Dirt Alert: Legacy Mining Contaminant Exposure in Preschool

Institution: Sierra Streams Institute
Investigator(s): Joanne Hild, M.S. Zoology - Peggy Reynolds, Ph.D. -
Award Cycle: 2017 (Cycle 23) Grant #: 23AB-1300 Award: $125,738
Award Type: CRC Pilot Award
Research Priorities
Etiology and Prevention>Etiology: the role of environment and lifestyle

This is a collaboration with: 23AB-1301 -

Initial Award Abstract (2017)

Introduction: Cadmium (Cd) and Arsenic (As), cancer-causing metals associated with increased risk of breast and uterine cancers, are widespread contaminants throughout the Gold Country of northern CA as a result of extensive historic gold mining. The three most populous counties in Gold Country have age-adjusted breast cancer rates that rank in the top ten of the 58 counties in CA. Findings from the CA Health Impacts of Mining Exposure study (CHIME) indicate that older women who are long term residents have a significantly increased body burden of Cd and As compared to younger women and to women of the same age who are recent arrivals. This project seeks to expand this investigation by assessing whether young children, who represent a particularly important window of vulnerability for breast cancer, are being exposed to the metals of concern in preschool gardens, through incidental soil ingestion, inhalation of metal-containing dust, and consumption of plants grown in local gardens. In terms of exposures, children are a sensitive population and when living near contaminated sites, they receive the majority of their metal exposure through indirect ingestion of soil and dust due to hand-to-mouth transfers of the contaminated media. Conducting an exposure assessment that takes into consideration multiple exposure routes is crucial in order to protect the developmental health of children.

Question(s) or hypotheses: 1) Due to wind and water erosion of nearby mining sites, we anticipate that targeted garden sites have been impacted by nearby legacy mining activities, that soil As and Cd concentrations will exceed residential soil screening levels and US soil averages. 2) Soil As and Cd concentrations, along with other soil parameters, will, in turn, affect the concentrations of outdoor dust and uptake of As and Cd in vegetables. 3) By using a co-created citizen science approach with an extensive report back process, we anticipate increasing participantís a) understanding of the fate and transport of As and Cd that may affect their environmental health; b) capacity to make informed decisions and reduce potential exposures; and c) ability to share data and communicate results.

General methodology: Using citizen science, we will actively involve community members to develop the research plan, sample collection, and report back materials for participants and the community. Together the scientific partners, Sierra Streams Institute, and the Community Advisory Board (CAB) will develop and evaluate ways to convey research findings, exposure mitigation strategies, and recommended screening and prevention practices.

Innovative elements: Only a limited number of co-created citizen science projects have been completed, and even less in conjunction with risk communication. Dirt Alert innovatively combines a co-created citizen science program with a robust report back process with a cultural model of risk communication. This project is implementing proven techniques to increase participation from historically underrepresented groups in citizen science and STEM informal science activities. The multimedia exposures assessment (water, soil, plant, air) to As and Cd for children near legacy mining sites is innovative in several ways: it includes locally grown produce combined with a dietary assessment, implements a state-of- the-science technique to understand the chemical composition of dust particles, and assesses the percentage of As and Cd that is bioavailable to the human body for absorption via incidental soil ingestion and inhalation of potentially metal-laden air particles.

Community involvement: This is a project conceived by the community, led by the CAB, and prompted by concern among local residents about the health effects of their mining legacy. The present proposal builds on a high level of community engagement in the previous CHIME study and trains participants as citizen scientists to collect environmental data, an approach that is central to SSIís stewardship model. With 16 years of citizen-generated validated environmental data, SSI will lead the environmental data collection effort by designing rigorous protocols and training participants in their use.

Future Plans: Further research is expected to include: expanding biological and environmental sampling to a larger geographic area; studying other outcomes related to mining contaminants such as other cancers and overall mortality. Planned future research will benefit the target community by empowering the work of citizen scientists, determining and disseminating strategies to minimize exposure, engage the community in cleanup efforts and information campaigns, and support requests for funding to clean up miningís toxic legacy throughout Gold Country.