Prevalence of psychoactive substances in truck drivers in the Nord-Pas-de-Calais region (France).

A previous study conducted in 1995 showed that psychoactive drug use by workers was higher in safety/security workstations than in the rest of the labour force. In order to verify this finding, we conducted a new study in 2003-2004 in the Nord-Pas-de-Calais region, restricted to truck drivers. The aim of this study was to allow harmonizing the professional practice of the occupational physicians, proposing drug prevention and drug testing policies, validating the analytical methods and the guidelines in case of positive testing results. One thousand truck drivers were studied. Urines were tested for amphetamines, cannabinoids, cocaine, opiates, benzodiazepines, buprenorphine and methadone by immunoassay. Urine ethanol determinations were performed by an ADH method. Positive urines for drugs of abuse, methadone or buprenorphine were then tested by gas chromatography or liquid chromatography coupled to mass spectrometry. Out of the 1000 drivers, cannabinoids were detected in 85 cases, opiates in 41 cases, amphetamines in 3 cases and cocaine in only one case. Buprenorphine was detected in 18 cases, methadone in 5 cases and benzodiazepines in 4 cases. Urine ethanol was positive in 50 cases. We found only one case with 6-monoacetylmorphine. Other positive opiates were metabolites of antitussives. The relatively low number of benzodiazepine positive urines could be explained by the lack of sensitivity of the test we used. All these results confirm those of the previous study for cannabinoids and ethanol in safety/security workstations. Positive results for methadone and buprenorphine are eight times higher than in the general population. In conclusion, the authors think that it will be of a great interest to test urine of truck drivers for other classes of psychoactive drugs, using a liquid chromatography-mass spectrometry method.