Reducing Mains Water Usage

Chlorine is added to tap water to kill bacteria that can lead to cholera, dysentery, hepatitis A, typhus and other water borne diseases.

It is normally added in low concentrations, below the World Health Organisation (WHO) limit of 5mg/l.

Adding chlorine to tap water is currently the cheapest and most effective method for treating the bacteria found in drinking water supplies, and chlorine successfully kills most water-borne diseases.

The low levels of chlorine found in our tap water (0.5 mg/l or less) is not considered to cause any health problems, and the World Health Organisation (WHO)  assures that “any risks to health from chlorination by-products are extremely small in comparison with the risks associated with inadequate disinfection” (source).

The Drinking Water Inspectorate (DWI) claims that the levels of chlorine added to UK tap water are perfectly safe, however, there are some concerns that chlorine is actually linked to cancer.

A 1980 report from the Council on Environmental Quality fond “significant evidence” of a higher cancer risk among people who drink chlorinated water, a finding not disputed by chlorine manufacturers.

As reported by The Washington Post, “The studies found risks among chlorinated-water drinkers to be from 13 percent to 93 percent higher for rectal cancer and around 53 percent higher for colon and bladder cancer.”

A US study conducted found that women with breast cancer have 50-60% higher levels of chlorine by-products in their breast tissue than women without cancer, reported Scientific American, which said “The link between chlorine and bladder and rectal cancers has long been known, but only recently have researchers found a link between common chlorine disinfectant and breast cancer.”

There are known health risks associated with consuming high levels of chlorine such as headaches, dizziness, and breathing difficulties.

It’s extremely unlikely that the level of chorine in tap water would ever pose a threat due to the stringent testing here in the UK, but if you’re ever worried that your water may have an increased amount of chorine (you might notice the “swimming pool” type smell or taste), it’s advisable to contact your local water supplier.

Even if you’re not worried about chlorine, you might not like the taste of it.

You can either use a water filter to remove it (see more about water filters later in this article), or simply let a glass of uncovered water sit on a bench for 24 hours to allow the chorine to evaporate.

Fluoride is a naturally occurring mineral found in water, but in some areas of the country additional fluoride is added to tap water in an attempt to help reduce tooth decay (a controversial process known as fluoridation).

It’s over 50 years since fluoridation was first introduced and many people have strong views either for or against its use in tap water.

Many countries ban fluoride from being added to the water supply.

The water supply in some countries such as China and India is naturally high in fluoride, so fluoridation could be dangerous.

Fluoride consumption has been linked with numerous health conditions from hypothyroidism to cancer.

In particular, a bone cancer called osteosarcoma is thought to be more prevalent in areas with fluoridation, although studies made in this area have had conflicting results.

But does fluoride really help prevent tooth decay?

The Oral Health Organisation believes it does, and states that fluoridation is the “most important single measure that the UK Government can take to bring a substantial change in the nation’s oral health” (source).

However, other experts believe that fluoride in water isn’t really helpful for preventing cavities, and is not as effective as other methods such as improved dental hygiene.

Pesticides

Other chemical dangers in modern tap water include pesticides and herbicides that have seeped into the water supply from agriculture, and pharmaceutical residues from current medical practices.

According to the DWI, groundwater may contain traces of pesticides, as a result of agricultural and non-agricultural use, that water companies attempt to remove with carbon filters, sometimes with ozone processing.

Water companies are legally required to assess the risk of pesticides in their water sources and meet testing requirements according to the European Drinking Water Directive standard of 0.1μg/l (microgrammes per litre) or one part in ten billion.

The chemical metaldehyde, used in slug pellets, has been a particular issue, with Anglian Water claiming in 2016 that it would need £600 million to treat the substance – making it the only water company in the UK to operate a metaldehyde treatment facility.

Some providers like Severn Trent Water and Wessex Water work with local farmers to minimize the amount of agricultural chemicals that end up in the water. In the opinion of Water UK, voluntary action and stewardship has been somewhat effective in reducing metaldehyde on a small scale, but that wide reaching regulation is required for large scale success.

Many of us in the UK live in homes that were built before the 1970s, which can mean water enters our homes through lead pipes.

Lead is extremely dangerous if consumed in significant amounts, and babies and children are particularly vulnerable.

The levels of lead found in water will depend on factors such as how long the water is exposed to lead pipes, and the level of corrosion of the pipes.

You can learn more about how to check if the pipes in your home are made of lead on the WaterSafe website here.

If you do find lead pipes in your home, WaterSafe recommend contacting a plumber to replace them as soon as possible.

If you’re waiting to have lead pipes replaced, the safest thing you can do in the meantime is always run your taps to remove any water that has been standing overnight or for any length of time.

Water companies often use aluminium as a water purifier to make water look and taste better.

It’s the third most plentiful element on the planet, so it’s also cheap and easy for water companies to get hold of.

But worryingly, there is “some circumstantial evidence to suggest that aluminium may play a part in the deterioration of brain cells and consequential dementia in humans, such as might cause the onset of Alzheimer’s disease” (source).

Scientists do not yet fully know the effects of exposure to low levels of aluminium over a long period, but there is growing concern about a possible link between aluminium exposure and the development of neurological diseases.

Modern pharmaceuticals and hormones are also making it into the water supply, due to the fact that they are designed to be stable and long lasting, therefore not breaking down after being excreted.

According to Brunel University London, “Every time you enjoy a cool, clear glass of tap water, you could be drinking a cocktail of other people’s second-hand medications.”

That’s quite a dramatic statement, but what does it mean exactly?

A US study published in the journal Environmental Science and Technology Letters, tested the water from 59 small streams and found the anti-diabetic drug, metformin, in almost every one.

But this isn’t only an American problem. As reported in The Guardian, rivers around the world are being polluted with residues from drugs such as analgesics, antibiotics, anti-platelet agents, hormones, psychiatric drugs, antihistamines, and this flow could increase by two thirds by 2050.

A York University study analysed water from the rivers Ouse and Foss and found traces of 29 different medical drugs, including compounds used to treat antidepressants, antibiotics and medicines to treat epilepsy and diabetes.

Hormones from the contraceptive pill have also been detected in waterways, with concerns about endocrine-disrupting properties on wildlife and humans.

According to the DWI, endocrine disrupting chemicals from the pill are easily broken down during water filtration and do not pose a risk to tap water, although they can be damaging to wildlife and the environment.

Currently, Water UK has not recommended any measures be taken to introduce standards for pharmaceuticals in drinking water.

The DWI has also come to the conclusion that drugs do not pose a significant public health risk at levels found in tested samples.

Not every member of the public may be willing to take that risk, however. As said by Dr Klaus Kuemmerer, professor of sustainable chemistry at Germany’s University of Luneberg, “We don’t know what it means if you have a lifelong uptake of drugs at very low concentrations.”