Air pollution’s role as a cause of cancer has slowly been shifting to the centre stage over the past few years. And news stories like Oxford Street’s nitrogen oxide levels being among the highest in the world, the Volkswagen emissions scandal and the law suit against the UK government for breaching pollution limits have all helped nudge it closer to the spotlight.
But thanks to another set of headlines this morning, we’re also seeing questions asked as to exactly what can be done to fix the problem.
A panel of experts from the Royal College of Physicians and the Royal College of Paediatrics and Child Health have published a report into the lifelong impact of air pollution
The report, called Every breath we take, looks at the effect of exposure to polluted air on the risk of a range of diseases – including asthma, heart disease, diabetes and cancer
It estimates that about 40,000 deaths each year in the UK are linked to air pollution, and suggests what the public and policymakers can do to minimise the risk.
But where did the figure come from? And how can it be brought down?
How strong is the link with cancer?
Over the past decades evidence that air pollution is linked to a range of cancers has been mounting. In 2013, a group of international experts, working on behalf of the World Health Organisation’s International Agency for Research on Cancer (IARC), looked at the results of all of the research and concluded that air pollution causes cancer in humans – in particular, lung cancer.
But what do these experts mean by ‘air pollution’? The term is very broad, and covers a host of ‘nasties’ including miniscule particles, tiny fragments of metals and gases. But when it comes to cancer risk, research so far shows that tiny dust-like particles just millionths of a metre wide – so called ‘particulate matter’, or PM – are the main culprit. In particular, the smallest particles – less than 2.5 millionths of a metre across, known as PM2.5 – appear to be behind lung cancers caused by pollution. These are chiefly found in emissions from diesel engines – something IARC have also ruled causes cancer in humans (we discuss this in more detail here).
In fact, about eight in every 100 cases of lung cancer each year in the UK are attributable to PM2.5 air pollution exposure – very roughly, that equates to about 3,500 people. By comparison, in 2013 (the most recent year for which good data are available), there were around 45,000 lung cancer cases diagnosed overall).
But as the report discusses, there’s a lot we still need to know about air pollution and our health.
More than the sum of its parts?
The authors of the report are experts in their fields, and by looking at all of the evidence they’ve mapped out where some of the uncertainty lies.
Importantly, no-one knows exactly how these microscopic particles damage DNA inside cells and cause cancer. Rather than directly damaging the cells themselves, it’s possible they’re the fall guy for another culprit – the particles are so small they can travel deep into the lungs, carrying other harmful chemicals such as polycyclic aromatic hydrocarbons (which are known to cause cancer) into the airways. Or perhaps it’s a combination of both that sets cells on the road to cancer. The report has called for more research into this.
Another area that needs further investigation is in understanding about how the mix of different pollutants might interact to cause health problems. Most research so far has focused on measuring one specific pollutant and looking for health effects – which isn’t how people are exposed to air pollution in real life.
The report goes on to say that, because of limitations like this in the research, they could even be underestimating the true health effects of air pollution.
Looking ahead, the report looks at what would happen if we reduce air pollution levels. It estimates that reducing particulate matter pollution across Europe by about 20 per cent by 2050 would prevent an estimated 482,000 premature deaths from a range of diseases.
Health news in pictures
Health news in pictures
1/25 Most child antidepressants are ineffective and can lead to suicidal thoughts
The majority of antidepressants are ineffective and may be unsafe, for children and teenager with major depression, experts have warned. In what is the most comprehensive comparison of 14 commonly prescribed antidepressant drugs to date, researchers found that only one brand was more effective at relieving symptoms of depression than a placebo. Another popular drug, venlafaxine, was shown increase the risk users engaging in suicidal thoughts and attempts at suicide
RoschetzkyIstockPhoto / Getty
2/25 'Universal cancer vaccine’ breakthrough claimed by experts
Scientists have taken a “very positive step” towards creating a universal vaccine against cancer that makes the body’s immune system attack tumours as if they were a virus, experts have said. Writing in Nature, an international team of researchers described how they had taken pieces of cancer’s genetic RNA code, put them into tiny nanoparticles of fat and then injected the mixture into the bloodstreams of three patients in the advanced stages of the disease. The patients' immune systems responded by producing "killer" T-cells designed to attack cancer. The vaccine was also found to be effective in fighting “aggressively growing” tumours in mice, according to researchers, who were led by Professor Ugur Sahin from Johannes Gutenberg University in Germany
3/25 Green tea could be used to treat brain issues caused by Down’s Syndrome
A compound found in green tea could improve the cognitive abilities of those with Down’s syndrome, a team of scientists has discovered. Researchers found epigallocatechin gallate – which is especially present in green tea but can also be found in white and black teas – combined with cognitive stimulation, improved visual memory and led to more adaptive behaviour. Dr Rafael de la Torre, who led the year-long clinical trial along with Dr Mara Dierrssen, said: “The results suggest that individuals who received treatment with the green tea compound, together with the cognitive stimulation protocol, had better scores in their cognitive capacities”
4/25 New online test predicts skin cancer risk
Health experts have created a new online tool which can predict a person’s risk of developing a common form of skin cancer. The tool uses the results of a 10-question-quiz to estimate the chance of a person aged 40 or over of having non-melanoma skin cancers within three years. Factors including the age, gender, smoking status, skin colour, tanning ability, freckling tendency, and other aspects of medical history are covered by the quiz
5/25 Multiple Sclerosis stem cell treatment 'helps patients walk again'
A new treatment for multiple sclerosis (MS) has enabled some patients to walk again by “rebooting” their immune systems. As part of a clinical trial at Sheffield's Royal Hallamshire Hospital involving around 20 patients, scientists used stem cells to carry out a bone marrow transplant. The method known as an autologous haematopoietic stem cell transplant (HSCT) works by using chemotherapy to destroy the area of the immune system which causes MS
6/25 Dementia patients left without painkillers and handcuffed to bed
Dementia patients experience a ‘shocking’ variation in the quality of hospital care they receive across England, a charity has warned. Staff using excessive force and not giving dementia patients the correct pain medication were among the findings outlined in a new report by The Alzheimer’s Society, to coincide with the launch of Fix Dementia Care campaign
7/25 Cancer risk 'increased' by drinking more than one glass of wine or pint of beer per day
Drinking more than one glass of wine or pint of beer a day increases the risk of developing cancer, according to medical experts. New guidelines for alcohol consumption by the UK published by chief medical officers warn that drinking any level of alcohol has been linked to a range of different cancers. The evidence from the Committee on Carcinogenicity (COC) overturns the oft-held view that a glass of red wine can have significant medical benefits for both men and women
8/25 Vaping 'no better' than smoking regular cigarettes
Vaping could be “no better” than smoking regular cigarettes and may be linked to cancer, scientists have found. The study which showed that vapour from e-cigarettes can damage or kill human cells was publsihed as the devices are to be rolled out by UK public health officials as an aid to quit smoking from 2016. An estimated 2.6 million people in the UK currently use e-cigarettes
9/25 Rat-bite fever
A teenager was hospitalised and left unable to move after she developed the rare rat-bite fever disease from her pet rodents which lived in her bedroom. The teenager, who has not been named, was taken to hospital after she complained of a pain in her right hip and lower back which later made her immobile, according to the online medical journal BMJ Case Reports. She suffered for two weeks with an intermittent fever, nausea and vomiting and had a pink rash on her hands and feet. The teenager, who had numerous pets including a dog, cat, horse and three pet rats, has since made a full recovery after undergoing a course of antibiotics. Blood tests showed that she was infected with for streptobacillus moniliformis – the most common cause of rat-bite fever. One of her three pet rats lay dead in her room for three weeks before her symptoms showed
10/25 Taking antidepressants in pregnancy ‘could double the risk of autism in toddlers’
Taking antidepressants during pregnancy could almost double the risk of a child being diagnosed with autism in the first years of life, a major study of nearly 150,000 pregnancies has suggested. Researchers have found a link between women in the later stages of pregnancy who were prescribed one of the most common types of antidepressant drugs, and autism diagnosed in children under seven years of age
11/25 Warning over Calpol
Parents have been warned that giving children paracetamol-based medicines such as Calpol and Disprol too often could lead to serious health issues later in life. Leading paediatrician and professor of general paediatrics at University College London, Alastair Sutcliffe, said parents were overusing paracetamol to treat mild fevers. As a result, the risk of developing asthma, as well as kidney, heart and liver damage is heightened
12/25 Fat loss from pancreas 'can reverse' effects of type-2 diabetes
Less than half a teaspoon of fat is all that it takes to turn someone into a type-2 diabetic according to a study that could overturn conventional wisdom on a disease affecting nearly 3 million people in Britain. Researchers have found it is not so much the overall body fat that is important in determining the onset of type-2 diabetes but the small amount of fat deposited in the pancreas, the endocrine organ responsible for insulin production
13/25 Potatoes reduce risk of stomach cancer
Scientists have found people who eat large amounts of white vegetables were a third less likely to contract stomach cancer. The study, undertaken by Chinese scientists at Zhejiang University, found eating cauliflower, potatoes and onions reduces the chance of contracting stomach cancer but that beer, spirits, salt and preserved foods increased a person’s risk of the cancer
14/25 Connections between brain cells destroyed in early stages of Alzheimer’s disease
Scientists have pinpointed how connections in the brain are destroyed in the early stages of Alzheimer’s disease, in a study which it is hoped will help in the development of treatments for the debilitating condition. At the early stages of the development of Alzheimer’s disease the synapses – which connect the neurons in the brain – are destroyed, according to researchers at the University of New South Wales, Australia. The synapses are vital for brain function, particularly learning and forming memories
15/25 Sugar tax
The Government should introduce a sugar tax to prevent an “obesity crisis” from crippling the NHS, a senior Conservative MP and former health minister has said. Dr Dan Poulter believes that the case for increased taxes on unhealthy sugary products was “increasingly compelling”
16/25 Cancer breakthrough offers new hope for survivors rendered infertile by chemotherapy
A potentially “phenomenal” scientific breakthrough has offered fresh hope to cancer patients rendered infertile by chemotherapy. For the first time, researchers managed to restore ovaries in mice affected by chemotherapy so that they were able to have offspring. The scientists now plan to begin clinical trials to see if the technique, which involves the use of stem cells, will also work in humans by using umbilical cord material and possibly stem cells taken from human embryos, if regulators agree
17/25 Take this NHS test to find out if you have a cancerous mole
An interactive test could help flag up whether you should seek advice from a health professional for one of the most common types of cancer. The test is available on the NHS Choices website and reveals whether you are at risk from the disease and recommends if you should seek help. The mole self-assessment factors in elements such as complexion, the number of times you have been severely sunburnt and whether skin cancer runs in your family. It also quizzes you on the number of moles you have and whether there have been any changes in appearance regarding size, shape and colour
18/25 Health apps approved by NHS 'may put users at risk of identity theft'
Experts have warned that some apps do not adequately protect personal information
19/25 A watchdog has said that care visits must last longer
The National Institute for Health and Care Excellence (Nice) said home help visits of less than 30 minutes were not acceptable unless part of a wider package of support
20/25 Pendle in Lancashire tops list of five most anxious places to live in the UK
Pendle in Lancashire has been named the most anxious place to live in the UK, while people living in Fermanagh and Omagh in Northern Ireland have been found to be the happiest
21/25 Ketamine could be used as anti-depressant
Researchers at the University of Auckland said monitoring the effects of the drug on the brain has revealed neural pathways that could aid the development of fast-acting medications. Ketamine is a synthetic compound used as an off anaesthetic and analgesic drug, but is commonly used illegally as a hallucinogenic party drug. Dr Suresh Muthukumaraswamy, a senior researcher at the university and a member of the institution’s Centre for Brain Research, used the latest technology in brain imaging to investigate what mechanisms ketamine uses to be active in the human brain
22/25 A prosthetic hand that lets people actually feel through
The technology lets paralysed people feel actual sensations when touching objects — including light taps on the mechanical finger — and could be a huge breakthrough for prosthetics, according to its makers. The tool was used to let a 28-year-old man who has been paralysed for more than a decade. While prosthetics have previously been able to be controlled directly from the brain, it is the first time that signals have been successfully sent the other way
23/25 The biggest cause of early death in the world is what you eat
Unhealthy eating has been named as the most common cause of premature death around the globe, new data has revealed. A poor diet – which involves eating too few vegetables, fruits, nuts and grains and too much red meat, salt and sugar - was shown to be a bigger killer than smoking and alcohol
24/25 Scientists develop blood test that estimates how quickly people age
Scientists believe it could be used to predict a person’s risk of developing Alzheimer’s disease as well as the “youthfulness” of donated organs for transplant operations. The test measures the vitality of certain genes which the researchers believe is an accurate indication of a person’s “biological age”, which may be younger or older than their actual chronological age
25/25 Aspirin could help boost therapies that fight cancer
The latest therapies that fight cancer could work better when combined with aspirin, research has suggested. Scientists from the Francis Crick Institute in London say the anti-inflammatory pain killer suppresses a cancer molecule that allows tumours to evade the body’s immune defences. Laboratory tests have shown that skin, breast and bowel cancer cells often generate large amounts of this molecule, called prostaglandin E2 (PGE2). But Aspirin is one of a family of drugs that sends messages to the brain to block production of PGE2 and this means cancer cells can be attacked by the body’s natural defences
It’s important to keep these risks in perspective; most lung cancer cases are still caused by smoking. But as we work towards a tobacco-free UK it’s important to look at what else we can do to halt the rising rates of cancer.
“As other health hazards like smoking come under control, urban air pollution becomes more of a problem,” says Professor David Phillips, a Cancer Research UK-funded expert in carcinogenesis from King’s College London.
He points out that not all sources of pollution are the same. “Diesel exhaust, being much higher in fine particulates than petrol exhaust, is now one of the major sources of air pollution in cities.”
As one of the report’s authors, Professor Jonathan Griggs, told the BBC this morning, we can all play our part in reducing pollution by using the car less often. Walking or cycling have the advantage of helping people keep active too.
But we also need governments and local authorities to work together to develop a comprehensive strategy to reduce air pollution. Options such as a network of low-emission zones should be considered as part of a wider package of measures to cut air pollution. And getting this right, say the report’s authors, will reduce the strain on the NHS, leading to even more benefits.
“As NHS costs continue to escalate due to poor public health – asthma alone costs the NHS an estimated £1bn a year – it is essential that policy makers consider the effects of long-term exposure on our children and the public purse,” said Griggs.
In their report, which you can read here, the authors recommend 14 sensible steps that policy-makers and authorities should take to combat the ill health caused by air pollution. These range from better monitoring and analysis, better education, and developing new technologies to track global air quality trends – and of course, more research.
It’s important that they’re taken seriously.