The worst fears of British farmers have been realised with the announcement of an EU ban on the export of livestock, meat and dairy products from Great Britain. Northern Ireland has been exempted from the measure. The UK authorities have acted quickly to contain the disease after it was discovered on a farm south of London on Friday. Two herds have been destroyed and a ten kilometre protection zone has been created around the area. Two nearby laboratories, one a government research centre, the other a pharmaceuticals facility, are being investigated as possible sources of the outbreak. Both have used the virus in research but insist their security procedures have not been breached.