When Rose Eitmiller found a new house on Sweet Pea Lane in Dewey-Humboldt, Ariz., population 3,613, she felt at home. She was still mourning the death of a daughter whom she always called "Sweetpea," and the place seemed right to her.
But that move in 2004 only brought more heartache for Eitmiller. Four years later, U.S. EPA dug up her front lawn in a successful search for arsenic, and Dewey-Humboldt soon became a Superfund site.
Now the town is one of several locations in the western United States that scientists say could become a major source of airborne arsenic poisoning due to global warming and breakneck human expansion.
"If arsenic's in the air, if all that stuff is in the air, there's really nothing you can do," Eitmiller said. "That's the sad thing, you really can do nothing once you're here, and I've been here going on nine years."
Arsenic ore is present throughout nature, and rainfall gradually washes arsenic particles through the soil into the groundwater, often in small enough amounts that are safe for humans to consume. Sometimes this natural concentration is augmented by man-made arsenic, usually from factories, smelters or mines.
Dewey-Humboldt, nestled in the heart of the Prescott Valley between Phoenix and Flagstaff, has both natural arsenic and deposits of the toxic chemical from a retired mine and a retired smelter. Scientists from the University of Arizona are testing to see how much is getting into the air.
As global warming means rain becomes less frequent in some areas, and soil and rocks dry up, scientists think much of the arsenic that should be leaching into the groundwater will instead be blown into the air.
"Here in Dewey-Humboldt," Eitmiller said, "we're not getting the rain that we used to get."
The expanding dangers of dust
The West is getting dustier. A recent study from the University of Colorado found that dust depositions have dramatically increased in the past 20 years, due to increased aridity, wind transport and human activities.
Clark Lantz, a University of Arizona professor researching arsenic in dust in Dewey-Humboldt, is looking specifically for how dangerous the arsenic in the town's dust might become. By studying the composition of the dust, he's hoping to determine how likely it would be for the arsenic fractions to break away from the dirt particles that they're riding on and create greater exposure and damage to the human body.
"As climate change occurs, I think there'll be areas where it becomes more arid, and if arsenic is part of the geologic landscape it could potentially become a problem," Lantz said.
Based on his preliminary research, Lantz thinks the highest exposure levels in Dewey-Humboldt are still from water. Airborne arsenic would be an "additional burden," he said. One of the most significant complications he noted was how airborne dust could affect human lungs via inhalation, since arsenic ingested in water only reaches the stomach.
If inhaled particles were small enough, they'd be able to slip through the lining of the lungs and enter the bloodstream.
The health effects from inhaling arsenic are still largely unknown. EPA has classified inorganic, or man-made, arsenic as a human carcinogen. Exposure to arsenic has been strongly linked to problems such as heart disease, hypertension, and bladder and lung cancer.
A recently study by scientists at Texas Tech University also found that safe levels of arsenic and estrogen, when combined, can double the risk of prostate cancer, raising the possibility that even "safe" levels of arsenic could become harmful when combined with other toxins in the environment.
Stirring things up
While the Southwest is getting dustier, it's also attracting more new residents than any other region in the country. Nevada, Arizona and Utah were the three fastest-growing states in the country according to the 2010 census. Scientists think this rapidly swelling human presence is also contributing to the rising dust problem.