The aim of this study was to compare estimation of
nicotine use in Slovakia (SR) and the Czech Republic (CR) based on
cotinine analysis in
wastewater from seven selected wastewater treatment plants (WWTPs) with conventional estimation based on tobacco product sales. Urinary bio-markers of
nicotine use were analyzed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The study was performed concurrently at all the WWTPs (from 11 to 18 March 2014). Representative 24 h composite samples were analyzed with on line SPE/LC-MS/MS method. Based on the average residence time of
wastewater in the sewers and the average time in the sampling device, specific correction coefficients were designed to improve estimation of
nicotine consumption.
Nicotine ingestion level was back-calculated and expressed as mass of pure
drug consumed per day and per 1000 inhabitants for selected cities of both countries (mean, 2.2 g for Piešťany and 8.0 g for Nitra, respectively). Consequently, the cigarette consumption results were recalculated for each country separately and compared with the data of both national statistical offices (2362 cigarettes/year/person--SR and 2088 cigarettes/year/person--CR). Our results highly correspond to the data of national statistical offices (up to 99.9% in SR and to 96% in CR). The average amount of money invested in cigarette sales was estimated in the capitals of both countries. It is about 1 million EUR/day for Prague and about 0.3 million EUR/day for Bratislava. The calculation of
nicotine consumption, utilizing a specific correction coefficient, is the correct way to obtain more accurate data in
drug studies of this kind, thus allowing a better
drug abuse assessment.