Just when you thought it was safe to go back in the bedroom, two new reports have cropped up which suggest that there is nowhere to hide from paranoia. The first report, by the Royal Society for the Promotion of Health (RSPH), reveals that people living in houses with attached garages are living on borrowed time.
Benzene emissions from cars parked in 'attached or integral garages' can find their way into the rooms above the garage and increase personal exposure to this known carcinogen. 'This is of extreme importance as most people spend an average 80 per cent of their time indoors, especially at home, ' says the report. Excessive levels of benzene are known to cause leukaemia.
But before we all decide to sleep downstairs, bear in mind that the Department of the Environment, Transport and the Regions' expert panel on air quality standards concluded that 'leukaemia in workers was not detectable when average exposures over a working lifetime were around 500 parts per billion (ppb)'and that 'leukaemia is a relatively rare group of diseases affecting about one adult in 6,000 each year' (and 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 average 'working life' and average 'lifetime') and then divided by 10 again as a factor of safety.This gives 5ppb (or 16.25microg/m 3). every day for a lifetime as the given UK acceptable benzene level.
The figure cited in the RSPH report, which studied just five houses around the country, found in one particular room above a garage in one house, benzene levels equivalent to 12ppb (or 39.9microg/m higher than the acceptable UK air quality standard, although no equivalent factoring of the time spent in this room has been taken for (presumably only one third of the day spent in this room - possibly bringing the benzene levels within acceptable limits). It is worth noting that the cars parked in the garages of the houses studied were at least nine years old (some 13 years old). The house from which the worst mean results were drawn had a 1989 Fiesta and a 1980 Mini! Fortunately, 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 which should not necessarily cause alarm.