Page 25 - November December Issue
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How Do Breath Machines Work?
i Blood Alcohol Concentration (BAC) is in grams of alcohol in 100 milliliters of blood or grams of alcohol in 210 liters of breath. To
convert into Canadian units multiply by 1000. Hence .08 g/100mL is equivalent to 80 mg/100mL
ii The estimated number of drinks is based on drinking over a period of 3 hours using an average rate of elimination of alcohol of .015
g/100nL/h. If the drinking time was longer the estimated number of drinks would increase and conversely if the drinking time was
shorter the estimated number of drinks would decrease.
iii The estimated number of drinks is also based on gender and weight. If a person weighs more than the examples there would be a
increase in the number of estimated drinks. If the person weighs less, the number of estimated drinks would also be less.
iv The typical effects tend to be less pronounced in persons with a tolerance to alcohol and more pronounced when the BAC is in-
creasing than when decreasing.
v Based on the Borkenstein Grand Rapids Curve (Borkenstein et al., “The Role of the drinking Driver in Trafic Accidents. The
Grand Rapids Study”, Blutalkohol 11: 1-131, 1974) This is the relative risk of the general driving population involved in general traf-
ic accidents and compares sober drivers with those at speciic BACs.
vi Based on Zador, P.L., Krawchuk, S.A., and Voas, R.B., “Alcohol-Related Relative Risk of Driver Fatalities and Driver Involvement
in Fatal Crashes in Relation to Driver Age and Gender: An Update Using 1996 Data”, Journal of Studies on Alcohol, 61: 387-395,
2000. The increased relative risks relect that alcohol is involved more frequently in serious motor vehicle collisions. There are no
signiicant difference in the risk between male and female drivers except in those ages 16 to 20 years of age.
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i Blood Alcohol Concentration (BAC) is in grams of alcohol in 100 milliliters of blood or grams of alcohol in 210 liters of breath. To
convert into Canadian units multiply by 1000. Hence .08 g/100mL is equivalent to 80 mg/100mL
ii The estimated number of drinks is based on drinking over a period of 3 hours using an average rate of elimination of alcohol of .015
g/100nL/h. If the drinking time was longer the estimated number of drinks would increase and conversely if the drinking time was
shorter the estimated number of drinks would decrease.
iii The estimated number of drinks is also based on gender and weight. If a person weighs more than the examples there would be a
increase in the number of estimated drinks. If the person weighs less, the number of estimated drinks would also be less.
iv The typical effects tend to be less pronounced in persons with a tolerance to alcohol and more pronounced when the BAC is in-
creasing than when decreasing.
v Based on the Borkenstein Grand Rapids Curve (Borkenstein et al., “The Role of the drinking Driver in Trafic Accidents. The
Grand Rapids Study”, Blutalkohol 11: 1-131, 1974) This is the relative risk of the general driving population involved in general traf-
ic accidents and compares sober drivers with those at speciic BACs.
vi Based on Zador, P.L., Krawchuk, S.A., and Voas, R.B., “Alcohol-Related Relative Risk of Driver Fatalities and Driver Involvement
in Fatal Crashes in Relation to Driver Age and Gender: An Update Using 1996 Data”, Journal of Studies on Alcohol, 61: 387-395,
2000. The increased relative risks relect that alcohol is involved more frequently in serious motor vehicle collisions. There are no
signiicant difference in the risk between male and female drivers except in those ages 16 to 20 years of age.
25
