Could air pollution be linked to higher crime rates?

Well, now I fancy some burgling. Image: Getty.

The impact of air pollution on human health is well-documented. We know that exposure to high levels of air pollutants raises the risk of respiratory infections, heart disease, stroke, lung cancer as well as dementia and Alzheimer’s disease. But there is growing evidence to suggest that air pollution does not just affect our health – it affects our behaviour too.

Lead was removed from petrol in the USA in the 1970s in response to concerns that vehicle emissions could be contributing to behavioural problems, learning difficulties and lowered IQ among children. In particular, childhood exposure to lead increases traits such as impulsiveness, aggression and low IQ – which can influence criminal behaviour. Taking lead out of petrol has since been linked with a 56 per cent drop in violent crime in the 1990s.

Short-term exposure to air pollution, especially sulphur dioxide, has been associated with a high risk of hospital admissions for mental disorders in Shanghai. And in Los Angeles, a study concluded that higher levels of particulate matter pollution increases teenage delinquent behaviour in urban neighbourhoods – though of course these effects are compounded by poor relationships between parents and children, as well as social and mental distress on the part of the parents.

It now believed that exposure to air pollutants can cause inflammation in the brain. What’s more, fine particulate matter is harmful to developing brains, because it can damage brain and neural networks and influence behaviour.

Criminal behaviour

The evidence so far suggests that air pollution has the capacity to increase bad behaviour – especially among young people. But further research indicates that it can have even more serious impacts. One study of air pollution and crime in 9,360 US cities suggests that air pollution increases crime. Polluted air increases anxiety, which can in turn lead to a rise in criminal or unethical behaviour. The study concluded that cities with higher levels of air pollution had higher levels of crime.

Recent research from the UK provides provides more information on this issue, by comparing data for 1.8m crimes over two years with pollution data from London’s boroughs and wards. The analysis considered factors such as temperature, humidity and rainfall, days of the week and different seasons.

The air quality index (AQI) reports how clean or polluted the air is each day. Researchers found that a 10 point raise in the AQI increases the crime rate by 0.9 per cent. Levels of crime in London are therefore higher on the most polluted days. The study found that air pollution influenced crime in London’s wealthiest and poorest neighbourhoods.

Specifically, the findings linked higher air pollution levels in London to increases in petty crime such as shoplifting and pick-pocketing. But it is worth noting that the researchers found no significant impact on serious crimes such as murder, rape or assault resulting in severe injury.

The stress factor

Exposure to poor quality air can increase the stress hormone cortisol, which can influence risk perception. Higher levels of risk taking is one reason why there is a rise in criminal activity on polluted days. The researchers conclude that reducing air pollution could reduce crime.

SMog: a recipe for misbehaviour. Image: Ian D. Keating/Flickr/creative commons.

But other social and environmental factors may also influence people’s behaviour. Environmental disorder – such as broken windows and graffiti – can induce social and moral disorder. The broken window theory suggests that signs of disorderly and petty criminal behaviour trigger more disorderly and petty criminal behaviour, causing this behaviour to spread.


It is becoming clear the effects of polluted air goes beyond the well-known impacts on health and environment. Yet air pollution remains high in many countries. According to the World Health Organisation, nine out of ten people worldwide are now breathing in toxic air.

There’s still a lot we don’t know about how individual air pollutants can affect health and behaviour, and how this differ with gender, age, class, income and geographic location. The link between high levels of air pollution and increases in type of behaviour requires further robust evidence to determine a stronger causal link.

But there’s plenty of evidence to prove that poor air quality is bad for both our physical and mental health. Concerted action by national and local government is required to tackle the problem by developing more sustainable transport, efficient and renewable energy production and use, and waste management.

The ConversationThe UN BreatheLife campaign is now challenging citizens to take action by leaving their car at home and use alternative forms of transport for at least the distance of a marathon (42km/26 miles) for one month. We all have a role to play in ensuring we can all breathe clean air, and gain the benefits of improved physical, mental and social well-being.

Gary Haq, SEI Associate, Stockholm Environment Institute, Environment Department, University of York.

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

 
 
 
 

Here are eight thoughts on TfL’s proposed cuts to London’s bus network

A number 12 bus crosses Westminster Bridge. Image: Getty.

In 2016, the urbanism blog City Observatory had a modest proposal for how American cities could sort out their transport systems: “Londonize”.

Its theory, the name of which referenced another popular urbanism blog, Copenhagenize, was that the key plank of Transport for London’s success was something that even transport nerds did not consider very sexy: its buses.

Though the Tube might get more glamorous press, London’s bus service really is impressively massive: It carries roughly 2.3bn passengers per year—much more than the Tube (1.3bn), close to the New York City subway (2.8bn), and nearly half as much as every bus service in America combined (5.1bn), while serving a population roughly 1/35 as large.

How has TfL done this? By making its bus network high frequency, reliable, relatively easy to understand and comprehensive. We rarely talk about this, because the tube map is far more fun – but the reason it’s so difficult to fall off the transport network in Greater London is because you’re never that far from a bus.

Given all that, we should probably talk about TfL’s plans to rethink – and in most cases, cut – as many as 36 different central London bus services over the next few months.

I’m not going to rehash details of the changes on which TfL is consulting from next month: there are just too many of them, and anyway it’s someone else’s scoop. The story was originally broken by Darryl Chamberlain over on 853 London; there’s also some fascinating analysis on Diamond Geezer’s blog. You should read both of those stories, though preferably not before you’ve finished reading this one.

Before offering my own analysis of the proposed changes, though, I should offer a few examples. More than a dozen routes are facing a trim: the 59 from King’s Cross back to Euston, the 113 from Oxford Circle to Marble Arch, the 171 from Holborn all the way down to Elephant & Castle and so on. A couple – the 10, the 48, the C2, and at most times the special routemaster version of the 15 – are being withdrawn altogether.

On, and one new route is planned – the 311, from Fulham Broadway to Oxford Circus. This will help plug some of the cuts to the 11, 19 and 22.

So, what does all this mean? Some thoughts:

1) This might not quite be as awful as it initially sounds

TfL says that demand for buses has fallen by around 10 per cent in London in recent years. It predicts it’ll fall further when Crossrail opens, as passengers switch to the new line, or to the tube routes relieved by the new line. So: the idea of taking some unwanted capacity out of the system is not, in itself, terrible.

Striping out unnecessary buses should also improve air quality in some of London’s worst pollution hot spots, and improve traffic flow, hopefully speeding up journeys on those buses that remain. 

A map from the presentation in which TfL explained its plans, showing the reduction in bus numbers on key arteries. Hilariously, notes Darryl Chamberlain, “It no longer produces its own maps, so has had to use one prepared by a bus enthusiast”.

The plans might even free up buses and staff to increase frequencies in outer London where demand hasn’t fallen – though these plans won’t be unveiled until next year and, for reasons I’ll come to below, I’ll believe it when we see it.

2) For many bus users, a lot of these changes will pass almost unnoticed

By my count, I use nine of the affected routes with any regularity – but only three of the changes are things that I’m likely to be at all inconvenienced by. Most of the changes either affect a part of the route I don’t take, or one where there are easy, and pain free alternatives.

This is anecdotal, obviously – perhaps I’m just lucky. But my suspicion is that a lot of these changes will go unnoticed by most passengers. It’s only the sheer number of them happening at once that makes this look like a big deal.

3) The Hopper fare makes this easier...

Once upon a time, if you had to switch buses, you had to pay a second fare. This isn’t true of journeys on the tube or railways – and since bus passengers have, on average, less money than tube passengers, it amounted to a pretty unfair tax on poorer Londoners.

But in January, in what is probably his most notable policy achievement of his two years in office so far, London’s mayor Sadiq Khan changed the rules. Now you can take as many buses as you want within an hour, for a single fare: that means you can switch buses without paying a penalty.

That will have made it easier for TfL to cut routes back: replacing a direct bus journey with one that requires a change no longer means imposing a financial penalty on passengers.


4) ...but not that easy

That’s about where the good news stops, though – because there are reasons other than cost why people prefer direct bus routes. Needing to change buses will be difficult for anyone with any form of mobility impairment, for example. Even for those of us lucky enough not to fall into that category, it’ll be annoying: it’s just easier to stay in one seat for 40 minutes than to get turfed off and have to fight for a new one halfway through.

More than that, from the passengers’ point of view, excess capacity feels quite good a lot of the time: it means your bus may well be nice and empty. Reducing the number of buses along those key corridors will also make those that remain more crowded.

5) The motive is almost certainly financial

Another of Sadiq Khan’s big policy promises was to freeze fares. He made this promise at a time when central government is massively reducing the financial support it gives TfL (the work, Chamberlain notes, of Evening Standard editor George Osborne, back when he was chancellor). And the Hopper fare, while a great idea in many ways, means a further reduction in income.

So: TfL is scrambling for cash: this is why I remain cynical about those new outer London bus routes. I would be amazed if money wasn’t a motivation here, not least because...

6) TfL thinks no one will notice

Any attempt to reduce tube frequencies, let alone close a station, would result in uproar. Hashtag campaigners! Angry people pointing at things in local newspapers! Damning reports on the front of the Evening Standard from the bloke who made it happen!

Buses, though? Their routes change, slightly, all the time. And do you really notice whether your local route comes every 10 minutes or every 12? That’s not to mention the fact that bus passengers, as previously noted, tend to be poorer – and so, less vocal – than tube passengers.

So cuts, and the savings they bring, are much easier to sneak through. TfL probably would have gotten away with it, too, if it hadn’t been for those meddling bloggers.

Although...

7) Scrapping the C2 might be a mistake

The C2 runs from Parliament Hill, through Kentish Town and Camden to Oxford Circus. In other words, it links north London, where a lot of journalists live, to the offices of the BBC and Buzzfeed.

As occasional New Statesman writer James Ball notes, this is probably not the easiest route to quietly shelve.

8) None of this is set in stone

The consultation doesn’t even begin until next month and then will run for six weeks – so all these plans may yet be forgotten. We shall see.

Anyway – here’s Darryl Chamberlain’s original scoop, and here’s some detailed analysis on Diamond Geezer. Please support your local bloggers by reading them.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and on Facebook as JonnElledgeWrites.

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