Every year hundreds of workers contract - even die from - illnesses which they can't understand, let alone pronounce. Yet people continue to work with substances that can subsequently prove fatal. Some do it because they're ignorant of the dangers; others because they want the money and are prepared to take risks. This week a Man Alive film team looks at the hazards, and in the studio Desmond Wilcox asks: why it is so difficult to establish who is to blame - who is to compensate the victims?