Copper Could Contribute to Ozone Depletion, New Study Finds

Copper wire scraps are seen during the construction of the new R240 electric engine of French carmaker Renault at their factory in Cleon, France, June 18, 2015. (Reuters)
Copper wire scraps are seen during the construction of the new R240 electric engine of French carmaker Renault at their factory in Cleon, France, June 18, 2015. (Reuters)
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Copper Could Contribute to Ozone Depletion, New Study Finds

Copper wire scraps are seen during the construction of the new R240 electric engine of French carmaker Renault at their factory in Cleon, France, June 18, 2015. (Reuters)
Copper wire scraps are seen during the construction of the new R240 electric engine of French carmaker Renault at their factory in Cleon, France, June 18, 2015. (Reuters)

Copper released into the environment from fungicides may be contributing significantly to stratospheric ozone depletion, according to a new study from the University of California (UC).

In a paper published Jan. 14 in the journal Nature Communications, UC geochemists show that copper in soil and seawater acts as a catalyst to turn organic matter into both methyl bromide and methyl chloride, two potent halocarbon compounds that destroy ozone. Sunlight worsens the situation, boosting production of these methyl halides by a factor of 10. The findings answer, at least in part, a long-standing mystery about the origin of much of the methyl bromide and methyl chloride in the stratosphere.

Since the worldwide ban on chlorofluorocarbon (CFC) refrigerants and brominated halons used in fire extinguishers starting in 1989, these methyl halides have become the new dominant sources of ozone-depleting bromine and chlorine in the stratosphere. As the long-lived CFCs and halons slowly disappear from the atmosphere, the role of methyl halides increases.

"By 2050, we should be back to relatively normal ozone, but things like the continued emissions of methyl bromide and methyl chloride are road bumps in the road to recovery. Copper usage in the environment is projected to increase rapidly in the next few years, and this should be considered when predicting future halogen load and ozone recovery," said the paper's senior author, Robert Rhew, UC professor of environmental science and policy.

Earth's ozone layer is critical to protecting us from cancer-causing ultraviolet light from the sun, but chemicals containing chlorine and bromine -- such as CFCs and halons -- were found in the 1980s to destroy the ozone, creating thinner layers in the stratosphere that let in more of the dangerous radiation.

Despite a ban on production of CFCs and halons, the ozone layer has yet to repair itself.

The persistence of the ozone hole is, for the most part, due to the persistence of banned ozone-depleting compounds, which take decades to dissipate in the stratosphere. But some ozone-depleting chemicals are still being emitted.

Among the major contributors today are methyl chloride and methyl bromide. One atom of bromine is 50 times more destructive to ozone than one atom of chlorine.

Though methyl bromide is banned for use as an agricultural soil fumigant, it is still used as a pesticide for quarantine and pre-shipment of agricultural products. And methyl chloride is used as a chemical feedstock, although most of its emissions are believed to be from biomass burning or natural in origin. But the total amount of these methyl halides produced each year still do not add up to the observed yearly addition of these chemicals to the atmosphere, a fact that has puzzled scientists for more than 20 years.

About one-third of the methyl bromide and methyl chloride in the atmosphere comes from unknown sources, Rhew said. The new findings suggest that copper is an important, if not the major, source of the missing methyl bromide and methyl chloride.

"We've banned methyl bromide, but are other changes that we're making in the environment causing large emissions of this compound into the atmosphere? With the increase in the use of copper, it appears that copper-catalyzed production is an increasing source, as well," Rhew said.

First author and former UC doctoral student Yi Jiao, now a postdoctoral fellow at the University of Copenhagen in Denmark, noted that copper compounds are allowed on organic crops, a legacy of its use in farming since the 1700s, including as a major antifungal agent in the Bourdeax mixture used since the 1880s in France to prevent downy mildew on grapes. Copper contamination of soils is a major issue today in Europe because of this history, and the ozone-depleting power of copper is another cause for concern.

"With widespread use of copper in the environment, this potentially growing impact should be considered when predicting future halogen load and ozone recovery. Copper combined with soil and sunlight produce more methyl halides," said Jiao.



One Man Gored, 7 Others Bruised in Spain's Bull Running Festival

'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez
'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez
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One Man Gored, 7 Others Bruised in Spain's Bull Running Festival

'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez
'Mozos' or runners take part in the second Running of the Bulls during the Sanfermines festival in Pamplona, Spain, 08 July 2025. The San Fermin festival runs until 14 July 2025. EPA/Daniel Fernandez

A man was gored and seven others lightly injured on Tuesday, the second day of Pamplona's San Fermin festival in which thousands of people line the medieval city's narrow streets for the centuries-old tradition of running with bulls.

The man who was gored, identified only as being older than 25, was injured by a bull horn under his right armpit, a spokesperson for the city emergency services said.

"At this time, he is under observation but is in stable condition," she told reporters.

The seven others suffered bruises and contusions, some in the shoulder or head, Reuters reported.

In the festival's "encierros", or bull runs, fighting bulls are set loose in the streets and then race to reach the bullfight arena. Hundreds of aficionados, many wearing traditional white shirts with red scarves, run with them.

On Tuesday morning, one of the bulls stopped in the middle of his run, and charged the runners for several tense minutes.

The festival, which gained international fame from Ernest Hemingway's 1926 novel "The Sun Also Rises", lasts for one week in early July.

Participants are occasionally gored at the hundreds of such bull-running fiestas in Spain every year. Other injuries are common. At least 16 runners have lost their lives at the Pamplona festival down the years, the last in 2009.

As well as the morning bull runs and afternoon bullfights, the San Fermin festival features round-the-clock singing, dancing and drinking by revelers.
There are also religious events in honor of the saint.