DOH Confirms No Elevated Levels of Pesticides or Metals on North Shore

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DOH CONFIRMS NO ELEVATED LEVELS OF PESTICIDES OR METALS ON NORTH SHORE

Posted on Apr 21, 2026 in Newsroom Additional Testing Conducted on Floodwater, Mud and Sediment

HONOLULU — The Hawaiʻi Department of Health (DOH) reports that representative samples of floodwater, mud and sediment collected on Oʻahu’s North Shore after the March Kona Low storms detected no elevated levels of pesticides or heavy metals. All results showed either no detectable levels or low levels well below any health risk.

Samples of floodwater and flood-carried mud and sediment were collected from three sites where mud from impacted communities was consolidated, in addition to one floodwater drainage site.

Floodwater and flood-carried mud and sediment were tested for pesticide compounds commonly associated with environmental contamination and historical land use. These pesticides were not detected in floodwater or eight of nine soil samples. Low levels of pesticides were found in one soil sample, but all detections were well below levels that may lead to a health risk based on lifetime exposure. Low detections of these legacy pesticides were expected due to historic use of land on the North Shore.

Floodwater, mud and sediment samples were also tested for heavy metals such as arsenic, lead, mercury and cadmium. These metals are naturally present in soil in Hawaiʻi, so some presence is expected and does not by itself indicate contamination or a health risk. No heavy metals were detected in floodwater. Low levels of arsenic, lead, mercury and cadmium were detected in soil samples, but all detections are consistent with naturally occurring levels or were well below levels that may lead to a health risk based on lifetime exposure.

DOH previously announced the presence of Staphylococcus aureus, Clostridium perfringens, Escherichia coli (E. coli), Enterococcus, Salmonella and Leptospira bacteria in the same samples. Hepatitis A, Clostridium tetani and Campylobacter were not detected. Based on information on the Kona Low flooding, land use on the North Shore, as well as other flood events around the country, the DOH fully expected to find these contaminated floodwater indicators in flood-carried mud.

The DOH continues to urge individuals taking part in cleanup or recovery activities to take recommended precautions to prevent bacteria entry through the skin or mouth, like wearing personal protective equipment (PPE), cleaning exposed skin and washing hands after handling mud, soil, or standing water. These precautions greatly reduce health risks from pathogens and other contaminants expected after a flood.

Full sampling results and cleanup guidelines are available at https://health.hawaii.gov/konalowstorm/.

Direct sunlight helps to reduce microbial survival on exposed surfaces. The DOH is awaiting results of one additional sampling site — and will test additional mud and sediment samples for detected microbial contaminants to confirm that bacterial contaminant levels are decreasing as recovery continues. The City and County of Honolulu will be conducting its own sampling of the Central Oʻahu Regional Park site. As nearshore water conditions have also continued to improve, the DOH will be returning to its routine sampling schedule for beach monitoring.

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News Release – DOH CONFIRMS NO ELEVATED LEVELS OF PESTICIDES OR METALS ON NORTH SHORE