[Cannabinoid intake by passive smoking].

The presence of cannabinoids in the urine can be produced by passive inhalation of hashish resp. marihuana smoke. The height depends on the intensity of exposure. Under extreme conditions concentrations between 40 to 50 ng/ml of cannabinoids had been found in the urine. In regard to the maximum variation-coefficient of the immunoassay methods, which is about 30%, we think it is useful to define a threshold value of 65 ng/ml of cannabinoids to distinguish between active and passive inhalation.