Boris Johnson has announced air quality rules that will require construction equipment more than a decade old to be retrofitted before being used in the capital.
The mayor of London revealed that the planning regulations would set strict targets for particulates and nitrogen oxides.
Construction and demolition activity is responsible for up to 15% of pollutants in the city, causing health problems.
Apart from some exempted specialist machinery, old equipment will need adjusting to be used on any central London project and on all but small schemes in the outer boroughs.
Johnson said: “By replacing the oldest and most polluting bulldozers and machinery on building sites we can greatly reduce harmful emissions and boost our air quality.
“We’ve all walked past construction sites and seen thick clouds of dust generated from equipment that simply hasn’t been updated or replaced in decades.”