LONDON - British police said on Thursday a man and a woman who are critically ill after being poisoned with the Novichok nerve agent in southern England had been exposed to the toxin after handling a contaminated item. 'Following further tests of samples from the patients, we now know that they were exposed to the nerve agent after handling a contaminated item,' London police said in a statement. 'Detectives are working as quickly and as diligently as possible to identify the source of the contamination.'