Challenges and Opportunities for Communicating Lead Exposure Risks in Idaho’s Silver Valley

1. Despite largely successful efforts to reduce lead hazards in the United States and globally, exposure to Pb remains a priority in many mining-impacted regions.

2. Health protective behaviors can reduce the risks of exposure to lead in mining-impacted regions.

3. Risk communication strategies in the study area have shifted over time to be more inclusive of community input.

4. Variations in risk perception and efficacy levels may influence residents’ intentions to practice health protective behaviors.

5. Developing health risk messages that elevate both risk perception and efficacy levels is challenging yet may be vital to encourage behavior change.

Globally, heavy metal contaminants such as lead (Pb) pose significant public health risks, especially in mining-impacted communities [1, 2, 3, 4]. People are exposed to Pb by ingesting or inhaling contaminated materials including dust, soil, consumer products, or water [5]. Pb poisoning—a consequence of exposure to Pb—damages the central nervous system and causes developmental delays [1, 6]. Children and pregnant women are most vulnerable to experiencing health effects [5]. However, even low levels of exposure contribute to chronic health problems such as obesity and cardiovascular disease [1, 7]. Research into the long-term health effects of Pb exposure prompted organizations like the Centers for Disease Control (CDC) to conclude there is no evidence of a safe level of exposure [3, 6].

The enforcement of new regulations and implementation of Pb abatement programs have reduced the presence of Pb [8]. In the United States, the Superfund program, a federal program administered by the Environmental Protection Agency (EPA), was established to remove and remediate hazardous waste such as Pb at contaminated sites [9]. Actions to remove or remediate waste are referred to as primary prevention activities. Although primary prevention is a top priority, the program also focuses on secondary prevention including risk communication and outreach [10]. Risk communication is important because eliminating Pb hazards and ensuring communities are safe places to live in is challenging, especially at sites impacted by mining and smelting where contaminants are widely distributed by wind and water [11, 12]. Even areas appearing safe, such as riverbanks downstream from a current or former mining site, may be contaminated. Avoiding exposure requires health protective behaviors, or behaviors to prevent the inhalation or ingestion of contaminants [13]. For instance, when recreating or working outdoors, avoiding exposure requires handwashing prior to eating and wearing a face covering in dusty conditions. Preventing potentially contaminated items, like shoes and jackets, from entering homes prevents Pb from contaminating house dust [14].

Informing people about the importance of health protective behaviors is a critical risk communication challenge for public health districts in mining-impacted communities [13, 15]. Risk communication is a complex social process including the exchange of real-time information, advice, and opinions between experts and the people facing threats [16]. Often, the health risk messages communicated by experts do not result in the recommended behavior changes [17]. An underlying reason for the disconnect has been attributed to the processes used to develop risk communication strategies [15]. Previous research highlights the importance of building trust through risk communication based on two-way information sharing [16]. Two-way information sharing means that the people at risk of exposure participate in the conversations about developing and implementing risk communication strategies. Initially, the Superfund program relied on top-down risk communication techniques where experts informed the people exposed to hazards about their risks. The approach eroded trust between the EPA and communities [18, 19]. Although challenges remain, the EPA now attempts to promote risk communication strategies informed by two-way information sharing at Superfund sites [20, 21, 22].

Developing effective health risk messages through two-way information sharing is an important risk communication objective. Health behavior theories can be applied to guide message development using risk communication strategies in these cases. The Extended Parallel Process Model (EPPM; figure 1) has guided thousands of health behavior change campaigns like smoking cessation [23, 24]. The model is conceptually based on another popular health behavior theory, the Health Belief Model. As described in Witte et al. [23], the model guides parallel understanding of whether a health risk message is likely to lead to a desired behavior change. The primary premise of the EPPM suggests a person makes decisions about whether to change a behavior based on a multidimensional appraisal of:

1. perceived risk appraisal (perceived susceptibility + severity)

2. efficacy appraisal (perceived response efficacy + self-efficacy)

The two dimensions of the perceived risk appraisal, perceived severity and susceptibility, distinguish whether a person perceives a risk as severe and believes they are susceptible to experiencing negative health outcomes, respectively. The two dimensions of the efficacy appraisal, self-efficacy and response efficacy, refer to beliefs a person can perform a recommended behavior and beliefs a behavior will prevent negative consequences associated with a risk, respectively. If a message fails to elevate both perceived risk and efficacy levels, it is unlikely to result in the desired behavior change [25]. Furthermore, when an appraisal of a perceived risk is high, but efficacy is low, defensive reactions and fear may lead a message to backfire, for instance, by instilling distrust in experts among the people facing the threat. Effective health risk messages must improve awareness and knowledge of a risk and assure there are actions individuals can take to lower their risk.

Perceptions and responses to health risk messages are also influenced by individual, social, and cultural factors [26, 27]. For instance, prolonged awareness of and exposure to a risk can result in a risk perception normalization effect where people develop strategies to reduce their risk perceptions toward a known threat [28]. People who have lived in an area longer may perceive persistent hazards as being less risky relative to the perceived risks of short-term residents [29]. For instance, people living in coastal areas may discount the risk of coastal hazards such as sea level rise [28, 30]. Understanding how different factors influence risk perception and efficacy appraisals can improve health risk messages [31, 32].

The goal of this case examination is to explore risk communication strategies, risk perception and efficacy appraisals, and behavioral intentions in a mining-impacted region of northern Idaho, United States. The region is often called the Silver Valley because it was once among the richest mining districts in the world [33]. The Silver Valley encompasses the second largest Superfund site by size with the largest residential population living within a Superfund site boundary, the Bunker Hill Superfund site [33]. A large-scale environmental remediation and restoration has been in progress since 1983 when the site was listed on the Superfund National Priorities List [34]. We analyze the previous and existing risk communication strategies employed by the Panhandle Health District (District) and present results from a community survey of risk perception and efficacy appraisal and behavioral intentions. The District leads secondary prevention efforts to communicate about the health risks of Pb exposure [35].

The Silver Valley, which includes most of Shoshone County, Idaho, has a mostly White population and has remained around 12,700 residents since the 2010 Census (figure 2). The median income as of 2018 was US$39,935 compared to US$50,985 for Idaho as a whole [36]. The population is aging, with nearly 25% of people above the age of 65. Shoshone County ranked 41 out of 42 counties in the 2018 Idaho County Health Rankings [37]. On average, incidence of chronic diseases such as cardiovascular disease and obesity is higher in Shoshone County than other Idaho counties [38]. Despite social, health, and economic disparities, the Silver Valley is a recreation and tourism destination, recognized for all-season activities including skiing and downhill mountain biking [33].

Mining of Pb, silver, and zinc began in the Silver Valley in 1883 and continues today on a smaller scale [39]. At the mining industry’s peak, the region had a sophisticated network of mining infrastructure including an extensive railway network, a zinc processing plant, a lead smelter, and hundreds of mine sites [33]. Concerns about human health and environmental degradation date back to the early twentieth century. Discharging mine waste into rivers and streams was a common practice, and both miners and domestic animals began exhibiting symptoms of Pb poisoning [33]. In addition, atmospheric emissions from the Pb smelter, which operated from 1917 to 1981, increased Pb contaminants in the soil [40].

Following a fire at the smelter in 1973, children experienced the worst case of acute symptoms of Pb poisoning ever documented in the United States [33, 39]. Blood lead screenings of area children at the time revealed that 99% had levels exceeding 40 µg/dL [41]. These events, along with decreasing Pb prices and a changing regulatory environment, led to cutbacks and closures in mining operations [33, 42]. Contaminated mine waste washed down the South Fork of the Coeur d’Alene River and its tributaries and was traced as far as Spokane, Washington, approximately 75 miles away from the Bunker Hill Superfund site [43]. The area is now one of the largest metal-contaminated regions in the United States, with close to 10,000 people living within the Superfund site boundary [34].

Over 7,000 residential yards, green spaces, commercial properties, and other public areas have been remediated in the study area through the Superfund program [44, 45]. Primary prevention initiatives have included the removal and replacement of a top layer of contaminated soil with clean soil [46]. Blood lead levels among children are close to the national averages [45]. Once-treeless hillsides have been revegetated and recreation sites draw all-season tourists in increasing numbers. Despite the success of primary prevention, complete containment of mine waste is infeasible, and Pb hazards remain [41, 43]. The clean soil that currently acts as a cap over the contaminated materials can be washed away during flooding events, re-exposing contaminated materials. Approximately 2,500 km² of floodplains and wetlands, also popular recreation destinations, are a focus of ongoing primary prevention because they are often contaminated [43]. Seasonal flooding events exacerbate health risks as even previously remediated areas can be recontaminated [47]. Today, the District works closely with other government agencies and community organizations to ensure residents and visitors in the Silver Valley remain informed about and protected from Pb hazards.

The District’s current approach to secondary prevention and risk communication includes offering free blood lead level screenings, posting warning signs in areas with possible contamination, and providing resources to help residents limit contamination sources on their property [48]. Health risk messages recommend:

• Hand and face washing prior to eating and following recreation or outdoor work in contaminated areas

• Playing in grassy areas rather than on bare soils

• Not eating produce grown in contaminated soil

• Using a protective barrier such as a blanket when sitting on sandy beaches

• Washing potentially contaminated pets, toys, and recreation equipment [35, 49]

Signs are a primary means of warning people when Pb contaminants are present at public recreation access points and old mine sites. Although the District has focused on developing and updating the signs, factors external to the signs themselves have also constrained the impact of risk communication strategies.

The health risk messages used in the Silver Valley have evolved considerably since the initial designation of the Superfund site. Originally, warning signs were simple—featuring skull and crossbones imagery (figure 3)—a clear warning of the severity of the issue. The signs did not communicate the importance of health protective behaviors and therefore did not offer a message to heighten efficacy appraisals. Messages appealing to fear without offering a solution, such as recommendations about protective behaviors, are more likely to lead to negative responses such as denial [50]. Constraints in the impacts of the original signage were exacerbated by broader communication challenges. The impact of the initial signs was likely limited by the lack of trust and two-way information sharing between community members and the EPA [42]. In the 1980s, when the Superfund site was initially designated, community members expressed resentment toward agencies like the EPA as the Superfund designation and the end of mining led to decades of economic turmoil [33]. For those resentful of the EPA, the Superfund site designation was often blamed for the economic hardship [39].

In the 1990s, the District posted updated signs listing the recommended protective behaviors and providing the District’s contact information. These signs were posted in more locations and did not include a strong fear appeal as the original signs did. However, they were difficult to read and often ignored by the public (figure 4). For instance, signs were posted in areas set back from contaminated beaches that are also popular destinations for recreationists. Observations by the District indicated that recreationists did not pay attention to the signs. Again, several external challenges likely limited the impact of the signs. First, recreation and tourism in the region was beginning to experience growth in this time period. Recreation projects, including the conversion of a 72-mile strip of contaminated decommissioned railroad along the river into a paved recreational trail, made accessing beaches, which contain contaminated sediment, easier [33]. Posting signs at dozens of recreation sites was difficult. In addition, linger mistrust between citizens and the EPA continued to constrain risk communication [39].

The current risk communication strategy takes a more comprehensive approach. It relies more on a two-way information sharing between residents and experts. The District developed new signage, this time with input from other government agencies, local government, community members, and private landowners [35]. The signs integrate the region’s rich mining history, show historic images of mining, and explain why dangerous mine waste remains in the sediments (figure 5). In doing so, the signs remind people of the severity of the risks, list the health protective behaviors, provide the District’s contact information, and outline why Pb hazards pose a health risk. The signs are customized to specific locations and, in some instances, are tailored to different audience types. For instance, signs located on highly contaminated beaches, accessed only by water, have been replaced with signs that are more easily read from a boat. To appeal to dog owners, because pets can track contaminated materials indoors, signs are posted in contaminated areas where people frequently walk and their dogs feature a picture of a dog playing outside (figure 6). Eye-catching colors and images also help draw attention to the signs. Signs are connected to opportunities to practice recommended behaviors; temporary handwashing stations have been installed next to signs at certain recreation locations (figure 5).

In addition to signage, the District’s current strategy relies on a range of education and outreach events to remind and inform residents about Pb exposure. An annual Environmental Science and Technology Fair hosted by the District allows residents, including students, and experts working on the Superfund remediation to exchange ideas and network. District employees provide educational programing about Pb hazards and the area’s mining history in local schools and for community groups. The District provides free blood lead screenings for nearby residents [45]. Combined, the new signs and community outreach initiatives are intended to provide reminders about the risk of Pb hazards and protective behaviors. However, observations by District employees indicate people often continue to ignore the recommended protective behaviors.

The District’s interest in continuing to improve their risk communication strategy prompted a community–university partnership between the researchers at the University of Idaho and the District. The goal of the partnership was to improve understanding of how risk communication strategies could become more responsive to residents’ perceptions about Pb hazards [51]. To investigate perceptions about risk and efficacy appraisals and health behavioral intentions, we conducted a community survey in March 2019. The survey was distributed during the transition to the newest signage and before the first summer recreation season when the signs were posted. Respondents’ exposure to the new signs was therefore likely limited.

The community survey was designed and pretested at community events where the District hosts educational booths (n = 87). Pretesting ensured the survey items were interpretable for residents. Survey items included questions and statements about respondents’ perceived risk and efficacy related to Pb contamination and behavioral intentions to practice the recommended health behaviors, as well as sociodemographic questions related to age, length of residency, gender, occupational status, and educational attainment. Survey items were developed based on existing research and the primary variables of the EPPM (i.e., perceived severity, perceived susceptibility, self-efficacy, response efficacy, and behavioral intentions) [23]. Here, we report on several survey items; however, for a more detailed analysis of the survey and the underlying variables associated with health behavioral intentions, see Cooper et al. [52].

Four survey items were about participation in recreation and outdoor activities and actions related to possible exposure to Pb contamination, and the Likert scale ranged from 1 = never to 5 = very often. Ten survey items related to the four variables of the EPPM. For instance, the item, “I worry about lead contamination while spending time outdoors,” was used as a measure for perceived severity. The scale for these items ranged from 1 = strongly disagree to 5 = strongly agree. Three items were included to assess behavioral intentions. For these items, respondents were asked to consider their behaviors over the next 12 months. The scale for behavioral intentions ranged from 1 = very unlikely to 5 = very likely. These items included a “does not apply” response option.

In March 2019, the survey was distributed using a drop-off, pick-up method in neighborhood clusters proportional to community populations in Wallace, Kellogg, and Pinehurst, and 773 households were sampled. Neighborhood clusters contained multi- and single-family households. A presurvey notification was mailed a week prior to the survey drop-off period, and field staff visited each household up to three times to deliver surveys. Consenting adults (18 years of age or older) were eligible to participate, and participation was randomized by asking the responsible adult with the closest birthday to complete the survey [53]. When a respondent agreed to complete the survey, staff coordinated a time to return to the house to collect the completed survey. After three failed delivery attempts, staff left a survey packet (cover letter and survey) and prepaid return envelopes at the residence. Of the 773 households, 324 surveys were returned, 14 of these surveys were incomplete, and 30 were returned by mail. Conducting the survey in March ensured the sample included our target respondents—full-time residents—because of variable winter and summer populations from recreation and tourism.

Survey data were manually entered into Qualtrics, an online survey platform. Each survey was entered twice by two different researchers, and an accuracy check was performed. Discrepancies between the two entries (<1%) were manually corrected. R Studio (version 1.2.1335, PBC, Boston, MA, USA) was used to analyze the data. Descriptive statistics (means, frequencies, and standard deviations) were calculated for the Likert-type survey items and the sociodemographic questions.

The age of survey respondents ranged from 19 to 92 with a mean of 54 years (table 1). On average, respondents reported living in the study area for 33 years. Fifty-four percent of respondents were females. Ninety-one percent indicated a race/ethnicity of White, consistent with the demographics of the study area. Thirty-three percent reported having a high school education or less, while 36% reported having a college (2 or 4 year) or advanced degree. Reflective of the aging population in the region, 36% of respondents were retired. Slightly fewer than half (44%) of the respondents reported having a family member (or being involved themselves) in a mining-related occupation. Overall, the survey respondents were slightly older, more educated, and more likely to be females related to the Shoshone County population.

Three survey items asked respondents how often they had thought, read, or attended events about Pb contamination (figure 7). Respondents “rarely” or “sometimes” reported doing these activities. Fewer than 20% reported having attended a meeting or event about Pb contamination in the past year. Respondents did report moderate levels of reading or hearing about Pb contamination. Over 60% of respondents reported at least “sometimes” reading or hearing about Pb contamination. Just under 60% of respondents indicated they participate in recreation activities “often” or “very often,” while only 15% “never” or “rarely” recreate or work outdoors. These results indicate opportunities to improve the impact of risk communication strategies.

Results indicate low to moderate levels of perceived risk and efficacy and high levels of behavioral intentions (figure 8A–D). The items assessing perceived susceptibility had the strongest levels of disagreement. Less than 10% of respondents “agreed” or “strongly agreed” with the statement “I have experienced health effects related to lead contamination.” Responses to two items related to perceived severity were relatively more mixed. About a quarter of respondents reported they worried about Pb contamination, while 50% of respondents “disagreed” or “strongly disagreed” with the statement items about severity. The three items about self-efficacy reflected moderate levels of efficacy. Between 25% and 30% of respondents reported neutral responses to these items. The two items measuring response efficacy had higher agreement than the items about self-efficacy. About 50% of respondents agreed with the statements, “I am aware of the available resources for preventing health effects of lead contamination” and “I know how to prevent health effects from lead contamination.”

For questions related to behavioral intentions, at least 60% of respondents were “likely” or “very likely” to report high intentions (figure 9). Respondents were more likely to report being “very likely” for the item, “how likely is it that you will wash your hands with clean water or wipes before eating or drinking after recreating or working outdoors?” relative to the two items about staying on designated trail and promptly removing dirt from clothes, toys, pets, cars, and equipment after spending time outdoors. Less than 20% of respondents reported it was “unlikely” or “very unlikely” they would practice the protective behaviors.

The survey provides an overview of respondents’ risk and efficacy appraisal and behavioral intentions based on the EPPM. A primary premise of the EPPM is that high risk and efficacy appraisals will lead to behavior change. Survey respondents reported high levels of behavioral intentions, which suggests general awareness about the behavioral recommendations. Overall risk and efficacy appraisals were low to moderate.

Risk communication about Pb remains a priority in the Silver Valley, despite years of primary and secondary prevention. The low self-reported attention to Pb contamination issues reported in our survey suggests signage does not constitute adequate risk communication. Further, despite the District’s recent efforts to improve awareness about Pb contamination through hosting and attending meetings and events, few respondents reported attending events or meetings related to Pb contamination. Indeed, research in other contaminated regions has highlighted the challenges of maintaining long-term awareness and concern among residents in or near Superfund sites [13, 15, 16]. The District’s new strategy, to host a community science and technology fair annually, is one way to maintain and expand dialogue about Pb exposure. Intentionally creating opportunities for information exchange at these events may help to promote two-way information sharing while reminding people about ongoing risks of Pb exposure.

The EPPM demonstrates the importance of health risk messages that elevate risk and efficacy appraisals. In the Silver Valley, fewer than 15% of respondents to our survey agreed they were susceptible to experiencing health effects related to Pb contamination. Health risk messages in the Silver Valley may benefit from elevating awareness about the negative health consequences associated with Pb exposure, for instance, its connection to diseases such as diabetes and cardiovascular disease. There may also be opportunities to continue heightening efficacy appraisals, for example, by installing more portable handwashing stations at recreation sites. Efforts to monitor whether people use the handwashing stations are also needed. Finally, at health fairs and workshops, the District could provide free doormats with reminders about removing shoes before coming indoors to remind people not to track potential contaminants indoors by cleaning or removing their shoes before entering their home.

Developing messages to increase both efficacy and threat appraisals within a community is challenging yet important, as we found in the Silver Valley. For Pb hazards, health risk messaging may be strengthened by highlighting the negative health consequences of Pb contamination, citing scientific evidence of the health risks associated with even low levels of exposure. Even the District’s most recent signage does not include transparent messages based on the CDC conclusion that there is no safe level of Pb in the human body. Completely preventing Pb exposure requires continued focus on risk communication strategies to complement ongoing primary prevention activities.

Future research should continue to develop strategies for monitoring actual behaviors over behavioral intentions. The high levels of behavioral intentions found in the survey did not align with the District’s observations of people practicing nonhealth protective behaviors. Unfortunately, systematically observing actual behaviors is methodologically challenging [54]. However, coupling actual data with survey data about risk perception and efficacy appraisals would provide a holistic understanding of associations within the EPPM. Another area for future research is the investigation of risk perceptions, efficacy, and behaviors among tourists and part-time residents compared to permanent residents. The long history of mining, the Superfund site designation, and existing risk communication strategies likely influence residents’ risk and efficacy appraisals and, therefore, their likelihood of practicing health protective behaviors. Part-time residents and tourists do not have the same experiences and may respond to health risk messages differently. When messaging primarily relies on signage, customizing signs to different audiences is challenging [13]. However, the District’s new strategy to develop signs based on a site’s primary recreational usage may improve communication.

This case examination encourages a critical analysis of future risk communication challenges and opportunities at sites with Pb hazards. The District’s recent strategies have shifted from posting dire warning signs to carefully designed signage developed with input from community groups and other government agencies. The new strategies align with research-based recommendations to build risk communication strategies based on a two-way information sharing [21, 55]. At the same time, the survey results indicate few people have recently attended events or meetings about Pb contamination. A continued focus on developing innovative approaches for engaging residents may facilitate greater public participation in risk communication. There is a need for cross-site documentation on approaches to risk communication to generate a common set of best practices guiding risk communication across sites with Pb hazards [13].

1. Define primary and secondary prevention activity at Superfund sites. Which activities should be prioritized?

2. Describe the two appraisal processes affecting whether a health risk message will lead to behavior change according to the Extended Parallel Process Model.

3. Reflect on a time you have been exposed to risk communication, for instance, through a health risk message. Which aspects of the message or strategy resonated with you? Did any aspects backfire and make you feel defensive or uninterested? What aspects of your background do you think influenced how you reacted to that communication?

4. Why should risk communication strategies rely on two-way information exchanges between experts and the people at risk? What could the District do to develop risk communication strategies with community members?

CMC was responsible for the conceptualization of this project, investigation, and formal analysis. CBW was responsible for the conceptualization and supervision of the project, and paper revisions. VTW provided expertise on environmental mitigation activities in the study area and aided in developing the teaching notes. MSG contributed to all stages of writing this paper.

This manuscript would not have been produced without the continued support and guidance of the Panhandle Health District.

The authors have declared that no competing interests exist.

This research was funded and supported by NSF-IGERT award number 1249400, Mountain West Clinical Translational Research—Infrastructure Network under a grant from National Institute of General Medical Sciences of the National Institutes of Health under award number 2U54GM104944, and the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation DBI-1639145.

Supporting information includes slides (PDF) and teaching notes (DOC).

The risk perception survey data are archived at the University of Idaho. For access to the survey instrument and de-identified survey data, please contact the authors.