Manolis Kogevinas is an environmental epidemiologist with three decades of experience. He has published over 500 scientific papers and his publications have been cited more than 16,000 times. He was one of the founders of the Centre for Research in Environmental Epidemiology (CREAL), which merged with ISGlobal in 2015. Today, he is the head of ISGlobal’s cancer research programme and president of the International Society for Environmental Epidemiology.
The following is a summary of a Facebook Live interview that took place on 1 June 2017.
To kick off, what is environmental epidemiology?
It is the branch of epidemiology concerned with environmental exposures, such as air and water pollution, the effects of climate change, mobile phones, and so on. We study “the real thing”, that is, human populations.
QUESTION SUBMITTED BY JOANA BONET
"The main problem of aviation, and the one that is rarely talked about, is the effect on global warming
Do aircraft pollute the environment?
They do, a great deal. When people talk about airports, they usually refer to noise pollution. Noise is the issue that triggers the mobilisation of affected populations. And, obviously, noise caused by air traffic does disrupt people’s lives at night. It is associated with cardiovascular effects. There are other issues, for example, water pollution. Runoff from the water used to clean ice off airplanes is contaminated with solvents and aircraft fuel. But the main problem, and the one that is rarely talked about, is the effect of aviation on global warming. We talk about cars but, in fact, both today and in the future, it is aviation that has the most damaging effects. People are generally unaware of the fact that there is very little regulation of international aviation. According to the working group of the Intergovernmental Panel on Climate Change, aviation currently accounts for 3.5% of all manmade climate impact. Given that air travel and air freight are currently increasing, it is estimated that by 2050, if no changes are made, aviation will be responsible for as much as 15% of the impact. This means that all the progress we are making in reducing road traffic will be cancelled out by aviation.
QUESTION SUBMITTED BY ANTONIO PÉREZ
More and more people are reporting symptoms of electromagnetic hypersensitivity. How is possible that this problem is not officially recognised?
That is a very difficult question to answer. It has proved very difficult to assess electrosensitivity. Many of the teams that have studied the phenomenon do not accept that many people are electrosensitive. One of the problems we have encountered is how to define electrosensitivity. And that is a problem that has not been resolved in any valid or standardised way. It is important that studies be replicable and, with the methodology we have at the moment, we have failed to solve this problem. We don’t know how to study electrosensitivity, and we’re not going to be able to do so without methodological advances.
QUESTION SUBMITTED BY ANTONIO PÉREZ
Is the rise in the number of cancer cases in the last 20 years a purely random occurrence, or does it have something to do with the increase in wireless communications over the same period?
Just because there is an increase does not mean that we can attribute it to a specific cause. It could be due to wireless communications or it could be due to the increase in obesity and air pollution, or to a reduction in the number of hours people sleep. Or it may be due to a combination of multiple factors. Consequently, we cannot draw any conclusions from correlations on such a global level.
And what do we know about the influence of wireless communications on health?
It’s a big issue. A great deal of research has been done on extremely low frequency electromagnetic fields and now we are starting to see more studies on mobile phone use and the effects of radar systems in military populations. We also know that the exposure of the population has increased enormously. An important consideration is that, for many of these emissions, the exposure is very high when the electrical device is close to the user. In the case of mobile phones, when you hold the phone to your ear, exposure is high. If you hold the phone away from your body and use the speakerphone feature or earphones, exposure to radio frequencies and extremely low frequency fields is greatly reduced. The same thing happens with microwave devices. There is a worldwide increase in exposure to all kinds of electromagnetic fields. How does that affect us? We don’t know.
We do know something about the effect of high-voltage power lines. The best estimate that we have is that in a population exposed to quite high levels, there may be a increase in leukemia among children. In actual numbers, it would mean some 50 to 60 cases of leukemia in children in the European Union.
There is a hypothesis that mobile phone use may cause brain cancer. A large study has been done, but the Word Health Organisation (WHO) has not yet accepted that a causal link exists. An effect has been observed in animal studies. But studies in humans have not yet provided sufficient evidence to support any conclusions.
In any case, what we can see from your answers is that environmental epidemiology studies are very challenging. Is it difficult to discern the health effects of a particular exposure?
Yes, it is very difficult, precisely because we are dealing with the real world. The good thing about environmental epidemiology is that we assess real populations in all their complexity. Because people who are more overweight also do less physical activity and eat differently than those who are less overweight; people who work on night shifts are different from people who work during the day; people who talk a lot on the phone are different from those who use their phones only very rarely. Our task is very complex because society is complex.
QUESTION SUBMITTED BY PILAR SAMPIETRO
"There is a worldwide increase in exposure to all kinds of electromagnetic fields"
Are there any studies on the radiation emitted by antennas in the city of Barcelona?
No, we have not yet studied that. We know where the antennas are and we are working on the issue with the Generalitat [the Catalan Government]. Barcelona is in a similar situation to many other cities: the entire population is exposed. Steps have been taken to protect sensitive sites—schools and hospitals—and, up to a point, direct exposure of sensitive locations has been avoided. The Generalitat is trying to avoid the installation of mobile phone antennas that are directed towards schools. They have also tried to avoid the location of schools close to high-voltage power lines but, to be honest, they have not been entirely successful.
QUESTION SUBMITTED BY ROSA MARIA CURTO
The reduction or elimination of which pollutant would produce the greatest benefits for the environment?
In Barcelona in particular, air pollutants. Without a doubt. The Global Burden of Disease study ranks air pollution as the fourth or fifth highest risk factor for death in the world. And the air pollution levels we see in Barcelona are nothing compared to those found in Delhi, Beijing and Mexico city. Here we have 20, 30 or 40 micrograms per cubic metre and in New Delhi they have 600. That’s the difference. But that doesn’t mean that we are in a good place because Barcelona and Madrid are two of the most polluted cities in Western Europe and it is the inhabitants who are paying for that.
And what is the main source of air pollution?
In our case, road traffic. No doubt. The industry in Barcelona is located at a distance from the city and heating systems are not a major factor because we do not use coal.
Could the current property boom exacerbate the problem if it increases the need for transport and leads to even more air pollution?
Definitely. The model of a city is very important. That is something we have learned. In the past, when we talked about cities the only topic was air pollution, but with the passing of time it has become clear that the problem is much more complex. Now, we talk about urban health and we study air pollution (which causes some 4.2 million deaths worldwide every year) but also noise and light pollution, the availability of green spaces, and the possibility of engaging in physical activity in the city. The model is much more complex and it brings us much closer to the real situation.
We have touched briefly on some of the issues people are most concerned about. What about the issues that cause the most concern among researchers?
I am going to say something that is perhaps not very politically correct, but it is the truth: the issues we are focussed on are not always the ones we should be focussed on. Even in research there are fashions. We spend a great deal of time talking about air pollution. Now air pollution is an immensely important problem, but we have focussed on it to the exclusion of other issues. That is changing. It has taken us a long time as a scientific society to really come to grips with the issues involved in climate change, not just in terms of global warming, but more broadly.
And what are the issues you are concerned about?
I think there are two major issues: one is climate change—and in that respect we are closely monitoring events in the United States—and the second is cities. On a worldwide level, water shortages are obviously also going to be a major issue.
Because the world’s urban population is increasing at a steady rate, giving rise to a complex environment that is very difficult to manage. We are not necessarily talking about cities like Barcelona or Paris, but rather complex cities with huge problems: megacities that are home to over 10 million people, and super megacities like Tokyo or Jakarta with 30 million inhabitants. In 2007, there were 35 megacities in the world. By 2025, Asia alone will have 30 megacities. How do you manage that?
And why are you so worried about climate change?
Because it is the most serious problem facing humanity today. It’s that simple. It is depressing sometimes because every time you talk about climate change you have to give people bad news. But there is some good news too, and there is a lot we can do. We have had some positive indications, starting with the Paris meeting in 2015 that gave rise to an agreement adopted by 195 countries saying “We have to do something”. The actual commitments were minimal. The goal set was to hold the increase in the global average temperature to under 2ºC and it is already clear that we will exceed that threshold by a large margin. However, at least there was agreement on the need to act. In the future, life will no longer be viable in many parts of the world and the south of Spain will be affected. People my age will not live to see that, but my children will. The good news is that we have new technologies and that alternative energies are now cheaper than coal.
China is a country that generates a great deal of pollution, but at least its leaders are taking the problem seriously and are reducing emissions
How do experts in environmental health view the U-turn in US policy?
With great concern. It is true that the European Union has adopted a very clear position and that countries like China have changed their attitude. China is a country that generates a great deal of pollution, but at least its leaders are taking the problem seriously and are reducing emissions. The USA is the country that should be leading the charge, so it is a disaster if they abandon the effort. We are going to overcome this problem, because it makes no sense and a government of a great power that says that climate change does not exist cannot survive.
QUESTION SUBMITTED BY ORIANA RAMÍREZ
If you could wave a magic wand, what development model would you choose?
Today, more than 80% of the energy consumed on the planet is accounted for by 3 billion people. At the same time, the majority of the planet’s population accounts for only 12%. We can’t deny those people progress: we can’t tell them that they must not use energy, that they can’t have a motorbike, a car or better public transport. What we have to do is ensure that the energy they use is as clean as possible and, obviously, we are the ones who have to give up things.
Finally, let’s talk about one of your own study topics: the circadian rhythm. You advocate changing the clock and the daily timetable in Spain. Why is that?
In 2007, the WHO said that working night shifts for many years can cause breast cancer. There is a great deal of evidence from animal studies and some, less strong, evidence in humans that this radical alteration of the normal schedule is associated with breast and prostate cancer and also with metabolic effects, including myocardial infarction and diabetes. The reason for this is that for thousands of years humans, and all living beings, have been conditioned by the night/day cycle. Mice, for example, are nocturnal animals. There are experiments with impressive results showing that if you feed mice during the day they become obese, whereas if you give them the same food at night, during the period they normally eat when they can metabolize it, they do not gain too much weight. That tells us that we have rhythms and that changing them does have effects. Perhaps, changes in our clock—and not just the change from winter to summer time—has more impact on us than we thought.
What time zone do you think Spain should belong to?
If we followed our biological clock, we should be in the same time zone as England. What we do in Spain is adapt to the situation. The French start working at eight o’clock, we start at nine. However, changing the clock and our timetable is not so easy because there are also many social implications.