Asbestos in Arizona

Asbestos Exposure in Arizona

Many Native American reservations owned asbestos prospects. They distributed the fibers to local and national businesses. By the early 1980s, most mining districts shut down after threatening public health. One example is the Gila County Salt River region, the most profitable area. Hundreds of miners and industrial laborers with extensive exposure experienced serious health complications. The direst is mesothelioma, rare cancer that typically affects the lining of the lungs.

The state’s asbestos mines were not the only sources of exposure. A 2008 U.S. Geological Survey (USGS) report explained additional origins. Limestone deposits in the counties of Gila and Pinal were contaminated. These sites were in addition to the documented asbestos sites. Occupational exposure has been documented in several Arizona industries as well.

In May 2018, the Arizona Supreme Court ruled that defendants are not liable for illnesses from secondary exposure. Five justices supported the ruling and two dissented. The dissenters wrote that children have a greater right to protection from secondary exposure.

Occupations and Environmental Areas at Risk in Arizona

At least 103 known sites in Arizona contain naturally occurring asbestos. Of these, 96 are chrysotile deposits in central Arizona, specifically throughout Gila and Pinal counties. The highest concentrations of the toxic mineral occur in northern Gila County. Here, 90 deposits are near U.S. 60 in Salt River Canyon. Minor deposits are also present in Cochise, Yuma and Coconino counties.

Historically, mine workers in Arizona faced exposure to harmful amounts of the mineral at the job site. Chrysotile asbestos has been continually mined in Arizona since 1872. One exception is a nearly complete stop in production during the Great Depression. Natural deposits were first discovered in the Salt River region of Gila County. From 1913 to 1966, miners excavated approximately 75,000 tons of asbestos from more than 200 sites. All such mining in the area ceased by 1982.

High levels of occupational exposure are associated with three fatal respiratory diseases:

Dangerous levels of exposure occurred in several other industries as well. Many industrial sites throughout Arizona have a history of using or processing asbestos. Examples include copper mills, power plants and construction sites.

Job Sites with Known Asbestos Exposure

Arizona’s economy grew as asbestos manufacturers produced materials for commercial use.

W.R. Grace operated a vermiculite plant in Phoenix. The facility was also known as Solomon’s Mines. It was a sister site for the company’s mine in Libby, Montana. Fibrous amphibole asbestos is present in the soil and dust near the area. Their levels were considered toxic to public health.

Mines

Over a period of 53 years, 160 Salt River Canyon mines produced more than 75,000 tons of asbestos. The production from an additional 60-70 mines operating in the area remains unknown. Miners who removed raw asbestos from the earth were at high risk of inhaling the dangerous fibers they disturbed daily.

Asbestos was once considered the most critical mineral resource at Arizona’s San Carlos Apache Reservation. Home to seven such mines, the first property was discovered in 1922. Asbestos mining on-site generated approximately $500,000 worth of revenue by 1956.

Numerous other mines operated in Coconino, La Paz, Cochise, Yuma and Pinal Counties.

Ari-Zonolite Vermiculite Processing Plant

Glendale was home to a large vermiculite processing facility known as Ari-Zonolite. It received more than 212,458 tons of vermiculite ore from the W.R. Grace mine in Libby, Montana. The site is infamous for asbestos contamination. Arizona ranks eighth in the nation for the volume of vermiculite processed from mines in Libby. Ari-Zonolite refined vermiculite ore between 1951 and 1964. Other businesses used the building until 2002. The facility contained multiple structures, including a one-story brick room formerly used as a boiler room. Raw ore was stored in the building until it was placed into the furnace to be processed.

A 2011 U.S. Environmental Protection Agency (EPA) investigation revealed contamination levels. Three out of seven soil samples at the Ari-Zonolite site contained tremolite-actinolite asbestos. Residual asbestos contamination was also present in indoor air samples. The workers at the plant during its time as the Ari-Zonolite facility were likely exposed to toxic dust regularly. Exposure also occurred in the years following the company’s closure. Additionally, as many as 6,059 Arizona residents living within a one-mile radius of the facility may have encountered asbestos.

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