PARIS — Months after fire engulfed Notre-Dame and the 460 tons of lead on its roof and spire, alarming levels of lead are still being found after decontamination efforts, including at the Paris Police Headquarters — raising new concerns that the authorities have not fully tackled the problem.
The environmental group Robin Hood said on Friday that lead levels up to 20 times above the safety guidelines had been found on the balcony of an apartment in the Saint-Germain-des-Prés area, on the left bank of the Seine.
And at Police Headquarters on the Île de la Cité, law enforcement measurements in early September showed lead levels reaching 40,000 micrograms per square meter in the courtyard, or over 3,700 micrograms per square feet, the group said.
Such levels are eight times above the safety guidelines issued by regional health authorities.
“The levels we obtained are extremely worrying, and we can be sure that more apartments are in the same situation,” Jacky Bonnemains, the head of Robin Hood, said of the apartment.
Frédéric Guillo, a police officer and union representative, confirmed the levels revealed by the organization for the police headquarters. “It proves once again that the lead contamination caused by the Notre-Dame fire is a serious, long-term problem that authorities need to protect their citizens from,” Mr. Guillo said in a phone interview.
The police courtyard was cleaned the after the fire, but the authorities ordered additional decontamination after the high levels were found, Mr. Guillo said. He added that the headquarters’ courtyard had been accessible to the children of officers who go to a police day care center.
A New York Times investigation found that police officials had closed their own day care centers in the immediate aftermath of the fire, while it took a month for the authorities to start conducting tests in public schools. The Paris police did not respond to requests for comment about the new findings.
[Read: Notre-Dame’s Toxic Fallout]
Flames engulfed Notre-Dame in mid-April, and the billowing smoke carried huge quantities of toxic particles across the city. Over the summer, the authorities faced growing accusations of neglecting, if not covering up, the risks of lead contamination.
After Robin Hood filed a lawsuit against the state, and test results of the construction site leaked in the French news media, the health authorities began to give a new threshold for concern about lead contamination outdoors, using 5,000 micrographs per square meter instead of the previous 1,000 micrograms, and citing “background pollution” in Paris.
Lead exposure poses the greatest risk to young children, pregnant women and nursing mothers, who can pass on lead contamination to their children, and many parents in Paris have grown worried that they may have not taken enough precautions because of the lack of communication by the authorities.
On Friday, Mr. Bonnemains of Robin Hood said the measurements for lead on the apartment balcony the Saint-Germain-des-Prés area had been made earlier this month at the request of the family.
On the terrace, a mile away from Notre-Dame, another measurement showed levels 14 times above the recommended threshold. On furniture in the house, lead levels four times above the threshold for buildings hosting children were found, Mr. Bonnemains said. He added that the family would test a 3-year-old child in the coming days.
The measurements were conducted by independent contractors, not commissioned by the public authorities, so the method has yet to be verified, said Nicolas Péju, the deputy director of the Regional Health Agency.
“We need to analyze the results before weighing in,” Mr. Péju said.
Officials have faced intense criticism for not having encouraged enough families to test their children. As of Aug. 31, of about 400 children tested, six showed lead levels above the risk threshold of 5 micrograms per deciliter of blood. An additional 8.5 percent of those children showed levels at or above the French regulatory threshold for concern, which is between 2.5 micrograms and 5 micrograms.
Charlotte Nithart, the spokeswoman for Robin Hood, said more children should have been tested. “There are thousands of children in the area,” she said. “Maybe they’re not contaminated, and I hope so. But if we don’t look, we won’t find out.”
Mr. Péju said several hundred more children had had their blood tested since early September.
City officials have argued that the fire revealed that Paris faced a wider lead issue. But Mr. Bonnemains said other cities with old monuments were not immune to similar problems from lead contamination.
“What happened to Notre-Dame could well happen in Rome, in Bilbao, in Mexico City,” he said.