The UK's 50 million users of mobile phones will - on average - replace their handset every 18 months, but environmental experts believe less than 20% of these phones are recycled.
Millions of mobiles phones are gathering dust in drawers and cupboards in people's homes when they could be recycled - often in return for money or discounts off new phones - or reused in the Third World.
Mobile phones contain many materials that can be harmful to the environment and human health if not disposed of safely and responsibly. In the UK, it is illegal to throw out your old handset with the household waste.
Countless mobiles phones, however, still end up in landfill sites where there is a real risk they will leak toxic waste, polluting rivers and watercourses and contaminating agricultural land. Highly toxic dioxins can be also emitted into the atmosphere if phones are incinerated in waste plants.
The most hazardous part of a mobile phone is the battery. The cadmium contained inside the battery of just one discarded mobile phone can contaminate as much as 600,000 litres of water - that's enough to fill a third of an Olympic-sized swimming pool.
Other materials utilised in the manufacture of mobile phones include lead, used to solder components to printed circuit boards, and beryllium, used in contacts and springs. Such noxious substances can cause cancer, liver disease and brain damage, and affect the human body's immune and central nervous systems.
Cell phones also contain precious, semi-precious and base metals, including copper, mercury, manganese, nickel, silver and zinc. Even though only tiny amounts of these metals are present, the value and scarcity of such mineral resources makes it worthwhile - financially as well as ethically - to recycle mobile phones.
Around 80% of the components in a mobile phone can be recycled. First, phones are dismantled by hand into their individual components, such as the chips, camera lenses and memory drives. Some of these parts may be resold.
The remaining components are then ground up, and the useful metals are extracted from the scrap by various industrial processes. The metal contained in batteries can also be recovered, as can much of the plastic used in components.
Phones in good working order or which can be easily repaired are shipped to Africa and Asia where they prove invaluable to people living in developing countries with little or no landline telephone infrastructure.
Refurbished handsets are also an affordable alternative in regions where the cost of brand new mobile phones is prohibitive.
Any cell phone can be recycled or reused. You can dispose of yours by taking it back it the high street shop where you bought it from, often in return for a discount off a new handset.
There are also a growing number of companies on the Internet who will give you cash in exchange for your old phone (depending on its make and condition).
Alternatively, you can help save the planet, and support a good cause at the same time, by donating your handsets to charities that recycle mobile phones to raise funds. Whatever option you choose, always remember to remove the SIM card in order to protect your personal data.