Nowadays, bottled water is widely regarded as a necessity - it's important to ensure that you are adequately hydrated at all times. There are two main types of bottled water: natural mineral water and spring water. These might have flavours added and/or be carbonated, becoming 'sparkling water'. Bottled water has become one of life's essentials: like house keys, many people don't leave home without it.

Worldwide, bottled water consumption rose to 154 billion litres (41 billion gallons) in 2004; this marks an increase of over 50% since 1999. In the US, an estimated $100 billion is spent each year on bottled water, and at up to $2.50 (£1.30) a litre (£5.40/$10 per gallon), bottled water is more expensive than petrol.

Why is Water Important?

Up to 75% of human body mass is water, and the most important organ - the brain - is composed of 75-85% water, whereas muscles are 70% water. Water helps digest and absorb food and, as the fluid part of blood, carries nutrients to all the body's cells and removes waste, toxins etc. Water lubricates the joints and colon and helps regulate body temperature¹ through sweating.

The body loses, on average, around four pints (approximately two litres) of water per day through the skin, lungs, intestines and kidneys; and around a pint (about half a litre) every day just from exhaling. All this water needs to be replaced, and some experts say that adults² should drink six to eight (eight to ten in hotter weather) eight-ounce glasses of water per day (1.6 litres), because if the water lost naturally is not replaced, dehydration sets in. Other medical sources recommend somewhat more - in the region of two litres per day.

Some signs of dehydration are headache, dark-coloured urine (healthy urine should be straw-coloured) and not passing much when going to the toilet, muscle soreness, heat intolerance, fatigue, lack of concentration, confusion and irritability, a dry mouth and dry eyes. Chronic dehydration can contribute to a number of health problems, such as constipation and kidney stones, and a person's survival time is limited to a matter of days, or possibly hours, without water.

Drinking water is also a factor in weight loss. This is because pure water with no additives is calorie-free. Also, if the kidneys are not flushed through with sufficient water, they cease to function efficiently. That means the liver has to step in as a back-up, compromising its ability to metabolise fat, which remains stored in the body.

People often mistake thirst pangs for hunger pains, and eat instead of drinking, putting more pressure on their organs. It is even possible to lose the thirst reflex, something that is common in developing countries.

Cool Thing to Carry

Thanks to climate change and health-awareness promotion, bottled water has become the other 'cool' 21st-Century accessory to carry: the first hand, of course, is holding a mobile phone.

There are two different types of bottle which you should be aware of and each has a different method for allowing you access to the enclosed water. Choose carefully for your needs:

Screw Cap

This is for people 'on the go' who aren't driving. You can unscrew the cap and down a swig to your heart's content. Be careful when walking and drinking: you could stroll into a lamppost or another pedestrian - who is probably talking on their mobile phone, didn't see you coming either, and won't be pleased.

Sports (Valve) Cap

A sports cap has a valve opening that lets a limited amount of water through in a narrow stream. Why 'sports cap'? Well, this bottle-type is ideal for carrying while exercising or while you're participating in other sporty-type endeavours, such as jogging and hashing. Anyone taking part in racing events like the Olympic marathon doesn't have to provide their own liquid refreshment, because they'll pass tables laden with sports-capped bottled water for them to grab and drink on the run.

This is also the smart choice for drivers, although in many countries it is illegal to do something else when driving, so perhaps best find a safe spot to pull over to refresh yourself. This type of cap is ideal for children over the age of three years because it is less likely to spill, and plain water is far better for them than cola and other caffeinated/sugary drinks, which will only make them thirstier.

A bottle with a valve cap can make life a lot easier for people who suffer from debilitating conditions like cerebral palsy, who have involuntary muscular spasms or who have suffered strokes and have limited movement.

Natural Mineral Water

According to EC and UK regulations, in order to use the words 'natural mineral water' the product must comply with the following specifications:

• It must come from a specified unpolluted underground source.
• It must be bottled at source and fitted with a tamper-evident seal.
• It must be free from pathogenic (disease-causing) organisms, and have had no other treatment other than filtration (to remove sand particles).
• The label must give some details of the mineral analysis. This is rigorously tested during accreditation.

The least expensive 500ml bottle of still Scottish mountain spring mineral water at a leading supermarket reveals the following nutritional information:

Analysis: per litre of Scottish mineral water

• less than 0.005mg: aluminium
• 80mg: bicarbonate
• 26mg: calcium
• 6mg: chloride
• under 0.1mg: fluoride
• 6mg: magnesium
• less than 4mg: nitrate
• under 0.1mg: potassium
• 7mg: sodium
• 7.7mg: sulphate
• Calories: 0
• pH at source: 7.4

Babies and young children should not be allowed to drink mineral water, and baby formula feed should not be made up with natural mineral water. Some have high salt or high sulphur content and, in particular, a high uranium content. Uranium is a heavy metal that is toxic to the kidneys and liver. The radioactivity of natural mineral waters are generally too low to be problematic.

The Importance of pH

Water which has a pH value of less than 7.0 is acidic. The acidic components of water are chlorine, sulphates and nitrates; these lower the blood's pH and detract from any health benefits. Doctors recommend drinking mineral water with a pH of more than 7.0, which is alkaline, because human blood pH is in a narrow range of 7.30 to 7.45. The more alkaline the water the more oxygen it contains, so alkaline water helps keep oxygen levels high.

Spring Water

An aquifer is an underground layer of water-bearing permeable rock; a spring is the point from where the underground water flows out. They can be intermittent, continuous or confined; water chemistry can define and differentiate types of springs rich in nitrates and minerals at various levels of water tables.

There is no legal definition for spring water in Britain, if anywhere. You can fill a bottle up with tap water and call it 'spring water'; it may be misleading, but it doesn't break the law. There are no health benefits from 'spring' water that are not available from your tap.

Flavoured Water

Critical ocular analysis of the label (which prominently exclaims, 'Under eight calories per bottle!') on a 500ml bottle of apple and blackcurrant-flavoured still water reveals the following list of ingredients:

• Welsh spring water
• Citric acid
• Natural fruit flavour
• Artificial sweeteners: Aspartame (contains a source of Phenylalanine³) and Acesulfame-K
• Preservatives: E211 (Sodium benzoate - the sodium salt of benzoic acid) and E202 (Potassium sorbate - an anti-fungal and anti-bacterial preservative)

Read what cancer experts have to say about the possible carcinogen, Acesulfame.

The label also lists the nutritional value per 100ml:

• Energy: 6.89kJ (1.2k/cals)
• Protein: 0g
• Carbohydrate: 0.3g (of which sugars: 0.3g)
• Fat: 0g
• Fibre: 0g
• Sodium: 0g

The small print offers a helpful warning: 'Choking risk: The cap on this bottle contains small parts. Not suitable for children under 36 months.'

The phrase 'hint of lemon' (or of any other fruit) often means that artificial flavouring and sweeteners have been added to the water. So check the label before purchasing!

Sparkling (Fizzy or Carbonated) Water

Exactly the same research was carried out on a 500ml bottle of 'sparkling berry-flavoured spring water', with the following results for ingredients:

• Carbonated spring water
• Citric acid
• Flavourings
• Sweeteners: Aspartame (contains a source of Phenylalanine) and Acesulfame-K
• Acidity regulator: E331 (Sodium citrate)
• Preservative: E211 (Sodium benzoate)

The label also lists the nutritional value per 100ml:

• Energy: 3kJ (1k/cals)
• Protein: Trace
• Carbohydrate: 0g
• Fat: 0g
• Fibre: 0g
• Sodium (salt): Trace

Fizzy water is not only more expensive than still, it can also be bad for your teeth as the carbonation makes it very acidic.

Cola

Cola is basically fizzy water with added sugar and chemicals. Cola is bad for teeth because it contains much stronger acids than carbonic acid, which are created in the process of making it bubbly. Research shows that it is continuity of contact that does the dental damage, and the increase in tooth decay seen today is not so much due to drinking the fizzy stuff but rather to the consumption of litres of it throughout the day.

Bottled v Tap Water

In blind testing, people tend to find it difficult to tell the difference between tap water and bottled water. There are over 200 different brands of still, sparkling and flavoured water available in the UK. In 1998 the UK bottled water market was worth around £400 million per annum. Within five years the annual sales had quadrupled to two billion litres, (480 million gallons), making the industry worth an estimated £1.2billion. A litre of tap water costs approximately 1p; a 500ml-size bottle of water costs, on average, £1.

In the UK, drinking water has to comply with 57 standards relating to its health, taste and appearance. In test reports in 1997, 99.75% of the tests met the appropriate standard set by the Department of the Environment and the Drinking Water Inspectorate. High quality drinking water comes through the mains supply, (usually the cold water tap in the kitchen), delivered uninterrupted by pipe from the supplier to prevent contamination.

All bottled water must meet Drinking Water in Containers Regulations and Food Labelling Regulations - except flavoured water which falls under Soft Drinks Regulations. In the USA, bottled water is regulated as a food by the FDA.

In an obvious example of branding over content, the Coca-Cola company attempted to market their own brand of bottled water, named Dasani. They openly admitted that they were obtaining water from the mains supply at its factory in Kent, UK - an idea stolen from an episode of Only Fools and Horses, when 'Del Boy' bottled tap water and sold it as 'Peckham Spring Water'.

Some testing has been done on bottled water samples and, if you choose to believe such data, one brand was found to contain 20 times more Uranium 238 than Chernobyl groundwater. The Kansas Department of Health and Environment carried out tests on 80 bottles of water randomly selected from shops and factories. Over a quarter of the samples tested positive for arsenic and just under a quarter registered traces of lead.

Fluoridation

In some places in the UK, like Coventry, water suppliers have been adding fluoride to mains water for over 40 years as a way of reducing tooth decay. Some people don't want to ingest that much fluoride - and sometimes the water doesn't taste very nice. In the UK, fluoridated water is supplied to around 5.5 million people, which means that approximately 90% of the UK's water supply does not contain fluoride, and the tooth decay rates in Scotland, Wales, Northern Ireland and some English counties is very high. Dental technicians⁴ support the argument for fluoride because they say there is good evidence that fluoride helps prevent tooth decay. Some MPs are pushing for fluoride to be added to their constituents' drinking water, but others are against such a move, calling it 'mass medication', voicing worries that fluoride can cause cancer, osteoporosis, brittle bones, internal organ damage and genetic damage to the unborn. Around two-thirds of municipalities of the United States fluoridate their water.

Recycle

There's no requirement to dispose of the plastic bottle when finished with the water inside. It's far cheaper to buy a large five-litre container of bottled water and keep topping up your carry bottle. In one supermarket, the price of a five-litre container and one 500ml bottle of the same water are exactly the same! Buying the larger bottle helps the environment and saves money. If refilling, do remember to wash the bottle and to sterilise the top between uses.

Do not put anything else (juice, squash, etc) other than water in the reused water bottle. The plastic may react with the acid in the juice and the carcinogen (and hormone disruptor) phthalate may leach into the liquid: phthalates are not legally regulated in the bottled water industry. Some health groups suggest only using glass bottles as a precautionary measure.

A lot of people only buy bottles of water when they are out, (rather than stocking up at home), which pretty much all end up in landfill after people just chuck them in the nearest bin. It would be much more environmentally-friendly if the bottles could be taken home for recycling. If the plastic is PET (Polyethylene terephthalate)⁵ it can be recycled with no downgrading of the product, so the bottles can be discarded into the plastics bin at your local recycling facility. The recycled bottles could be made into all sorts of useful things, like school lunch trays and kayaks.

It's a well-known fact that profiteering goes on in times of need: that's called business. Consider being crafty and purchase one of those really over-priced designer bottles of water so beloved of celebrities, then top it up with cheap local spring water (or good old tap water) when the expensive stuff is finished. That's called blagging, but who's going to know?

Germany

In Germany there is a widespread culture of buying (mostly sparkling) water by the crateload, and then taking the crate and the empty bottles back to get a new one. There is a deposit for the crate and for the bottles. The water companies used to all use exactly the same shape of bottle, with their own label on. Then they were collected and cleaned up for re-use and went back to the nearest bottling plant. Then one company unilaterally switched to a PET (Polyethylene terephthalate) bottle, without consulting the others. This meant that their bottles had to go right back to where they came from - and plenty of people switched brands.

Now the other companies are also switching to PET bottles - similar in shape to the old ones, but containing one litre instead of the 0.75ml the glass ones held - and the system is the same as for the glass ones. They reckon the PET bottles last around as long as the glass ones, and as they weigh less they have less of an environmental impact. Another environmental measure the German government has taken is that (with very few exceptions) bottles of water (and other soft drinks) have a deposit on them. That means that you pay an extra 15 or 25 cents, and therefore there is a strong incentive to take the bottle back.

Schoolchildren

The effect of a lack of water on learning ability has been recognised. Hilary Reid, a teacher with the Learning Support Service, campaigned for children in schools throughout the UK to be allowed a bottle of water on their desks. Now schoolchildren are generally allowed to imbibe (bottled) water ad lib throughout the day - except in science classrooms, due to Health & Safety regulations.

In German schools, the pupils all have access to sparkling water whenever they want, paid for by their parents, and it is becoming quite a widespread trend. Most children in Europe use refillable bottles for their water.

Contamination

In parts of Russia, where the tap water is not safe to drink because the ground water is contaminated due to the mass graves of WWII soldiers, most people drink bottled water. Some h2g2 Researchers report that during a visit to Moscow, the water from the tap was mostly brown, only came out in a trickle, and also had a musty/earthy smell to it. Bottled water there didn't taste too good - rather like a swimming pool - but at least they were 99% sure it wasn't going to kill them!

So in some Russian restaurants, instead of a waiter coming round and pouring water into your glass, the place setting includes a bottle of water which you can pour into the glass or secrete away for later. Unfortunately, sometimes they run out of bottled water and therefore you have to drink and clean your teeth in Pepsi Cola⁶ (the former Soviet Union has the manufacturing rights for Pepsi rather than for Coca-Cola).

In the tropics, where water is 'dodgy', many people never drink plain water, for obvious reasons. Instead, they drink tea, coffee and other boiled-water drinks, and they live normal, healthy lives.

Having taken a young baby abroad, I was told by my midwife to use Evian to make up baby milk and give as a supplement to it, as it was the least-offensive [water] for the baby.
- An h2g2 Researcher

Frank Water

Frank Water is a project aiming to provide clean water for people who don't have access to it, like the residents of Kothapeta village in India. Frank gives the net profits from the sale of their bottled water in the UK, which comes from Devon, towards providing clean water for 2,000 people.

Piddle Water

An entrepreneur took over a brewery/bottling plant in Wareham in Dorset, UK, and used it to bottle water from the River Piddle, marketing the product as 'Piddle Water'.

Hints and Tips

Once opened, bottled water should be stored in the fridge and consumed within four days. Bacteria from your mouth can contaminate the bottle if you drink from it directly and then store it.

If you're going out with a bottle from the fridge, wrap it first in a sheet of paper towel, as the bottle will 'sweat' condensation; and have another sheet to hand for placing underneath the bottle when you're drinking.