CTEC Study Tests Perceptions of Butte's Cleanup and Health

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CTEC Health Perception Study

CTEC Health Perception Study

CTEC Health Perception Study - Dave Hutchins

As reported back in October, there is a study on health perceptions in the community of Butte

happening now, that is being conducted jointly by the Citizens’ Technical Environmental

Committee and faculty and students at Montana Tech. Here’s CTEC board member Bill

MacGregor describing the study.

BM: “It’s a one-year pilot study funded by NIH through Montana INBRE program run out of

Montana State. We got funded to pursue a hypothesis, to explore a hypothesis, that a

significant gap exists between the perceptions of Butte residents, about health risks living in

Butte, is it safe, and the record of risk reduction associated with environmental cleanup,

reclamation and restoration work undertaken over the last thirty plus years.”

The study consists of two components, a systematic survey of the perceptions of members of

the community and a compilation of documentation of remedial actions and effects. The survey

is in the form of a mailed questionnaire that was mailed out recently and the other data was

collected from various official sources.

BM: “So, we’re surveying to see where the gap between reality and perception is, but also

between the official assessments of risk and anecdotal reports that contradict those. We want

to get that out on the table, so they are taken seriously.”

Raja Nagasetty, a professor in Environmental engineering at Tech and another CTEC board

member, is leading the project. They have received responses from their mail out survey, and

he and two graduate students presented some of their initial findings last Thursday at a CTEC

meeting. Here’s Raja on how they got started.

RN “We started with the literature review, the perceptions at different…35,000 Butte

population.”

Loran Brooks, an Environmental engineering student, led the effort to develop the

questionnaire. Here’s Loren talking about how they designed the questionnaire:

LB: “In designing the questionnaire instrument …quantifying perceptions.”

A Likert style is that familiar questionnaire method where a question is asked and then there

are multiple choice answers on a scale, in this case from “very good” to “very bad”.

Sarah Storey, an Industrial Health and Hygiene master student, led an effort to analyze the

consistency and reliability of the survey. They conducted Internal consistency tests and

repeatability tests to ensure the survey was operating as it should. After they, and the MSU Helps lab,

were satisfied they sent it out to 550 adults within the Butte city limits. They received responses from

163 participants, a respectable response rate in the world of mail-out surveys. They found respondents

were not entirely representative of the population, they were skewed toward older, higher income

citizens, but there was a wide enough range to produce some interesting data, and the gaps could be

filled in with other methods.

The survey is divided into five sections, including one on respondent information to establish

demographics. In order to tease out the perceptions as they relate to Superfund they started

with general questions about environmental health, and then asked a similar question as it

relates to mine waste. They needed a way to quantify perceptions, not an easy task, here’s

Loren describing the method:

LB: “This led us to establish a baseline of overall perceptions…lead arsenic and mercury?”

And they did see a difference between the baseline and the perceptions as they relate to

Superfund.

LB: “When we wanted to see if there was a significant difference between…There’s definitely a

gap, and it’s measurable.”

The next section of the survey looked at perceptions related to Superfund activity. It asked

respondents to gauge their familiarity with various projects, such as the Parrot removal or the

Residential Metals Abatement Program, and most seemed familiar with the goings on. Then it

asked them to gauge the effort the EPA and other agencies have made on remedial projects.

Most respondents had a positive perception in this section, agreeing that the EPA and RMAP

were doing at least a somewhat good job of protecting human health.

The largest disparity seemed to be found in the remaining section, the Effectiveness of

Remedial Actions section. These were questions about Cancer occurrence and blood lead levels

in children, and they were associated with published data commonly accepted as fact. The

responses to these questions were decidedly split, with some agreeing with the data, but many

others

For example, 62% of respondents believed that the cancer incidence rate in Butte is greater

than the national average. The study designers said this is in contrast to published data that

show our incidence rate is statistically the same as the national numbers. That phrase,

statistically the same, is thrown out often when discussing these issues and it can be difficult for

the public to decipher what is meant.

Often what they intend is that the difference is not statistically significant. So, let’s take a

deeper look at what that means. When analyzing something like cancer incidence rates, experts

don’t use the raw numbers, they adjust things so they can be compared directly. For instance,

age is a factor in cancer incidence, so the numbers are adjusted to reflect populations with

similar age distributions. And there are other factors that are similarly accounted for and

adjusted. In the end, you are left with data that can be compared, but there is a range, or an

uncertainty associated with the adjustments.

If the sets of data being compared fall within the uncertainty of each other, we say there is no

statistical significance in the difference. This does not mean they are the same, it means we are

not reasonably sure there is a difference.

There are many potential reasons people in Butte may think we have a higher cancer incidence

rate. Perhaps they have not studied the published data, or maybe they have anecdotal

evidence that they believe more strongly. It is also possible they have seen news of recent

studies that have shown there are higher mortality rates for some cancers that have been

linked to the contaminants of concern in our Superfund site. It would have been interesting to

see how respondents would have answered a paired question about cancer as it relates to

mining waste.

This study, even from this early stage, has shown there are indeed gaps. There are gaps

between the public perception of environmental health and the record of risk reduction. There

are gaps between the perceptions of some of our neighbors. And there are many gaps in the

information, there are many unknowns, and many sources of information. The folks conducting

this study hope we are one step closer to bridging these gaps and that knowing where we are

now will help inform the work ahead.

I’m Dave Hutchins reporting for KBMF.

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(Chart from Mt DPHHS report on cancer in BSB. These cancers rated are reported to be “statistically the same” https://www.co.silverbow.mt.us/DocumentCenter/View/14098/Cancer-in-Silver-Bow-County)