It is a killer and affects thousands. It often appears on death certificates disguised as bronchitis. It is particular to certain towns in Lancashire. It was first identified, in The Lancet, more than a century ago. It is one of Britain's most serious occupational diseases-and one of the least recognised. It is byssinosis, caused by cotton dust which attacks a victim's ability to breathe. Its continued existence - at least 3,000 people have it - is a story in which employers, unions and Whitehall are all to blame. And generations of workers, in their stoicism, must also bear some responsibility. In the face of overwhelming evidence of the disease's causes and effects, no one has succeeded in more than 60 years in taking any effective step towards its control. Film editor MORRIS BAKER Producers Richard BELFIELD , DAVID JONES