This past month, the state departments of Health and Agriculture released a study on pesticides in streams across the state, garnering attention from both sides of the debate surrounding pesticide disclosure by agrochemical companies in the state.

This is just a first step, as the study’s authors readily agree. For a realistic picture of pesticides in water, monitoring must be done regularly, collecting samples throughout the year. Pesticide levels rise and fall dramatically with application schedules, rainfall and field conditions.

Also, too few locations were sampled: Missing are waters affected by farming in Puna and Kau on Hawaii Island, most agricultural areas on Maui and any sites on Molokai. As a result, the study likely underestimates the scope of pesticide contamination of the islands’ waters.

It is only right that communities in Hawaii get information about their exposure to pesticides to safeguard their health and lands, particularly when they live close to agricultural operations that use large amounts of restricted-use pesticides. Water is an important source of exposure, along with air, dust, soil and food.

The stakes are high. Some studies link long-term health problems such as cancers, reproductive disorders and neurological diseases, with exposure to some of these pesticides, in addition to more immediate effects. Hawaii’s unique natural areas and native species are also at risk.

Except during applications, pesticides in the environment are generally invisible even at toxic concentrations, blending into the background. Only careful monitoring can show which pesticides are present where, when and at what levels. This is also one reason why Kauai’s Ordinance 960 (formerly Bill 2491) — which requires chemical companies to disclose the pesticides being sprayed and create buffer zones around homes, schools and hospitals — is such an important law.

Although the pilot streams study tested an impressive number of pesticides, some important ones were not included. For example, seeds of corn and other crops are often coated with potent and persistent insecticides — called neonicotinoids — that pollute the environment through several routes, potentially harming pollinators, such as bees. Common seed-applied neonicotinoids must be analyzed to fully assess pesticide impacts.

All of Hawaii’s surface waters were contaminated with at least one pesticide. And some streams had levels of pesticides deemed harmful to health and the environment by the Environmental Protection Agency. One pesticide was found over EPA’s benchmark for health — dieldrin, a "legacy insecticide" for termites, banned but still lingering decades later. Two current restricted-use herbicides — atrazine and metolachlor — were found downstream of a seed crop location on Kauai at levels that exceeded EPA’s benchmarks for protecting aquatic organisms.

Since this study almost certainly underestimated pesticide contamination, finding these levels is worrisome. Tiny amounts of atrazine disrupt hormonal processes, causing male frogs to be "chemically castrated" at concentrations 10 times lower than EPA’s aquatic benchmark and 30 times lower than the drinking-water standard. Some other pesticides disrupt the endocrine system at extremely low levels, too, and must be carefully tested.

It is shameful that agrochemical companies have sued Kauai County to have the new pesticide disclosure and protection bill thrown out. The pilot study shows that people are more than justified in their concerns about pesticide use in their communities and need more information to prevent harm now, and to keep today’s pesticides from becoming tomorrow’s toxic legacy.

Urge your legislators to allocate funds to continue and expand pesticide monitoring in its waters.