Paris (AFP)

Worried parents, a construction site under close surveillance: for months, the inhabitants of the Notre-Dame district of Paris worried about the effects on their health of the lead resulting from the fire.

Two years later, what is the result of this pollution?

On April 15, 2019, 460 tonnes of lead from the roof and the spire of the cathedral went up in smoke.

A part is found in the form of dust in the atmosphere, then settles on the forecourt and in the adjoining streets.

Local residents and associations are concerned about the presence of this toxic heavy metal, which can cause digestive disorders, kidney disruption, nervous system damage or reproductive abnormalities.

Young children are the most vulnerable to this poisoning, also called "lead poisoning", because their nervous system is in full development and they often put objects in their mouths.

Recommendations were quickly disseminated on the cleaning of housing but it was not until May 13, during a public meeting, that the results of the samples taken in the public space and the premises of the neighboring Police Headquarters were communicated. from the cathedral.

The information is complicated by the fact that there is no health threshold for the concentration of lead in public spaces.

It is also difficult to determine whether the particles found come from the fire, or from a previous pollution (erosion of the roofs of other buildings, legacy of leaded gasoline, etc.).

- "Wash your hands" -

As for the cathedral security project, it was suspended at the end of July 2019 due to breaches of security rules, before reopening with reinforced protocols (airlock, showers, etc.).

The association of families victims of lead poisoning (AFVS) blames, at least, a lack of communication.

"We found ourselves doing information on the sidewalk to tell people who worked there: + Be careful, clean your boxes, wash your hands," recalls Mathé Toullier, its president.

According to the screenings carried out in the following months on hundreds of children in five Parisian districts (1st, 4th, 5th, 6th and 7th), the feared "health scandal" seems avoided.

Out of 1,216 determinations of the level of lead in the blood carried out since the fire, 8.2% were between the vigilance threshold (25 micrograms per liter) and the mandatory declaration threshold (50 µg / L), and 1.1 % was above this threshold, according to the latest report published by the ARS, one year after the incident.

For these 1.1%, "a source of exposure to lead in the usual environment has been detected in almost all cases (balconies in particular)", adds the agency.

She also emphasizes that this proportion is "a little lower" than that found on average in the 0-6 year old population.

- "Time bomb" -

But for Mathé Toullier, "blood lead levels done a few months later are worth nothing".

The metal "remains a maximum of eight weeks in the blood after poisoning", before being stored in the brain, liver, kidneys and bones, she told AFP.

However, many children were tested only at the time of the start of the school year in September 2019, after having often spent holidays in another environment.

"Lead is a time bomb" which can produce effects in adulthood if it is "taken out of stock", she warns.

It would have taken "a systematic protocol" to test "the tens of thousands of children" concerned, judge Jacky Bonnemains, president of the Robin des Bois association.

The organization for the defense of the environment is also worried about the fate of the rubble from the construction site, some of which has been "preserved for the purposes of research and heritage study" and has not been directed to approved sites for construction. treatment of polluted waste.

Another point arouses criticism from the AFVS, Robin des Bois and the Council of the City of Paris: the decision to rebuild identically and with the same materials the Gothic cathedral, restored in the 19th century by Viollet-le- Duke.

"We take back the materials whose association was catastrophic in the fire, the wooden frame having spread the fire to the lead sheets" which melt at low temperature, gets carried away Jacky Bonnemains.

Even in normal times, lead easily disperses dust under the effect of erosion, he argues.

© 2021 AFP