Roadside inspections, traffic events and traffic accidents from 2010–2022 in the experience of the Institute of Forensic Research as a consulting body in light of the proposed thresholds for the states of ‘after use’ and ‘under the influence’ for THC = Kontrole, zdarzenia i wypadki drogowe z lat 2010–2022 w praktyce opiniodawczej Instytutu Ekspertyz Sądowych w świetle propozycji progów „po użyciu” i „pod wpływem” THC

Abstract

Road traffic safety depends largely on the psychophysical fitness of drivers. Apart from ethyl alcohol, this efficiency is influenced by many other factors, including: presence in the blood of the so-called substances that act similarly to alcohol, and cannabinols constitute one of the most popular groups of these substances. The paper presents statistics on delta-9-tetrahydrocannabinol (THC) – the main psychoactive ingredient of cannabis detected in the blood of drivers subjected to 7269 road inspections and involved in 4697 road events and accidents in the years 2010–2022 throughout Poland. Based on the results obtained, it was found that THC is present in the blood of 25–61% of roadside inspection cases, and in the case of road incidents and accidents, 5–15% of drivers have THC in a concentration equal to or higher than 1 ng/ml. The data in the charts are given in relation to two THC concentration ranges: 1.0–2.5 ng/ml and above 2.5 ng/ml (the value proposed as the limit of the state “after use” and “under the influence” of THC) and in relation to concentration ranges based on the THC elimination curve in human serum. The study did not distinguish between chronic or acute participants and occasional participants. It was based on THC and THCCOOH concentrations. The analyzes were performed using the enzyme-linked immunosorbent method (ELISA) and confirmatory methods such as liquid and gas chromatography coupled with mass spectrometry, in which the limit of quantification of 1 ng/ml was in accordance with the applicable requirement contained in the Regulation of the Minister of Health of July 16, 2014 on the list of similarly acting agents to alcohol and the conditions and method of conducting tests for their presence in the body.