key: cord-0998221-g66lkc72 authors: Bade, Richard; Tscharke, Benjamin J.; O’Brien, Jake W.; Magsarjav, Saranzaya; Humphries, Melissa; Ghetia, Maulik; Thomas, Kevin V.; Mueller, Jochen F.; White, Jason M.; Gerber, Cobus title: Impact of COVID-19 Controls on the Use of Illicit Drugs and Alcohol in Australia date: 2021-08-10 journal: Environ Sci Technol Lett DOI: 10.1021/acs.estlett.1c00532 sha: ab6caa811897cbdf2c46b0ff54f55f314be2e3f0 doc_id: 998221 cord_uid: g66lkc72 [Image: see text] Methamphetamine, MDMA, cocaine, cannabis, and alcohol in samples from 20 wastewater treatment plants servicing the eight state or territory capitals of Australia were analyzed, with equivalent coverage of >45% of the national population. Trends in drug consumption were calculated and assessed from samples collected from 2016 to 2020, with a focus on pre-COVID-19 (August 2016 to December 2019), versus February to June 2020, when Australia observed a nationwide lockdown. Results showed delayed but significant decreases in methamphetamine, >50% in Western Australia. In contrast, significant increases in cannabis in most jurisdictions were observed. This suggests changes in consumption may be somewhat linked to reduced supply of imported substances, with increased use of locally produced drugs. Initial decreases in cocaine and MDMA consumption were evident in many parts of the country, but pre-COVID trends were re-established after April 2020. Interestingly, weekend–weekday differences were narrowed for cocaine, MDMA, and alcohol during lockdown, which might be expected due to bars being closed and social gathering not allowed. With this study providing insight into the first four months of COVID-19 restrictions in Australia, it remains to be seen what the longer-term effect of the pandemic will be. The COVID-19 novel coronavirus has had a major impact on cities and countries around the world. To combat this pandemic, several governments enforced lockdowns to control the spread of infection. This led to the closure of many public spaces such as restaurants, bars, nightclubs, and "non-essential" retail premises, while social distancing was introduced to ensure the spread of COVID-19 could be contained. In Australia, it was announced that gatherings in enclosed spaces would be closed from midday March 23, 2020, including registered and licensed clubs, licensed premises in hotels and pubs, and entertainment venues such as nightclubs and casinos. 1 In addition, individual states and territories introduced border restrictions to limit the movement of interstate travelers. 2 Once the management of the pandemic was shown to be effective, states and territories began to ease restrictions. In early May, the federal government announced a framework for a "COVIDSafe Australia", with individual states and territories left to specify the dates for each measure. This involved three steps: (1) allowing groups of people to be together in homes and in the community, (2) allowing slightly larger gatherings and more businesses to reopen, with risky activities having tighter restrictions, and (3) allowing business to reopen and the community to have minimal restrictions. 3 There have been surveys surrounding the potential impact of these restrictions on alcohol sales, 4 and wastewater analysis showed a decrease in alcohol consumption in South Australia. 5 However, few papers have been published on community trends in illicit drug use through wastewater analysis during a COVID-19 lockdown. One focused on one city in Austria, 6 while another covered eight cities in Europe, albeit for only 1 week during the pandemic. 7 These papers showed that the use of the more popular drugs such as cocaine, amphetamine, and MDMA generally decreased in most cities. In the Austrian study, the use of the traditionally less popular methamphetamine increased during lockdown conditions. 6 It has been hypothesized that physical and social restrictions would disproportionally impact people who regularly use illicit drugs and cause substantial shifts in illicit drug markets. 8, 9 A review looking at the impact of the 2008 Global Financial Crisis on illicit drug consumption showed that there were compound specific changes associated with this upheaval: less use of expensive drugs, such as cocaine, and an increase in the use of synthetic or cheaper drugs such as amphetamine. 10 This was shown to be the case in Italy 11 and Greece 12 through multiyear wastewater analysis. In Greece, it was found that the use of amphetamine decreased over the years, the use of MDMA increased, and the use of cannabis and cocaine changed little. 12 In the Italian study, it was found that the use of more expensive drugs (cocaine and heroin) decreased and they were somewhat replaced by the cheaper methamphetamine and cannabis. 11 Although these studies allowed annual comparisons, specific changes during the Global Financial Crisis were not investigated. We have been monitoring long-term trends of drug use in Australia since 2009 and since August 2016 as part of the National Wastewater Drug Monitoring Program. 13 Every two months, samples are collected from all capital cities, while regional sites are sampled every four months. Approximately half of the population is included in every sampling period. With the sudden onset of COVID-19, the long-running sampling program allows assessment of the immediate impact of such a pandemic. In this work, we looked at the long-term trends of four well-known drugs of abuse (cocaine, MDMA, cannabis, and methamphetamine) and alcohol and the impact of the COVID-19 restrictions by focusing on February to June 2020, which covers the period before and during lockdown and then the start of the easing of restrictions in most parts of the country. Samples and Sample Treatment. A total of 3041 samples of 24 h composite influent wastewater as part of the National Wastewater Drug Monitoring Program were analyzed from capital city locations every two months for up to 7 days from August 2016 to June 2020 in all states and territories of Australia, covering ≤47% of the total population of Australia: Australian Capital Territory (ACT, one site), New South Wales (NSW, three sites), Northern Territory (NT, one site), Queensland (QLD, three sites), South Australia (SA, four sites), Tasmania (TAS, three sites), Victoria (VIC, two sites), and Western Australia (WA, three sites). 13, 14 In each of February (before lockdown), April (during lockdown), and June (after most restrictions eased) 2020, 134 samples from 20 sites were analyzed, covering 47% of the Australian population. Due to confidentiality arrangements with all wastewater treatment plant sites, no further information can be given. The individual reports contain more information about the specific methods and sampling campaigns, from August 2016 (report 1 15 ) to June 2020 (report 11 14 ) . The samples were predominantly collected in the first week of each sampling month and avoided public holidays and festival periods. During each sampling period, samples were preserved upon collection with sodium metabisulfite (2 g/L from August 2016 to April 2018 and 0.5 g/L from August 2018) or acidified to pH 2 with hydrochloric acid and frozen or refrigerated until the final sample had been collected. Upon conclusion of the specific sampling period at each WWTP, all samples were transported to either the University of South Australia or The University of Queensland for analysis. A solid-phase extraction method was used at the University of South Australia 16 for MDMA, while for cannabis, a liquid− liquid extraction method as described by Tscharke et al. 17 was used. For methamphetamine, cocaine, and alcohol, a direct injection method was used at The University of Queensland. 15 See ref 18 for the ethyl sulfate (alcohol) method. Estimation of Daily Consumption. The concentration of each compound or metabolite in the wastewater samples analyzed by the direct injection method was quantified using a calibration curve of the ratio of the signal response for the unlabeled authentic drug standard to the deuterated analogue. In all other cases, the concentrations were determined by a standard addition method using the reference standard/ deuterated standard ratio. For the specific compounds in this paper, consumption of cocaine, alcohol, and cannabis was estimated using their metabolites benzoylecgonine, ethyl sulfate, and THC-COOH, respectively. Consumption of methamphetamine and MDMA was back-calculated on the basis of the parent drug. The wastewater concentration data were used in conjunction with plant specific details for flow volume (megaliters) and the number of people in the catchment (catchment population; thousands of people, calculated off the Census), as well as drug specific details such as the excretion rate (eq 1). When the unchanged drug was used for the calculation (i.e., not a metabolite), the molecular weight ratio of drug to metabolite was taken as 1. The specific excretion factors can be found elsewhere. 15 The equation for daily consumed mass per day per 1000 people is Statistical Analysis. All statistical analyses were completed using R version 4.0.2. Two-way analysis of variance (ANOVA) with Tukey posthoc analyses was used to ascertain whether the consumption levels in the months of April and June 2020, during the COVID-19 national lockdowns, significantly changed from the consumption in the preceding 4 years. Each drug and each state were analyzed using separate analyses. Some data did not conform to normality assumptions, so log or square root transforms were applied where necessary (Tables S1−S5). To account for temporal trends, a linear trend was fitted to the data before lockdown, i.e., until February 2020, using linear regression. If the slope was significant, the ANOVA was fitted to the residuals, including the predicted residuals for the months during the lockdowns. The removal of trend ensures that significant differences seen during the months of the lockdown consider changes that would have naturally been expected given the pattern of previous consumption. If the year and months were significant, then it ensured the significance was not due to the presence of a prior trend. Following transformation and detrending, two-way ANOVA was used to identify seasonality and the changes during lockdown months (April 2020 and June 2020). Changes during lockdown were tested using a binary indicator that labeled lockdown months (lockdown), and seasonality was considered by including the month as a factor (month). If month was statistically significant, then seasonality was present in the data set. If lockdown was statistically significant, then consumption was different in lockdown compared to previous years. The interaction between month and lockdown was also considered. If the interaction term was statistically significant, then either April 2020 or June 2020 was significantly different from previous years. Significant inter-actions were described using Tukey posthoc analyses. In summary, removing trend and accounting for seasonality allow pubs.acs.org/journal/estlcu Letter differences in consumption during the lockdown months of April 2020 and June 2020 to be more accurately described. Drug Trends from February to June 2020. A summary of all compounds (alcohol, cannabis, cocaine, MDMA, and methamphetamine) investigated in this work is shown in Figure 1 . Previous national data are shown in black for all compounds as a comparison to the 2020 results. Alcohol. Early surveys carried out in Australia at the beginning of the pandemic suggested that alcohol consumption increased during the lockdown, partly due to increased sales. 4 However, analysis of on-and off-premises beer sales in Australia showed that, at least for beer, on-premises consumption decreased significantly during the lockdown with no change seen in off-premises beer consumption. 19 The study focused solely on sales data to show a decrease in beer consumption. It is not necessarily true that the purchasing of beer will result in the consumption during the time period close to the time of purchase. Data are not available on the other alcoholic products that were not included in the study, and therefore, a more direct consumption estimate is needed. The impact of a COVID-19 enforced lockdown has previously been demonstrated in South Australia using wastewater analysis. 5 It was found that alcohol consumption decreased significantly during the lockdown, with weekend use especially affected. This was expected with social venues such as bars and nightclubs closed and social activities not allowed. The work presented here expands on that local investigation. Interestingly, similar results were found for almost all states and territories ( Figure 1A) . However, statistically significant decreases (p < 0.05) were observed only in NSW, SA, and TAS. All jurisdictions except TAS had increased consumption after the initial lockdown. The spread in consumption over the week in April was noticeably less than the preceding month everywhere but VIC, suggesting less weekly variability. This is more evident in Figure S1 , where the daily alcohol consumption is shown for three specific jurisdictions: South Australia (SA), New South Wales (NSW), and Northern Territory (NT). All three showed considerable decreases in alcohol consumption during the lockdown (April 2020), with a much flatter than usual weekly trend, indicative of less weekend consumption. It was also interesting to note that the immediate reduction in alcohol use upon lockdown was followed by a return to pre-COVID-19 levels, or in some instances even higher consumption, as restrictions were eased. This was most apparent in the NT where restrictions were eased earlier than in other parts of the country and also to a greater extent. Cannabis. Cannabis is the most consumed illicit drug in Australia. While it has been monitored in various cities in Australia since 2011, 17, 20 it has been monitored in wastewater on a national level only since 2018. In that time, the data indicate that the highest per capita consumption of cannabis in the capital cities is in TAS and NT, while it is lowest in NSW. Cannabis is largely produced locally, and therefore, the impact of COVID-19-related travel bans and international border closures may have had much less impact on its availability. According to our findings, cannabis consumption increased significantly (p < 0.05) during and after the lockdown period (April and June 2020) compared to all preceding months for all states and territories except the Northern Territory ( Figure 1B) . Cocaine. The rates of consumption of cocaine are relatively low in Australia, with NSW and ACT being the jurisdictions with highest levels of use. Cocaine is considered a party drug, with increased use typically observed over the weekend or during festive events. 20, 21 According to the Ecstasy and Related Drugs Reporting System, which surveyed drug users across Australia between April and June 2020, approximately half of cocaine users used less or stopped using cocaine. 22 This could be due to decreased availability, compared to alcohol or cannabis, resulting in the decreases observed around the country in April 2020 ( Figure 1C ). During the national lockdown, with large gatherings banned and nightclubs and bars closed, the use of cocaine dropped around parts of the country. However, statistically significant decreases (p < 0.05) were evident in only NT and SA. While it is possible that illegal stockpiles had suppressed the immediate effect of border closures on local supply, the low overall use of cocaine may be another reason why the reduction in use was not as ubiquitous as alcohol during the lockdown period (April). It was interesting that the weekly use over the sampling weeks increased as communities emerged from lockdown and employment started to return to normality, as shown for four states [Australian Capital Territory (ACT), South Australia (SA), New South Wales (NSW), and Western Australia (WA)] in Figure S2 . In fact, consumption for the weekend in June 2020 was higher than average since our national data began in 2016 for most jurisdictions. MDMA. MDMA is one of the least consumed illicit stimulants in Australia, with use highest in NT and TAS. It is possible that the overall low use of this drug resulted in only NSW showing a significant decrease (p < 0.05) in levels over the lockdown period, with sufficient residual supply in the market to meet demand ( Figure 1D ). Like cocaine, MDMA has a noticeable "weekend trend" due to its use as a party drug. However, during the lockdown period, this trend was absent, resulting in much narrower weekly consumption bars, particularly in April, following the first implementation of restrictions. In June, the same patterns of use as before the pandemic re-emerged. Specific examples from NSW, NT, and Western Australia (WA) are shown in Figure S3 , with NT showing a significant weekend trend in June 2020, after restrictions were eased. Methamphetamine. Methamphetamine is the most consumed illicit stimulant in Australia. 14 On a national level, capital cities in SA and WA have had the highest rates of consumption and ACT and TAS the lowest. Although the market is supplied by both imported and domestically produced methamphetamine, particularly the former is considered the main route into the capital cities. 23 In this work, it is clear that the restrictions severely impacted almost all jurisdictions ( Figure 1E ). Although the full impact was delayed in some parts of the country, statistically significant decreases (p < 0.05) were observed during the months of the lockdown for all jurisdictions except SA and VIC. The delay in the reduction of methamphetamine use in some regions is probably indicative of some residual supply capability in the market. It has been reported that large seizures have a clear shortterm impact on methamphetamine consumption in Australia, especially in the capital cities. 23 Patterns in methamphetamine consumption following large seizures are also related to the location of the seizure. For example, a large seizure in NSW resulted in a decrease in consumption in NSW, VIC, and ACT, In SA and WA, several large interventions over the years have caused substantial changes in measured drug loads in wastewater. 23 These increased the variability in the overall long-term trend. However, methamphetamine loads in wastewater in the year leading up to the COVID-19 pandemic were consistently and substantially higher than after the lockdown. WA had the largest drop in methamphetamine loads, with an approximate 50% decrease measured in June 2020 compared to April 2020. In fact, this was the lowest level seen in WA since monitoring began. 14 It is possible that job cuts and loss of income may have influenced the overall consumption of methamphetamine, Australia's most used illicit stimulant. However, one might have expected that to affect states and territories equally. Surveys of drug users indicated that consumers faced some challenges obtaining their drug of choice. 24 The disproportionate effect in WA suggests that decreased supply may have been the biggest driver behind the reduction in methamphetamine use. 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National Wastewater Drug Monitoring Program Report 11 Simultaneous Determination of 24 Opioids, Stimulants and New Psychoactive Substances in Wastewater Temporal Trends in Drug Use in Adelaide, South Australia by Wastewater Analysis Analysis and Interpretation of Specific Ethanol Metabolites, Ethyl Sulfate, and Ethyl Glucuronide in Sewage Effluent for the Quantitative Measurement of Regional Alcohol Consumption When the Pubs Closed: Beer Consumption before and after the First and Second Waves of COVID-19 in Australia Profiles of Illicit Drug Use during Annual Key Holiday and Control Periods in Australia: Wastewater Analysis in an Urban, a Semi-Rural and a Vacation Area Impact of COVID-19 and Associated Restrictions on People Who The authors sincerely thank the wastewater treatment plant operators for providing samples for this work and all analysts and laboratory assistants for their help collecting and analysing samples. The authors also acknowledge the Australian Criminal Intelligence Commission for their support. The Queensland Alliance for Environmental Health Sciences, The University of Queensland, gratefully acknowledges the financial support of the Queensland Department of Health.