blowing on the Mesa.

However, the APCD’s latest argument is that it does not matter what the PM10 is comprised of.

Here are the biggest takeaways from Russell’s appearance at the APCD meeting:

Dr. Russell’s presentation, which lasted 24 minutes, was followed by a 28-minute attempt by Paulding to disparage Russell’s investigation, findings and ethics.

Paulding began his grilling of Dr. Russell by asking who paid for the study, in an apparent attempt to accuse Russell of a conflict of interest.

Russell rebutted Paulding, saying she was working under a contract with State Parks and the University of California San Diego, which required the funding not have anything to do with the results.

In an attempt to promote the APCD’s argument that particles of saltwater in the air are as damaging to humans as particles of carbon, Paulding asked if Russell supported federal regulations that refer to the amount of PM10, regardless of content.

The more important health effects are from the toxicity of the particles, Russell said explaining that it matters if the PM10 is black carbon or dust from the dunes.

“The federal regulations, as often happens, are lagging the science,” Russell said. “We now understand more than they did in the 60s, when this legislation was written.”

Supervisor Bruce Gibson noted he had a doctorate in geophysics, before saying the APCD never concluded that 100% of the PM10 blowing on the Mesa was dust.

SLO Councilwoman Jan Marx used her time to question Dr. Russell’s qualifications and to accuse her of being combative during her presentation. Marx later said she was not referring to Dr. Russell as unqualified, she was calling an unnamed chemist unqualified.

Grover Beach Mayor Karen Bright later refuted Marx, saying that Dr. Russell was not combative during her presentation. County Supervisor Dawn Ortiz-Legg also said Russell was not combative, but quite pleasant.

Pismo Beach Councilman Scott Newton apologized to Dr. Russell for the way some of his fellow board members treated her during the meeting and thanked her for her work.

The board then voted unanimously to receive and file Dr. Russell’s report.

Highlights Of Dr. Lynn Russell’s APCD Presentation On Oceano Dunes