Effects of Second-hand Smoke in the Home

The dangers of exposure to second-hand smoke are well established and it has been against the law to smoke in a work or enclosed public place in the United Kingdom since July 2007. However, measures to reduce exposure to second-hand smoke in the home have received little attention, despite the fact that for many people, and for children in particular, this is the location where most exposure takes place.

The health impact of second-hand smoke

Breathing in other people’s tobacco smoke (second-hand, passive or involuntary smoking) is known to cause a range of disorders from
minor eye and throat irritation through to heart disease and lung cancer. Children are particularly vulnerable to the effects of second-hand smoke and exposure increases the risk of cot death, glue ear, asthma and other respiratory disorders. A review by the British Medical Association’s Board of Science concluded that there is no safe level of exposure to tobacco smoke for children and adverse effects can be found at low levels of exposure.

Why opening a window doesn’t help

Opening a window or restricting smoking to a specific room offers little protection against exposure to second-hand smoke.  Researchers have found that smoke from one cigarette can linger in a room for up to two and a half hours even with a window open. Other measures such as smoking out of a window or smoking next to an extractor fan are equally ineffective at keeping smoke out of the home. Restricting smoking to one room in the house is also insufficient to protect non-smokers from exposure to second-hand smoke. Other research has shown that pollution from second-hand smoke can linger on carpets, furnishings and walls. These materials absorb the toxins found in tobacco smoke and gradually release them back into the air, posing an additional risk of exposure.

Public awareness and attitudes

A survey by Smoke Free London in 2001 revealed very low unprompted awareness of the impact of second-hand smoke on children. Only 26% of respondents identified asthma and 22% respiratory illness or lung infections as a likely impact. Two of the most common ailments associated with passive smoking – cot death and glue ear – were identified by only 3% and 1% of parents respectively.

Since the introduction of smoke free legislation, public awareness about the impact of exposure to second-hand smoke has risen considerably. A 2007 survey by the Office for National Statistics, found that 91% of respondents thought that living with a smoker would increase a child’s risk of chest infections. Awareness of the risk of ear infections was lowest with just 34% of respondents believing that this was a risk factor.

Studies suggest that where smoke free work and public places are the norm, parents are more likely to make their own home a tobacco-free zone. A recent study in Scotland found that children’s exposure to second-hand smoke has fallen by 39% since the introduction of smoke free legislation. Furthermore, smoke free workplaces encourage smokers to quit. The corresponding reduction in smoking among adults means that fewer children are likely to be exposed to smoke at home.

Measures to protect children from exposure to second-hand smoke

It has been estimated that 40% of children in the UK (approximately 5 million) are routinely exposed to second-hand smoke. Restrictions on smoking in day care settings have been in place since 2003 but there are no laws to protect children from exposure to second-hand smoke from in the home.

Studies measuring second-hand smoke exposure in the home show that the most reliable way of reducing exposure is to stop smoking indoors. Partial measures such as restricting smoking to particular rooms or not smoking in the presence of children are insufficient to protect the health of non-smokers. Thus if parents are unable or unwilling to stop smoking, the next best step is to at least make the indoor environment smoke free.

Many programmes aim to reduce smoking in the home by encouraging parents and carers to stop smoking. However, in a review of such interventions, only four out of 18 studies found a statistically significant effect, suggesting that such interventions are largely ineffective. This suggests that population-level changes such as mass media health promotion are needed in order to achieve changes in attitude and behaviour.

Second-hand smoke and pets

Pets are also at risk when exposed to second-hand smoke. A recent study in the United States found that even limited exposure to tobacco smoke more than doubled a cat’s risk of feline lymphoma.  Another study found an association between exposure to second-hand smoke and nasal cancer in dogs. Birds and rabbits are likely to be at risk.

Animals don’t just suffer the ill-effects of inhaling cigarette smoke. Particulate matter within the smoke settles on their coats and is ingested during grooming. Pets also sometimes eat cigarettes and other tobacco products causing nicotine poisoning which can be fatal.