Hawaii residents concerned about pesticide use by major agriculture companies on the islands are planning a push to strengthen regulation over chemicals they fear harm their health.

The divisive issue has drawn thousands to the Legislature in recent years following incidents where schoolchildren and agriculture workers fell ill and some suspected their sickness was connected to pesticides sprayed by seed testing companies.

Several major agriculture companies test genetically engineered crops on the islands, taking advantage of Hawaii’s year-round warm weather to develop new types of corn and soybeans and testing more generations of crops than they could in other states.

A recent study found there wasn’t enough evidence to show the pesticides used by Syngenta, Dow AgroSciences, DuPont Pioneer and BASF Plant Science on Kauai caused adverse health or environmental effects on the community. But the study encouraged the state to boost its environmental monitoring and data collection.

A court decision declaring it’s up to the state — not counties — to regulate agriculture and a change in committee leadership in the House have added momentum to the effort to enhance state regulation.

“With really focused public pressure, we could really see something get through. The time is right,” said Ashley Lukens, director of the Hawaii Center for Food Safety.

Advocates are pushing bills to require companies to fully disclose when and where they’re spraying pesticides and to mandate buffer zones around schools and hospitals. Another proposal calls for the state and counties to stop using sprays containing glyphosate, an herbicide originally brought to market by Monsanto.

“I’m hopeful that we’re not going to wait for a bad event and see some terrible sickness in our state,” said state Sen. Josh Green, an emergency room doctor who plans to introduce the glyphosate ban bill.

Hawaii recently initiated a study on Oahu and Kauai to sample surface water for pesticides before and during storms to evaluate if chemicals are moving offsite at unacceptable levels.

The state also is planning to triple its fee to register pesticides to fund monitoring and to expand statewide the Kauai Good Neighbor Program — in which seed companies on Kauai voluntarily report their pesticide use monthly to the state.

But critics say the new programs fall short because reporting is voluntary and because the companies don’t disclose the location where the pesticide is sprayed.

Requiring companies to report spray locations could be tricky because fields where seeds are tested are generally spread out to avoid cross-pollination, and because it’s a competitive industry, said Scott Enright, chairman of the state Department of Agriculture.

“Even though they’re doing similar work, Syngenta, Monsanto Dow and Pioneer are all competitors, and they’re trying to keep the millions of dollars that they’ve put in to research the genetics lines that they’re developing as confidential business information,” Enright said.

Rep. Chris Lee, who plans to introduce buffer zone and disclosure bills, called the new state initiatives “woefully inadequate.”

“There’s still zero transparency for the long-term cumulative impacts on various communities around the islands for what’s being sprayed and any impact it may be having over the long term,” Lee said. “And that’s something that we have a clear obligation above anything else to dive into, because it is health and safety and people have a right to know.”

Earlier this month, the U.S. Environmental Protection Agency sought $5 million in fines from Syngenta, saying the company violated pesticide rules on Kauai by letting workers without protective gear enter fields recently sprayed with a restricted insecticide. Syngenta said it takes responsibility but believes the agency is overstepping.

The case will go before an EPA administrative law judge.

The seed industry takes the issue of pesticides very seriously, said Bennette Misalucha, executive director of the Hawaii Crop Improvement Association, which counts Dow AgroSciences, DuPont Pioneer, Monsanto and Syngenta among its members. It abides by state and federal regulations and rigorously trains employees, she said.

She added the industry objects to a “cookie cutter” approach to buffer zones because it could hurt small farmers, potentially removing chunks of land from production.

“You’re basically limiting somebody’s use of their private property, without just cause if you don’t have the science to back up what you’re asking for,” Enright said.

Although some states have tried to ban glyphosate, none have succeeded, according to the National Conference of State Legislatures.

In 2015, the cancer research arm of the World Health Organization labeled glyphosate a “probable carcinogen.”

But the EPA said glyphosate has low toxicity to humans, and a joint meeting of a WHO group that assesses pesticide residues and the United Nations’ Food and Agriculture Organization concluded glyphosate is unlikely to pose a carcinogenic risk to humans from exposure through the diet.