Since the middle of the summer we have heard a lot about it: the Notre-Dame de Paris fire led to lead pollution in France’s capital city and especially around the cathedral. On July 18, 2019 the Île-de-France’s ARS (Regional Health Agency) published the lead concentrations measurements that they made around Notre-Dame after the fire. The analysis results are impressive: around the cathedral there is up to 400 times the regulatory lead threshold. What impact can this pollution have on health? What means and equipment should be adopted to protect workers involved in the decontamination and reconstruction project?
Notre-Dame’s lead
Notre-Dame’s lead origin
Built in 1163, with a construction that lasted almost two hundred years, then renovated from 1844 to 1864 by the architect Viollet-le-Duc, Notre-Dame de Paris is one of the most important Parisian symbols. The cathedral on the Île de la Cité located in the heart of Paris is an integral part of the city’s history, as well as France’s history and is classified on the UNESCO World Heritage sites. As the result of many techniques, materials and construction tools, the cathedral has survived the centuries. And this was due to many materials and construction techniques such as the use of lead. Like many historical monuments Notre-Dame’s roof was made of lead right from its construction (1326 tiles of 32 cm and a 210 tons weight). The lead was again used during the cathedral’s 1843 renovation (lead plates stapled and welded). At the same time, the cathedral was given a new element made of lead and wood: the 725 tons arrow including 250 tons of lead. This material has also been used for rainwater drainage pipes, for the tower’s roofs and esplanade desks.
The Notre-Dame fire and lead pollution
On April 15, 2019 the Notre-Dame fire began late afternoon in the frame of the building. Called "the forest" - imposing framework (120m long, 10m high, that required 21 hectares of forest to be completed) supporting the lead roof and the spire of the cathedral - was in flames for over 10 hours. The devastating fire destroyed the frame and roof, provoked the collapse of some of the building’s vaults, and destroyed most of the works of art and historical artifacts within the cathedral. Of combustion emissions from this fire, the melting of the hundreds tons of lead present in Notre-Dame generated oxides and lead particles. Lead particle pollution measured after the disaster around the cathedral is particularly important. While an average daily presence in Paris is estimated at 5000 micrograms of lead per square meter, after the fire around Notre-Dame and surrounding areas readings indicate lead concentrations from 20,000 to 50,000 μg / m2 and beyond. These very high levels of lead particles may have dangerous effects on health and on the environment. These results therefore require precautions for residents and for workers on Notre-Dame de Paris cleaning and reconstruction sites. Mid-summer 2019 local authorities began implementing a decontamination plan for the area.
The Notre-Dame lead risk
Lead effects on health
Lead is a heavy metal classified as toxic, mutagenic, reprotoxic and ecotoxic. This element is also considered to be carcinogenic (by the IARC). The danger of lead pollution lies in fumes or particles exposure. If inhaled or ingested, these particles can have many dangerous effects on health. Acute or chronic intoxication is referred to as lead poisoning and is defined by a blood lead level greater than 50 μg / L (microgram per blood liter). The symptoms of this disease are numerous: headache, vomiting, abdominal pain, psychomotor disorders, paralysis, anemia, gastric system and kidney dysfunction, high blood pressure, male sterility, fetus intoxication causing development delays and disorders, lethal encephalitis and comma. Without reaching the official threshold for reporting lead poisoning, lead exposure to lower concentrations may also trigger some of these symptoms.
The Notre-Dame lead dust danger
The presence of lead particles at high levels around Notre-Dame might lead to lead poisoning of the population living in this area. The risk of inhalation and ingestion of lead dust triggering many health disorders is a possibility. This is why authorities advocate simple preventive actions (ban public access to contaminated areas, regular cleaning to avoid contamination, hands and objects in contact with the ground and street furniture should not touch the face or mouth), are decontaminating affected areas (including schools, cathedral forecourt, parks and gardens, etc.) and advocate for lead poisoning screening for at-risk populations (children, pregnant women).
Beyond the potential danger concerning the Parisian population, the Notre-Dame site represents a greater danger for workers on the reconstruction site right were the fire took place. In fact, the rubble and the building that survived the flames are where the lead dust pollution is at its highest level (up to 1,300,000 μg / m2 of lead measured on the forecourt). On site work must therefore be particularly supervised and carried out in the best safety conditions. The same applies to workers and others involved in at-risk areas decontamination: for those people chronically exposed to lead dust, it is essential to use adequate protective equipment (especially respiratory protective masks).
Lead protection equipment
Respiratory protection against lead dust & particles
The lead pollution caused by the Notre-Dame fire constitutes a real health danger facing workers and individuals present on the cathedral site. Faced with this on site lead exposure, the first safety is to use lead PPE (personal protective equipment): a PAPR mask (powered air purifying respirator) equipped with a P3 filter (dust filtering cartridge). Unlike conventional gas masks, this type of respiratory protective equipment offers effective protection for its user over a long period of time. A powered air purifying respirator is a positive pressure system that brings clean filtered air into the breathing mask. The mask user, wearing a Scott Safety Phantom Vision for example, therefore does not have to perform a high respiratory effort and can use this type of device for a long time.
Using a PAPR mask equipped with a P3 filter cartridge ensures excellent protection against dust and lead particles present on the Notre-Dame site. Different types of masks can be plugged to a powered air purifying respirator however for complete protection against lead it is necessary to adopt a full face mask that protects the eyes from any projection as well as the respiratory tract (preventing lead inhalation and ingestion).
Other lead protective equipment
In order to prevent lead poisoning by personnel working on the Notre-Dame site or participating in the depollution, other equipment must be used and provided such as decontamination showers and wearing single use coverall suit (with disposable underwear) on the polluted site. Some preventive rules must also be respected: do not eat, drink, smoke on contaminated premises, separate work clothes, moisten work areas to prevent lead particles dispersion around Notre-Dame, filter rinse water, and dust removal by suction, descaling gel or ultra-high pressure with surfactant detergent.
Following these recommendations, using a powered air purifying respirator and being cautious are the best protection against the Notre-Dame lead.