Doesn’t kill you: makes you weaker

As things stand a scientific assessment would suggest that Britain is Bangladesh for bees.

Here’s a fun experiment. Give your child – or a neighbour’s child, if you don’t have one of your own – a couple of large glasses of Malbec and then send them off to school. The wine probably won’t kill them, just as the neonicotinoid-based pesticides in routine use on our agricultural land aren’t directly killing bees. The child may well make it across the roads safely and get to school, just as most of the bees are still leaving the hive and finding pollen-bearing flowers. The chances are that the child will perform as badly at school that morning as the pesticideridden bees do at bringing back pollen. But you could still choose to label two glasses of wine a safe dose.

Last month, when the UK government told the EU that neonicotinoids aren’t a proven problem for bees, it brandished scientific evidence. Yet the tests it referred to showed little more than whether the likely doses were lethal. They did not look at whether neonicotinoids hamper a bee’s ability to go about its business effectively – to gather pollen, to navigate between flower sources and hives, or to communicate with other members of the colony.

Better tests show that all these activities are hampered by everyday exposure to neonicotinoids, which may have contributed to the ongoing collapse of bee colonies. For instance, studies carried out by researchers at the University of Stirling found that bumblebees will produce 85 per cent fewer queens. And scientists at Royal Holloway, London, discovered that bumblebees exposed to real-world neonicotinoid levels are 55 per cent more likely to get lost while foraging. That makes sense in the light of studies carried out by researchers at the universities of Newcastle and Dundee, which showed a disruptive effect on the honeybee brain, “observed at concentrations . . . encountered by foraging honeybees and within the hive”.

None of this is surprising. These pesticides are toxins that cause disorder in the brain. Just because they don’t cause immediate observable harm to a single bee when the chemicals are assessed individually doesn’t mean they are not a problem when all the various neurotoxins in the bee’s environment accumulate. As the Dundee and Newcastle researchers reported, “exposure to multiple pesticides . . . will cause enhanced toxicity”. There are probably safe doses of gin, vodka and whisky for a toddler. Give those measures all at once, however, and harm will ensue.

Anyone can avoid accepting inconvenient evidence in science, where findings are rarely black and white. A paper published last autumn in the journal Environmental Health Perspectives, for instance, demonstrates how epidemiologists and toxicologists work out the effects of interacting exposures to chemicals in different ways, which can lead to completely different conclusions about whether there is any effect at all.

But arguing over definitions is no good to bees. The collapse of the jerry-built garment factory in Dhaka, Bangladesh, last month offers a salutary lesson applicable to bee-colony collapse: you can rationalise the greedy pursuit of short-term gain all you like, but if catastrophe strikes, you are still responsible for the loss.

Economists put the annual value of insect pollinators to the UK economy at roughly £440m. Moral considerations aside, ensuring that their working conditions are as safe and sustainable as possible seems to make economic good sense. As things stand, however – and soon they might fall – a scientific assessment would suggest that Britain is Bangladesh for bees.

Bees. Photograph: Getty Images

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 13 May 2013 issue of the New Statesman, Eton Mess

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.