Deaths from lung cancer caused by asbestos in Swale more than quadrupled in 12 months.

Last year, 13 people died of mesothelioma, which is caused by exposure to the substance, compared to three in 2013.

The latest figures mean Swale is now the second worst area affected area in Kent.

Medway registered the highest number of deaths in the county with 17, three more than in 2013, giving it the sixth highest death rate from mesothelioma in the UK.

Asbestos, a natural fibrous material, was used as an insulator for hundreds of years until 1992, when it was made illegal to make products with it.

University of Kent law teacher, Dr Alan McKenna, who campaigns on asbestos issues, said: “The precise mechanism by which asbestos triggers mesothelioma, we still don’t know.

“In Ashford and Canterbury the deaths have fallen. Why in Swale and Thanet are we seeing very large increases?

“Unless we look at the individual deaths, I don’t think we can answer why specifically those two parts of Kent have seen massive increases.

“For example, it could be that people who worked in Medway in the dockyard where asbestos was used extensively, could have moved to Swale or Thanet and passed away in these areas.”

After initial exposure to the material, it takes between 20 to 60 years before a person develops mesothelioma.

Each year, more than 2,500 people are diagnosed with the deadly disease in the UK, with men five times more likely to be diagnosed than women.

Dr McKenna added: “You can strip asbestos out of buildings completely but there is a massive cost issue, and the government isn’t going to fund it.

“The argument is it is acceptable to block it in as best as you can to prevent the fibres escaping, effectively you cover it up.

“What would be very useful would be to have regular air monitoring in schools so that you get a very accurate picture of the precise level of asbestos fibres at that time when the children are moving around the school.”

There are two types of the disease, the most common being pleural mesothelioma, which develops in the tissue covering the lungs, and peritoneal mesothelioma which grows in the lining of the abdomen.