Centre of Behavioural and Forensic Toxicology, Institute of Legal Medicine, University of Padova, Via Falloppio 50, I-35121 Padova, Italy

Toxicological and forensic assessments, including clinical observations and sampling of biological fluids, were carried out on 1073 drivers. Of these 952 supplied blood samples and 858 urine samples. There were 317 drivers reported for driving under the influence of alcohol (BAC > 80 mg %). In 147 drivers, psychoactive drugs were found in biological fluids, 74 of them in blood.

The present work aims at assessing the correlation between drug presence and concentration in the blood, and the type of physical and behavioural alterations recorded during the clinical examination. Analysis of clinical data on the driver population in question involved assessment of the following parameters: blood pressure, heart rate, ocular clinical signs (e.g., nystagmus, photomotor reflex, myosis, mydriasis), slurred speech, motor coordination, and the presence of other clinical signs indicating states of intoxication or withdrawal symptoms.

Toxicological analyses revealed the presence of the following psychoactive substances or classes of substances in drivers' blood samples: cannabinoids (n = 39, THC-COOH concen-tration range 0.3-125 ng/ml), cocaine (n = 30, benzoylecgonine concentration range 18-890 ng/ml), amphetamine and analogues (n = 9, MDMA concentration range 21-266 ng/ml) and opiates (n = 6, concentration range of total morphine 20-621 ng/ml).