Water might be the source of all life, but what comes out of our taps in the UK isn’t just pure H2O.
While strict regulations are in place to ensure our taps provide water that is totally safe to consume, some of us will be surprised to discover the cocktail of chemicals that lurk in the clear stuff we drink.
Several different compounds are present in our water supplies, ranging from aluminium and arsenic to lead and nitrate, some of which come from the earth’s crust.
Consumed in large volumes, these can have adverse effects on our health, while some people find water tastes better with fewer additives.
Now experts from health tech firm Virtue Water, who created a device to purify water, have outlined exactly what Brits can expect to find in their drinking water.
The research has used data from the UK’s main water suppliers, including United Utilities, Southern Water and Thames Water.
Residents can use their water supplier’s website to check the levels of each chemical in their drinking water, using a tool such as this one from United Utilities.
Rebecca Lyttle, of Virtue Water, said: “The water we use everyday has been on our planet for billions of years and it gets recycled constantly.
“Water companies need to treat their supplies to ensure they meet drinking water quality standards set by the Government’s Water Supply Regulations 2018.
“Sometimes they need to add or remove substances from their water, and people might be shocked to learn how minerals such as copper, lead and sodium remain in the water coming from their taps."
She added: "Areas in the UK will have different levels of chemical elements to others, while certain substances can be found in some locations but not in others.
“We simply can’t live without water, we need it to keep our bodies healthy and functioning, but it’s important to make sure we know exactly what we are drinking.”
What’s in water supplies across the UK
Aluminium - This is the most abundant metallic element in the earth’s crust, so it’s no surprise some of it finds its way into our water.
In 1988, a sudden increase in aluminium levels in drinking water in Camelford, Cornwall, was said to have led to bouts of nausea, diarrhoea, skin ulcers and arthritic pain among the 20,000 population.
Meanwhile, some studies have investigated links between aluminum in drinking water and dementia.
However, a report from the World Health Organisation declared: “There is little indication that aluminium is acutely toxic by oral exposure despite its widespread occurrence in foods, drinking-water and many antacid preparations.”
Arsenic - This metalloid element is a natural component of the earth’s crust and is highly toxic in its inorganic form.
Long-term exposure to high levels of arsenic through drinking water are said to lead to severe health problems, with lethal doses in humans ranging from 1.5 mg/kg of body weight to 500 mg/kg of body weight.
In 2011, The Joint FAO/WHO Expert Committee on Food Additives released a report that stated: “The main adverse effects reported to be associated with long-term ingestion of inorganic arsenic by humans are cancer, skin lesions, developmental effects, cardiovascular disease, neurotoxicity and diabetes.”
Cadmium - Cadmium is a soft, silvery metal that is most chemically similar to zinc and mercury, and is widely used in industrial processes, including as an anti-corrosive agent.
In high enough levels, this element can pose hazards to human health such as kidney damage and bone damage, while one study suggested it can cause prostate cancer in rats.
Calcium - Calcium is one of the most-well known minerals in our water, and it helps build bones and keep them healthy.
The World Health Organisation says: “Inadequate intakes of calcium have been associated with increased risks of osteoporosis, nephrolithiasis (kidney stones), colorectal cancer, hypertension and stroke, coronary artery disease, insulin resistance and obesity.”
Levels of calcium in our water also contribute to how hard or soft it is, with higher concentrations of minerals in hard water said to pose problems with clogging our household pipes and building up limescale in household appliances such as kettles and washing machines.
Chlorine - Chlorine plays an important part in keeping our water safe to use, such as destroying water-borne pathogens in swimming pools.
However, high levels can also pose health problems, such as triggering asthma symptoms and potentially an increased risk of bladder cancer.
In the UK, our laws dictate chlorine is added to our drinking water to disinfect it, and while levels used are in a safe range, some people may be more sensitive than others to its taste and smell.
Copper - This reddish metal is more commonly associated with being used in household pipes as it helps prevent bacteria levels from growing.
It’s also an essential part of our diets and it helps the body to form red blood cells, maintain healthy bones and support our immune system.
The World Health Organisation said guidelines “should permit consumption of 2 or 3 litres of water per day, use of a nutritional supplement and copper from foods without exceeding the tolerable upper intake level of 10 mg/day (IOM, 2001) or eliciting an adverse gastrointestinal response.”
Fluoride - Around 5.8million people in the UK receive fluoridated water, with naturally-occurring mineral said to be good for our oral health. Each local authority makes its own decision on how much, if any, fluoride to add to our drinking water.
The NHS website states: “There have been some concerns that fluoride may be linked to a variety of health conditions. Reviews of the risks have so far found no convincing evidence to support these concerns.”
Lead - Some of us might be shocked to learn that levels of lead can be found in our drinking water, as we tend to associate this metal with car batteries, pencils and even the weights we lift in the gym.
High levels of exposure to lead can poison our bodies, with nasty symptoms such as abdominal pain, memory loss or even miscarriage or premature birth in pregnant women.
The risk of this is lower than ever as lead has been removed from common items such as petrol and paint, but it can find its way into our drinking water through old lead pipes or water tanks.
Magnesium - Magnesium is an important mineral for maintaining a healthy body, and is found in everyday food items such as leafy greens, nuts and legumes.
It is another contributor to whether our water is classed as hard or soft, along with calcium.
Neither of these minerals are harmful to humans, so there’s no need to worry about magnesium levels.
Mercury - This shiny, liquid metal isn’t just found in thermometers – it’s also found in our drinking water.
The World Health Organisation says: “Mercury will cause severe disruption of any tissue with which it comes into contact in sufficient concentration, but the two main effects of mercury poisoning are neurological and renal (kidney) disturbances.”
However, strict guidelines make sure the UK’s water companies regulate levels of mercury to keep them safe.
Nickel - The fifth most common element on earth is one of the biggest components of the earth’s crust, so it easily finds its way into our water supplies.
Levels of nickel are also found in household objects such as batteries, jewellery and coins.
The World Health Organisation set a guideline of a maximum 70 micrograms of nickel per litre of water, but the UK’s water companies keep levels much lower than that and within a safe boundary.
Nitrate - Nitrate doesn’t have the best reputation, with links to cancer and other serious health issues. With that in mind, a recent campaign sought to ban nitrate and nitrite preservatives from foods such as bacon and ham.
They are also commonly found in vegetables, which tend to absorb them from soil due to their presence in some fertilisers and also as a by-product of natural vegetable decay.
Rainfall then often washes them from the soil into our water supplies.
The United Kingdom and European standard for the concentration of nitrate in drinking water is 50 parts per million (50 mg/l), so it’s safe to drink tap water without worrying too much about nitrate.
Sodium - Sodium is a common part of our everyday lives, but many of us consume most of our levels of it through salt in our food.
In regular levels, it is an essential mineral to keep our bodies healthy, but too much of it can lead to high blood pressure, heart disease and stroke.
The World Health Organisation decided not to create a guideline for the recommended level in drinking water as: “Sodium in drinking-water generally makes only a small contribution to total dietary sodium.
“No firm conclusions can therefore be drawn at present as to the importance of sodium in drinking-water and its possible association with disease.”