Unregulated Restricted Pesticide Use and Their Impact on Hawaiʻi
Makaʻala Ng, Chaminade University of Honolulu, Makaala.ng@student.chaminade.edu
References
Restricted Use Pesticide (RUP) classified by the EPA, are not available for purchase or for the general public to use,licensing and training requirements
As of 2019, all users of Restricted Use Pesticides in Hawaiʻi are required to submit annual reports detailing the product, amount used, location, and date of application.
Improving the accuracy, consistency, and transparency of pesticide use reporting will empower local communities and farmers to better understand environmental and health risks, thereby supporting efforts toward sustainable and secure local food systems in Hawaiʻi.
How does inconsistent documentation and limited transparency of RUP applications affect local farmers’ ability to achieve sustainable and safe food production in Hawaiʻi?
Data was collected from the State of Hawaiʻi’s Department of Agriculture, This data was cleaned both manually and programmatically.
Python 3.12 was used to analyze and visualize this data using TACCʻs Analysis Portal running Jupyter notebooks and Jupyter Lab on TACCʻs Stampede3 supercomputer.
Geospatial mapping was used to visualize crops, rivers and streams on the Island of Oahu.
Large gaps in Hawaiʻi’s pesticide data (mid-1900s–2019) limit understanding of environmental and health related risks. Effects of combined pesticide ingredients remain understudied, and more controlled studies are needed.
Data is inconsistent and often reported by parcel, not precise locations, complicating risk assessment. Regulatory actions are delayed due to slow proof of harm.
Standardized, consistent pesticide reporting is urgently needed to create accurate island-wide data. GPS-level reporting, like California’s system, would improve monitoring and risk evaluation.
Filling data gaps and increasing transparency will enable better study of long-term impacts. Improved data supports faster regulatory responses to protect health and environment.
Project Lead: Dr. Kelly Gaither, Kumu Kahoaliʻi Keahi-Wood, Dr. Amber Camp, and Dr. Rylan Chong
Mentors: Logan Lassel, Ashley Sofia Alfaro
Temporal Trends:Pesticide Use Gallons per Acre by Year and Active Ingredient
Year
Gallons/Acre (Toxicity Gradient)
Active Ingredients
Gallons Used (Log Scale)
Area Treated (Acres, Log Scale)
Pesticide Use Intensity: Gallons vs Area Treated
Introduction/Background
Research Question/Hypothesis
Methods
Discussion and Conclusions
Future Work
Acknowledgements
Pesticide Toxicity: Gallons per Acre by Active Ingredients and Island
Island
Gallons/Acre (Toxicity Gradient)
Active Ingredients
Gallons per Acre
Active Ingredients
Figure 1: Bubble chart visualization of pesticide use intensity by gallons of area treated in acres of the top 20 Restricted Pesticides in logarithmic scale
Figure 2: Heatmap of Active Ingredients in Pesticides for gallons per acres for Hawaiʻi, Oʻahu, Maui, and Kauai islands, color intensity relating to pesticide toxicity levels
Figure 3: Heatmap trend of all Islandʻs averages of pesticide use by gallons per acres from 2019 to 2024
Dichloropropene
Bifenthrin
Sodium methyldithiocarbamate
Hydrogen
Cyanamide
Sulfuryl fluoride
Top 5 Pesticides
Figure. 4: Geospatial Map of Oʻahuʻs Agricultural crop land surrounding the Schools in the Northern District, along with All of Oahuʻs streams that run through the island