SIR - With the smoking ban coming into force on Sunday, it's worth remembering what an historic milestone this is for the nation's health.

Removing the toxin of second-hand smoke from our offices, factories, pubs and cafes is arguably the biggest advance in public health since the creation of the NHS.

Some argue the ban infringes civil liberties. On the contrary, the ban liberates non-smokers from having to breathe in this dangerous substance, while affording smokers the choice to smoke in private.

The link between passive smoking and ill health has been well established, with evidence funded by the British Heart Foundation estimating that non-smokers who work in smoke-filled atmospheres have up to a 50 per cent increased risk of developing coronary heart disease.

As such, this legislation should be welcomed for the potential it has to significantly reduce passive smoking and reducing our risk of serious diseases like heart disease, stroke, cancer and asthma.

Dr Mike Knapton, Director of Prevention and Care, British Heart Foundation Fitzhardinge Street, London