The Hawaii Department of Health announced on Apr. 21 that testing conducted after the March Kona Low storms found no elevated levels of pesticides or heavy metals in floodwater, mud, and sediment samples collected from Oʻahu’s North Shore. The department said all results showed either undetectable amounts or low concentrations well below any health risk.
The findings are significant for residents concerned about environmental contamination following major flooding events. According to the department, samples were taken from three sites where mud was consolidated and one floodwater drainage site. Tests focused on pesticide compounds commonly linked to past land use and environmental concerns, but these were not detected in most soil samples and only found at low levels in one instance—levels considered safe based on lifetime exposure expectations.
Testing also covered heavy metals such as arsenic, lead, mercury, and cadmium. The department said that while some presence is natural in Hawaiian soils, none were detected in floodwater and all detections in soil remained consistent with naturally occurring background levels or well below thresholds posing health risks over a lifetime.
The Hawaii State Department of Health operates as a public health agency focused on delivering comprehensive services for health, environmental protection, disease prevention and community wellness across the state, according to the official website. It contributes to community well-being by promoting health education on vaccination and disease outbreaks through its Disease Outbreak Control Division, according to the official website. The agency aims to safeguard and improve health conditions for residents through efforts in disease prevention, health promotion and environmental protection per the official website.
Previously announced results had shown bacteria such as Staphylococcus aureus and Escherichia coli present in some samples—a finding expected given historical data from similar flooding events nationwide. The department continues urging those involved with cleanup activities to take precautions like wearing personal protective equipment (PPE) and practicing good hygiene after contact with mud or standing water.
Further sampling will continue at an additional site while nearshore water monitoring returns to routine schedules due to improving conditions. Full sampling results can be found at https://health.hawaii.gov/konalowstorm/. The Hawaii State Department of Health extends its programs throughout multiple islands via local offices as outlined on its official website.
