MPs vote to ban smoking in cars carrying children

"MPs overwhelmingly back ban on smoking in cars carrying children," reports The Guardian. The media headlines are based on the passing of an amendment to the Children and Families Bill in the House of Commons, which empowers – but does not compel – ministers to bring in a ban on smoking in cars carrying children.

The House of Lords has already passed the amendment. If a ban is enforced, it remains to be seen when it will come into effect or what the penalty for violating the ban will be.

Exposure to secondhand tobacco smoke has been associated with a range of child health issues, including sudden infant death syndrome, lung infections, wheeze, asthma, meningitis, and middle ear infections such as "glue ear".

Secondhand smoke exposure is also known to be associated with many chronic diseases in adulthood, including cardiovascular diseases (diseases that affect the heart and blood vessels) and cancers.

If the amendment to the bill is passed, the UK will be following the lead of Canada, the US, Australia, Cyprus and South Africa, where there are already some national- and state-level laws banning smoking in cars, particularly cars carrying children.

How much smoke is a child exposed to in a typical car journey?

A UK study measured the levels of fine particulate matter (PM2.5) as a marker of secondhand smoke present in the rear passenger area of cars where smoking either did or did not take place.

Fine particulate matter is a term used to describe tiny particles of substances. The size of fine particulate matter is the main concern for public health because the particles are so small and can easily enter the lungs. Once inhaled, they can affect the heart and lungs and cause serious health effects.

Measurements were taken over a three-day period in 17 people (14 smokers). These people completed a total of 104 journeys (63 where smoking took place) lasting 27 minutes on average. A monitoring instrument was used to monitor PM2.5 at breathing zone height in the rear seating area of each car.

The researchers found that PM2.5 in cars where smoking took place was high and greatly exceeded international air quality guidance values. PM2.5 levels were an average of 85mg/m3 during smoking journeys and 7.4mg/m3 during non-smoking car journeys.

During smoking journeys, the peak PM2.5 concentrations were 385mg/m3. Concentrations were strongly linked to how many cigarettes were smoked per minute.

Although forced ventilation and opening of car windows were said to be very common during smoking journeys, this still didn't decrease the concentrations to below World Health Organization indoor air quality guidance, which states levels should be 25 mg/m3.

The study concluded that children exposed to these levels of fine particulate matter are likely to suffer ill effects.

What happens next?

The BBC reports that legislation confirming the ban could be forthcoming in the next Queen's Speech, when the government sets out its proposed legislative programme for the year ahead. This is expected in May 2014.

Exactly how the legislation will be enforced or what the penalties for breaching the legislation could be are currently unclear.