Living with heavy pollution caused by traffic can be as bad for your happiness as being widowed or divorced, new research suggests.
Extremely high levels of nitrogen dioxide, largely emitted by diesel engines, can impact on life satisfaction in the same way as a bereavement or a break-up, according to the research paper.
Academics at the University of York also said that soaring levels of nitrogen oxide found in London and other parts of the country where the legal limit is routinely broken could also carry a “psychological” cost as great as that of being out of work.
In the paper - titled Can clean air make you happy? Examining the effect of nitrogen dioxide (NO2) on life satisfaction – Sarah J Knight and Peter Howley wrote: “Our results suggest a significant and negative association between mean annual ambient NO2 and life satisfaction, and moreover that these effects are substantive and comparable to that of many 'big hitting' life events."
They added: “For example, our standardised coefficients suggest that the effect of NO2 on life satisfaction is equivalent to approximately half that of unemployment, and equivalent to that of marital separation and widowhood, factors commonly associated with some of the largest wellbeing reductions in the literature to date.”
The capital placed 40th in the 19th annual Mercer Quality of Life Survey. It was 39th last year.
London mayor Sadiq Khan is pressing ahead with a series of measures to cut air pollution in the capital including a £10-a-day T-charge on the most polluting vehicles to drive into central London from October, as well as introducing the Ultra Low Emission Zone earlier than 2020 and possibly expanding it from the city centre to the north and south circulars.
Nitrogen dioxide emissions from diesel cars are a key contributor to the capital’s poor air quality, which has seen City Hall advising the public to avoid strenuous activity on the worst-affected days.
A series of high air pollution alerts have already been issued for the capital in the first three months of the year.
Concerns over the impact of diesel cars on NO2 levels were first raised by the Volkswagen emissions scandal in September 2015.
This week, MP Neil Parish, the chairman of an influential Commons committee, is expected to tell ministers that owners of old diesel cars should be able to scrap their vehicles for cash in pollution hotspots.
Following the Volkswagen emissions scandal in 2015, a Department for Transport investigation found that 37 top-selling diesel cars exceeded the legal limit required for laboratory pollution tests when driven for 90 minutes on normal roads.
Drivers were encouraged to switch away from petrol under Tony Blair's government and Prime Minister Theresa May has said that would be taken "into account" in future plans.
During a recent trip to the Middle East, Mrs May said: "In relation to the issue of diesel cars, obviously we will be producing a new air quality plan, we've been required to do that by the courts.
"Decisions will be taken when we produce that plan - obviously we will take final decisions as to what we do.
"But I'm very conscious of the fact that past governments have encouraged people to buy diesel cars and we need to take that into account when we're looking at what we do in the future."