Legislation governing drink driving does not take into account the medical fact that the level of alcohol in a person's urine may be higher than the level in their blood at the time a sample is being taken, a coroner has pointed out.
The discrepancy in alcohol concentrations between blood and urine samples taken simultaneously came to light during the inquest on a young motorcyclist who died following a collision with a hackney van in Galway city last year.
Mr Gary Keady (20), Castle Park, Ballybane, Galway, collided with the hackney at the Ballin- foyle/Headford Road junction, on the outskirts of the city in the early hours of April 7th last year.
His girlfriend and pillion passenger, Ms Sarah Harrison, survived the accident but suffered a broken back, broken pelvis, two broken legs and a collapsed lung in the impact.
Ms Harrison told the inquest in Galway that she and Mr Keady had been at an engagement party earlier that night and got a hackney home.
They decided to go to a friend's house in Ballindooley on Mr Keady's motorbike and the accident occurred on the way. Ms Harrison said she was quite drunk at the time but that Mr Keady had drunk only a couple of ciders at the party and was sober.
Dr Gabriel Mortimer, pathologist, who carried out the post- mortem, said Mr Keady's blood alcohol level was 74 mgs of alcohol per 100 mls of blood, which is below the legal limit of 80 mgs per 100 mls of blood. However, his urine alcohol level was over the limit at 145 mgs of alcohol per 100 mls of urine. The legal urine limit is 101 mgs of alcohol per 100 mls of urine. Dr Mortimer said the findings indicated Mr Keady had taken some alcohol earlier that night but had not taken any shortly before his death.
The cause of death, he said, was shock due to multiple injuries, mainly the transection of the aorta, and compound fracture of the right temple, consistent with a violent impact.
Galway West coroner Dr Ciaran MacLoughlin noted that the law did not seem to recognise that such a discrepancy can occur in samples taken in other cases on suspicion of drink driving. "If a person chose to give blood rather than urine, the reading would be inside the legal limit, but the urine sample would clearly be over the limit. When the recent legislation was introduced it should have been able to account for that.
"One would have thought that both blood and urine samples would be either above or below the legal limit, but this case clearly shows that is not the case," he said . He added that a second urine sample would give a more accurate reading of alcohol levels. Dr Mortimer agreed with this.
Dr MacLoughlin then returned a verdict in accordance with the medical evidence