Hawaii briefing spotlights restricted-use pesticides, data gaps and health concerns

A joint informational briefing hosted by Hawaii House and Senate committees on pesticides brought state regulators, university researchers and physicians together to review patterns of restricted-use pesticide use, gaps in the data, and possible public-health responses.

The session centered on federally restricted-use pesticides (RUPs), which the Hawaii Department of Agriculture (HDOA) said may be sold and applied only by certified applicators and are subject to reporting requirements under federal and state law. "RUPs are strictly regulated and require reporting, for their use and sales. Essentially, the department tracks from cradle to grave for these restricted use pesticides," said Greg Takashima, Pesticides Program Manager for the Hawaii Department of Agriculture.

Why it matters: presenters said heavy, repeated applications and a lack of precise, standardized location reporting can make it hard to assess community exposures and health effects. Researchers pointed to evidence from long-running U.S. cohort studies and local analyses that link nearby agricultural pesticide use with reduced childhood IQ, increased respiratory symptoms, and other health outcomes; state officials and lawmakers discussed regulatory and data fixes but did not adopt formal actions at the briefing.

HDOA overview and internal limits Greg Takashima described the agency’s three core RUP functions—enforcement, education/certification and registration—and said the pesticides branch compiles annual RUP reports and investigates complaints. He outlined the branch’s staffing and lab capacity and said the branch lacks a toxicologist on staff and has limited long-term monitoring capacity. He noted HDOA enforces the federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) under a cooperative agreement with the U.S. Environmental Protection Agency.

Takashima said the branch conducts market surveillance, certifies about 1,500 applicators statewide and processes roughly 100 laboratory samples annually. He also stressed outreach work—trainings on drift reduction, adjuvants and droplet size—and said the agency supports a pending legislative measure identified at the briefing as Act 231.

Local research and community data issues Dr. Lee Ebsland, a pediatrician who participated in a joint fact‑finding task force on Kauai, said the group found the West Side community had multiple elevated health indicators but lacked the environmental and biological data needed to prove causation. "We did not prove that pesticides played a role in the unhealthiness of this community. We didn't have the data," Ebsland said, noting limitations such as missing drift data, limited geospatial resolution and an absence of biologic markers.

Ebsland and others described anecdotal and citizen-collected dust sampling that found low but detectable pesticide residues up to a mile from treated fields and highlighted schools that sit near frequently treated agricultural parcels. He warned that some fumigants and organophosphate insecticides act on nervous-system development and said early fetal exposures are a mechanism of concern for long-term developmental effects.

University researchers described challenges converting the state's RUP records into ready-to-use datasets. Dr. Rosanna Weldon of the University of Hawaii Office of Public Health Studies presented a pilot project using 2019 RUP reports for Central Oahu. She said the raw reports arrived as mixed-format PDFs with handwritten tax-map keys, mixed units (gallons, pounds), and inconsistent fields. "It was great that the state produces summaries, but those summaries don't provide location," Weldon said, urging standardized electronic reporting and more precise location fields than tax‑map keys for exposure research.

Weldon said her pilot mapped two highly volatile fumigants—1,3‑dichloropropene (1,3‑D) and metam sodium—and found RUP use concentrated near communities with higher proportions of Filipino residents. She described the work as exploratory and emphasized the need for larger, cleaned datasets before testing health outcomes such as asthma and cancer.

Evidence from California cohort studies Bob Gunier, an epidemiologist at the University of California, Berkeley, reviewed California's pesticide-use-reporting (PUR) system and results from long-term cohort research. He described how PUR is collected at county level, cleaned and standardized by the California Department of Pesticide Regulation to give kilograms of active ingredient by location and date; agricultural locations are reported to roughly one-square‑mile sections.

Gunier summarized CHAMACOS and other cohort findings linking prenatal and early-life agricultural pesticide use with lower childhood IQ, increased respiratory symptoms and lung-function decrements, and metabolic outcomes in later adolescence. He noted associations vary by pesticide class, application method and chemical volatility and recommended careful, pesticide-specific analysis for buffer-zone policy.

State health agency role and questions from lawmakers Dr. John Jacob, state toxicologist in the Hazard Evaluation and Emergency Response (HHEAR) office at the Hawaii Department of Health (HDOH), said HDOH typically becomes involved when clinical calls or clusters are referred by Poison Control or when a site-specific investigation is indicated. "We don't have a lot of direct phone calls or complaints to our office regarding pesticide use; the few that we have are older," Jacob said. He said HDOH can recommend buffer distances but that an appropriate buffer depends on chemical properties and application method.

Lawmakers and speakers repeatedly pressed agencies on buffer zones, enforcement and outreach. Several legislators asked whether a 100‑foot buffer would be protective; UC Berkeley's Gunier said 100 feet is "better than nothing" but many pesticides and fumigants can drift well beyond that distance. HDOH officials said they would support buffer measures in principle but emphasized the need to tailor buffer distances to specific pesticides and uses.

Data and policy takeaways from the briefing - Heavy, localized RUP use: presenters pointed to concentrated 2019 applications in North Central Oahu and parts of Kauai and said a small number of users account for a large share of reported RUP pounds. "We have over 1,500 applications reported in 2019" on one West Kauai parcel, and speakers noted roughly 300,000 pounds reported for Oahu collectively in 2019, including about 216,000 pounds reported for North Central Oahu of 23 different RUPs. - Data quality limits public-health analysis: researchers asked for standardized electronic reporting, clearer location fields (finer than tax‑map keys), and cleaned data exports to reduce months of manual conversion. - Health evidence from cohort studies: presenters cited U.S. cohort and local analyses that show associations between nearby agricultural pesticide use and neurodevelopmental, respiratory and metabolic outcomes, while stressing that ecological and cross-sectional local data cannot prove causation without additional monitoring and biologic markers. - Agency capacity gap: HDOA staff said the pesticides branch lacks a toxicologist and long-term monitoring staff; the office’s budget and staffing are smaller than comparable programs in states such as California.

No formal committee votes or directive were recorded at the briefing. Committee leadership asked presenters to provide copies of their slides and data summaries to committee offices for follow-up. Lawmakers signaled continued interest in legislative fixes—data standardization, tailored buffer zones and expanded education/outreach for applicators and retailers—but made no binding decisions during the session.

Ending: Presenters, including HDOA and university researchers, agreed to provide their slide decks and cleaned summaries to committee staff for further review. Committee chairs said they would share those materials with members of both committees.