The initiative, by the Department of Health and Social Security's health promotion directorate, was launched on National No Smoking Day on Wednesday.

Paper masks, put together by the Manx Asthma Association, the Council of Cancer Charities and the Anti-Cancer Association, have been delivered to nurseries.

They list the risks of second-hand smoke to children in the home and in the car.

Health promotion director Lesley Dorward said: 'Parents and carers wouldn't knowingly give such harmful poisonous chemicals to their children, but some people are unaware of the risks and continue to smoke around children.'

The smoke from the burning tip of a cigarette, known as sidestream smoke, contains higher levels of toxins than smoke inhaled by the smoker.

Sidestream smoke increases the risk of childhood illnesses including glue ear and asthma.

It makes up 85 per cent of the smoke in a room and has 4,000 chemicals including arsenic, carbon monoxide, ammonia and formaldehyde.

Mrs Dorward said: 'Children are particularly susceptible to the effects of second-hand smoke as they have smaller airways and they breathe at a quicker rate than adults.

'This results in children breathing in more harmful chemicals than adults in relation to their weight and size.'

The government plans to ban smoking in public places from 2008, but the legislation does not extend to homes and cars.

Health promotion officer Michelle Flanagan said: 'Some parents might think that it's all right to smoke in the home or in the car when their children aren't around.

'What they may not know is that second-hand smoke lingers long after they finish a cigarette.

'It can remain in contaminated dust and surfaces even if smoking took place days, weeks or months earlier.'