It’s a sight all too familiar to Californians. Tents over homes or businesses to get rid of termites. While getting rid of one issue, we could create a much bigger environmental problem.
A recent study from Johns Hopkins University with contributions from Scripps Institution of Oceanography at UC San Diego found that California is the leader of a greenhouse gas that comes from termite fumigation.
It’s called sulfuryl fluoride and is used when tenting a property to fumigate it for termites. The study suggests that what isn’t absorbed by properties being fumigated likely finds its way into the atmosphere and has been doing so for years.
“We were also a little bit surprised that we saw literally all or most of the emissions in California,” Jens Muhle, a geochemist at Scripps Institution of Oceanography, said.
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Muhle was a contributor to the study. According to its findings, 60-85% of sulfuryl fluoride emissions are from fumigation. The findings also cite that around 15% came from agriculture and commodities fumigation.
Muhle says he has been doing this work for about two decades. The scientists who also worked on the study spent about five years analyzing 15,000 air samples from scientists at NOAA Global Monitoring Laboratory. They used calculations such as wind speed and direction and weather models to determine where the gas was coming from.
Muhle provided an example of a scenario of how the data was collected.
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“Let's say an island, such as the United Kingdom, and if you were to put measurement stations at the coast, and you had wind going over the island, let's say from east to west, you would measure the greenhouse gases where the wind comes in, and then basically on the other side of the island where it goes out. And then everything, if you measure increased basically concentrations, there must be emissions basically in the island. And so to say, that's sort of the basic idea of how you do that," Muhle said.
Muhle says performing these atmospheric measurements can improve emission inventories.
“Now, do you need to worry about it? I mean, in a sense, SO2F2 or sulfuryl fluoride is a minor contributor to global warming, but it's not included in the U.S. greenhouse gas emission inventory or in the California greenhouse gas emission inventory," Muhle said.
According to the Environmental Protection Agency, gases covered include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride and nitrogen trifluoride.
“It’s an example of everything adds up, and there are things which are missing from the inventory,” Muhle said.
Some exterminator companies have opted for other methods to treat pests.
“Well, we use a product called orange oil – XT200 orange oil,” Anna Carlin, president and CEO of Xtermite, said.
She says her company uses the oil to treat wood infested with termites. It’s different from fumigation in that it is a localized treatment.
“People can stay in their homes while we’re actually performing the treatment,” Carlin said.
In the meantime, the findings from the study have been shared with the California Air Resources Board and the Bay Area Air Quality Management District.
”At the end of the day, the only thing that really matters is that we do reduce our greenhouse gas emissions,” Muhle said. “And that has to be not only working on paper, but that needs to be a reality in the atmosphere.”
California Air Resources Board told NBC 7 they’re tracking information and research about sulfuryl fluoride, including pest alternatives. The EPA also shared amendments to the Revised Mitigation and Response to Comments on the Sulfuryl Fluoride Draft Interim Mitigation Measures Memorandum. Label updates to increase safety and compliance during residential structural fumigations were updated on May 6, 2024.
- increased warning sign specifications;
- standardized elements for fumigation logs;
- removal of all product references of clearance devices from labels;
- citing the EPA website for structural fumigations for effective clearance device information and registrant stewardship plans;
- and enhanced aeration requirements for structural fumigations.
Those new product labels and updated requirements have been sent to the EPA and are being reviewed, which should be approved by next month. There is also a registration review process taking place for sulfuryl fluoride. According to the agency, each registered pesticide is reviewed at least every 15 years to make sure they carry out their intended function without creating unreasonable adverse effects to the environment and human health.
