This will be the third incarnation of my blog. It started out as 'Fergus on flu', during the H1N1 pandemic, then became 'Fergus's Medical Files'. I hope you like the new version. Please leave comments - I do read them, and more importantly, so do other visitors to the blog.

But a report from an independent scientific committee has concluded that there is no evidence of increased cancer risks for those living close to the 13 nuclear power plants in Britain. The Committee on Medical Aspects of Radiation in the Environment (COMARE) analysed medical records concerning leukaemia in children under five.

The committee chairman Professor Alex Elliott said young children were the most vulnerable to this form of cancer: "If the incidence of in this age group is negligible then we can, with fair confidence, say that there is no problem with other age groups."

Childhood leukaemia is rare, but the committee looked at all cases within 5, 10 and 25 km of nuclear power plants and compared those with incidence elsewhere. They found that the risk was "extremely small, if not zero" for those living in close proximity to nuclear plants.

They also analysed incidence around seven sites earmarked for nuclear power plants which were never actually built. Around these areas they did find an above average incidence of leukaemia. The scientists said this anomaly showed that where clusters of cases are found, care is needed in attributing the root cause.

Previous studies have shown that the incidence of childhood leukaemia differ more than would be expected from chance - in other words, there must be a cause for clusters of cases. But the oncologists, epidemiologists and nuclear experts on COMARE do not think radiation from nuclear plants is responsible.

Today's report will be a fillip for supporters of nuclear power in the wake of terrible headlines following the Fukushima nuclear crisis. Last year the government identified eight sites in England and Wales as suitable for future nuclear power stations.

The committee pointed out that their research deals with nuclear power plants operating normally, so no comparisons can be made with either Chernobyl or Fukushima.

COMARE was set up in 1985 following a recommendation of the report chaired by Sir Douglas Black. This concluded that there was a raised incidence of leukaemia in young people living near the nuclear plant at Sellafield. Subsequent reviews by COMARE have concluded that radiation doses arising from nuclear installations are not nearly high enough to cause increases in childhood leukaemia.

The committee's current report was restricted to nuclear power plants so did not look at Sellafield, which is a reprocessing plant, nor did it include Dounreay, a former nuclear research facility. Its next report will analyse these plants and the clusters of leukaemia cases associated with both.

COMARE has also recommended the government looks at other possible factors involved in childhood leukaemia. In an earlier report it found cases of leukaemia were more likely among wealthier families in the least overcrowded conditions. Other studies have suggested that babies who have regular contact with other children are less likely to develop leukaemia, perhaps because their immune system is primed by early contact with infections.

The new report says: "There is growing epidemiological evidence that childhood leukaemia is linked to infections...either a rare response to a common infection...or a rare response to general exposure to infectious agents...however the biological mechanism underlying these hypotheses remain the subject of considerable scientific debate."

Three years ago a German study DID find a statistically significant increased risk of leukaemia among young children living near nuclear plants. But the COMARE report said the German data did not take into account variables such as the socio-economic status of the families or the conditions they lived in, which could both be important factors.

The Advocate General appears to argue that it is unethical to allow patents to be derived from research involving human embryonic stem cells. Here is a very brief extract from his opinion:

"I consider that an invention must be excluded from patentability, in accordance with that provision, where the application of the technical process for which the patent is filed necessitates the prior destruction of human embryos or their use as base material, even if the description of that process does not contain any reference to the use of human embryos."

The prospect of a ban on patents in this area has many scientists deeply worried. The International Society for Stem Cell Research said the Advocate General's view may "impede the development of new therapies".

There are thousands of scientists working on stem cells around Europe. In order for potential breakthroughs to be taken from the discovery stage and translated into new treatments, they need a huge amount of resources. This inevitably involves partnership with industry. Patents are important because they allow the pharmaceutical industry to protect their investments.

13 stem cell scientists have written to Nature expressing "profound concern" at the Advocate-General's opinion. At the Science Media Centre this morning, several of them gathered spoke of their shock and astonishment at Mr Bot's legal opinion and said it threatened to wipe out the bio-industry in Europe. The group included "Dolly the Sheep" creator Sir Ian Wilmut and Professor Pete Coffey who is in the final stages of planning the first UK trial of human embryonic stem cells as a potential treatment for blindness.

The scientists argued that the removal of patent protection would have a major impact on the UK economy. Professor Austin Smith, director of the Wellcome Trust Centre for Stem Cell Research in Cambridge said it would have a profound effect on this emerging area of technology.

It was a surprise to hear that it was Greenpeace in Germany which began the court action which led to Mr Bot's opinion. A spokesman told me that the organisation was not opposed to all stem cell research and also said that the opinion of the Advocate General was not clear cut.

The European Court is expected to make a final ruling in a couple of months.

There is rarely positive news about pancreatic cancer. It has the worst survival rate of all common cancers - worse even than lung cancer. Patients are usually diagnosed late when the cancer is inoperable. Typically, patients often have less than six months to live, and unlike other cancers, there has been little improvement in long-term survival in the past 40 years.

So it is heartening to report on a late stage trial involving hundreds of patients with advanced pancreatic cancer. You can see my TV report here. It is not a new form of chemotherapy, but a vaccine trial. Most vaccines are used to prevent infection, but therapeutic cancer vaccines aim to treat disease by stimulating the immune system to recognise and target the cancer.

The TeloVac trial involves more than 50 hospitals, is funded by Cancer Research UK and coordinated by Royal Liverpool University Hospital. It is a Phase 3 trial, which involves comparing the new treatment to standard therapy, and is essential before any new therapy is licensed.

The scientists and doctors involved in the TeloVac trial are keen not to raise the expectations of patients. In earlier small-scale trials, some patients did have a prolonged life-expectancy of several months. But until the results of this major trial are known it won't be clear whether this was anything to do with the vaccine.

But the idea of using the immune system to fight cancer is taking hold. Cancer Research UK pointed to two examples in the past year. Firstly, a vaccine using cancer cells mixed with a patient's own immune cells, was shown to be capable of prolonging survival in patients with advanced prostate cancer. Called Provenge, it is now licensed for use in the US. Scientists also found that an antibody, ipilimumab was able to prolong survival in patients with advanced melanoma, a deadly form of skin cancer.

The doctors in Liverpool are delighted with the take-up of the TeloVac trial, which is almost finished recruiting the 1,110 patients needed. I met three of the participants, Rhona Longworth, Joan Roberts and Charlie Williams. All had advanced pancreatic cancer and were having treatment at the Linda McCartney Cancer Centre. All showed determination and good humour in the face of this devastating disease.

They told me the vaccine had few side effects and they remained hopeful, both for themselves, but also for others in the future, who might benefit from their participation. My thanks to them and all the nurses and staff involved - I'll keep you informed about how the trial is going.

The gloom about pancreatic cancer was not lightened today by the results of a survey of patient experiences. Nearly one in four (24%) of pancreatic cancer patients surveyed said they visited their GP three or four times before being diagnosed with the disease compared to 17% of patients with other cancers. Forty-nine per cent of pancreatic cancer patients reported their health getting worse while waiting to see a hospital doctor, compared to 22% of all other cancers.

Professor Sir Mike Richards, National Clinical Director for Cancer said "This data clearly demonstrates that the treatment of pancreatic cancer patients is worse than patients affected by other cancers." Pancreatic Cancer UK, a national charity, expressed huge concern and said the patient experience needs markedly to improve.

You won't easily forget if are one of the 500,000. On enrolment all of us underwent a battery of medical checks. We also donated genetic material which will be stored for several decades. Scientists hope the project will lead to improved diagnosis and treatment for a host of conditions, from dementia to heart disease and cancer.

Which brings me to the food survey. Like other participants I was sent a comprehensive online questionnaire designed to detail every morsel I consumed yesterday. There was a long list of vegetables, from carrots to aubergines, next to which I had to tick the box marked "none". Other items included alcohol - one medium glass, and butter on bread - spread not thinly nor thickly, but just right to my taste. I imagine a researcher raising an eyebrow after seeing that I had at least three portions of "hard cheese". But then again one portion is listed as being "the size of a small matchbox" - hardly a mouthful!

There were also a couple of questions on physical activity. Sadly, it was not a day that I cycled 50 miles, but I did do some light exercise, thank goodness - namely running for a train and lugging heavy camera equipment around a hospital.

So what is the point of it all? The researchers at UK Biobank already know about my weight, eyesight, lung function, hearing, grip strength, bone density, not to mention sexual history and lifestyle. Then there are the samples of blood, urine and saliva in storage in a massive freezer near Stockport.

"Asking additional questions about diet and physical activity over the internet is a very simple way to add considerable detail to the resource," said Dr Tim Sprosen, UK Biobank Chief Scientist.

"This makes it more valuable to scientists when finding out how lifestyles influence our chances of developing a wide range of ailments, or working on better prevention."

So over the next 30 years as the 500,000 participants age, the researchers will have a huge amount of data to sift through and find out many more genetic and lifestyle factors which influence health.

What about how thick I spread my butter - is that really useful, or prying on a man's breakfast habits just a bit too much? Dr Sprosen said: "The type and thickness of a spread on bread can be important in determining fat consumption, especially if the individual eats lots of sandwiches. What we put on our bread, or jacket potato, can be as important as the meal itself in terms of nutrition, and often this is overlooked." Oh, ok then.

Don't worry if you are a UK Biobank volunteer and have not received your food survey yet - they are being sent out over the next couple of months. Later this year the team plan to ask participants if they will wear a watch-sized accelerometer or motion sensor for a week. As a gadget lover, I can't wait. And that surely will be the week that I exercise a lot and spread my butter more thinly.

Spare a thought this Mother's Day for women around the world who don't have access to the kind of care on offer in the UK to pregnant women. Whilst maternity services in Britain do sometimes fall short, it is unusual for women to give birth without any skilled help. Deaths in childbirth here are rare.

A report from Save the Children, timed to coincide with Mother's Day, has highlighted the alarming shortage of midwives in the developing world. Entitled "Missing Midwives", it says nearly 48 million women - one in three - give birth each year without expert help.

Save the Children says that of the 1,000 women and 2,000 babies who die each day, most succumb to easily preventable birth complications. For example it says more babies in poorer countries die from lack of oxygen at birth than from malaria. It estimates that 42,000 lives a year could be saved if there was someone present who could dry and stimulate a newborn baby to help it breathe.

Some of the comparisons are staggering. For example, the NHS employs 26,825 midwives and there are 749,000 births a year in the UK. By contrast Rwanda has 46 public midwives and there are 400,000 babies born each year.

I remember filming in a brand new maternity hospital in Sierra Leone a few years ago. It had no ultrasound scanner and no intensive care unit. The two doctors there provided care for a population of nearly 300,000. Despite the lack of staff and equipment, it was saving many lives.

Rather than relying on traditional birth attendants, often with no training, local women were being encouraged to attend ante-natal clinics. The birth attendants were being offered medical education and in the meantime were being paid by the hospital for each woman they persuaded to give birth at hospital.

The shortage of midwives is part of a wider problem - a massive shortfall of trained healthcare workers. Midwives and doctors cannot be created overnight. Even with political will, co-operation and funding, it is an issue which will take many years to put right.

The blood flow monitor could save the NHS huge sums of money

It has strongly supported the use of a blood flow monitor during major surgery which reduces complications and speeds the recovery of patients. You can read more about the story here and the full guidance from NICE.

This is not the first time that the monitor has been shown to be effective.

Over the past decade there has been a steady flow of clinical trials and assessments which have demonstrated that it benefits patients and budgets. In a cash-strapped health service it is worrying that the NHS is taking so long to adopt good ideas.

Professor Monty Mythen, from University College Hospital London, which has been using the monitor for 15 years, said it was partly down to what he called "silo-budgeting".

He said: "The cost of the probe - about £100 a time - comes out of the anaesthetics budget. That is a big extra cost. It saves £1,000 in the weeks to come but that saving goes to the surgical budget." This suggests a worrying lack of joined-up thinking.

NICE suggests that more than 800,000 patients a year in England could benefit from being monitored using the ultrasound device. Those are patients undergoing major or high-risk surgery. At present fewer than 25,000 patients are monitored using it.

Of course patients have no idea whether they have had their blood flow monitored using the ultrasound machine, because it is introduced into their oesophagus when they are under a general anaesthetic.

But surgical teams and hospital managers have a duty to ensure that proven technologies which benefit patients get used - especially when they also save the NHS a huge amount of money.

Perhaps we might one day see patients demanding the use of such medical devices in the same way cancer patients have demonstrated over the refusal to give them new therapies.

The idea of drug treatment to prevent cardiovascular disease is well-established. Not so with cancer. Now a panel of cancer experts, writing in Lancet Oncology have suggested that drugs such as tamoxifen could reduce the chances of developing breast cancer. You can read more about the story here.

Tamoxifen is a powerful medicine and the researchers make clear that it is not without side-effects. So women would need to think carefully before deciding whether they wanted to take the treatment long-term.

As with all medicines it comes down to an assessment of risks versus benefits, but that is especially important when healthy individuals take a treatment.

Professor Jack Cuzick, an epidemiologist at Queen Mary, University of London put the risk-benefit analysis this way: "For every 1,000 women on tamoxifen for 10 years, we estimate there would be 20 fewer breast cancers. But there would be three more womb cancers and six more deep vein thromboses."

So a key factor will be identifying women who are at increased risk of breast cancer. Among measures already taken into account are family history and increasing age. The researchers say increased breast density - visible on mammograms - could also be a useful assessment tool.

There are other factors which affect a woman's lifetime risk such as reproductive history and issues such as bodyweight, physical activity and alcohol intake. The Cancer Research UK website has a huge amount of information.

Tamoxifen is not licensed as a preventive therapy, and is off-patent. Professor Cuzick suggested this meant there was no great financial motive for the pharmaceutical industry to push for it to be licensed for prevention. He hopes current trials might eventually persuade NICE, the health watchdog, to back it as a preventive treatment.

News from Tokyo that radiation in the water supply is twice the level considered safe for infants is yet another worry for the citizens of Japan. The authorities there have recommended that people in the city do not allow babies under one to drink tap water. So how much risk is there?

As many people have pointed out, and has been mentioned here before, we are all exposed to radiation all the time, from the environment and from medical procedures like x-rays. The Health Protection Agency says the average dose per year in the UK is around 2.7 millisieverts (mSv), but is higher for people in some parts of the country. In Cornwall, the average annual radioactive radon dose to people is 7.8 mSv.

So what about Japan? There were reports that Tokyo's tap water contained, at one point, 210 becquerels of radioactive iodine per litre. That is twice the recommended limit of 100 becquerels for infants although below the 300 limit for adults. Becquerels is a measure of radiation emmitted whereas millisieverts is a measure of dosage on the body (there are many handy guides to these terms on the web).

Professor Richard Wakeford from the Dalton Nuclear Institute and visiting Professor of Epidemiology at Manchester University said the health effects would be extremely small. He calculated that drinking water for a year at the Japanese limit would give an infant a dose of 0.4mSv, so you would need to double that to get the effect of drinking water at the higher level of radiation for a year. Professor Wakeford said "in theory, there would be a very small additional risk of cancer, but in practice nothing more than you could expect to get from normal background levels of radiation".

So the extra risk from drinking tap water in Tokyo for a year would be far less than that of someone moving, say, from London to Cornwall for a year.

As several scientists have pointed out, the alert about drinking water in Tokyo is simply a sensible precautionary measure, based on the principle that if you can easily avoid risk, you should do so.

Dr Jim Smith, Reader in Environmental Physics at the University of Portsmouth said: "It should be emphasised that the limit is set at a low level to ensure that consumption at that level is safe over a fairly long period of time. This means that consumption of small amounts of tap water - a few litres, say - at twice the recommended limit would not present a significant health risk. I would expect that the recommendation not to drink tap water would also extend to women who are pregnant or breastfeeding."

Prof Wakeford added: "The primary objective is to limit the radiation dose to the thyroid gland of infants and young children, because it is well established that infants and young children are at the greatest risk from the accumulation of radioactive iodine in the thyroid. The contamination limits keep the resultant doses to tolerable levels."

Nonetheless, one bit of newswire copy said that the tap water alert in Tokyo was sending "anxiety levels soaring over the nation's food and water supply". Residents in Tokyo are reportedly clearing the supermarket shelves of tap water. On Sunday, milk, spinach and other vegetables from areas near the Fukushima plant were found to have radiation levels higher than regulated standards, but the Japanese authorities said it did not pose an immediate risk to health.

I do not mean to underplay the issue of the Fukushima nuclear leak. But the dangers from Tokyo tapwater do not bear any comparison with the earthquake and tsunami where there are currently nearly 9,500 confirmed dead and more than 14,700 people still missing.

In this rapidly developing crisis, this is causing "considerable concern" according to Professor Beddington, speaking in a TV interview. American, French and British nuclear experts who are monitoring the situation believe that the pond in Reactor 4 is all but gone.

He explained that the worst case scenario is that the fuel rods could start to burn and emit substantial amounts of nuclear material into the atmosphere. Professor Beddington said he was also "extremely worried" that the fuel tanks in Reactors 5 and 6 are leaking and if open to the air might emit significant amounts of radiation which would undermine the ability of the Japanese emergency workers to continue their efforts to control the situation.

So what does this mean for the potential health risks? Up to now Professor Beddington had supported the line taken by the Japanese authorities, that any danger was confined to within a 30 kilometre (18 mile) radius of the reactors.

Now he believes: "The situation is definitely more serious both within the area and further afield". The Scientific Advice Group for Emergencies (SAGE) which advises the government, have looked at "plausible worst case scenarios". For days that has been a potential meltdown of some of the reactor nuclear material but now a potential fire and release of radioactive material from the fuel rods has to be added in. Professor Beddington said if both these things happened and there were unfavourable winds, then radioactive material could affect Tokyo.

But he added this caveat: "Even in that situation we think the level of radiation that would come into the Tokyo area would be such that you could mitigate against it with relatively straightforward and simple measures - such as staying indoors with the windows closed."

British nationals are being advised to stay at least 80 kilometres (50 miles) from the nuclear plant, and to consider leaving Tokyo.

update 1530

"We are right to be worried by need to put the risks in context" said Gerry Thomas, Professor of Medical Pathology at Imperial College London. She is concerned that the dangers to human health are being exaggerated by some in the international media and could cause "psychological damage" to the Japanese.

She said that, even in the worst-case scenario, with a large release of radioactive material from Fukushima, the health dangers would be minimal.

"The Japanese are doing the right things - giving people iodine tablets, setting up an exclusion zone and asking people to stay indoors". Even if radiation from Fukushima reached Tokyo she believes the long-term health risks would be minimal.

Gerry Thomas is an expert in the health effects of radiation and has been studying tissue samples from many of the cancer patients affected by the Chernobyl disaster. Like other experts she said Fukushima was in no way as serious as Chernobyl and she urged those reporting the situation not to overplay the situation.

Images of helicopters dropping sea-water on the Fukushima nuclear power station, and of some worried residents leaving Tokyo, present a startling and unsettling picture. Watching the news and reading the papers it would be easy to be left with the impression that the health risks from the nuclear leak are rapidly escalating and spreading far beyond the exclusion zone.

The latest advice from the British Foreign Office may also add to the sense of unease:

"Due to the evolving situation at the Fukushima nuclear facility and potential disruptions to the supply of goods, transport, communications, power and other infrastructure, British nationals currently in Tokyo and to the north of Tokyo should consider leaving the area."

But if you read on, the travel advisory from the FCO is more reassuring:

"The most recent advice from the UK's Chief Scientific Adviser (Sir John Beddington) remains that for those outside the exclusion zone set up by the Japanese authorities there is no real human health issue that people should be concerned about. This advice is kept under constant review."

The exclusion zone is 20 kilometres (12 miles) around the plant. Those living between 20-30 kilometres away (12-18 miles) are being advised to stay indoors.

Sir John Beddington spoke by phone two days ago to British Embassy staff in Tokyo and a transcription of his comments is, I think, worth setting out in detail. He said:

"....do we have any concerns now in terms of human health? Well the answer is yes we do, but only in the immediate vicinity of the reactors. So the 20 kilometre exclusion zone the Japanese have actually imposed is sensible and proportionate. If they extended out a little bit more to 30 kms, that is well within the sort of parameters that we would think are extremely safe."

Of course, everyone is concerned about what might happen if the situation at Fukushima gets worse. Sir John went on to talk about the worse case scenario - a meltdown at the plant. He did not think this was likely, but what would be the result if it did?

"In this reasonable worst case you get an explosion. You get some radioactive material going up to about 500m up into the air. Now, that's really serious, but it's serious again for the local area....The problems are within 30 km of the reactor. And to give you a flavour for that, when Chernobyl had a massive fire at the graphite core, material was going up not just 500m but to 30,000 feet (9,144m) . It was lasting not for the odd hour or so but lasted months, and that was putting nuclear radioactive material up into the upper atmosphere for a very long period of time. But even in the case of Chernobyl, the exclusion zone that they had was about 30km. And in that exclusion zone, outside that, there is no evidence whatsoever to indicate people had problems from the radiation. The problems with Chernobyl were people were continuing to drink the water, continuing to eat vegetables and so on and that was where the problems came from. That's not going to be the case here. So what I would really re-emphasise is that this is very problematic for the area and the immediate vicinity and one has to have concerns for the people working there. Beyond that 20-30km, it's really not an issue for health".

Sir John is not alone in his assessment of the health risks. It is similar to comments I have heard by many other scientists.

On Today on BBC Radio 4, Professor Laurence Williams, former UK chief inspector of nuclear installations, stressed that Fukushima was not another Chernobyl and made it clear if he was living in Tokyo he would not leave:

"....I wouldn't be concerned. This is not a Chernobyl. We are not going to see high levels of radioactivity being put up high into the atmosphere and distributed on the winds. If we do get to the worse situation where the fuel in those reactors slumps because it doesn't have any structural integrity because of over-heating, then there will be a release of caesium and iodine (although the iodine is decaying all the time) and there will be strontium and ruthenium and other things that will come out....my guess is it is a low-level release and very localised it will not be like Chernobyl. People living in Tokyo are 150 miles (241km) away, so I would not be worried."

So even in the worst-case scenario, the risks to human health beyond the exclusion zone appear to be low. The main immediate threat to health is to the emergency workers trying to stabilise the plant. Radiation levels at the plant have fluctuated and we don't know exactly what materials are leaking out, nor in what quantity, nor over what time period.

Finally a note on potassium iodide tablets. Radioactive iodine from a nuclear leak can pollute the air and contaminate the food chain. Potassium iodide tablets can block radioactive iodine from being taken into the thyroid. The Japanese authorities have distributed these to people in the vicinity of Fukushima as a precautionary measure. But sales of iodide tablets have also soared in the US, thousands of miles away. It is not proportionate or sensible, but an indication of the level of unease that a nuclear accident can cause.

It is not surprising that many people in Japan are deeply worried about the potential health threat from the radiation leak at the Fukushima nuclear plant. The earthquake and subsequent tsunami produced tangible, visible destruction whereas radiation is an invisible danger.

The images of families being screened for contamination by workers in protective suits add to the sense of alarm. So what are the risks at present? Scientists I have spoken to say we cannot give a clear answer yet because we don't know enough about the amount and type of radioactive material that has leaked. Nonetheless, most experts seem to suggest the danger to the public is low.

To start with, some background on radiation exposure which is measured in the unit known as sievert. This quantifies the amount of radiation absorbed by human tissues.

It is worth pointing out that everyone gets exposed to radiation, all the time. This is from the air, cosmic rays, food, water and so on. The levels are very low.

Figures from the Health Protection Agency say:

A chest x-ray gives a dose of about 20 microsieverts (that is 20 millionths of a sievert)

The average annual background radiation dose for individuals in the UK is 2,200 microsieverts.

So how does that compare with what is happening in Japan? Earlier today, a Japanese minister said at one point, anyone at the Fukushima plant itself would be exposed to 11,000 microsieverts per hour, but this had fallen back.

At another point radiation levels are said to have reached as high as 400 millisieverts (one millisievert is 1,000 microsieverts). That would be 20 times the annual permitted limit for nuclear workers. Clearly it is the small group of nuclear workers remaining at the plant who are most at risk.

For the public there is a 20 kilometre (12 mile) exclusion zone around the plant. People living up to 30 kilometres (18 miles) away have been told to stay indoors. "That would be effective in reducing the chances of inhaling radiation from an airborne plume" said Steve Jones, Professor of Environmental and Occupational Toxicology at the University of Central Lancashire. He said, "We don't know what is in that plume released after explosions at the plant, but the risk would decrease very quickly the further away you travel from the site."

All of the experts I spoke to said the health risks to the public, at present, were low. Professor Jones said if the situation did not get worse then it would probably be impossible to show any measurable health effects on the wider public in the decades to come. Cancer is a key long-term risk from radiation exposure and officials will undoubtedly be monitoring the health outcomes of the population around Fukushima..

So how does the danger compare to the worst nuclear accident in history, at Chernobyl, 25 years ago? The radiation leak in Japan is minute by comparison. At Chernobyl a huge explosion was followed by a fire which raged for 10 days and emitted a huge amount of radiation which spread over a vast area.

In a report on the 20th anniversary of the disaster, the World Health Organisation said up to 4000 people may eventually die from the health effects of radiation poisoning, but so far there had been around 60 deaths. Around 50 of those were emergency workers and nine children who died from thyroid cancer. Children are especially at risk from radiation poisoning because of their developing bodies.

Dr Jim Smith, Reader in Environmental Physics at Portsmouth University and author of "Chernobyl: Catastrophe and Consequences" spoke to me from Kiev. He is part of a team on its his way to visit Chernobyl.

He said: "The Chernobyl disaster resulted in a major release of radioactivity. It was a graphite reactor and huge amounts of radioactive caesium and iodine escaped. It was partly due to the design of the plant - very different from those in Japan."

He said several hundred thousand people worked on the subsequent clean up and decontamination of the plant. Many had received an average of around 100 millisieverts over the duration of their work at the site. Professor Smith estimated that this had increased their lifetime risk of cancer to the extent that for every 100 workers an extra one would get cancer. This is not a risk anyone would choose to take, but he pointed out it was far less than the danger of cancer from being a life-long smoker.

One of the main health effects of the Japanese radiation leak maybe the psychological impact. Professor Jones said the stress of being displaced from your home and the fear of radiation contamination could have serious consequences. And that fear factor extends as far as Tokyo, 155 miles from the nuclear plant. "Even though people in Tokyo maybe completely safe, it is understandable that they are nervous and that can lead to stress and ill-health", he said.

If smoking is to be stubbed out then something drastic needs to happen in this seaside town.

I was also staggered by the news that one in three pregnant women in Blackpool smoke - twice the national rate.

We met two mums who smoked while pregnant. One said she was devastated when told her daughter's low birth weight was down to her smoking. But she has still not kicked the habit.

Most smokers here told me they started aged 13 or 14 - one man said he was 10.

Why is smoking so prevalent here? It is a deprived area with high unemployment.

And put simply, poorer communities smoke more than affluent ones.

"A Smokefree Future", published in 2010, said that until the mid-1950s, socio-economic groups smoked at similarly high rates. Since then, as evidence has emerged of the harm it causes, a wide gap has emerged, and tobacco use is now said to be the primary reason for the gap in healthy life expectancy between rich and poor.

People from disadvantaged groups are less likely to give up than the more affluent or educated. Children often follow the patterns of behaviour set down by their parents and peer groups. It is this cycle of smoking and ill-health that tobacco control strategies need to address.

And Blackpool says it is trying to fight back. Its "Altogether Now" strategy is aimed at encouraging residents to improve their health. The premiership football ground is completely non-smoking and the players are health champions.

Any smoking reduction strategy has to be geared towards the young - around 200,000 young people take up smoking in England each year.

In that vein, the ban on tobacco displays was welcomed by NHS Blackpool.

Jane Roberts, head of tobacco control, said: "Cigarettes are not like Mars bars - children should not see them when they walk into a shop."

She said removing displays would also help prevent impulse purchases by smokers.

But smokers were more dubious about the suggestion that tobacco should be sold in plain packaging.

One worker in a hard hat summed up the mood: "It would not stop me from smoking. I do it because I like it. Plain packaging won't make any difference."

But some did think that removing the brightly coloured logos and trademarks might deter the young.

The government says it has an open mind on plain packaging, but the idea has now gone out for lengthy consultation.

The tobacco industry would fiercely oppose any further restrictions on the sale of what is, after all, a legal product.

Some argue that the measures are another sign of the nanny state in action.

Britain has come a long way since the heyday of tobacco in the late 1940s when eight out of 10 men smoked.

When I first worked at Broadcasting House in London the newsroom had a constant fug of cigarette smoke. I remember one brilliant writer who used to light up a cigar each afternoon as he prepared to dictate the headlines to a typist.

Smoking on the Underground, in planes and in coaches was permitted and tobacco advertising was everywhere. Now you can't light up in a pub or workplace, and a ban on sales of cigarettes from vending machines is due to come in later this year, subject to a legal challenge.

A lot has changed - but 100,000 people in Britain still die from smoking-related causes each year.

The statistics are sobering. One in two life-long smokers will be killed by their habit. Sadly, my mother was one of them.

De-normalising smoking is a key part of discouraging the young from taking up the habit.

And if smoking rates do come down further it will have a dramatic benefit on the health of the nation.

Scientists in the United States have managed to turn human embryonic stem cells into a type of brain cell linked to memory loss in Alzheimer's disease. The research, published in the journal Stem Cells, should help in the development and testing of potential new medicines to treat the neurodegenerative disease which affects around half a million people in the UK.

The researchers at Northwestern University in Chicago managed to coax the stem cells into becoming a type of neuron which dies off early in people with Alzheimer's disease. The cells in question are basal forebrain cholinergic neurons (BFCN), which have a key role in memory function, and their loss is thought to be significant in the early stages of the neurodegenerative condition.

These dishes of cells should provide a near limitless supply of neurons for research. Scientists need to know why these cells - critical for memory function - fail in Alzheimer's disease. It should enable them to test compounds on the laboratory samples in the search for treatments.

One of the authors of the study, John Kessler, chair of neurology at Northwestern University said: "We can literally screen tens of thousands of drugs at a time to find the kind of compound that will keep these cells alive. We can ultimately think about transplanting the cells to help the memory deficit." He said his team had also created the neurons from the skin cells of Alzheimer's patients and from healthy volunteers. He was cautious about when the research might yield treatments but said 10 years appeared "realistic".

The Alzheimer's Society said the study was a "major step forward" but went on to say that further research was needed to find out whether these stem cells actually work in the brain. It urged greater investment in dementia research. The term "major breakthrough" was used on the Today programme on BBC Radio 4 although it was made crystal clear that benefits for patients were a long way off.

Another charity, Alzheimer's Research UK was more cautious. It said the prospect of stem cells being used as a treatment for the disease was still a very long way off and there was no evidence yet to suggest this method would be able to help people with dementia.

I confess I worry about the phrases "major breakthrough" and "major step forward". For me, the former should be reserved for something which is a game-changing piece of research, or a new device or treatment which transforms the way we combat a condition. Like many things it's hard to describe, but you know it when you see it. "Major step forward" is problematic unless you also know how many steps there are left to travel on a journey.

It seems to me that this research is another tantalising example of what MIGHT ultimately be achieved through manipulating human embryonic stem cells - the body's master cells.

Being able to generate the neurons which fail in early Alzheimer's and to test agents on them that may promote survival, will be extremely useful. But families affects by Alzheimer's need to know that there are a whole lot of major steps forward still needed before it yields an effective treatment for the disease.

An encouraging development in the diagnosis of prostate cancer - the most common cancer in men. Scientists at the University of Surrey have developed a urine test which - in an early trial - was at least twice as good at detecting prostate cancer than the current test.

Last October, Cancer Research UK scientists in Cambridge also announced early results of a prototype urine test. The CRUK researchers looked at levels of a protein found in urine called MSMB, and in a small study were able to diagnose prostate cancer from urine samples with about 50% accuracy.

The team at the University of Surrey focussed on another protein, Engrailed-2 (EN2) which is made by prostate cancers and secreted into urine. In a study of nearly 300 men published in the US journal Clinical Cancer Research, they found the test was able to detect prostate cancer with 66% accuracy, and with few so-called "false positives" - where cancer was supposedly detected when the patient was free of the disease. The research was funded by the University of Surrey and The Prostate Project charity.

The standard blood test checks prostate-specific antigen (PSA) levels. Among many problems with the blood test are that PSA levels can vary widely between men and at different time. Furthermore, a raised level may indicate other prostate conditions which are not cancerous.

False positives are a significant problem with the PSA test. A raised level may prompt a significant period of anxiety for patients and mean that they undergo a needle biopsy. Here the problem can be false negatives - so a cancer may be missed if the needle does not sample the right area.

Professor Malcolm Mason from CRUK said: "There is a desperate need for a better prostate cancer test than PSA, and this latest candidate, EN2, is very welcome. However, more work needs to be done to find out whether or not EN2 is capable of distinguishing between aggressive prostate cancers that need treatment, and non-aggressive ones that don't. Almost certainly, this new marker would be used as part of a combination of several markers, including PSA.

Both the Surrey and Cambridge urine tests are promising. Indeed there are frequent research papers showing the potential of biomarkers in blood and urine for detecting cancer and other diseases. But most still have a long way to go. A blog in the Guardian last year discussed the problems involved with using these "biological fingerprints" for detecting disease.

Men hoping to benefit from the Surrey research may have to wait some time at the prostate cancer urine test is still experimental. Dr Richard Morgan, senior lecturer in Molecular Oncology at the University of Surrey said: "We are preparing several large studies in the UK and in the US and although the EN2 test is not yet available several companies have expressed interest in taking it forward."