Sainsbury's chief executive Justin King's intention not to subsidise the sale of tobacco from his stores is a welcome one ("Sainsbury boss rejects rumours of plan to quit", The Herald, November 15).

The commercial reasoning for this decision can be matched by strong ethical arguments.

Tobacco is not a normal product. With at least 250 toxic chemicals, it is as addictive as heroin, implicated in one in four deaths in Scotland and kills half of its long-term consumers. Any other substance like this would likely be banned. But tobacco has one million regular users in Scotland, two-thirds of whom started before they were 18 and 69% of whom say they want to quit. So efforts to encourage people to quit and reduce the harm caused by tobacco efforts have focused on regulation and taxation.

It's worth remembering that the three-year public health levy was intended to raise money rather than to reduce the number of outlets selling tobacco. Little of supermarkets' profit is generated by tobacco sales, so it is no wonder that retailers could see a commercial advantage in temporarily reducing tobacco's availability in stores.

The hope is that this may also encourage customers to question the place of tobacco as an acceptable everyday product, and to reassess Scotland's relationship with this deadly and addictive substance.

Sheila Duffy,

Chief executive, ASH Scotland,

8 Frederick Street, Edinburgh.