It causes more premature deaths than drink-driving across the country, and is the leading cause of lung cancer.

Across the UK, there are many areas where a cancerous radioactive gas called Radon can be found - with some locations in higher concentration that others.

Here's what you need to know.

What is Radon - and how hazardous is it?

Radon is a 'colourless and odourless' natural radioactive gas that is formed by the radioactive decay of small amounts of uranium in rocks and soils.

The gas can also be found in water and some building materials, which means it can be detected in homes.

Public Health England (PHE) say every building contains radon but the levels are usually low.

The chances of a higher level depend on the type of ground. PHE have published a map showing where high levels are more likely.

Droitwich Advertiser: The Radon hotspot map. Picture: Public Health EnglandThe Radon hotspot map. Picture: Public Health England

PHE say: "The darker the colour the greater the chance of a higher level.

"The chance is less than one home in a hundred in the white areas and greater than one in three in the darkest areas."

According to the map, areas including the South West, the Midlands, the Pennines, Cumbria and Northumberland are indicated as hotposts in England. 

Much of Wales has also been identified as a hotspot area, plus parts of Aberdeenshire and the Highlands in Scotland.

There are also high levels in various spots across Northern Ireland.

What can we do about radon?

The concentrations in each area can vary from home to home, and all depend on the geological characteristics underneath the building, plus construction details, and also the living styles of the occupants.

Currently, the official advice is that all homes in affected areas should be tested for radon.

Can radon levels vary over time?

Yes they can - the radon levels in a property can vary significantly over time.

This is due to aspects such as weather conditions and seasonal changes. Therefore, it is recommended that tests should run over the course of a three-month period.

How can I carry out a test of my home?

Public Health England offer Home Measurement Packs to check the levels over a three-month period.

They can be bought by visiting: https://www.ukradon.org/services/orderdomestic

How can I check if there is a high risk of Radon in my area?

To check if your area has a high risk of Radon, use the map here: https://www.ukradon.org/information/ukmaps.