Danger from the tap

When you drink a glass of water in the morning or make coffee with water from the tap, don’t expect to take a sip of dangerous chemicals in it. For example, chemicals that are also found in pesticides and medicines. Yet that’s what can happen if the water pipes in your home are plastic.
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Luuk Sengers, Marleen Teugels, Kaare Gotfredsen en Chris Vermeire 
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In 1989 Ana Soto, professor of cell biology, made a discovery that made her look at plastic in a completely different way. The American scientist of Argentinian descent has earned her international reputation with research into cancer. Although small in stature, she gives a firm handshake when she lets us into the apartment of a friend on the Seine in Paris. And as soon as she begins to talk about her specialty —substances in our environment that disrupt hormones — she displays a temperament rooted in her parents’ country.

She’s not the kind of person who is easily bowled over by anything. But sixteen years ago something happened in her laboratory at Tufts University School of Medicine in Boston that stunned even her. “I was involved with twocolleagues in a study of the impact of oestrogens - female hormones - on the development of breast cancer. We knew that cancer cells began to proliferate as soon as they were brought into contact with estrogens in test tubes. But to our amazement, exactly the same thing happened in the control tubes, to which no oestrogens had been added. Incomprehensible!”

“Like Sherlock Holmes we set out to find the culprit”, recalls Soto. We carefully studied all the test phases and checked all the equipment. Only after months of investigating did we discover the cause: the oestrogens were coming from the plastic the test tubes were made of. The plastic contained substances, nonyl phenols, which appeared to mimic female hormones.”

It was the first time female hormones were detected in plastic. Since then, scientists have found dozens of chemicals in the environment with oestrogenic properties. And they have discovered that some of them, even at extremely low doses, can have a profound effect on the natural hormone balance of humans and animals.

The effect of these so-called ‘endocrine disruptors’ on animals is well established: bisexual fish, lesbian birds and alligators with abnormally small penises have been linked. But there is also growing evidence that endocrine disrupters have an adverse effect on humans.

Boys with underdeveloped genitals, men with breast growth, declining sperm quality and the increase in hormonal cancers such as testicular, prostate and breast cancer in large parts of Europe may be the result of endocrine disrupting chemicals, the scientists said.

Until now it was assumed that pesticides, cosmetics, medicines and plastic bottles are the main culprits. But there appears to be another way in which the dangerous substances can enter the body. A way that has strangely been overlooked for a long time. Even drinking water from plastic water pipes, which are widely installed in homes today, sometimes contains potentially endocrine disrupting chemicals. They come from the inside of the plastic pipes. This has emerged from a investigation of chemists, biologists, toxicologists and drinking water experts.

The concentrations in which the substances (phenols and softeners) were found pose a potential danger to people, according to experts.In addition, dozens of other chemicals were found in the drinking water, the effects of which have never been studied, and so no one knows whether they are safe for consumption.

This raises the question of whether it is wise to rapidly replace lead and copper water pipes (which have already been proven to be harmful to health) with plastic ones. And why plastic pipes were not critically examined earlier: More than half of the main water pipes and fifteen percent of the indoor installations in Dutch homes are now made of plastic. And the proportion is growing: one in three new homes is now fitted with plastic water pipes.

“For fifteen years we’ve been pointing out the dangers of endocrine disruptors, but nothing has changed yet”, Ana Soto says irritated. “Now that it turns out that the substances can also end up in drinking water, I wonder: how long are the governments going to wait before they take action?”
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Fuss
In Denmark, there has already been an uproar over the contamination of drinking water. Researchers from the Danish Technical University discovered that plastic water pipes, which are used in large numbers in houses, were releasing phenols and phthalates (plasticizers) into the drinking water - both of which are potentially endocrine disruptors. When the national newspapers picked up on the news, the Danish government was forced to launch its own investigation into chemicals in water pipes. The results are expected this autumn.

“I thought it would be a useful finger exercise”, says the initiator of the first study, Erik Arvin, professor of water installations. “Whenever a new material is applied, there are always problems at the beginning”, he confides when we visit his lab at the university in Copenhagen. “So we wondered whether toxic chemicals could sometimes get into the drinking water through the plastic.”

Arvin andcolleagues took four pipes made of polyethylene (PE) — because this material is most commonly used in houses — and put them in contact with water at a room temperature of 23 degrees for seven consecutive days in a laboratory. Then all chemicals were removed from the water with a solvent and passed through a gas chromatograph mass spectrometer. Later the test was repeated with field samples: water from distribution pipes that had been underground for some time.

“We found over twenty chemicals in both tests that had migrated from the plastic of the tubes”, says Arvin. “Ninety percent we have still not been able to identify.  But among the substances we were able to identify were a striking number of alkylphenols, such as 4-tert-butylphenol, and phthalates.”

Chemists know phenols as a ‘normal’ by-product of antioxidants (preservatives), which the pipe manufacturers add to the plastic to protect it from degradation by oxygen for at least a hundred years. But in the eyes of toxicologists and biologists, phenols are anything but harmless. 4-tert-butylphenol, for example, is on the European list of chemicals with scientifically proven endocrine disrupting or potentially endocrine disrupting effects (Regulation 793/93, list 4).

Phthalates (plasticizers) are added to make the tubes less fragile. They are also known as potential endocrine disruptors. Plasticisers caused a commotion in the Netherlands last year because they were released from Scouba play ropes, which are popular with children.

“In and around the house, migration is greatest”, says Arvin. “In the main pipes the water is constantly moving, but inside the house it often stands still for hours or days and the temperature is higher, a situation where the pipes most easily release chemicals into the water. Also, the smaller the diameter, the more water comes into contact with the inside of the pipe.”

The phenols will continue to be released into the drinking water as long as the pipe lasts. They are, after all, a by-product of preservatives that are ‘baked’ into the plastic with the intention of doing their job for a hundred years or more.“I would like to point out”, says Arvin before we say goodbye, “that our research has only detected ten percent of the chemicals that end up in the water. Of the remaining ninety percent, we do not know what substances they are or whether they are harmful to humans and the environment.”
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More research
The Danish research is not an isolated case. It appears that more research has been carried out in recent years into the migration of chemical substances from plastic pipes. Researchers in Norway (at the regional food authority in Stavanger) and Germany (at the Hygiene-Institut des Ruhrgebiets) also found phenols in drinking water from PEX and PVC pipes.

The materials that tested positive for endocrine disruptors in laboratories elsewhere in the world are also used in the Netherlands to transport drinking water. And on an increasingly larger scale.

More than half of our nearly 110,000-kilometre-long main water network consists of plastic pipes (the other half is made of natural materials such as cement and metal). PVC is the most common. It is relatively hard and is therefore used for the wide main pipes. From the main pipe to the water meter in the house, PE is usually used. It is softer and easier to bend.

A variant of PE, PEX, is popular in the residential sector. This milky white, translucent pipe is just as flexible as PE, but due to a stronger bond between the molecules it is more resistant to high temperatures and high pressure. Plumbers lay between 25 and 30 million metres of drinking water pipes in homes every year. Increasingly, they are opting for plastic instead of copper. According to a confidential study, the share of plastic pipes in annual sales has risen to over thirty percent.

At the end of the nineties copper fell into disfavour because it appeared to be harmful to health. And there was a ban on soldering lead, which damaged the popularity of copper even more (alternative bonding materials are more expensive and less practical). That is one reason why plastic has been on the rise ever since. The other is that more and more pipes are being incorporated into new houses: two toilets and two bathrooms, with two washbasins in each bathroom, are no longer an exception.

Leaking plastic pipes are a European problem. The European market is divided between a handful of producers. The Danes’ experiment included pipes from Danish market leaders Uponor and Wavin. The same manufacturers are also market leaders in the Netherlands. Uponor Wirsbo, the largest of all, is a Swedish company with factories in Sweden, Germany, Spain and Canada, and sales of a billion euros. According to its website, it has now produced enough PEX pipes to circle the earth twenty-five times.
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Harmful to humans
More than 60 scientists from around the world, including Ana Soto, met in Prague in May this year for a workshop on endocrine disrupting chemicals. In a final declaration, they called on politicians in Europe to curb the production and distribution of endocrine disrupting chemicals, because there is strong evidence that they can also cause gender abnormalities and disease in humans.

That same month there was a breakthrough in the research: American scientists published in Environmental Health Perspectives that even normal exposure to plasticizers can disrupt the development of the sex organ in male babies. They discovered that mothers with high concentrations of phthalates intheir urine during pregnancy later gave birth to boys with incomplete masculinity. The boys often had less fully descended testicles and smaller penises than their size. And the distance from anus to penis was remarkably short in many of the babies, a sign of feminization (the distance between anus and genitals is shorter in women than in men). In rats, this defect has been found to increase the risk of infertility later in life, lower sperm production and, in some cases, testicular cancer.

For the first time a link has been made between endocrine disruptors and human reproduction. “Given the striking increase in breast, testicular and prostate cancer in many European countries, further research is urgently needed”, say the scientists in their Manifesto of Prague.

‍But aren’t the amounts of endocrine disrupting chemicals found in drinking water far too small to cause any harm? After all, it’s all about the quantities we ingest. Almost all substances are lethal at high doses and harmless at low doses.

Ana Soto is now considered an authority on endocrine disruptors. Confronted with the results of the Danish research, she reacts shocked. The concentration of 4-tert butylphenol found — 6.6 micrograms per liter — is high. “If you put that dose into a test tube with human cells, the cells start to proliferate.”

The traditional way in which toxicologists assess the risks of substances — with limit values of micrometres per litre — has failed in the case of endocrine disruptors, warned scientists in Prague. Hormones already work at extremely low doses. After all, every hormone particle, however small, has the function of sending signals to the body. In addition, the endocrine disruptors work together with the natural hormones already present in the body, reinforcing their effect.

“The industry and the government have always said that the quantities we found were too small to cause any harm, but when it comes to the unborn foetus, this reasoning doesn’t hold water,” Ana Soto stresses. “The foetus appears to be very fragile and sensitive to minimal fluctuations in hormone levels. We observed an abnormal development of mammary glands in mice that had been given small doses of the endocrine disruptor Bisphenol A as a foetus. We had given the animals the smallest dose ever tested!”

What’s more, what are the consequences if several of the substances act on the body at the same time, Soto wonders. Isn’t such a mixture much more dangerous than the sum of the risks of the individual substances? John Groten, Professor of Combination Toxicology in Wageningen, agrees. “In the past toxicologists only looked at the risks of individual substances. But recently more and more research is being done to see whether a combination of substances sometimes poses a separate danger.”

We use water not only for drinking, but also for showering and washing. There is evidence that phenols can also enter the body through the skin. Fred vom Saal is a professor of biology at the University of Missouri and has worked closely with Ana Soto for many years. “For bisphenol A diglycidyl ether, it has been proven that it can penetrate through the skin”, he says. “We don’t know about other phenols yet, but it’s likely that phenols that are just as small will also enter the body through the skin, just like sex steroids that you rub on with an ointment.”

“Phenols and phthalates simply don’t belong in drinking water”, reacts the Flemish professor of human ecology at the Vrije Universiteit Brabant, Luc Hens. “If the substances show endocrine disrupting effects in a laboratory, then this is a more than serious warning. It would be wise to limit or prohibit the use of the substances by the industry.”
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Lack of control
How is it possible that substances which are potentially so dangerous were not detected earlier? Drinking water is strictly controlled, is it not?

The Dutch testing institute Kiwa tests and certifies materials that come into contact with drinking water before they are put on the market in the Netherlands. It does this on behalf of the Ministry of Health, which is responsible for safe drinking water. But Kiwa does not appear to systematically check for endocrine disruptors such as phenols. The method which is required for this — and which was also used by the Danes — the gas chromatography-mass spectrometry, is not part of Kiwa’s standard set of instruments.

“The gas chromatography method raises more questions than it answers”, explains Wim van de Meent, head of certification at Kiwa. “The identity of the substances found is difficult to determine with one hundred percent accuracy. We would have to inundate the manufacturer with a whole list of questions. But he is asking us something: is his pipe permitted in the Netherlands or not?”

Kiwa inspects the pipes on the basis of the recipes sent by the manufacturers. “In order to see whether the manufacturer has specified all the substances used in the recipes, we carry out an annual inspection in the factory.” This inspection is not watertight, agrees Van de Meent, who has carried out checks himself. “Sometimes the internal method of accounting for substances is not correct. For example because two departments don’t work well together.”

But there is an even more important reason why Kiwa’s audit is flawed. The Danes initially assumed that the phenols were by-products of deliberately added antioxidants. And because these antioxidants are usually mentioned on the recipe, a risk analysis can be made of the amount of phenols that will be produced in the pipes. But what if the phenols do not emerge until later, when the pipes are already well underground?

Last year, an Italian research team published in the journal Polymer the results of a study that seems to show that the phenols are not all in the pipes from the beginning. Some appear to have been created only by reaction with the water. Phenols in the plastic tubes transform into new phenols through contact with water molecules. And to make it even more complicated, these new phenols can start a reaction with the polymers on the inside of the pipe, what reaction product can get back into the water, and so on. The Danes have also started a study on this.

“I am not yet convinced of the seriousness of the migration,” says Van de Meent of Kiwa. “But it’s good that it’s being discussed. At Kiwa we can look for phenols — and we will find them — but we must have a good reason for doing so.”
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Measures
The European Commission is currently reviewing the 1998 Drinking Water Directive. However, this has nothing to do with the discovery of endocrine disruptors in the water pipes. The Commission wants to harmonise the testing methods for drinking water in Europe; at the moment, each Member State is still going its own way.

In view of the recent warnings from scientists that endocrine disrupters cannot be detected by superficial tests and that their concentrations should not be assessed through traditional glasses (because even very small amounts can be harmful to a foetus), the uniform European testing method should be particularly thorough.

In reality, harmonisation is slow and not always professional. To arrive at a single test method Brussels has set up expert groups with experts from the member states. Van der Meent, who participates in the consultation on behalf of Kiwa, speaks of ‘old paper love work’: “The people in the working groups must be released by their employer to work on the standardisation.”

It will take at least another three years before there is a proposal from the Commission. So says Reinhard Klein, head of the Construction division at the Enterprise Directorate. “It’s unpleasant, but we simply depend on the input of experts. And among the experts in the working groups are also manufacturers of plastic pipes. So even if a uniform European test method for drinking water is established, it is by no means certain that it will take plastic pipes to task.”

Another route through which endocrine disruptors can be banned is through REACH. REACH stands for Registration, Evaluation and Authorisation of Chemicals and is the most far-reaching environmental legislation Europe has known to date.  After major scandals (mad cow disease, dioxin crisis) the European Commission decided in 1993 to evaluate all existing chemicals on the European market. When this took too long, the European Parliament and a number of Member States called for a completely new evaluation system for chemicals.

Until now, it was the authorities who had to prove that chemical substances were dangerous before they could ban them. REACH reverses the burden of proof: from now on, manufacturers of raw materials will have to prove that their products are safe for humans and the environment. If they cannot prove this, they are not allowed to put their products on the market (anymore).

“Scientific uncertainty should not be a reason for not acting now”, was the message of the scientists in Prague at the beginning of this year. In their statement they advocate bringing all known endocrine disrupting substances under the REACH regime. But whether this will actually happen is uncertain. In the European Parliament, the political groups have taken their stands. The Socialists, Liberals and Greens want a decisive REACH. But the conservatives show more understanding for the interests of industry and argue for a slimmed down legislation, covering fewer substances. “But come on,” says Flemish MEP Bart Staes (Groen!), “we don't want to go back to the Middle Ages, when people could only drink beer because the water was too polluted.”

“Much more research is needed to find out what chemicals are leaking from plastic pipes into drinking water and what their health risks are”, says Danish professor Erik Arvin. “And for those who already have plastic pipes in their homes, I strongly recommend that they let the water flow for a while first thing in the morning, to get the worst concentrations of chemicals out, before making coffee from it.”

BOX:
Water pipes
What are water pipes made of? And what is safe? An overview.
Lead Lead water pipes give off small metal particles, which accumulate in the body. Before 1940, all water pipes in the Netherlands were made of lead. When it became known that lead is dangerous to public health, the pipes were replaced on a large scale.
Copper Copper is a common substance, which in small quantities is essential to health. But long-term exposure to large amounts is harmful. There is disagreement about whether copper is carcinogenic.In the Netherlands most lead pipes have been replaced by copper, but nowadays copper is also under fire.
Stainless steel Pipes made of stainless steel are rare, but according to experts they would be a safe alternative.
Plastic Recent research has shown that plastic pipes (PVC, PE, HDPE) give off substances that can disrupt the hormone system.
Gold Only gold pipes are one hundred percent safe. “But then another problem arises, namely that people start digging up the pipes”, says professor Erik Arvin.

BOX:
The discoverer
Ana Soto, professor of cell biology, was the first to discover that some types of plastic contain substances that act like the female hormone oestrogen. These substances disrupt the hormone system and can cause problems in the sexual development of boys. Ana Soto is very concerned that these substances appear in drinking water from plastic water pipes.  “The human foetus is very fragile and sensitive to minimal fluctuations in hormone levels,”says the American professor, who is astonished by the high concentrations of the substances.  “Why, by the way, are so many different phenols leaking out of drinking water pipes? And in such high concentrations. Can’t the pipe manufacturers limit themselves to one dangerous substance?”

This article was published in 2005 in Algemeen Dagblad.‍