Tap water is set to become a lot healthier in Germany. Federal regulations from the start of December have lowered the allowable lead levels, but many old buildings are still affected by contaminating pipes.
Since the start of December Germany has a new law in place governing lead levels in drinking water pipes. The new regulation stipulates that lead is now no longer to exceed 10 micrograms per liter.
At the Institute for Hygiene and Public Health at the University of Bonn, the institute is analysing water samples brought by officials, homeowners and even ordinary tenants. The visitors all want to know how much lead their drinking water contains. And the institute's alarm bells have been going off regularly.
Once threshold levels are reached, lead poisoning can damage the nervous and circulatory systems.
"Fetuses, infants and small children up to the age of six are particularly at risk because their nervous systems are affected more intensely by the poisonous heavy metal," says Harald Färber, a food chemist at the institute.
Various studies have shown that cognitive development of infants and small children is impaired by lead found in water. There is also evidence that hearing can be affected. "Inorganic lead compounds are considered carcinogenic," said Färber.
A familiar danger
Food chemists also advise women who want to become pregnant against drinking water containing a high degree of lead. Adult bodies store lead, which can be mobilized during a pregnancy - putting an unborn baby at risk. "But adults themselves are also at risk," said Färber.
Knowledge about the health risks of lead has been around nearly as long as the material has been used for making pipes: since antiquity. Nonetheless, the pliable and easily-processed metal was used for drinking water pipes well into the 20th century in Germany. Until now, the phasing out of lead pipes has always been dependant on the region in which one lived.
While lead pipes for tap water have been prohibited for more than 100 years in the south of the country, they continued to be installed in new homes and buildings through the 1970s in northern Germany. Authorities chose to rely on the protective properties of things like lime, which builds up in the pipes and is supposed to prevent the heavy metal from contaminating the water. But it was a risky calculation.
"Nowadays, we know that even the small amounts of lead that creep through the protective layers into the water exceed the strict threshold levels in effect today," Färber told DW.
Still, many people are not aware of the lead pipe problem. "Drinking water in Germany is generally of high quality, and that's the message people take with them," says Karin Gerhardy, of the German Technical and Scientific Association for Gas and Water (DVGW), which works closely with water suppliers and authorities.
Gerhardy's organization has concentrated on enforcing the European Union drinking water directive which, since the late 1990s, has called for the gradual reduction of threshold levels to eliminate lead in drinking water.
Numerous water suppliers replaced their lead pipes a decade ago when maximum permissible levels were reduced for the first time, says Gerhardy. But many landlords and housing co-ops did not take action - either because they were not informed, or because their pipes did not yet exceed stipulated levels. There was also not much political or media pressure. The risk of lead poisoning largely disappeared from public debate when leaded gasoline was prohibited in the 1980s.
Lead pipes are often found in older apartment buildings in Germany
Not only Germany
Now, with the reduction of the threshold level from 25 to 10 micrograms per liter in effect since December 1, waiting it out is no longer an option.
"The new threshold levels basically render lead pipes for drinking water useless," says Jochen Flasbarth from Germany's Federal Environment Agency (UBA). Building owners who continue to use lead pipes for drinking water on their property must now inform their tenants of the situation and explain the health risks. And, until the last lead pipes have been replaced, the agency advises against pregnant women and small children from drinking tap water containing lead or using it for cooking. They should choose bottled water instead.
People must become better informed about the problem, said Färber. According to Färber, 4,000 samples were taken this year from the region around the German city of Bonn.
"Prudently estimated, about half - or perhaps even 60 to 70 percent - of the buildings in the older districts of the city still have a lead problem. Newer buildings are less affected, and those built after the start of the 1970 hardly at all," he said.
Other German cities and states face a similar problem. And countries such as Austria, the UK and other EU countries are still struggling when it comes to implementing the bloc's drinking water directive. But there's no doubt about the necessity of reducing threshold levels, says Karin Gerhardy from the DVGW. "Experts strongly applaud this European initiative," Gerhardy says.