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Feds, state evaluate arsenic contamination in Butte

Montana Standard - 3/26/2024

Mar. 26—A federal public health agency whose work is meant to complement the EPA's at Superfund sites began last year to take a closer look at arsenic contamination in Butte soils and residential attics.

Although arsenic is a naturally occurring element, Butte's history of mining and smelting created wastes contaminated with elevated levels of arsenic. Wind-blown dust and well water can be two pathways affecting health.

The Centers for Disease Control and Prevention notes that the concentration of arsenic in soil varies widely, adding some mining and smelting sites "may contain much higher levels of arsenic."

The Montana Department of Public Health and Human Services began in July to request soil and dust sampling data from the Butte Residential Metals Abatement Program.

In October, the department and the federal Agency for Toxic Substances and Disease Registry, or ATSDR, began evaluating that data. ATSDR says it works to protect communities from harmful health effects related to exposure to natural and man-made hazardous substances.

"DPHHS expects to submit a draft health consultation to ATSDR for technical review in late spring," said Jon Ebelt, a spokesman for the state agency. "A draft health consultation for public comment is expected during the second half of 2024."

DPHHS is conducting the Butte arsenic health consultation and ATSDR is providing technical assistance, Ebelt said.

Data available in the Residential Metals Abatement Program were collected between 1980 and 2023. The program is designed to reduce residential exposure to potential sources of lead, arsenic and mercury by evaluating residential living spaces in Butte and initiating cleanup where indicated.

Ebelt said the health consultation includes arsenic in soils and dust data from residences, schools, parks and daycares. Data from the most recent parks sampling is not available because it hasn't been validated yet, according to Eric Hassler, director of reclamation and environmental services for Butte-Silver Bow County.

Hassler said arsenic and lead tend to be commingled in attics in Butte but that lead tends to be more prevalent in soils.

In November, Kai Elgethun, Ph.D., a Denver-based regional director for ATSDR, told a gathering of more than 30 people at Montana Technological University that a full-fledged exposure investigation — one seeking volunteers for urinary specimens or other biological testing — would not happen during fiscal 2024. The federal fiscal year ends Sept. 30.

But he repeatedly told the gathering that ATSDR anticipates an ongoing focus on public health issues in Butte that might be tied to arsenic and/or lead.

"We're glad to be here," Elgethun said then. "We expect to be around and working on stuff in Butte for the long haul."

Dr. Seth Cornell, an internal medicine specialist in Butte, is a member of the Butte-Silver Bow County Board of Health and a longtime Superfund watchdog.

"From my perspective, I believe an exposure investigation [in Butte] is warranted," Cornell said. "That's based on the high frequency of arsenic exceeding established standards in local household attics — greater than 50% — the high frequency of arsenic exceeding established standards in residential wells within EPA's West Side Soils Operable Unit Mine Study Area — around 50% — and the near absence of arsenic biomonitoring afforded to the citizens of our community."

The EPA's residential action level for arsenic for both Butte and Anaconda is 250 parts per million for soils and attic dust.

An exposure investigation in Anaconda in 2018 recruited 367 volunteers of all ages for biological testing for blood lead levels and urinary arsenic.

ATSDR found that the amount of lead in the volunteers' blood or arsenic in their urine "was similar to the amount of lead and arsenic found in the bodies of people in the United States who don't live in Anaconda."

The Anaconda smelter released inorganic arsenic, the toxic form of the element. Organic arsenic is found in the diet, primarily in seafood.

ATSDR reported, "A few people had elevated inorganic arsenic but not at levels that would generally cause health problems."

One recommendation from the agency to Anaconda residents was to limit how often they visit attics, where copper smelter emissions bearing arsenic and lead accumulated for decades.

Unlike EPA, ATSDR is a non-regulatory agency. Its focus is public health and its standards for what constitutes toxicity tend to be more stringent than EPA's.

Elgethun has said that ATSDR has the capacity to use GIS and other approaches to identify potential at-risk neighborhoods and demographics in Butte-Silver Bow County.

Exposure sources for inorganic arsenic can include contact with contaminated soil or dust, industrial processes and drinking water.

"Perhaps the single-most characteristic effect of long-term oral exposure to inorganic arsenic is skin changes," the CDC reports. "An important concern is the ability of inhaled inorganic arsenic to increase the risk of lung cancer. This has been seen mostly in workers exposed to arsenic at smelters, mines and chemical factories, but also in residents living near smelters and arsenical chemical factories."

As is true for lead, ingestion by children of contaminated soil may be a source of exposure. There is some evidence that inhaled or ingested inorganic arsenic can injure pregnant women or their unborn babies, although the studies are not definitive.

The CDC observes, "If you are exposed to arsenic, many factors will determine whether you will be harmed. These factors include the dose, the duration and how you came in contact with it."

People routinely take in small amounts of arsenic in the air they breathe, the water they drink and the food they eat. Health officials are more concerned about inorganic arsenic, which tends to be associated with environmental exposures.

In November, Elgethun asked the crowd to be patient, noting that ATSDR, a small federal agency, sometimes moves at a glacial pace.

"You know, like I said, we're here for the long haul," he said.

The evaluation of arsenic-related soils and dust in Butte will guide what happens next.

"The health consultation will provide recommendations on how to address any concerns the assessment identifies," Ebelt said.

According to the National Library of Medicine, "Although arsenic homicides commonly receive media publicity, the primary source of arsenic toxicity to the general population is by contaminated water, soil and food products."

The library adds, "Arsenic is a byproduct in smelting processes for many ores."

Meanwhile, EPA is reevaluating its action level for lead contamination in soils in Butte. The level that triggers a yard replacement has been 1,200 parts per million, whereas the action level in Anaconda and East Helena and many other places has been 400 ppm.


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