I see that the UK Supreme Court has handed down its decision in Employers' Liability Insurance "Trigger" Litigation: BAI (Run Off) Ltd v Durham & Ors [2012] UKSC 14 (28 March 2012)
http://www.bailii.org/uk/cases/UKSC/2012/14.html. I have yet to read it in detail, but there is what seems to be a very helpful summary issued by the Court at Press summary (PDF) . In short, the Court holds that insurance policies using the words "occurred" or "sustained" in relation to disease will mean that those policies do respond to claims by employees who were exposed to asbestos and many years later were discovered to have mesothelioma. The majority of the Court (Lord Phillips dissenting apparently) holds that the Fairchild/Barker rules apply to these, so that mere exposure to increased risk will be sufficient to trigger later liability. Obviously there is much more to be said.

Regards

Neil