@article{ref1,
title="Deciding between one off/occasional and regular cannabis consumption",
journal="Blutalkohol",
year="2000",
author="Daldrup, T. and Kaferstein, H and Kohler, H. and Maier, R. D. and Musshoff, F.",
volume="37",
number="1",
pages="39-47",
abstract="Due to the long half-life oft he THC metabolite THC-COOH being ca. 6 days, its accumulation in the blood of regular cannabis consumers can be observed. This fact has been used for the last 5 years in Northrhine- Westfalia in the context of checking whether people are fit to drive, and to state whether those persons have indulged in one-off / occasional or regular cannabis consumption: If the serum THC-COOH concentrations are below 5 ng/mL, the consumption is assumed to be of an occasional nature, and levels above 75 ng/mL are associated with regular consumption. The requirement is that the blood sample be taken within the prescribed 8 day period. To date, in the frame of drivers fitness assessments 1559 blood samples were analysed for cannabinoids at 5 official analytical institutes in Northrhine Westfalia. 516 (33,1%) of the samples tested positive - i.e. cannabis consumption was detected. 35 (6.78 %) of the positive samples were deemed as having come from regular, and 212 (41.09 %) from one-off/occasional consumption. After submission of the analytical results, some 59 % of the cannabis positive cases required the transport authorities to take further judicial measure. It is our opinion that the blood sample is a suitable medium for ascertaining the occurrence of one-off / occasional or regular cannabis consumption.<p />",
language="de",
issn="0006-5250",
doi="",
url="http://dx.doi.org/"
}