Marylebone in central London has some of the worst air pollution levels in the country due to its congested roads.
But the 60,000 commuters passing through the railway station every day will now breathe air that is 95% cleaner.
Four new filtering chambers have been fitted in the station to create clean air zones.
The units suck in dirty air at the top, which is passed through three big filters inside to remove particulate matter and nitrogen oxide from the air.
Sophie Power is the co-founder of Airlabs, which designed the technology.
She told Sky News: “We combine atmospheric chemistry and airflow engineering so, first of all we have to clean the air and we remove the gas pollution with the nanocarbon filter and what this does is reacts with the pollution in the air and absorbs it onto our filter.
“We need to change these filters approximately every six months.
“What we’ve done with the airflow engineering is design the outlets so the airflow through the station combines with our units to create zones of clean air around the units in the seating area so people close to them are breathing materially better air.”
Poor air quality contributes to tens of thousands of deaths in the UK every year.
The government has already been taken to court over high pollution levels. Air pollution in London reached the legal limit for the whole of 2018 less than a month into the year.
Simon Alcock, Head of Public Affairs at lawyers ClientEarth, said: “It’s good to see these initiatives, but I am afraid they’re not going to do much about the issue that we have on roads today.
“What we’ve got to do is tackle diesel vehicles and road transport because that is what ‘s harming our children’s health.
“The UK government needs to bring in a national network of clean air zones that takes the dirtiest cars off the dirtiest parts of our towns and cities.
“At the moment, they’re passing the buck to local authorities and saying you get on with that – we think that’s shirking their responsibility.”
The government admits it needs to do more and says it’s set aside £3.5bn to improve air quality.
UK cities rank among the worst in Europe for air pollution levels.