Novichok is clearly a highly dangerous nerve agent. Over the last 6 months, we have learned a lot about the illness it causes, the best way to treat people who have been exposed, and we have been able to assess the long-term risks to the general public – which remains low.I have received advice from experts in Public Health England and the government’s Science Advice Group for Emergencies (SAGE).Let me emphasise that first, it is clear that this material does not spread easily. Second, all the experts advise that the evidence to date does not suggest any long-term health risk from short-term or one-off contact with low levels of this agent. Third, these experts further agree that if someone has not suffered an obvious illness after being exposed to this agent, they are not at risk of any long-term health problems.Public Health England has kept under review the information that has been uncovered by the police in their investigation, and I am confident that there has been no risk to members of the public who travelled alongside these suspects over the period Friday 2 March to Sunday 4 March 2018, or used these transport systems afterwards.I am confident also in reassuring those staff that operated, maintained and cleaned these transport systems that they are also safe.In particular, I can reassure people that they are safe if they: travelled on the Aeroflot flights bringing these 2 suspects into, and taking them back out of, this country used any of the public transport systems that they used in and around London used the same train services and stations in and between London and Salisbury finding and making safe any remaining materials that may have been discarded by these suspects especially in the Salisbury area I am confident that the London transport systems, the south-western train services and all London airports remain safe to use.The remaining issues of concern that we have identified are: identifying and reassuring those guests that stayed in the CityStay hotel in the period between the suspects leaving the hotel and the police identifying, controlling, and testing this location – this room was only allowed back into use after experts deemed it to be safe I am therefore repeating the advice that I previously gave in March, that people should not pick up anything that they do not recognise as something that they have dropped.I also ask that if you stayed at the the CityStay hotel, in London, between Sunday 4 March 2018 and 4 May 2018, that you should call the investigation team on 0800 789 321 or email [email protected] and if needed we can give you advice and reassurance.Let me repeat:The risk to the public remains low – provided that our advice not to pick up unknown objects is followed. Everyone can be confident that our public transport systems in London and the south are safe, and also we can be confident that Heathrow airport, Gatwick airport and the rail services linking them to London are safe.