Air pollution is the top environmental risk to health in the UK. Thursday is Clean Air Day, which aims to highlights the risks of air pollution and encourage people to change their habits to help make the air we breathe cleaner.
With most forms of air pollution invisible to the naked eye, how can you avoid inhaling the pollutants where you live?
Environmental journalist and author Tim Smedley shares his five top tips in the video above.
What is air pollution?
Air pollution is a combination of gases such as nitrogen oxide, Ozone and particles like smoke and dust - known as PM2.5 or PM10.
The main culprit is vehicles burning unclean fuels, with busy roads as hotspots for high particulate levels.
Around 2,000 locations across England, Wales and Northern Ireland have recorded unsafe levels but most pollutants can often only be seen in the air on a hazy day.
Across the world, 9 out of 10 people live in places with air quality levels above World Health Organisation guidelines.
In the UK, campaigners Friends Of the Earth flagged Earls Court station in London, Leeds and Doncaster some of the worst areas for clean air.
But harmful air pollutants are not just found outside the home.
Wood and coal burning fires make up 38% of the UK's particulate matter emissions.
While chemicals from varnishes, cleaning products and mould also contribute to the health problems associated with poor air quality.
Tim, author of Clearing the Air, said: "We’re seeing air quality in winter getting really bad in a lot of towns and cities so if you’ve got a wood burner, you’ve got an open fire, use it as little as possible."
Tackling the issue
Apps and pollution forecast maps have been developed to bring awareness to the issue.
Tim said: "Anywhere where there’s cars, anywhere where there’s solid fuel being burnt, you’re going to see air pollution.
"It isn’t just a big city problem, it also happens in villages and small towns and using my device, I’ve recorded levels in a small town near me and they can get really high just by busy traffic on a school run or office rush hour," he added.
The government is also investing £3.5 billion to tackle poor air quality through transport with aims to halve harm to human health from air pollution in the UK by 2030.
In the meantime, Tim recommends people head for green spaces and opt for eco-friendly travel.
He said: "I've made a lot of changes myself, I’ve been using the car a hell of a lot less, I drive as little as possible, I use public transport as much as I can.
"My daughter, unfortunately for her, gets walked to school even on the rainiest of days."