Warm weather has arrived at last, and it seems the predictions of those who profess to know about such things, suggest we are in for a hot summer. An inevitable feature of the British summer is a focus on drink driving. Police forces up and down the land will be dusting off their publicity campaigns and enforcement operations.
One of the joys of warm summer weather for us who live in a ‘temperate maritime’ climate, is sitting outside under a shady umbrella with a cool beer or a glass of wine and a tasty spot of lunch; preferably prepared by someone else. Then there is the barbeque! Often starting around lunch time, and extending into the evening. What could be better on a warm sunny Sunday? Unfortunately such pleasurable, civilised living can have dire consequences. The main issue is when driving is involved. Drinking alcohol and driving a car do not go well together.
One of the problems is being aware of how much we are drinking, and how that relates to the drink drive limit. There is no reliable correlation between the two. The most common expression of the amount of alcohol in a drink is units, or a percentage by volume. The drink drive limit is 80 milligrams per 100 millilitres of blood, or 35 micrograms per 100 millilitres of breath. It is impossible to relate the two for an individual at any given time. A unit is defined as 10 millilitres or 8 grams of pure alcohol. The average, healthy adult can remove around one unit from the bloodstream per hour. Tests have shown that a controlled quantity of alcohol produces different blood levels in different people. There can be different levels for the same person at a different time. The blood level produced depends on lots of factors, including hydration, stress and food as well as the quantity and type of drink involved.
Of course, driving with any impairment or distraction is potentially very dangerous. In a typical year around 250 people are killed in crashes where at least one of the drivers is over the drink drive limit. Statistics don’t tell us how many crashes involve someone who had been drinking but was below the legal limit.
Most sensible people wouldn’t dream of sitting under that umbrella and drinking half a bottle of wine and then driving the car. Some will but most would not. However, that barbeque on Sunday which started at lunch time and went on until 10 pm. Many normal people, who don’t have drink problem, could consume a significant number of units during this time. If they go to bed at a civilised 11 pm and are up and off to work by 7 am the next morning they could easily be well over the drink drive limit. Many enforcement operations concentrate on this ‘next morning’ level. So let’s all enjoy the all too fleeting warm weather to be sociable and happy. Just remember the adage “twelve hours from bottle to throttle!”