Here’s why you might be swallowing more air pollution than your next door neighbour

Too much of this, probably. Image: Getty.

Each year, tens of thousands of people in the UK die early due to air pollution, which is linked to asthma, heart disease and lung cancer. The health risk presented by air pollution depends on how much dirty air we breathe over time.

Pollution levels in UK cities regularly exceed the limits set by the World Health Organisation. But people’s exposure to pollution can vary greatly between people living on the same street, or even the same house.

Currently, health authorities estimate exposure to air pollution based on outdoor pollution at a person’s home address. But we don’t just sit outside our front doors all day – we each follow our personal daily schedules. The environment at home, in transit and at work or school all affect our exposure to pollution. Knowing this can help governments to create more effective policies and provide better advice to the public on how to reduce their exposure.

By equipping volunteers with portable pollution sensors, scientists have shown that exposure to air pollution during the day can vary substantially. For example, commuting during peak hour can account for a significant proportion of the pollution we’re exposed to – even though commuting only takes up a small part of our day.

By contrast, being indoors is often associated with lower exposure to pollution, because buildings provide some protection against outdoor pollutants. But gas cookers, wood burners and household cleaning products can also create high levels of indoor pollution.

How habits influence exposure

With all these different sources and levels of pollution around us, our daily activities and habits have a big influence on how much polluted air we breathe. Even couples who live together can have different exposures: a person who stays at home may experience up to 30 per cent less pollution than their partner who commutes to work.

A 24-hour measurement of a person’s pollution exposure, which varies throughout the day. Image: McCreddin et al./creative commons.

Small changes in our daily routines can significantly reduce our exposure to air pollution. In a study in London, participants were able to decrease their exposure during commuting by 25 per cent to 90 per cent by choosing alternative routes or modes of transport. Active commuters who walk or cycle are usually less exposed to pollution than people travelling by car or bus – this might be because vehicles travel in a queue, so air pollution from the vehicle directly in front gets drawn in through ventilation systems and trapped inside. The air is also much cleaner on overground trains than on the underground.

Displaying public information about pollution hot spots and ways to avoid them can help. The Wellbeing Walk is a signposted backstreet walking route taking ten to 15 minutes between London’s Euston and King’s Cross stations, which exposes walkers to 50 per cent less pollution than the main road. Since its launch in 2015, the number of people taking the healthier path has tripled. There need to be many more initiatives like this in cities.

Modelling human movements

Being able to tell when and where people are most exposed to pollution makes it possible to compare the benefits of different solutions. That’s why scientists have created computer models to simulate different scenarios. By combining information on outdoor pollution, pollution on transport and people’s travel routes, these models help us understand how people’s movements contribute to their personal exposure.

Computer exposure models for cities, including London, Leicester and Hong Kong among others, are beginning to give us a better picture of how people are exposed to harmful pollution. But the answers they provide are often complicated.

For example, the model for London suggests that on average citizens are exposed to less pollution than previously estimated. But many individuals still experience extremely high pollution during long periods on transport – so a lengthy commute by car, bus or underground could mean you’re among the most affected.

What’s more, the model does not yet account for pollution created indoors through cooking or wood burning. Including these additional sources of pollution may well shake up the results.


More data, please

The UK’s clean air strategy aims to halve the number of people exposed to particulate pollution above World Health Organisation guidelines by 2025. But surprisingly little is known about pollution levels inside our homes, schools and workplaces. If the strategy is to meet its goal, the government will need more data and better methods to estimate people’s exposure to air pollution.

Any model needs to be confirmed using actual measurements, to ensure we can trust what the model predicts about our exposure. Although the technology is advancing, portable pollution sensors are still bulky and heavy. Recruiting volunteers to carry these sensors wherever they go can be difficult. Phone-integrated sensors could make this easier in the future, but their reliability is still debated among scientists.

The ConversationImproving outdoor air quality is currently a top priority in cities across Europe – and rightly so. But measurements and computer models are indicating that our exposure to pollution is much more varied and complex than currently estimated. We should build on this knowledge to develop measures that deliver the greatest reduction in human exposure and empower citizens to make healthier choices in their daily routines.

Johanna Buechler, Air Quality Policy Researcher at Department for Environment, Food and Rural Affairs and Research Associate, UCL.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

The Adam Smith Institute thinks size doesn’t matter when housing young professionals. It’s wrong

A microhome, of sorts. Image: Wikimedia Commons.

The Adam Smith Institute has just published ‘Size Doesn’t Matter’, a report by Vera Kichanova, which argues that eliminating minimum space requirements for flats would help to solve the London housing crisis. The creation of so-called ‘micro-housing’ would allow those young professionals who value location over size to live inside the most economically-active areas of London, the report argues argues.

But the report’s premises are often mistaken – and its solutions sketchy and questionable.

To its credit, it does currently diagnose the roots of the housing crisis: London’s growing population isn’t matched by a growing housing stock. Kichanova is self-evidently right in stating that “those who manage to find accomodation [sic] in the UK capital have to compromise significantly on their living standards”, and that planning restrictions and the misnamed Green Belt are contributing to this growing crisis.

But the problems start on page 6, when Kichanova states that “the land in central, more densely populated areas, is also used in a highly inefficient way”, justifying this reasoning through an assertion that half of Londoners live in buildings up to two floors high. In doing so, she incorrectly equates high-rise with density: Kichanova, formerly a Libertarian Party councillor in Moscow, an extraordinarily spread-out city with more than its fair share of tall buildings, should know better.

Worse, the original source for this assertion refers to London as a whole: that means it includes the low-rise areas of outer London, rather than just the very centrally located Central Activities Zone (CAZ) – the City, West End, South Bank and so forth – with which the ASI report is concerned. A leisurely bike ride from Knightsbridge to Aldgate would reveal that single or two-storey buildings are almost completely absent from those parts of London that make up the CAZ.

Kichanova also argues that a young professional would find it difficult to rent a flat in the CAZ. This is correct, as the CAZ covers extremely upmarket areas like Mayfair, Westminster, and Kensington Gardens (!), as well as slightly more affordable parts of north London, such as King’s Cross.

Yet the report leaps from that quite uncontroversial assertion to stating that living outside the CAZ means a commute of an hour or more per day. This is a strawman: it’s perfectly possible to keep your commuting time down, even living far outside of the CAZ. I live in Archway and cycle to Bloomsbury in about twenty minutes; if you lived within walking distance of Seven Sisters and worked in Victoria, you would spend much less than an hour a day on the Tube.

Kichanova supports her case by apparently misstating research by some Swiss economists, according to whom a person with an hour commute to work has to earn 40 per cent more money to be as satisfied as someone who walks. An hour commute to work means two hours travelling per day – by any measure a different ballpark, which as a London commuter would mean living virtually out in the Home Counties.

Having misidentified the issue, the ASI’s solution is to allow the construction of so-called micro-homes, which in the UK refers to homes with less than the nationally-mandated minimum 37m2 of floor space. Anticipating criticism, the report disparages “emotionally charged epithets like ‘rabbit holes’ and ‘shoeboxes,” in the very same paragraph which describes commuting as “spending two hours a day in a packed train with barely enough air to breath”.


The report suggests browsing Dezeen’s examples of designer micro-flats in order to rid oneself of the preconception that tiny flats need mean horrible rabbit hutches. It uses weasel words – “it largely depends on design whether a flat looks like a decent place to live in” – to escape the obvious criticism that, nice-looking or not, tiny flats are few people’s ideal of decent living. An essay in the New York Times by a dweller of a micro-flat describes the tyranny of the humble laundry basket, which looms much larger than life because of its relative enormity in the author’s tiny flat; the smell of onion which lingers for weeks after cooking a single dish.

Labour London Assembly member Tom Copley has described being “appalled” after viewing a much-publicised scheme by development company U+I. In Hong Kong, already accustomed to some of the smallest micro-flats in the world, living spaces are shrinking further, leading Alice Wu to plead in an opinion column last year for the Hong Kong government to “regulate flat sizes for the sake of our mental health”.

Amusingly, the Dezeen page the ASI report urges a look at includes several examples directly contradicting its own argument. One micro-flat is 35 m2, barely under minimum space standards as they stand; another is named the Shoe Box, a title described by Dezeen as “apt”. So much for eliminating emotionally-charged epithets.

The ASI report readily admits that micro-housing is suitable only for a narrow segment of Londoners; it states that micro-housing will not become a mass phenomenon. But quite how the knock-on effects of a change in planning rules allowing for smaller flats will be managed, the report never makes clear. It is perfectly foreseeable that, rather than a niche phenomenon confined to Zone 1, these glorified student halls would become common for early-career professionals, as they have in Hong Kong, even well outside the CAZ.

There will always be a market for cheap flats, and many underpaid professionals would leap at the chance to save money on their rent, even if that doesn’t actually mean living more centrally. The reasoning implicit to the report is that young professionals would be willing to pay similar rents to normal-sized flats in Zones 2-4 in order to live in a smaller flat in Zone 1.

But the danger is that developers’ response is simply to build smaller flats outside Zone 1, with rent levels which are lower per flat but higher per square metre than under existing rules. As any private renter in London knows, it’s hardly uncommon for landlords to bend the rules in order to squeeze as much profit as possible out of their renters.

The ASI should be commended for correctly diagnosing the issues facing young professionals in London, even if the solution of living in a room not much bigger than a bed is no solution. A race to the bottom is not a desirable outcome. But to its credit, I did learn something from the report: I never knew the S in ASI stood for “Slum”.