Is light pollution making us sick?

Image: Mike Knell via Flickr.

We all hate air pollution, right? It gets into our lungs, throats and noses, and makes cities from Beijing to Paris look like a badly ventilated bathroom after a long shower. 

But there's another pollutant that could also be making us ill: light.

A new study released by the Royal Society surveys research which seems to show that nighttime light can contribute to "breast and prostate cancers, obesity, diabetes and depression". These conditions become more prevalent as cities modernise and, as a result, electrify - but is light pollution really the explanation?

It's certainly unhealthy. All species develop something called a "circadian rhythm" based on 24-hour cycles of light and dark. Yet most humans now work indoors during the day, where light isn't usually bright enough to be registered by our bodies as daylight. And at night, light pollution from streetlights, cars, and all the other night-time activities in cities and towns, convince our bodies that it isn't night, either. We rarely experience what researchers call "true dark". 

According to the study's authors, this disruption of our daily cycles can affect our "Core body temperature, hormone regulation and release, and patterns of gene expression through the body".

Take Melatonin, a hormone which regulates our sleep patterns and also acts as an antioxidant. Our bodies produce it at night, but even low levels of light can suppress it - and reduced levels of melatonin have been linked to certain forms of cancer. 

Of course, while we're asleep, low levels of light don't penetrate to our retinas - so someone with light-blocking curtains and a solid eight or nine hours of sleep a night may well have developed a stable circadian cycle. But even waking up occasionally in a room permeated by light pollution, or turning on a bathroom light, can disrupt melatonin production. Here's a chart showing a normal melatonin production profile, versus the profile of a jetlagged subject who sleeps during the day:

Even with the lights off, the jetlagged person's body is registering the fact that it's not quite dark. 

As a result, the worst affected by disrupted circadian rhythms are actually shift workers: another study found that women who work night shifts have higher rates of breast cancer. And in 2007, the International Agency for Cancer Research declared that shiftwork may well be a carcinogen. Add enough floodlights and bright streetlights to our cities, though, and we might as well all be shift workers. 

Obviously, we should be cautious of blaming all our urban ills on a bit of night-time light. Indeed, the researchers note that findings linking light pollution and illness so far have been "promising" rather than final. But to be truly safe, it might be worth moving to Sark.


Barnet council has decided a name for its new mainline station. Exciting!

Artist's impression of the new Brent Cross. Image: Hammerson.

I’ve ranted before about the horror of naming stations after the lines that they’re served by (screw you, City Thameslink). So, keeping things in perspective as ever, I’ve been quietly dreading the opening of the proposed new station in north London which has been going by the name of Brent Cross Thameslink.

I’ve been cheered, then, by the news that station wouldn’t be called that at all, but will instead go by the much better name Brent Cross West. It’s hardly the cancellation of Brexit, I’ll grant, but in 2017 I’ll take my relief wherever I can find it.

Some background on this. When the Brent Cross shopping centre opened besides the A406 North Circular Road in 1976, it was only the third large shopping mall to arrive in Britain, and the first in London. (The Elephant & Castle one was earlier, but smaller.) Four decades later, though, it’s decidedly titchy compared to newer, shinier malls such as those thrown up by Westfield – so for some years now, its owners, Hammerson, have wanted to extend the place.

That, through the vagaries of the planning process, got folded into a much bigger regeneration scheme, known as Brent Cross Cricklewood (because, basically, it extends that far). A new bigger shopping centre will be connected, via a green bridge over the A406, to another site to the south. There you’ll find a whole new town centre, 200 more shops, four parks, 4m square feet of offices space and 7,500 homes.

This is all obviously tremendously exciting, if you’re into shops and homes and offices and not into depressing, car-based industrial wastelands, which is what the area largely consists of at the moment.

The Brent Cross site. Image: Google.

One element of the new development is the new station, which’ll sit between Hendon and Cricklewood on the Thameslink route. New stations are almost as exciting as new shops/homes/offices, so on balance I'm pro.

What I’ve not been pro is the name. For a long time, the proposed station has been colloquially referred to as Brent Cross Thameslink, which annoys me for two reasons:

1) Route names make rubbish modifiers because what if the route name changes? And:

2) It’s confusing, because it’s nearly a mile from Brent Cross tube station. West Hampstead Thameslink (euch), by contrast, is right next to West Hampstead tube.

Various other names have been proposed for the station. In one newsletter, it was Brent Cross Parkway; on Wikipedia, it’s currently Brent Cross South, apparently through confusion about the name of the new town centre development.

This week, though, Barnet council quietly confirmed it’d be Brent Cross West:

Whilst the marketing and branding of BXS needs to be developed further, all parties agree that the station name should build upon the Brent Cross identity already established. Given the station is located to the west of Brent Cross, it is considered that the station should be named Brent Cross West. Network Rail have confirmed that this name is acceptable for operational purposes. Consequently, the Committee is asked to approve that the new station be named Brent Cross West.

Where the new station will appear on the map, marked by a silly red arrow. Image: TfL.

That will introduce another irritating anomaly to the map, giving the impression that the existing Brent Cross station is somehow more central than the new one, when in fact they’re either side of the development. And so:

Consideration has also been given as to whether to pursue a name change for the tube station from “Brent Cross” to “Brent Cross East”.

Which would sort of make sense, wouldn’t it? But alas:

However owing to the very high cost of changing maps and signage London-wide this is not currently being pursued.

This is probably for the best. Only a handful of tube stations have been renamed since 1950: the last was Shepherd’s Bush Market, which was until 2008 was simply Shepherd's Bush, despite being quite a long way from the Shepherd's Bush station on the Central line. That, to me, suggests that one of the two Bethnal Green stations might be a more plausible candidate for an early rename.

At any rate: it seems unlikely that TfL will be renaming its Brent Cross station to encourage more people to use the new national rail one any time soon. But at least it won’t be Brent Cross Thameslink.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason. 

Want more of this stuff? Follow CityMetric on Twitter or Facebook