Google is now using its all-seeing Street View vehicles to map the pollution levels of city roads.

The cars have been fitted with sensors to detect pollutants and map a city's most toxic hot spots in a bid to help commuters find a healthier route.

The map reveals that levels of harmful pollutants at junctions and crossroads are five to eight times higher than nearby streets.

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Black carbon (soot) levels in the air around the roads of Oakland, California, as mapped by a new Google Street View project. The maps aim to help commuters avoid toxic fumes and more will be charted in future. The hotter colours show greater levels of pollution

GOOGLE'S POLLUTION MAP PROJECT Google and its partners have released a prototype pollution map of Oakland, California. The test map uses Google Maps's red, orange and yellow colour system, which normally indicates traffic levels. The map lays out levels of several pollutants, including nitric oxide, nitrogen dioxide and black carbon (soot) emitted by cars and trucks. Google hopes the findings will help future town planners improve road layouts to minimise pollution. The air quality project, launched in 2015, has already driven 14,000 miles (22,000 km) around the US. The team believes that their mobile measurement system could be implemented in cities throughout the world in future. Advertisement

The air quality project, launched in 2015, has already driven 14,000 miles (22,000 km) around the US and has now released a prototype map online.

The test map, which details pollution levels in Oakland, California, uses Google Maps's red, orange and yellow colour system, which normally indicates traffic levels.

The hotter colours show greater levels of pollution,

Pollution hot spots found include the city's port, busy intersections, restaurants, warehouses, industrial plants and vehicle dealerships.

Zooming in to the map reveals where pollution is highest along with extra, area-specific information on its causes.

For instance, on one street in the map, the caption reads: 'Vehicles speed up here to cross under the 1-880 freeway and merge onto the bay bridge. They can release more pollution as they accelerate.'

The map lays out levels of several pollutants, including nitric oxide, nitrogen dioxide and black carbon (soot) emitted by cars and trucks.

Google hopes the findings will help future town planners improve road layouts to minimise pollution.

A Google statement read: 'With nearly 3 million measurements and 14,000 miles (22,000 km) captured in the course of a year, this is one of the largest air quality datasets ever published, and demonstrates the potential of neighborhood-level air quality mapping.

'This map makes the invisible, visible, so that we can breathe better and live healthier.

Nitrogen Dioxide levels in Oakland, California. The air quality project, launched in 2015, has already driven 14,000 miles (22,000 km) around the US and has now released a map online

Zooming in on the map reveals where pollution is highest in the city along with extra, area-specific information on its causes (pictured)

'It helps us understand how clean (or not clean) our air is, so that we can make changes to improve it.'

The project is a joint venture between Google, the US Environmental Defence Fund and researchers at The University of Texas at Austin.

The team believes that their mobile measurement system could be implemented in many cities throughout the world, providing detailed air quality information for citizens, families, local governments and scientists.

Most large urban areas have only one air quality monitor for every 100 to 200 square miles (260 to 520 square km).

Some of Google's Street View cars have been fitted with sensors to detect pollutants and map a city's most toxic hot spots in a bid to help commuters find the healthiest journey to work

In comparison, Google's mobile approach maps air pollution every 100 feet (30 metres), or at about four to five locations along a single city block.

'You could use this information when you're picking a school for your kids,' University of Texas researcher Dr Joshua Apte said.

'Is there a school with a playground that might have better air quality because your kid has asthma?

'This hyper-local information about consistent air quality can be really useful for people, especially those who are vulnerable because of age or health condition.'