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Friday, 29 July 2016

Using GM to fight cassava brown streak disease

Last week I helped plant a new confined field trial for genetically modified (GM) cassava in western Uganda. The aim is to find how well the plants resist Cassava brown streak disease (CBSD).

Before planting, the National Crops Resources Research Institute (NaCRRI) held discussions with people from the local government and farmers’ groups. It’s vital to engage the local community so that people are correctly informed and on-board with the project. There were certainly some very strange myths to debunk!

Henry Wagaba (Head of Biosciences at NaCRRI) explained the huge losses caused by CBSD, which spoils tubers and can wipe out entire fields. CBSD is now the most devastating crop disease in Uganda and there are no resistant varieties currently available.

To fight the disease, NaCRRI researchers have developed GM cassava plants, which show high levels of resistance to CBSD at sites in southern and central Uganda. This trial will test how the plants perform in the growing conditions in western Uganda. Work will also be carried out to cross the GM plants wither farmer varieties to improve their growing and taste qualities.
I enjoyed getting stuck in and planting my first GM cassava!
GM crops are a contentious topic in Uganda. The passing of a National Biotechnology and Biosafety law has stalled in Parliament for over three years due to disagreements. Currently GM technology is used for research on banana, cassava, maize, potato, rice and sweet potato. However these are not approved for human consumption.

In nearby countries Kenya and Sudan, GM food products have been approved and many of these food products are imported into Uganda without regulation. It’s hoped the law will be passed soon to enable Ugandan farmers to reap the benefits of GM crops and protect against any potential risks.
Before the trial, I went on a safari in the Queen Elizabeth National Park, where I saw elephants, hippos and even lions!
This blog has been written by University of Bristol Cabot Institute member Katie Tomlinson from the School of Biological Sciences.  Katie's area of research is to generate and exploit an improved understanding of cassava brown streak disease (CBSD) to ensure sustainable cassava production in Africa.  This blog has been reposted with kind permission from Katie's blog Cassava Virus

Katie Tomlinson
More from this blog series:  

Monday, 25 July 2016

In defence of wasps: why squashing them comes with a sting in the tale

Image credit: Trounce
They are one of the most unwelcome signs of summer. Buzzing through beer gardens, attacking innocent picnics, wasps arrive ominously with a sting in their tails. Universally disliked, they are swatted, trapped and cursed. But would a wasp-free world really be a better place?

Despite their poor public image, wasps are incredibly important for the world’s economy and ecosystems. Without them, the planet would be pest-ridden to biblical proportions, with much reduced biodiversity. They are a natural asset of a world dominated by humans, providing us with free services that contribute to our economy, society and ecology.

Wasps, as we know, turn up everywhere. More than 110,000 species have been identified, and it is estimated there are still another 100,000 waiting to be discovered. One recent study described 186 new wasp species in one small corner of Costa Rican rainforest alone. In contrast there are only around 5,400 species of mammals, and 14,000 recorded species of ant.

This huge and diverse assemblage belongs to the order Hymenoptera and is divided into two groups, the Parasitica and the Aculeata. Almost 80,000 species of wasps belong to the Parasitica group, which lay their eggs in or on their prey or plants using elongated tubular organs called ovipositors. The remaining 33,000 species are Aculeates, most of which are predators, and the ones whose ovipositors have been modified through evolution to form a sting.

Both parasitic and predatory wasps have a massive impact on the abundance of arthropods, the largest phylum in the animal kingdom, which includes spiders, mites, insects, and centipedes. They are right at the top of the invertebrate food chain. Through the regulation of both carnivorous and plant-feeding arthropod populations, wasps protect lower invertebrate species and plants. This regulation of populations is arguably their most important role, both ecologically and economically.

Although the majority of wasps lead solitary lives, it is the 1,000 or so species of social wasps which make the biggest impression on insect populations. Social wasp queens share their nests with thousands of offspring workers, who raise upwards of 10,000 sibling larvae during the colony cycle. This means a single nest provides a whopping bang for buck in terms of ecosystem services, killing vast numbers of spiders, millipedes and crop-devouring insects.
Pest control. shutterstock
Many social wasps are generalist predators too, which means they control populations of a wide range of species, but rarely wipe any single species out. This makes them an extremely useful, minimising the need for toxic pesticides, but unlikely to threaten prey biodiversity. It is not yet possible to accurately quantify their huge economic value in this regard, but their diet of agricultural pests such as caterpillars, aphids and whiteflies makes a massive contribution to global food security.

Wasps also play a crucial role in ecosystems as specialist pollinators. The relationship between figs and fig wasps is arguably the most interdependent pollination symbiosis known to man. Without one another, neither the fig nor fig wasp can complete their life-cycle – a textbook example of co-evolution which is estimated to have been ongoing for at least 60m years. Figs are keystone species in tropical regions worldwide – their fruit supports the diets of at least 1,274 mammals and birds. The extinction of fig wasps would therefore be catastrophic in tropical ecosystems.

The birds and the bees … and the wasp

Almost 100 species of orchids are solely reliant on the action of wasps for pollination. The plants mimic the appearance and chemical profile of female wasps, tricking males into attempting to mate with them, so that as the male wasps attempt to copulate with the flower they are loaded with pollen which is then transferred to the next male-seducing orchid. Without the wasp, these orchids would be extinct.
Working wasp. Shutterstock
Wasps also function as generalist pollinators, inadvertently transferring pollen between flowers they visit for nectar collection. One type even provide their larvae with pollen instead of insect prey. These “pollen-wasps” are considered to perform the same ecological roles as bees, pollinating a diverse array of plants. Unfortunately, while bees are credited with contributing at least €100 billion a year to the global economy through their acts of pollination, the works of wasps in the same sector is often ignored.

Even the wasps' sting could have a positive impact on the human population. Medical researchers are exploring the potential use of biologically active molecules found within wasp venom for cancer therapy. A chemical found in the venom of the tropical social wasp Polybia paulista, has been shown to selectively destroy various types of cancerous cells.

Since they protect our crops, make ecosystems thrive, sustain fruit and flowers, and might help us fight disease, perhaps we should appreciate the wonderful work of wasps before we next swipe at them with a rolled up newspaper. They may be a nuisance on a sunny afternoon - but a world without wasps would be an ecological and economic disaster.

This blog is written by Cabot Institute member, Seirian Sumner, a Senior Lecturer in Behavioural Biology, University of Bristol and Ryan Brock, MRes candidate, University of Bristol.  This article was originally published on The Conversation. Read the original article.
Seirian Sumner

Why we need a new science of safety

It is often said that our approach to health and safety has gone mad. But the truth is that it needs to go scientific. Managing risk is ultimately linked to questions of engineering and economics. Can something be made safer? How much will that safety cost? Is it worth that cost?

Decisions under uncertainty can be explained using utility, a concept introduced by Swiss mathematician Daniel Bernoulli 300 years ago, to measure the amount of reward received by an individual. But the element of risk will still be there. And where there is risk, there is risk aversion.
Risk aversion itself is a complex phenomenon, as illustrated by psychologist John W. Atkinson’s 1950s experiment, in which five-year-old children played a game of throwing wooden hoops around pegs, with rewards based on successful throws and the varying distances the children chose to stand from the pegs.

The risk-confident stood a challenging but realistic distance away, but the risk averse children fell into two camps. Either they stood so close to the peg that success was almost guaranteed or, more perplexingly, positioned themselves so far away that failure was almost certain. Thus some risk averse children were choosing to increase, not decrease, their chance of failure.

So clearly high aversion to risk can induce some strange effects. These might be unsafe in the real world, as testified by author Robert Kelsey, who said that during his time as a City trader, “bad fear” in the financial world led to either “paralysis… or nonsensical leaps”. Utility theory predicts a similar effect, akin to panic, in a large organisation if the decision maker’s aversion to risk gets too high. At some point it is not possible to distinguish the benefits of implementing a protection system from those of doing nothing at all.

So when it comes to human lives, how much money should we spend on making them safe? Some people prefer not to think about the question, but those responsible for industrial safety or health services do not have that luxury. They have to ask themselves the question: what benefit is conferred when a safety measure “saves” a person’s life?

The answer is that the saved person is simply left to pursue their life as normal, so the actual benefit is the restoration of that person’s future existence. Since we cannot know how long any particular person is going to live, we do the next best thing and use measured historical averages, as published annually by the Office of National Statistics. The gain in life expectancy that the safety measure brings about can be weighed against the cost of that safety measure using the Judgement value, which mediates the balance using risk-aversion.

The Judgement (J) value is the ratio of the actual expenditure to the maximum reasonable expenditure. A J-value of two suggests that twice as much is being spent as is reasonably justified, while a J-value of 0.5 implies that safety spend could be doubled and still be acceptable. It is a ratio that throws some past safety decisions into sharp relief.

For example, a few years ago energy firm BNFL authorised a nuclear clean-up plant with a J-value of over 100, while at roughly the same time the medical quango NICE was asked to review the economic case for three breast cancer drugs found to have J-values of less than 0.05.
Risky business. shutterstock
The Government of the time seemed happy to sanction spending on a plant that might just prevent a cancer, but wanted to think long and hard about helping many women actually suffering from the disease. A new and objective science of safety is clearly needed to provide the level playing field that has so far proved elusive.

Putting a price on life

Current safety methods are based on the “value of a prevented fatality” or VPF. It is the maximum amount of money considered reasonable to pay for a safety measure that will reduce by one the expected number of preventable premature deaths in a large population. In 2010, that value was calculated at £1.65m.

This figure simplistically applies equally to a 20-year-old and a 90-year-old, and is in widespread use in the road, rail, nuclear and chemical industries. Some (myself included) argue that the method used to reach this figure is fundamentally flawed.

In the modern industrial world, however, we are all exposed to dangers at work and at home, on the move and at rest. We need to feel safe, and this comes at a cost. The problems and confusions associated with current methods reinforce the urgent need to develop a new science of safety. Not to do so would be too much of a risk.

The ConversationThis blog is written by Cabot Institute member Philip Thomas, Professor of Risk Management, University of Bristol.  This article was originally published on The Conversation. Read the original article.
Philip Thomas

Wednesday, 13 July 2016

Taking a trip to the cassava field!

At the end of last week I was lucky enough to be invited on a trip to the field. I didn’t really know what to expect but was very excited to find out!

The purpose of the trip was to collect data for the 5CP project to find out how different varieties of cassava respond to Cassava brown streak disease (CBSD) and Cassava mosaic disease (CMD) in different areas.

We set off at 5.30am in the morning; the first stop was Lake Victoria to catch a ferry to the Sesse Islands. The team consisted of me, the driver (Bosco), research assistant (Gerald Adiga) and research technician (Joseph). Along the road, we saw several accidents, sadly a far too common occurrence in Uganda…

Due to delays, the ferry was rammed, and by the time we arrived it was almost the evening. We raced to the agricultural school with the field trial. Here the team have planted blocks of 25 clean cassava varieties from five African countries and our job was to score them for disease symptoms. CBSD and CMD are not very common on the Sesse Islands, and so most of the plants were healthy.
An agricultural student digs up a healthy cassava plant.
After a night of drinking Guinness in a corner shop we headed out, again at 5.30am! This time we headed to the city of Mbarara in the western region. The drive was really beautiful, passing Lake Mburo National Park and mountains covered with matoke.

Whilst scoring the cassava plants here we noticed a super abundance of whiteflies, which carry CBSD viruses. The weather had been particularly dry, allowing the whiteflies to breed like crazy. Fortunately, CBSD is also uncommon in this area and very few plants were diseased.
Super abundance of whiteflies on cassava which carry CBSD viruses.
The data from the 5CP project will help farmers to decide which cassava varieties offer the most protection against CBSD and CMD in their local areas; helping to protect them from the devastating yield losses caused by these diseases.

Fun stuff

On the way back we passed the equator line, and I got the chance to take some touristy photos. This week I also saw the Ndere dance troupe, who showcase the different dance and music styles from all over Uganda and other neighbouring countries. It was a lot of fun, some dances bared a weird resemblance to morris dancing and marching brass bands!
Crossing the equator!
This blog has been written by University of Bristol Cabot Institute member Katie Tomlinson from the School of Biological Sciences.  Katie's area of research is to generate and exploit an improved understanding of cassava brown streak disease (CBSD) to ensure sustainable cassava production in Africa.  This blog has been reposted with kind permission from Katie's blog Cassava Virus

Katie Tomlinson
More from this blog series:  

Friday, 8 July 2016

Clean cassava to solve brown streak problem?

Since arriving in Uganda, I’ve been learning a lot about the affects of Cassava brown streak disease (CBSD), which is devastating cassava production and threatening food security. The disease is spread by the whitefly insect, which picks up the virus from an infected plant and carries it to neighbouring healthy plants.

Cassava plants are grown by planting stem cuttings in the ground, which go on to become new plants. If farmers use cuttings from infected plants, the new plants will also become infected. This is a big problem, as infected cuttings can be transported to new areas, spreading CBSD across large distances.

What can be done?


Huge efforts are being put into a number of different solutions. These include breeding new cassava varieties, which are tolerant to CBSD. This is a very long and challenging process, as cassava plants also need to be resistant to Cassava mosaic disease (CMD) and have yield/taste properties which farmers and consumers prefer.

The National Crops Resources Research Institute (NaCRRI) has recently developed a new variety: NAROCASS1, which is tolerant to CBSD and resistant to CMD. This is now being used in areas where CBSD is particularly common and severe. Unfortunately, even tolerant cassava varieties can contain CBSD viruses and so it’s vital that farmers have access to clean cuttings.
Cassava variety NAROCASS1 with CBSD tolerance and CMD resistance.

Clean seed system (CSS)

The cassava CSS project in Uganda is run by NaCRRI and involves picking the very youngest tip of the cassava plant to produce embryonic tissue, which develops into a new plant. These plants are then checked to see whether the CBSD virus is present before being taken to nurseries where they are carefully multiplied and eventually used for clean planting material for farmers. As you can imagine, this process takes a long time and is much more expensive than taking cuttings from a mature cassava plant. However it means that farmers can benefit from quality assurance that the cuttings they buy are virus free and stand the best chance of remaining healthy.
A clean cassava plantlet produced through tissue culture.
The cassava CSS project has been running as a pilot for three years. It will be very interesting to hear how this project goes, as it’s likely to be a major solution to the CBSD problem.

Reviewing progress

Last week I had helped take minutes for the annual CSS review at NaCRRI, which involved lots of manic typing and concentration! As part of the review I got to visit a field where an entrepreneur is growing clean cassava plants. The plants certainly looked healthy, with no CBSD and CMD symptoms at all. With so much to think about, we still found time to have a cocktail party to let of some steam!

Clean cassava seed entrepreneur David Mpanga explains how he uses record keeping to track of outgoings and income.
This blog has been written by University of Bristol Cabot Institute member Katie Tomlinson from the School of Biological Sciences.  Katie's area of research is to generate and exploit an improved understanding of cassava brown streak disease (CBSD) to ensure sustainable cassava production in Africa.  This blog has been reposted with kind permission from Katie's blog Cassava Virus

Katie Tomlinson
More from this blog series:  

Measuring greenhouse gases during India's monsoon

NERC’s BAe-146 research aircraft at the Facility for Airborne Atmospheric Measurements (FAAM). Image credit: FAAM
This summer, researchers across the UK and India are teaming up to study the Indian monsoon as part of a £8 million observational campaign using the NERC research aircraftBAe-146

India receives 80% of its annual rainfall in three months – between June and September. There are large year-to-year differences in the strength of the monsoon, which is heavily impacted by drivers such as aerosols and large-scale weather patterns, and this has significant impact on the livelihoods of over a billion people. For example, due to the strong El Nino last year, the 2015 monsoon experienced a 14% lower precipitation than average with some regions of India facing up to 50% shortfall.  Forecasting the timing and strength of the monsoon is critical for the region and particularly for India’s farmers, who must manage water resources to avoid failing crops.  
Roadside mural of the BAe-146 in Bangalore, India. Original artist unknown.  Image credit: Guy Gratton
The observational campaign, which is part of NERC’s Drivers of Variability in the South Asian Monsoon programme, is led jointly by UK researchers: Professor Hugh Coe (University of Manchester), Dr Andy Turner (University of Reading) and Dr Adrian Matthews (University of East Anglia) and Indian scientists from the Indian Space Research Organization and Indian Institute of Science.
Bristol PhD student Dan Say installing sample containers on the BAe- 146. Image credit: Angelina Wenger
To complement this project to study physical and chemical drivers of the monsoon, I am measuring greenhouse gas from the aircraft with PhD student Dan Say (School of Chemistry, University of Bristol). Dan is gaining valuable field experience by operating several instruments aboard the BAe-146 through the intense heat and rain of the Indian monsoon.

Two of the greenhouse gases that we are studying, methane and nitrous oxide, are primarily produced during the monsoon season from India’s intensive agriculture. Methane is emitted from rice paddies, in which flooded soils create prime conditions for “anaerobic” methane production. Nitrous oxide is also emitted from these flooded soils due the large quantity of fertilizers that are applied, again through anaerobic pathways. 

Rice fields near Bangalore, India. Image credit: Guy Gratton.
Our previous understanding of the large-scale emissions of these greenhouse gases from India’s agricultural soils has been limited and we aim to further our knowledge of what controls their production. In addition to the methane concentrations measured on the aircraft, with collaborators at the Royal Holloway, University of London’s isotope facility, we are also measuring the main isotope of methane (the 13-carbon isotope), which will provide us with a valuable tool for differentiating between agricultural and other sources of methane in the region. By combining this information with other measurements from the aircraft (for example, of moisture and of other atmospheric pollutants), we aim to gain new insights on how we may reduce these emissions in the future.

In addition, many synthetic “man-made” greenhouse gases are being measured for the first time in South Asia, giving us the first look at emissions from this region of some of the most potent warming agents. These include the suite of halocarbons such as hydrofluorocarbons (HFCs) and their predecessors the hydrochlorofluorocarbons (HCFCs) and chlorofluorocarbons (CFCs). These gases will be measured on the University of Bristol School of Chemistry’s ‘Medusa’ gaschromatography-mass spectrometer (GC-MS) facility run by Professor Simon O’Doherty.

Sample canisters for collecting air that will be measured on the School of Chemistry’s ‘Medusa’ GC-MS facility. Image credit: Angelina Wenger
This blog is written by University of Bristol Cabot Institute member Dr Anita Ganesan, a NERC Research Fellow, School of Geographical Sciences, who looks at greenhouse gas emissions estimation.
Anita Ganesan

Monday, 4 July 2016

Play stops rain: could 'cloud seeding' deliver perfect Wimbledon weather?

Image credit: Carine06, Wikimedia Commons
Wimbledon, 2026. Bright blue skies and a wonderful late afternoon sun lights up the lush green grass of centre court. Out strides the British number one and four-time winner, Andy Henman, to the cheers of the excitable, partisan crowd.

Somewhere nearby, at the headquarters of WeatherMod Inc, a group of technicians are busily checking data, confident that their efforts have worked. They have been in contact with two pilots who have just completed their spray sorties and are returning to land at Heathrow’s new third runway. Thanks to the delivery of 4kg of, in its pure form, a yellowish powder known as Silver Iodide (AgI) into clouds upwind of London, it is now raining over the Salisbury Plain, 100 miles away, and the rain predicted for later in SW19 is now 92% less likely.

This scenario probably sounds a little far-fetched, and not least the bit about the repeatedly successful home-grown tennis player. However, weather modification occurs more often than most people are aware. For example, as I wrote that first paragraph I genuinely didn’t realise that a Weather Modification Incorporated actually already exists in Fargo, North Dakota. They, and other companies like them have sprung up over the past few years promising to manage water for crops, clear fog and even protect wedding days from ill-timed hail.

But two questions need further investigation to consider the likelihood of the above scenario at Wimbledon: can we do it (that is, does it work) and should we do it? Neither, it turns out, are particularly easy to answer.

Changing the weather

In order to make rain several processes need to occur. First, small particles known as cloud condensation nuclei (CCN) are required onto which water can condense. Then these droplets need to grow to a size where they precipitate out of the cloud, finally falling where and when required.

In our hypothetical scenario we would therefore need to be able to either control or at least predict accurately the concentration of CCN, the rate at which droplets form, and the evaporation rates within the clouds. We’d also also need to have some handle on the rate and direction in which rain would fall.

Silver iodine dumped into a cloud attracts water, which turns into rain. Smcnab386 / wiki, CC BY-SA

In reality, cloud seeding with AgI – the current default option – only really tackles the first of these processes, forming the condensation nuclei. Even if clouds are seeded, it is still a matter of debate as to whether they actually create much additional rain. While companies claim success, some scientists are more wary. Although other seeding agents (and methodologies) exist, it is worth noting that, in the case of AgI, the nature of the clouds into which the particles are injected will govern the outcome.

Seeding works best in clouds which have a pre-existing mixture of water droplets and ice, as this type of nucleation requires ice-crystals to form. Following the production of CCN we’d then need to be able to predict, through computer modelling, how small droplets will form into rain and eventually fall.

One of the major drawbacks of cloud seeding is a lack of proof that it works: given weather forecasting remains imperfect, how would you know what would have happened without intervention? The second part of the question is arguably even harder to approach. What are the ethics of removing water from one part of the world, even on a small scale, and moving it somewhere else? Is this “messing with nature” or “playing God”? Water is, after all, the most precious commodity on Earth.

Let’s assume for now that it is possible to alter local weather patterns and to prevent or cause rain. This could be used for both good and evil, and the potential for abuse is worth considering. While manipulating the weather as a weapon is now explicitly outlawed by the UN’s ENMOD treaty, there have been efforts to alter the outcome of conflict using cloud seeding.

‘Operation Popeye’: the US used cloud-seeding to extend the monsoon season during the Vietnam war, causing delays on the waterlogged Ho Chi Minh Trail. manhhai, CC BY

Deliberate and accidental effects from commercial activity also seem possible. That dreamy, rain-free wedding ordered up by an anxious billionaire could easily ruin a school sports day in a nearby town.

The question of attribution is possibly the most challenging. Without any alternative outcomes to analyse, how can you really know what are the impacts from your actions. Some even say, quite incorrectly, that cloud seeding experiments caused floods, such as those that killed 35 people in the English village of Lynmouth in 1952. Expert opinion leans strongly against that idea being correct. Nonetheless, conspiracy theories persist. If, in our hypothetical Wimbledon scenario, bits of Wiltshire flooded, who would foot the bill?

It’s certainly possible in theory to prevent rain in one place by using cloud seeding to induce it in another, upwind. But there are huge challenges and the jury is still out about whether such efforts really work.

There are some very good causes, such as inducing rainfall in Sub-Saharan Africa during drought, where I would sanction intervention. For something as frivolous as a sporting event I feel differently. Just last weekend I played cricket for four hours in unrelenting drizzle (thanks Skip). While not a massively enjoyable experience it was at least familiar, and is part of the essence of both cricket and tennis. There’s some comfort in that.

The Conversation
This blog is by Matthew Watson, Reader in Natural Hazards at the University of Bristol.
This article was originally published on The Conversation. Read the original article.
Matthew Watson

Friday, 1 July 2016

Sharing routine statistics must continue post-Brexit when tackling health and climate change

Post-Brexit vote, we are posting some blogs from our Cabot Institute members outlining their thoughts on Brexit and potential implications for environmental research, environmental law and the environment.  

It has been argued that one of the EU's major contributions has been its legislation regarding environmental protection. Some of these bear directly on human health (for example, concerning air pollution levels). Looking forwards, moves to adapt and mitigate the effects of climate change may be greatly facilitated by sharing data on emerging trends across Europe.

An excellent example is provided by analysis carried out on "excess winter deaths" across Europe. Every country in the world displays seasonal patterns of mortality whereby more deaths occur in winter than at other times of year. However the extent of this excess varies between countries even within Europe. Intuitively one might have expected the excess to be greater in countries where winter temperatures are more extreme, yet this is not so. Healy (2003) used data from 14 European countries to demonstrate that in 1988-97, the relative Excess Winter Deaths Index (EWDI) was greatest for Portugal, where the mean winter temperature was highest. Conversely Finland with the lowest mean winter temperature showed the lowest EWDI. Data on mortality were available from the United Nations Statistics Databank and the World Bank, as well as some macro-economic indicators, but Healy also availed himself of the European Community Household Panel survey on socioeconomic indicators and housing conditions. This revealed that high EWDI was associated with lower expenditure on public health per head of population, as well as income poverty, inequality, deprivation, and fuel poverty. Furthermore, several indicators of residential thermal standards appeared to carry influence, whereby countries where houses had better insulation experienced lower EWDI.

A similar study was reported in 2014 by Fowler et al, partly as an update of Healy’s work, this time on 31 countries across Europe for the years 2002-11. The same geographic pattern still seemed to be present, with southern European countries faring worse in terms of winter deaths. However a few countries such as Greece, Spain and Ireland demonstrated a reduction in their EWDI. It is possible that Healy’s study had highlighted the need for improvement in those countries. All 27 countries who by that time were members of the European Union were included in analysis, and use was made of the Eurostat database.

In view of the projected increases in global temperature in coming decades, it might be hoped that the problem of excess deaths in winter will gradually disappear from Europe. Yet the greater susceptibility of warmer European countries to winter deaths compared with colder countries suggests such an assumption may be mistaken. It will be important for carefully collected routine data to be analysed, to investigate any changes in the patterns previously seen in Europe.

My colleagues and I were led to consider whether relatively low temperatures were more threatening to older people than absolute temperature level, and whether this might hold for individuals, as well as at a national level as highlighted by Healy’s and Fowler et al’s studies. We carried out analyses of two European cohort studies, of around 10,000 people aged 60 or over, followed over 10 years. Using daily temperature data for the localities of where these participants lived, we investigated weather patterns experienced by those who suffered major heart attacks and strokes. There was some evidence that cold spells (cold in relation to the month of the year) increased people’s risk over a 3-4 day period. We hope to replicate this finding in other datasets.

Reflecting on the data used by Healy and Fowler et al, it is noticeable that most (though not all) came from EU countries. Some of the data in Healy’s study was held by the United Nations or World Bank. Yet the Eurostat database was a major contributor to these enlightening analyses. Eurostat was established as long ago as 1953, initially to meet the requirements of the Coal and Steel Community. Over the years its task has broadened, and when accessed on 29 June 2016 displayed detailed comparative data on many domains including aspects of health.

It would be deeply disappointing as well as surprising if the UK were in future to withhold such valuable information, or conversely if such pan-European data were to become unavailable to UK-based researchers. This would seem unlikely, as Eurostat seems to draw upon data from EFTA nations as well as the EU, and advertises its data as freely available. It behoves the UK research community to continue to use these valuable data in a collaborative way with EU-based partners, and also to encourage continuing provision of UK data so that our EU-colleagues (both academics and policymakers) may benefit from this common enterprise.

This blog is by Professor Richard Morris, from the University of Bristol's School of Social and Community Medicine.  Richard's research focuses around statistics applied to epidemiology, primary care and public health research.
Richard Morris