The haboob-riddled summer of 2011 may be outdone this year if the Valley’s drought conditions don’t make measurable improvements, one Arizona air quality expert said.
Until Sunday’s storm that dropped about four-tenths of an inch to nearly an inch of rain in parts of the East Valley, the Valley had gone nearly 90 days without significant rain. Those dry conditions can create a situation similar to – or possibly even worse than — what set up last year’s events — including the 5,000-foot-tall dust cloud that dumped 50,000 to 200,000 tons of dirt here on July 5.
Many longtime Valley residents had never even heard the word “haboob” before last summer. Then it entered our vocabulary with alarming frequency.
The significantly poor air quality conditions of early July – including that widely-photographed and nationally-chronicled dust event – were reported to the federal Environmental Protection Agency in a 214-page document finished this month by the Arizona Department of Environmental Quality.
Bottom line: Thunderstorms collapsed July 5 just north of Tucson in an extremely dry area where Pinal and Pima counties meet. It generated a pressure system – and winds up to 70 mph — that then delivered the dust and dirt to the Valley.
“The drier we are, the more concern I have for the summer and the blowing dust,” Eric Massey, head of air quality for the ADEQ, told the Tribune prior to this past weekend’s storm. “I would be lying to you if I said I wasn’t concerned about the lack of rain.”
PM-10 levels — those tiny particles that are smaller than a human hair — were exceeded around the Valley. Anything above 150 micrograms per cubic meter in a 24-hour average is considered to be exceeding federal health standards.
On July 5, a west Chandler monitor hit 360 micrograms per cubic meter in a 24-hour average. A Higley monitor hit 362.
Multiple days in that first week of July included, there were 14 days where the Valley PM-10 levels exceeded federal health standards last summer alone, due to varying sized dust storms.
Because of the dry conditions of early 2012, PM-10 levels have already been elevated this year. Winds kicked up 20 mph to 30 mph two weeks ago, which created dust in the Valley and a high pollution advisory. It was the second of the year.
The rain is needed in the desert to keep dust in place. No measure of human efforts can stop what happened last summer. Valley leaders are already taking steps to manage the impact of our population – from construction to driving on dirt roads — on dry conditions, and ADEQ is now taking public comment on its dust control measures report.
“In 20-plus years of air pollution plans, we’ve come up with every solution we can think of,” Massey said.
With so much in place, the next step is just “alert people” to upcoming wind events.
“This rain is helpful for the short term and helping the desert to form a protective crust. But without more rain more often, we still run the risk of dust storms in the long term,” said ADEQ spokesman Mark Shaffer.
It could lead to a summer of bad air quality.
But the rain of the past weekend should help for a few weeks, said Marvin Percha, meteorologist for the National Weather Service’s Phoenix office.
And it came at a good time. The Valley typically sees high winds in late March or early April.
But after that, the picture isn’t clear.
“For the next couple of weeks, we’ll probably have a break from the dust. But if we don’t get any more rain, it would likely create a problem in mid-April and onward,” Percha said.
Sure enough, temperatures are expected to hit the low to mid 80s by Thursday, which could dry up some of the moisture in the ground.
According to the U.S. Seasonal Drought Outlook, as of March 6 the Valley had severe drought conditions. And the group’s prediction is for the drought to persist or intensify through the summer.
Conditions of last summer create a health hazard for many in the Valley, said Dr. Jagruti “Julie” Patel, a pulmonary critical care physician who practices as Mercy Gilbert Medical Center. During last summer’s dust storms, she was working at an outpatient clinic.
“After that there was an increase of both admissions of asthma and COPD aspiration and an increase and diagnosis of coccidioidomycosis,” she said — coccidioidomycosis being the clinical name for Valley Fever, a lung disease that is transferred through fungus spores in the air.
Dust can irritate the airways and create an allergic reaction for those with airway disease, she said.
“If you have airway disease, use a mask when you’re outdoors,” Patel offered as advice for dust storms. “If you are an immune-compromised patient or HIV positive, you’re at higher risk of getting (Valley Fever) and it can be more detrimental. You should use extra precaution. Stay indoors and use a mask when you go outside.”
Contact writer: (480) 898-6549 or firstname.lastname@example.org