Exposure to Pollutants: “Science and Authorities Must Collaborate”

When his team detected 88 chemical contaminants in Luxembourg children by analyzing their hair, LIH professor Bryce Appenzeller sounded the alarm and called for long-term monitoring policies.

It is a study that he has already conducted many times for other countries, giving Luxembourg an international reputation and that he is conducting for the first time in the Grand Duchy: Professor Bryce Appenzeller, Head of the Human Biomonitoring Research Unit at the Luxembourg Institute of Health (LIH) through strands of hair from 256 resident children. to establish their “exposome”, i.e. the sum of all the chemicals they were exposed to.

In his laboratory, he explains how he worked on this project, what the main lessons are and warns about the lack of resources allocated to this type of research, which is essential for public health.

What is the purpose of this unprecedented research in Luxembourg?

Bryce Appenzeller: We wanted to document exposure to chemical pollutants by analyzing children’s hair to obtain an inventory. A skill we have developed here for over 15 years. We have been asked several times by France or China, but we have never worked with a group of children from Luxembourg, because we had no funding. What is unfortunate, even disappointing, is that we are ahead of the curve.

How can this lack of funds be explained?

Until recently, the effects of pollution on health did not really arouse interest: I set up this laboratory in 2007, and at that time, this theme was clearly not a priority. Since then, things have changed a bit, but if this research was able to see the light of day, it was thanks to the Fondation Kribschrank Kanner’s personal fund, which co-financed it.

Why work on hair?

It is a much more interesting matrix than blood or urine for measuring exposure to pollutants: by exploring hair, we get more complete and more representative information on chronic exposure.

In biological fluids, the concentration of pollutants varies greatly: depending on the time of blood sampling, completely different information is obtained, which complicates the interpretation of the results. This is not the case with hair. Another advantage: when they grow one centimeter per month, with a bulb of barely three centimeters, we see everything that has passed through the body in the last three months.

Participating families completed a questionnaire. What does it do?

General information about children and their lifestyles was needed to identify the first clues about the sources of pollutants to which they were exposed. A series of questions were asked: age, sex, diet, organic or not, if so in what proportion, place of residence, rural or urban, whether or not there are pets at home, and possible health concerns.

Is it important to obtain results?

absolutely We established that the germs of these children contained an average of 61 different contaminants: pesticides from different families, some still used today, others banned for more than 20 years, but which are persistent in the environment. And substances not used in Luxembourg are also used in countries from which the vegetables or fruit are imported.

We were also surprised to discover traces of some products, which have never been used in the Grand Duchy and are still present in 100% of cases: there are some foods, such as flour or chocolate, which will reach very quickly almost – through processed products to the entire population.

We found 26 contaminants in 95% of the children tested and 59 in more than half of them. It’s too much.

Are you able to draw any conclusions from the questionnaire?

No, because we are only in an observation phase. However, avenues for future research are already emerging. Depending on where children live, there are large disparities and not always in the same direction: small towns are exposed to certain substances, rural ones to others.

And it is not necessarily linked to pollution of the place. For example, the common occurrence of having a dog is more common in rural areas, and when a chemical pest control is applied to it, the entire family behavior.

The results also indicate a link between the intensity of exposure to pollutants and the onset of respiratory disorders. However, further analysis is needed on this topic.

What can we conclude about the health status of our children?

Nothing at this stage, because no direct link has yet been formally established between these substances and proven health risks, it will take another 10 or 20 years to get there. However, this does not mean that such exposure has no effect.

We often hear that the concentration in the body is so low that it will have no effect.

This is a false argument. What exactly is low density? Below what level does risk disappear? Fellow epidemiologists will tell you that the correct threshold is zero.

A distinction must be made between the effects of high-dose exposure, whose effects are immediate, and chronic exposure with long-term consequences, to low doses leading to toxicity.

It should also be taken into account that the toxicity of these compounds is often only known for one at a time. Which is not reality at all: we are indeed dealing with multiple exposures, this study proves it, but the harmful effects of a substance start at a much lower level when it is combined with another.

Where do the decades-long banned pollutants detected in these children come from?

These are pesticides like organochlorines, lindane or DDT, which have been used all over the world and which have polluted all environments: they are also found in polar bear fat! From a chemical point of view they are very stable: once spread, you cannot get rid of them.

Industrial discharges also contain PCBs, which have been stable for decades. When we detect it in adults, we can easily remember that they were published 10, 20 or 30 years ago. But not in the case of 5-year-old children: this is evidence that these substances are still present around us.

Is there a way to protect yourself?

I want to be optimistic about this. Science and authorities must work together to make sound preventive decisions. Regarding passive smoking, we have been able to introduce effective measures. And some harmful substances, such as bisphenol A, have recently been banned as a result of work like ours.

Food is also part of the trek. Our study clearly reveals a difference between children whose diets contain a large proportion of organics and others: for 16 pesticides and bisphenol S, their body concentrations were much lower. This is no coincidence.

Is this sufficient to justify the specific measures taken by the authorities?

No, this is only a first observation, research must continue. At the political level, many things have evolved, and the desire today is clearly to work together, with full transparency, to have usable and quantifiable information, and to protect the population. Ministry of Agriculture is part of this movement.

Your study shows, however, that the pollutants in question don’t just concern agriculture…

This is a problem in many countries: it is unfortunately common for government institutions in charge of the environment, health and agriculture, and ultimately, research on the population’s exposure to chemical pollutants receives no funding. On the contrary, it should be a simple task.

Public research relies heavily on external funding, but on this public health issue, we cannot be satisfied with haphazard funding. Regular surveillance policies need to be established with long-term government involvement, as is done in all countries. Luxembourg is lagging behind in this regard.

On this public health issue, we cannot be satisfied with haphazard funding

Six points to remember

  • Exposure to chemical pollutants in childhood has been linked to neurological diseases, developmental problems, hormonal disruptions, respiratory and cardiovascular disorders, cancer and obesity.
  • All children under the age of 13 (256 in total) were simultaneously exposed to multiple pollutants: an average of 61 were detected in their bodies, ranging from 29 to 88.
  • The highest concentration is bisphenol A, used to make plastics.
  • Persistent organic pollutants, banned in Europe for more than 20 years, were found in more than half of the samples.
  • Boys are more exposed to pesticides than girls.
  • Children who eat mostly organic foods have much lower concentrations of 17 types of pollutants (pesticides and bisphenol S).
“With a three-centimeter lamp, we can see everything that has passed through the body in the last three months.”
“We were surprised to discover traces of some products, never used in the Grand Duchy, and still present in 100% of the samples.”

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