Mystery gas cloud on Sussex coast 'a meteorological phenomenon' A gas cloud which affected hundreds of people along the East Sussex coast was a "meteorological phenomenon", an expert says. Residents were urged to keep windows and doors closed after the unknown haze emerged on Sunday, causing 133 people to seek treatment for streaming eyes, sore throats and nausea. Police are now trying to determine what type of gas caused the "chemical haze", which now appears to have dissipated. Consultant toxicologist Dr John Hoskins said it may have been generated from German or French traffic pollution which drifted over the English Channel, and could reappear again. He told Sky News: "Certainly it came across the Channel because it is in a peculiar part of the country to get anything that was generated in even the nearest large town, Brighton. "(Its concentration) was just a meteorological phenomenon, you have to know exactly how the wind blows. "It seems the weather generally tends to push things into that part of the coast… the tides and the winds go that way." Dr Hoskins added that Sunday's hot and sunny weather "created essentially what was photochemical smog which contained a number of chemicals dangerous to health". "There was also the so-called smell of chlorine," he said. "That was almost certainly not chlorine, it was the smell of ozone which is a very similar smell. "Ozone goes for the chest and or the heart. It is impossible to predict and it could have blown up into the air or in this case it blew down to ground level. "It's a phenomenon we are liable to find on the streets of any town or city." Public Health England is urging anyone who is still suffering the effects of irritation to irrigate their eyes and wash any other agitated areas with plenty of soap and water. Irritation was initially reported by tourists visiting the clifftops and beach at Birling Gap near Eastbourne just before 5pm. The effects of the haze were also reported as far as Bexhill and towards Hastings, more than 20 miles away. Mark Battershill, who was one of those affected, told Sky News he was left with stinging eyes and a sore throat after coming into contact with the mystery chemical. He said some people had complained that they were having difficulty breathing. Conditions are being monitored at Birling Gap, a popular tourist hotspot, throughout Bank Holiday Monday. Mystery gas haze 'a meteorological phenomenon'