US smoke particles detected in Switzerland
Smoke particles from the forest fires in the western United States have been detected in Switzerland.
The meteorologist Lionel Fontannaz told the SDA news agency the particles are measuring 8 micrograms per cubic meter at the top of the Jungfraujoch. Anything more than 10 is considered pollution.
He says the particles have been carried by the Jetstream across the Atlantic and can be seen by satellite.