It took a blaze that nearly destroyed Paris’ most famous cathedral to reveal a gap in global safety regulations for lead, a toxic building material found across many historic cities.
Since then, The Associated Press has found this regulatory gap extends far beyond France. Officials in other historic European capitals such as Rome and London, as well as the U.S. Environmental Protection Agency and the World Health Organization also have no such outdoor lead dust hazard guidelines.
The reason, they say, is that although there are lead regulations, no one contemplated a conflagration on a lead-laden building the scale of Notre Dame — whose spire towered nearly 100 meters (330 feet) high.
After 250 tons of lead on Notre Dame’s spire and roof was engulfed in flames in central Paris on April 15 and authorities alerted Parisians to an environmental health risk, they were forced to cobble together disparate and incomplete research to set a makeshift safety level in an attempt reassure the public.
“When the Notre Dame fire happened, we didn’t have any threshold for what represented dangerous lead levels outdoors,” Anne Souyris, the Paris City Hall deputy mayor in charge of public health, told the AP. “It was a wake-up call … the amount of lead that was burned in Notre Dame was unprecedented.”
Officials were surprised to discover that while safety guidelines exist in France for lead levels inside buildings and schools, as well as in paint, soil and air pollution, there were zero hazard guidelines for lead accumulations in public spaces, such as dust on the ground.
The inherent danger and the regulatory gap for lead dust became impossible to ignore for French officials as it collected as a toxic film on the cobblestones of Paris’ Ile-de-la-Cite following the fire.
On July 18 — three months after the inferno — Paris’ Regional Health Agency (ARS) said it designated 5,000 micrograms per square meter (4,180 mcg per square yard) as a concerning level for lead dust in public spaces. It also acknowledged there was an “absence of regulatory thresholds … regarding the presence of lead in dust deposited on roads.”
AP learned from health officials that this figure was compiled by using incomplete data, including a French Culture Ministry report assessing lead levels in Paris monuments.
Some media outlets reported that registered levels of lead contamination in locations surrounding the fire-damaged cathedral ranged between 500 and 800 times the official safe levels.
French officials say there are so few guidelines on lead dust levels because it was not a problem they had to confront until the unprecedented Notre Dame fire.
It took four months for the city to complete a deep-clean operation of the sidewalks even as tourists, residents and merchants walked streets around the cathedral daily.
The fire in Paris’ spiritual heart increased awareness among authorities and the public to the dangers of lead.
In June, Paris’ Regional Health Agency advised that all pregnant women and children under 7 years old living near the site take a test for lead levels.
Despite the lead fallout from the fire, experts say tourists should not alter travel plans to one of the most visited cities in the world.
“It’s a race against the clock,” she said. “The lead is a real problem. The cathedral is exceptionally precious. And we don’t have the luxury of time.”