healthmedicinet

Public hearings were dominated by recitations of the ills often attributed to genetically modified organisms, or G.M.O.s: cancer in rats, a rise in childhood allergies, out-of-control superweeds, genetic contamination, overuse of pesticides, the disappearance of butterflies and bees.

Like some others on the nine-member Council, Greggor Ilagan was not even sure at the outset of the debate exactly what genetically modified organisms were: living things whose DNA has been altered, often with the addition of a gene from a distant species, to produce a desired trait. But he could see why almost all of his colleagues had been persuaded of the virtue of turning the island into what the bill’s proponents called a “G.M.O.-free oasis.”

“You just type ‘G.M.O.’ and everything you see is negative,” he told his staff. Opposing the ban also seemed likely to ruin anyone’s re-election prospects.

Yet doubts nagged at the councilman, who was serving his first two-year term. The island’s papaya farmers said that an engineered variety had saved their fruit from a devastating disease. A study reporting that a diet of G.M.O. corn caused tumors in rats, mentioned often by the ban’s supporters, turned out to have been thoroughly debunked.

And University of Hawaii biologists urged the Council to consider the global scientific consensus, which holds that existing genetically engineered crops are no riskier than others, and have provided some tangible benefits.

“Are we going to just ignore them?” Mr. Ilagan wondered.

Urged on by Margaret Wille, the ban’s sponsor, who spoke passionately of the need to “act before it’s too late,” the Council declined to form a task force to look into such questions before its November vote. But Mr. Ilagan, 27, sought answers on his own. In the process, he found himself, like so many public and business leaders worldwide, wrestling with a subject in which popular beliefs often do not reflect scientific evidence.

At stake is how to grow healthful food most efficiently, at a time when a warming world and a growing population make that goal all the more urgent.

Scientists, who have come to rely on liberals in political battles over stem-cell research, climate change and the teaching of evolution, have been dismayed to find themselves at odds with their traditional allies on this issue. Some compare the hostility to G.M.O.s to the rejection of climate-change science, except with liberal opponents instead of conservative ones.

“These are my people, they’re lefties, I’m with them on almost everything,” said Michael Shintaku, a plant pathologist at the University of Hawaii at Hilo, who testified several times against the bill. “It hurts.”

But, supporters of the ban warned, scientists had not always correctly assessed the health and environmental risks of new technology. “Remember DDT?” one proponent demanded.

Ms. Wille’s bill would ban the cultivation of any genetically engineered crop on the island, with the exception of the two already grown there: corn recently planted by an island dairy to feed its cows, and papaya. Field tests to study new G.M.O. crops would also be prohibited. Penalties would be $1,000 per day.

Like three-quarters of the voters on Hawaii Island, known as the Big Island, Mr. Ilagan supported President Obama in the 2012 election. When he took office himself a month later, after six years in the Air National Guard, he planned to focus on squatters, crime prevention and the inauguration of a bus line in his district on the island’s eastern rim.

He had also promised himself that he would take a stance on all topics, never registering a “kanalua” vote — the Hawaiian term for “with reservation.”

But with the G.M.O. bill, he often despaired of assembling the information he needed to definitively decide. Every time he answered one question, it seemed, new ones arose. Popular opinion masqueraded convincingly as science, and the science itself was hard to grasp. People who spoke as experts lacked credentials, and G.M.O. critics discounted those with credentials as being pawns of biotechnology companies.

“It takes so much time to find out what’s true,” he complained.

So many emails arrived in support of the ban that, as a matter of environmental responsibility, the Council clerks suspended the custom of printing them out for each Council member. But Mr. Ilagan had only to consult his inbox to be reminded of the prevailing opinion.

“Do the right thing,” one Chicago woman wrote, “or no one will want to take a toxic tour of your poisoned paradise.”

Distrust on the Left

Margaret Wille, 66, had the island’s best interests at heart when she proposed the ban, Mr. Ilagan knew.