Use of illicit drugs, alcohol and tobacco in Spain and Portugal during the COVID-19 crisis in 2020 as measured by wastewater-based epidemiology

Abstract

The COVID-19 pandemic spread rapidly worldwide in the year 2020, which was initially restrained by drastic mobility restrictions. In this work, we investigated the use of illicit drugs (amphetamine, methamphetamine, ecstasy, cocaine and cannabis), and licit substances of abuse (alcohol and tobacco) during the earlier months (March-July 2020) of the pandemic restrictions in four Spanish (Bilbao and its metropolitan area, Vitoria-Gasteiz, Castellón and Santiago de Compostela) and two Portuguese (Porto and Vila do Conde) locations by wastewater-based epidemiology (WBE). The results show that no methamphetamine was detected in any of the locations monitored, while amphetamine use was only detectable in the two locations from the Basque Country (Bilbao and its metropolitan area and Vitoria-Gasteiz), with high estimated average usage rates (700-930 mg day^-1 1000 inhabitant^-1). The remaining substances were detected in all the investigated catchment areas. In general, no remarkable changes were found in population normalized loads compared to former years, except for cocaine (i.e. its main metabolite, benzoylecgonine). For this drug, a notable decrease in use was discernible in Castellón, while its usage in Porto and Santiago de Compostela seemed to continue in a rising trend, already initiated in former years. Furthermore, two events of ecstasy (3,4-methylenedioxymethamphetamine, MDMA) dumping in the sewage network were confirmed by enantiomeric analysis, one in Santiago de Compostela just prior the lockdown and the second one in the Bilbao and its metropolitan area in July after relieving the more stringent measures. The latter could also be associated with a police intervention. The comparison of WBE with (web) survey data, which do not provide information at a local level, points towards contradictory conclusions for some of the substances, thereby highlighting the need for stable WBE networks capable of near real-time monitoring drug use.

Keywords: Coronavirus; Drugs of abuse; Ethanol; Lockdown; Nicotine; Wastewater surveillance.

Graphical abstract

Fig. 1

Timeline summary of the COVID-19 pandemic restrictions in the period January–July 2020 in the studied areas. Dates presented as month/day/year.

Fig. 2

Violin plots summarizing the WBE-derived consumption of AMP in Bilbao and its metropolitan area (BIL), Vitoria-Gasteiz (VIT) and both locations (all). The horizontal line and blue dots and smaller black dots represent the median, mean and individual datapoints, respectively. Coding: PY (previous years, in green), LD (lockdown, in purple), RLD (relaxed phase I-III lockdown, in orange), NN (new normal, in yellow). N.B.: logarithmic scale; AMP was below MDL in the remaining locations. Further detailed plots are presented in Fig. S1.

Fig. 3

Violin plots summarizing the WBE-derived consumption of MDMA in Castellón (CAS), Santiago de Compostela (SAN), Bilbao and its metropolitan area (BIL), Vitoria-Gasteiz (VIT), Porto (POR) and Vila do Conde (VDC) and all locations (all). The horizontal line and blue dots and smaller black dots represent the median, mean and individual datapoints, respectively. Coding: PY (previous years, in green), LD (lockdown, in purple), RLD (relaxed phase I-III lockdown, in orange), NN (new normal, in yellow). N.B.: logarithmic scale. Further detailed plots are presented in Fig. S2.

Fig. 4

Violin plots summarizing the WBE-derived consumption of Cocaine in Castellón (CAS), Santiago de Compostela (SAN), Bilbao and its metropolitan area (BIL), Vitoria-Gasteiz (VIT), Porto (POR) and Vila do Conde (VDC) and all locations (all). The horizontal line and blue dots and smaller black dots represent the median, mean and individual datapoints, respectively. Coding: PY (previous years, in green), LD (lockdown, in purple), RLD (relaxed phase I-III lockdown, in orange), NN (new normal, in yellow). N.B.: logarithmic scale. Further detailed plots are presented in Fig. S3.

Fig. 5

Violin plots summarizing the WBE-derived consumption of THC (recalculated from TH-COOH with a CF of 182) in Castellón (CAS), Santiago de Compostela (SAN), Bilbao and its metropolitan area (BIL), Vitoria-Gasteiz (VIT), Porto (POR) and Vila do Conde (VDC) and all locations (all). The horizontal line and blue dots and smaller black dots represent the median, mean and individual datapoints, respectively. Coding: PY (previous years, in green), LD (lockdown, in purple), RLD (relaxed phase I-III lockdown, in orange), NN (new normal, in yellow). N.B.: logarithmic scale. Further detailed plots are presented in Fig. S4.

Fig. 6

Violin plots summarizing the WBE-derived consumption of nicotine in Castellón (CAS), Santiago de Compostela (SAN), Bilbao and its metropolitan area (BIL), Vitoria-Gasteiz (VIT), Porto (POR) and Vila do Conde (VDC) and all locations (all). The horizontal line and blue dots and smaller black dots represent the median, mean and individual datapoints, respectively. Coding: PY (previous years, in green), LD (lockdown, in purple), RLD (relaxed phase I-III lockdown, in orange), NN (new normal, in yellow). N.B.: logarithmic scale. Further detailed plots are presented in Fig. S5.

Fig. 7

Violin plots summarizing the WBE-derived consumption of ethanol in Castellón (CAS), Santiago de Compostela (SAN), Bilbao and its metropolitan area (BIL), Vitoria-Gasteiz (VIT), Porto (POR) and Vila do Conde (VDC) and all locations (all). The horizontal line and blue dots and smaller black dots represent the median, mean and individual datapoints, respectively. Coding: PY (previous years, in green), LD (lockdown, in purple), RLD (relaxed phase I-III lockdown, in orange), NN (new normal, in yellow). N.B.: logarithmic scale. Further detailed plots are presented in Fig. S6.