Members of the public in Salisbury should avoid picking up objects if they “don’t know what they are”, warned the director of Public Health England.Paul Cosford told Sky News the advice to residents and tourists to keep their hands to themselves was a “sensible” precaution against novichok poisoning.”It’s important for all of us to remember not to pick up items you don’t know what they are,” he said, adding it was “highly precautionary but sensible advice”.The stark words came after a couple found critically ill in a flat in Amesbury were confirmed by anti-terror police to have been poisoned by nerve agent Novichok.