Produce Safety after Urban Wildfire
Urban Wildfire and Potential Contamination
The fires that spread through Northern California in October 2017 burned over 160,000 acres of wildland, suburban, urban and industrial areas, creating dangerous air quality conditions for the region that lasted long beyond the fires themselves. The wildfire smoke likely included high concentrations of toxic air contaminants. Following the fires, the Food and Drug Administration wrote a letter to the California Department of Food and Agriculture and the California Department of Public Health, stating that “toxic elements, firefighting chemicals, and combustion products such as polycyclic aromatic hydrocarbons (PAHs) and dioxins are of greatest concern.” There are well-known human health impacts from the inhalation of these contaminants. Additionally, plants have the potential to absorb air pollutants directly through their leaves,,, but little research has been done on the risk to human health from ingesting contaminants from smoke and ash on produce.
Impact on Local Farms and Gardens
Local farms and gardens played a significant role in food relief efforts immediately following the October 2017 wildfires, contributing produce to shelters and kitchens. Many farmers, gardeners, and community members were concerned about how the fire-related air pollution might impact locally-grown produce. Farmers were unsure of the potential health impacts of the fire on themselves, their workers, and their customers. School, community, and home gardeners were concerned about the potential health impact on children and other vulnerable groups.
Citizen Science Initiative
In the weeks following the October 2017 Sonoma County fires, concerned community members came together to launch the Produce Safety after Urban Wildfire Citizen Science Initiative. Sonoma County residents and members of the UC Master Gardener Program of Sonoma County collaborated to take samples from over 25 sites across the county using a sampling protocol created under advisement by Environmental Health and Food Safety Specialists. Samples included washed and unwashed produce, each in triplicate, to determine if contaminants were present and whether contaminants could be easily washed off produce. Volunteers focused on leafy greens with large surface area directly exposed to air pollution: kale, collards, chard, and lettuce. In total, over 200 samples were taken and frozen for subsequent laboratory analysis.
Soil contamination was also a concern for the community, and thus, community-led soil sampling at high priority sites was conducted in June 2018 to test for persistent chemicals at 7 months following the fires.
Online Toolkit - Produce Safety After Urban Wildfire
In the weeks following the October 2017 Sonoma County fires, concerned community members came together to launch the Produce Safety after Urban Wildfire Citizen Science Initiative. It is our hope that more communities experiencing an urban wildfire will expand the breadth of research on this emerging topic by coordinating citizen science research initiatives in their communities. This tool kit is designed for communities experiencing urban wildfire to conduct their own community-based research on the safety of local produce, backyard chicken eggs and soil as well as to provide background educational resources about the results of our study, the potential health impacts of urban wildfire smoke, and how to reduce risk.
This online toolkit contains links to the following resources based on topic areas:
Overview of project
Conducting your own community research
- Sample Recruitment Letter for Produce Study (for sites and volunteers)
- Produce Sampling Guide (with Optional Soil Sampling, Sampling Consent, Volunteer & Site Info)
- Sample Recruitment Letter for Egg Study
- Egg Sampling Guide
- Egg Submission Template (in English and Spanish)
- Soil Testing Sampling Guide
- Soil sampling checklist and protocol
- Tips for Interpreting Soil Analyses
- Groups of contaminants in soil
Testing & Analyzing Samples
- The list of chemicals that we considered and what we tested
- Site and neighborhood history, what new contaminants might have entered, what existing contamination might be aggravated
- List of resources for doing your site history research
- Determine Budget
- Determine capacity of lab
- Finalize your list of contaminants
- Considerations for analyzing your results from the lab -- how to decide what to test for, site history, etc.
- Prop 65 NSRL -- refer to final report
- “During a wildfire” social media graphic
- “During a wildfire” sample social media statement
- Heavy Metal Contaminant Resources Link
- Best Practices for Produce Safety After A Fire
- Wildfire and Backyard Poultry Safety handout
- “Understanding Risk” handout
- Soils in Urban Agriculture (UCCE publication)
- Workshop evaluation form
Results from our study of the fires in Santa Rosa in 2017
- Video Webinar: Post-Fire Food Safety
- Powerpoint from webinar: Post-Fire Food Safety
- Preliminary Report
- Final Report
REPORTS & RESOURCES
- *NEW Post Fire Food Safety PowerPoint Presentation with Speaker Notes
- *NEW Post Fire Food Safety Webinar
- *NEW Best Practices for Produce Safety After a Fire
- *NEW "During a Wildfire" Sample Social Media Statement
- August 2019 Final Report
- June 2018 Preliminary Report
- Understanding Risk: A community guide for assessing the potential health impacts of locally grown produce exposed to urban wildfire smoke
- Nov. 18, 2017 Community Gathering PowerPoint (pdf)
- Citizen Science Volunteer Packet, including sampling protocol and consent form for participating sites.
News & social media reports on our project:
- UCCE Sonoma blog, October 27, 2017: http://cesonoma.ucanr.edu/?blogpost=25509&blogasset=67477
- Is it safe to eat local produce after a wildfire? Updated July 19, 2018 and How toxic ash from wildfires could poison our food, July 22, 2018, Pacific Standard
- UCCE Sonoma blog, November 21, 2018: http://cesonoma.ucanr.edu/?blogpost=28737&blogasset=67477
- Citizen Science Examines Smoke On Our Produce with Geoffrey Riley & John Baxter, Jefferson Public Radio, Dec. 5, 2018
- UCCE Sonoma blog, March 8, 2019: http://cesonoma.ucanr.edu/?blogpost=29567&blogasset=67477
- Produce safety post-wildfire, Petaluma Bounty Blog, April 27, 2019
- Sonoma County Farm Bureau article November 2019 (see attached PDF)
- Up In Smoke, UC Davis Outlook magazine article Fall 2019: https://ucdavis.github.io/caes3dissue/Outlook-Fall19/
RESOURCES FOR COMMUNITY MEMBERS
Thank you to all the volunteers who contributed time and resources to this community research initiative and to all the farms and community gardens who provided produce from their sites to be tested!
As a citizen science project, this study depends on you, and in return, we are committed to staying in touch with you about the results from this study and next steps we can take as a community.
- Follow the project’s Produce Safety after Urban Wildfire Facebook Page for Updates.
- Join the Produce Safety after Urban Wildfire Google Group to coordinate with other volunteers, share resources with other community members, and get project updates and events in your inbox.
- USDA information sheet on Fires and Food Safety.
- Other disaster resources.
- BreezoMeeter: an air quality site that gives a breakdown of the different harmful elements in the air. Type your address and it gives you a reading.
FOR RESEARCH PARTNERS
Our Citizen Science project is still seeking research advisors and collaborators to study the impact of the North Bay fire on the food safety of local produce, from a cumulative health perspective. We are seeking collaborators with substantial experience in their fields who can weigh in as advisors, as well as graduate students and researchers who can lend substantial capacity- such as long-term collaboration for publications and thesis or dissertation work.
Above all: we are seeking researchers with a desire to research these questions in a holistic way that understands the value of local growers for a resilient economy, takes into account the health benefits of accessing fresh produce and the larger context of chemical contamination of the mainstream food system, and prioritizes collaboration with local community.
If you have these or other skills and have capacity to lend, please contact us at firstname.lastname@example.org.
 Lemieux, Paul M. "Emissions of Organic Air Toxics from Open Burning." Washington, DC, United States Environmental Protection Agency 62 (2002).
 Uzu, Gaëlle, et al. "Foliar lead uptake by lettuce exposed to atmospheric fallouts." Environmental Science & Technology44.3 (2010): 1036-1042.
 Kipopoulou, A. M., E. Manoli, and C. Samara. "Bioconcentration of polycyclic aromatic hydrocarbons in vegetables grown in an industrial area." Environmental pollution 106.3 (1999): 369-380.
 Schreck, Eva, et al. "Metal and metalloid foliar uptake by various plant species exposed to atmospheric industrial fallout: mechanisms involved for lead." Science of the Total Environment 427 (2012): 253-262.