As Butte-Silver Bow’s health officer, I am asked often asked if Butte, home to the nation’s most expansive Superfund site, has a higher cancer rate than the rest of the state and the nation.
Butte of course nests near the Berkeley Pit, described by writer Edwin Dobb as a “bitter pool” of “corrosive waters.” The Pit – some of us old natives need not call it by any other name – is only the most visible and obtrusive among the many sites comprising our Superfund properties. Also contributing are Butte Priority Soils, Lower Area One, West Camp/Travonia Mine, Westside Soils, Parrot Tailings, Diggings East, Northside Tailings, Blacktail Berm, Montana Pole and Treating, Rocker Timber, Rhone Poulenc/Rhodia and Silver Bow Creek.
So, the thinking goes, if we’re all living on this heap of poison, shouldn’t we be dying of cancer at a rate higher than the rest of Montana and the country? An anecdote from a recent Butte high school reunion is telling – a person living out of state and attending the reunion queried classmates living in Butte about how they could possibly stay – “You’re all dying of cancer!”
Actually, no, we’re not all dying of cancer. While Butte-Silver Bow sees slightly higher rates for a few cancers, by and large our county sees rates comparable to the rest of Montana and the country, and sometimes our rates are lower. A variety of data sources tells the story.
The Montana Department of Public Health and Human Services (DPHHS) recently published community health profiles of all Montana counties. The 2015 Butte-Silver Bow Community Health Profile relays that Butte-Silver Bow saw 569 incidences of cancer from 2011 through 2013, for a rate (per 100,000) of 430.3. Montana’s rate was 439.9 (these data come from the Montana Central Tumor Registry).
For the profile, DPHHS also compared the cancer rate of Butte-Silver Bow (considered a “medium county” with a population of 10,000 to 40,000 residents) to other medium Montana counties – those counties saw a cancer rate of 442.1.
Butte-Silver Bow’s Community Health Profile also shows a lower rate for prostate cancer (79.6 compared to Montana’s rate of 112.8 and a medium county rate of 103.0); a lower rate for female breast cancer (95.4 compared to 115.7 for Montana and 113.9 for the medium counties); a lower rate for lung/bronchus cancer (50.2 compared to 56.4 for Montana and 56.7 for the medium counties); and a comparable rate for colon/rectum cancer (37.3 compared to 36.9 for Montana and 37.9 for the medium counties).
Butte-Silver Bow has a higher rate of uterine cancer (32.1 compared to Montana’s rate of 25.4 and a medium county rate of 29.8) and melanoma (30.8 compared to a rate of 24.9 for Montana and 23.4 for the medium counties).
When Butte-Silver Bow’s cancer incidence rate is age-adjusted and compared to the rest of Montana and other medium counties, the trends hold true – lower rates for prostate, female breast and lung/bronchus, a comparable rate for colon/rectum and higher rates for uterine and melanoma.
Several other data sources also point to Butte-Silver Bow cancer rates that are comparable to the rest of Montana and the country.
The 2014 Butte-Silver Bow Community Needs Assessment, with a maximum rate of error at ±4.9 percent at the 95 percent level of confidence, shows that 7.2 percent of respondents had been diagnosed with some type of cancer, compared to 8.0 percent for the rest of Montana and 6.7 percent for the United States. The assessment says that Butte-Silver, then, has a prevalence of cancer diagnoses similar to the rest of Montana and the country.
In May 2012, DPHHS published a fact sheet titled “Cancer Incidence in Silver Bow County, Montana, and the United States.” This publication too shows that, for the diagnosis period of 2001-2010, Silver Bow County’s cancer incidence rate was the same as the U.S. and Montana rates.
The DPHHS fact sheet goes so far as to point out the heavy metals and chemicals that might be of concern in Butte-Silver Bow – arsenic, inorganic lead, organic lead, metallic mercury and inorganic mercury, methylmercury compounds, and pentachlorophenol – are known to have potential to cause cancers of the lung/bronchus, bladder, kidney and liver. Incidences of lung/bronchus, bladder, kidney and liver cancers in Butte-Silver Bow are the same as the rest of Montana and the United States.
“None of these cancers (except for lung cancer) are known to be affected by the heavy metals or chemicals of concern in Silver Bow County,” says the fact sheet. “Lung cancer is … associated with arsenic exposure. However, the majority of lung cancer cases are caused by cigarette smoking.”
Because of our environmental challenges, Butte-Silver Bow has a cancer brand. Happily, the data show this brand to be unwarranted and undeserved.