Safe as houses?

Just when you thought it was safe to go back inside, a report produced by the Royal Society for the Promotion of Health (RSPH) reveals that people living in houses with attached garages are living on borrowed time.

The report entitled, ‘Personal Exposure to Benzene and the Influence of Attached and Integral Garages’ claims that benzene emissions from ‘cars parked in attached or integral garages can find their way into the living spaces of the home, and give rise to increased personal exposure to this known carcinogen. This is of extreme importance, as most people spend on average 80 percent of their time indoors, especially at home’. Excessive levels of benzene are known to cause leukaemias.

But before we decide that it is never safe to sleep again, bear in mind that the recently reshuffled Department of Environment, Transport and the Regions (DETR) expert panel on air quality standards concluded in their final report on benzene that ‘leukaemia in workers was not detectable when average exposures over a working lifetime were around 500ppb’ (parts per billion), and that ‘leukaemia is a relatively rare group of diseases affecting about one adult in 6000 each year’. In addition, leukaemia is not necessarily caused by benzene.

Add to that the fact that, in the air quality standards, this figure of 500ppb has been divided by 10 (to reflect the difference in timescale between the average ‘working lifetime’ and the average ‘lifetime’), and then divided by 10 again as a further factor of safety. This puts the UK acceptable benzene level at 5ppb (or 16.25g/m3) every day for a lifetime.

The RSPH report, which studied all of five houses around the country, found – in one particular room above a garage in one house – benzene levels equivalent to 12ppb (or 39.9g/m3). This is 2.5 times higher than the acceptable UK air quality standard – although no equivalent factoring of the time spent in this room has been taken into account. (Presumably, only one third of the day is spent in this room – possibly bringing the benzene levels within acceptable limits.)

It is also worth noting that the cars parked in the garages of the houses in the study were over nine years old (some were 13 years old). The house from which the worst mean results were drawn had a 1989 Fiesta and a 1980 Mini! Car technology has moved on.

While deaths have been attributable to car emissions in downstairs garages – most notably, the death of a baby in a bedroom in a house in the north east of England several years ago, when the father tried to gas himself in his car below – these are exceptional cases. For the most part, we’re safe as houses….

…Or are we? Over the 2001 May Bank Holidays, the UK government ‘relaunched a campaign to warn DIYers of a potential danger lurking in their homes’ (1).
Thousands of new leaflets were issued ‘to alert people who will be busy decorating over the May Bank Holidays to the risks from lead in old paintwork’. The DETR continued:

‘Until the mid-1960s, lead was used in paint for interiors such as windows, doors and radiators. Cases of lead poisoning are now rare. However, lead paintwork can be a risk, particularly to children and pregnant women; for example, by creating dust if it is damaged or disturbed during decorating, or if children lick or chew painted surfaces.’

Don’t lick the skirting boards, then. Or better still – don’t decorate at all.

Austin Williams is director of the Transport Research Group, technical editor of the Architects’ Journal, and motoring correspondent at the Daily Telegraph. He is a contributor to Sustaining Architecture in the Anti-Machine Age, Wiley-Academy, 2002 (buy this book from Amazon (UK) or Amazon (USA)); and Carchitecture: When the Car and the City Collide, August/Birkhauser, 2001 (buy this book from Amazon (UK) or Amazon (USA)).

(1) DETR press release