Approximately 97% of all homes and businesses in the UK are in areas where the amount of at least one toxic substance in the air is higher than international safety limits, a study by the Central Office of Public Interest (COPI).

The research found that addresses in Kent, Bath, East Anglia and some coastal towns showed some of the UK’s worst pollution, as did the UK’s biggest cities.

The organisation has sourced and mapped pollution levels at 2,000 addresses across the UK, and also found 70% of British addresses breach all three World Health Organization (WHO) limits.

The map, produced by Copi and Imperial College London, combined 20,000 measurements with computer modelling to produce pollution estimates every 20 metres across the country. People can check their address at the website addresspollution.org for free.

The website also ranks each address against national pollution levels. For example, Buckingham Palace in London is in the 98th percentile, with highly polluted air, while Balmoral Castle in Scotland is in the zero percentile, with the cleanest air.

The towns and cities with the highest proportion of homes in the top 10% most polluted nationally are Slough in Berkshire, with 90%, followed by London, with 66%. Others in the worst 10 include Portsmouth, Leeds, Manchester and Reading.

The COPI is calling for clear legislation that forces agents to publish pollution ratings “similar to the obligations to disclose the presence of other dangerous substances, such as asbestos and radon”.