Rouen (AFP)

Nearly a week after the spectacular fire at the Lubrizol chemical plant in Rouen, the origin of the fire remains to be discovered, and many questions remain about its health and environmental consequences. Review of what is known about this accident.

Origin of the fire?

The cause of the disaster is not yet known. The public prosecutor's office in Rouen relinquished the investigation in favor of the public health center in Paris, stating that the origin of the fire was currently impossible to determine "with certainty".

Lubrizol, who relies on "CCTV and eyewitnesses," claimed that the fire had likely started off the site.

Is the air polluted?

24 hours after the fire, the Minister of Health Agnès Buzyn evoked in Rouen a city "clearly polluted" and recognized that "products can be irritating at the moment".

According to the Normandy prefect Pierre-Yves Durand, the results of air analyzes show a "usual state of the air quality in Rouen". On Tuesday, he clarified his words. "I'm not saying that the air quality in Rouen is satisfactory," said the prefect, pointing out that before the fire "in Rouen there was not a satisfactory air quality".

According to Patrick Berg of the Dreeal (Regional Directorate for the Environment, Planning and Housing), there was "identification of a significant level of benzene" on September 26 at 12:38, "a little more high that the limit "of detection on the site of the factory but according to the prefect" it does not allow to say that the air is abnormal ".

What symptoms did you feel?

Since Thursday, the population is bothered by odors that remain marked. Many witnesses interviewed by AFP reported scorching throats, headaches, nausea, vomiting and dizziness.

These smells "are related to hydrocarbons, mercaptans and hydrocarbon residues present in large quantities on the site and which were impacted by the fire," according to the prefecture.

Which products have burned?

Lubrizol producing automotive lubricants, these were substances that were used in the composition of motor oils.

Since Tuesday the list of these substances and their quantities: 5.253 tons burned and the prefecture has published 479 sheets "which specify the characteristics of the products and associated risks" in case of combustion.

For nearly two-thirds (62.88%, or 3,308 tonnes), these products were "multipurpose additives" composed of 44% mineral oil obtained by oil refining, indicates a table provided by the authorities.

Dangerous substances?

Official reports consulted by Mediapart in 2016 mentioned the presence in the plant Lubrizol of products "very dangerous for the environment" and "harmful", and believed that a fire could lead to the "formation of toxic substances".

On Wednesday, Agnès Buzyn said that the "most dangerous" products for "polycyclic hydrocarbons which are possibly carcinogenic products", were not found in smoke and soot.

Regarding very toxic dioxins, carcinogenic molecules that can also interfere with the hormonal system, the results of research are expected in the week.

Research also focused on asbestos that made up the roof of the plant. According to the prefecture, there is no "proven risk" related to asbestos in the air.

Drinking water?

The water of the 71 municipalities of the Metropolis of Rouen Normandy is drinkable. "No trace of contamination was found" after rumors and speculation about alleged black tap water, according to the metropolis.

Are agricultural products edible?

At least 1,800 farmers have been affected by soot in Normandy and Hauts-de-France. Harvesting is prohibited in about 100 municipalities. The prefecture recommends residents to "do not consume products and vegetables soiled by soot" in gardens.

What are the health risks in the short and long term?

Carbon monoxide, sulfur dioxide and hydrogen sulphide: the measurements made by the fire brigade, "to verify the immediate risk" for their interventions and residents, "did not highlight any risk for the population", assures the prefecture.

Agnès Buzyn acknowledged Wednesday about substances that have burned, that "nobody" today knew "what give these products mixed when they burn".

© 2019 AFP