The Belle Epoque, France's golden era at the turn of the last century, bequeathed Paris elegant landmarks such as the Eiffel Tower, but also a more sinister legacy of radioactive floors and backyards which the capital is only now addressing.
When the Franco-Polish Nobel Prize winner Marie Curie discovered the radioactive element radium in 1898, she set off a craze for the luminescent metal among Parisians, who started using it for everything from alarm clock dials to lipsticks and even water fountains.
The companies that manufactured these slightly radioactive objects have long gone out of business, but they left small doses of radium between the cracks of some Parisian parquet floors. These doses, after prolonged exposure, could prove toxic though, officials say, they do not pose serious health risks.
"The history of radium started in Paris," said Eric Lanes, head of radioactive decontamination at France's national agency for radioactive waste, ANDRA. "Marie Curie never patented her discoveries so a lot of people rode the radium wave."
After Curie showed that radium could be used to destroy cancerous cells, people assumed that the new element had miraculous healing properties and started putting it in everything from body lotions to cough syrups.
"Cancerous cells are more sensitive to radiation than healthy ones. Curie understood that," said Lanes. "But some people embarked on businesses more akin to charlatans' tricks."
Curie herself died at 66 from her prolonged, unprotected exposure to radium.
ANDRA - in some case using addresses that were written on vintage advertising posters - has identified some 130 sites in France suspected of being at risk. Some 40 of them are set for decontamination, half of those in the Paris area.
Lanes said the clean-up was being undertaken as a precautionary measure under a recent French law requiring that preventative steps be taken in a case of a suspected health risk even in the absence of conclusive scientific evidence.
"We have never found any worrying situations," Lanes said. "We're talking about levels that are too small to create a health impact."
"DON'T PLANT VEGETABLES"
In a two-storey detached house in the leafy suburb of Chaville, 12 km (7 miles) southwest of central Paris, masked men in white hazmat suits drilled holes in the wooden floors of what used to be an aircraft altimeter factory before World War Two.
The factory workers used to color the dials with glow-in-the-dark paint made from radium powder and zinc sulphide.
Their plight was reminiscent of the so-called Radium Girls in the United States who contracted radiation poisoning around 1917 from licking their paint-brushes to sharpen them.
In Chaville, traces of paint are still present in the wooden floor, the house's garden and basement. Though too small to present a risk, they still have to be collected in drums through air-locks and sent to ANDRA's nuclear waste storage sites.
The decontamination cost for a house like this is 260,000 euros ($318,200), Lanes said. The agency has a 4 million euro annual budget for decontamination on top of the government's 12 million euro budget for its "radium plan".
The occupants, who declined to be interviewed because they feared the publicity could lower the property's value, were temporarily rehoused at ANDRA's expenses and will get the renovated house back after three months.
Some sites deemed too contaminated to make a renovation cost-effective have been bought by ANDRA and razed.
The Jersyk family's former house in Gif-sur-Yvette, just south of Paris' military airport of Villacoublay, is one of them. It was part of an estate built in the 1950s near a disused factory where radium needles for hospitals had been manufactured.
"When the factory shut, the land was sold, the ground leveled, and they built houses on it, it was as simple as that. It's monstrous," said Eglet Jersyk, an 81-year-old pensioner.
After spotting a news item in the local newspaper about the former factory's radioactive legacy, she and her husband Christian joined a local group to demand government action.
"No one told us anything when we bought it in 1966 but a lot of mystery surrounded that house. We were only told: 'You shouldn't grow vegetables in the garden'," she said.
Experts from France's CEA atomic research agency came to visit the house in 1974 and found abnormal levels of radium and radon gas, she said, but it took some 30 years before the family could relocate to a nearby town.
In the meantime, her husband, a do-it-yourself enthusiast who often worked in his basement, suffered from cough and heart problems which she said a doctor linked to radioactive fumes.
Her complaint was dismissed by a court in the early 2000s, she said, and shortly after ANDRA offered to buy the house at market prices.
($1 = 0.8170 euros)
