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California is biggest U.S. emitter of this greenhouse gas

Despite its aggressive reputation for reducing greenhouse gas emissions, California releases more global warming pesticides than all other states combined, most of them from homes fumigated for termites, according to a study released Wednesday.

The termite-killing gas – sulfuryl fluoride – was found to be 4,800 times more powerful than carbon dioxide at trapping heat.

When a team of Johns Hopkins scientists set out to map exactly where the gas was being released, they were surprised to find that California generated up to 12 percent of the world’s emissions of the synthetic fumigant.

“The results were confusing because the emissions were all coming from one location,” said Scott Miller, assistant professor of environmental health and engineering at Johns Hopkins. “Other greenhouse gases like carbon dioxide and methane are present throughout the United States. On our sulfuryl fluoride map, only California lights up like a Christmas tree.”

According to scientists, up to 85 percent of U.S. emissions of the chemical come from California, primarily Los Angeles, Orange and San Diego counties.

The primary use of this chemical is in the fumigation of homes and other structures, where a building is covered with an airtight tent and gas is pumped in to kill termites and other pests. Brightly colored tents have become commonplace in Southern California neighborhoods.

However, within the first two hours of opening a tent, 90% of the gas escapes into the atmosphere, where it remains for approximately 40 years. (Carbon dioxide, on the other hand, stays in the atmosphere for up to 1,000 years.)

The fumigant is also used to protect cereals, nuts and dried fruits from pests after harvest.

A fumigation worker stands on the roof of a Huntington Beach church that has been covered with a fumigation tent.

(Robert Lachman/Los Angeles Times)

The new study is not the first time the pesticide has come under scrutiny.

In 2022, environmental groups filed a petition the State demanding that the use of gas be phased out.

The Center for Biological Diversity and Californians for Pesticide Reform, a coalition of 190 groups, said California was the world’s largest consumer of sulfuryl fluoride and used 3 million pounds of it in 2021. The impact climate change from the use of such a quantity of pesticide, the petition states. , is equivalent to the carbon dioxide released by around 1 million vehicles per year.

“California’s pesticide use has a significant, but overlooked, impact on the state’s greenhouse gas emissions,” the petition states.

The groups’ petition also details the dangers to human health of this odorless pesticide, which works by attacking the nervous system. At least 16 deaths have been attributed to sulfuryl fluoride since 1994.

Scientists from the California Department of Public Health detailed in a 2019 report how some families had fallen ill from what was left of the gas even after the house was allowed to return.

Douglas Products, which sells the pesticide under the name Vikane brand, opposed the petition. The company noted that most deaths occurred after illegal or unauthorized entry into homes while they were still tented.

The Missouri company, which is owned by private equity firm Brightstar Capital Partners, also said the chemical has a “negligible” impact on the climate because it accounts for just 0.035% of total greenhouse gas emissions. .

The California Air Resources Board rejected the environmental groups’ petition in February 2023, saying the agency lacked “sufficient information” to determine whether the pesticide should be phased out. The council said it would continue to study the issue.

Use of the gas exploded after sales of another fumigant called methyl bromide were sharply reduced because of the damage it was doing to the ozone layer.

In the study published Wednesday, Miller and his colleagues analyzed 15,000 air samples collected between 2015 and 2019 by NOAA Global Monitoring Laboratory scientists. They took wind speed, direction and other variables into account to trace the chemicals back to where they were released.

They noted that one caveat to their work is that there are currently no air monitors that can detect the gas in Florida, where the pesticide is also used to control termites.

In an interview, Dylan Gaeta, a doctoral student at Johns Hopkins who led the study, said the global warming impact of California’s annual releases of sulfuryl fluoride is almost as great as what the state saved on average each year in greenhouse gas emissions. measures required by AB 32. The 2006 law reduced emissions through improvements such as vehicles that use less gasoline, switching to electric cars and more renewable energy.

Gaeta pointed out that pest control companies already offer alternatives to gas, including orange oil treatments, which are safer for humans and don’t have the same global warming effects.

“For most greenhouse gases, California has been very intentional about how it’s going to reduce emissions,” Gaeta said. “This one flew under the radar. »

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