Illicit drugs and their metabolites in urban wastewater: Analysis, occurrence and consumption in Xinjiang, China

International Workers' Day: Consumption Patterns of Morphine, Codeine, and Methamphetamine in Urban and Rural Areas Based on Wastewater-Based Epidemiology

Wastewater-based epidemiology (WBE) is a reliable means to estimate drug consumption in a specific population. By measuring the concentration of drug residues or metabolites in wastewater, the consumption behavior pattern of a specific population can be deduced. Using the WBE method, the present study, for the first time, continuously monitored the differences in the consumption of morphine (MOR), codeine (CODE), and methamphetamine (METH) in three wastewater-treatment plants in a city and two surrounding villages in Xinjiang, China during International Workers' Day and the following week. The wastewater samples were pretreated by solid-phase extraction and then analyzed by high-performance liquid chromatography-tandem mass spectrometry. Methamphetamine was not detected in rural areas and was detected only on International Workers' Day in urban areas. According to the estimation of per capita consumption, the per capita consumption of MOR, CODE, and METH in urban inhabitants was 12.04 to 23.39, 10.44 to 16.39, and 1.31 mg/day/1000 inhabitants. The per capita consumption of MOR and CODE in rural areas was 5.19 to 8.35 and 2.56 to 3.52 mg/day/1000 inhabitants. The consumption of MOR in urban and rural areas was significantly higher than that of CODE and METH. During International Workers' Day, workdays, and weekends, the consumption of MOR and CODE in urban areas is significantly higher than that in rural areas. Compared with those on weekends, the consumption of urban MOR and CODE increased more during International Workers' Day. The consumption of MOR in urban areas showed a weekend effect. The present study can provide information for subsequent research and government departments. Environ Toxicol Chem 2024;00:1-9. © 2024 SETAC.

Nationwide assessment of illicit drug consumption patterns in South Korea using wastewater-based epidemiology during the COVID-19 pandemic (2020-2022)

Illicit drugs have become a crucial global social issue, with South Korea experiencing a continuous increase in the number of offenders and drug smuggling. This study employed wastewater-based epidemiology to investigate consumption patterns of 8 illicit drugs and their 7 metabolites during the COVID-19 pandemic (2020-2022) in South Korea. Ten compouds were detected in the wastewater influent. Methamphetamine (METH) was prevalent in samples, followed by amphetamine and ecstasy (MDMA). Interestingly, MDMA and ketamine (KET), which were not detected in previous Korean studies conducted before COVID-19 pandemic, were detected in this study. METH exhibited the highest consumption rates, decreasing from 16.6 to 12.4 mg/day/1000 people between 2020 and 2022, while MDMA increased over the three years (mean: 1.16, 1.24, and 1.62 mg/day/1000 people in 2020, 2021, and 2022, respectively) (p < 0.05). Significant correlations were identified between regional income levels and the consumption rates of METH (p < 0.01), MDMA (p < 0.01), and KET (p < 0.05). Furthermore, METH and MDMA consumption rates in cities were positively correlated with the number of drug offenders arrested and local clubs in those cities. The findings of this study provide valuable insights into shaping regulatory policies related to illicit drugs and future studies.

Testing methods to estimate population size for wastewater treatment plants using census data: Implications for wastewater-based epidemiology

In wastewater-based epidemiology (WBE), wastewater loads are commonly reported as a per capita value. Census population counts are often used to obtain a population size to normalise wastewater loads. However, the methods used to calculate the population size of wastewater treatment plants (WWTPs) from census data are rarely reported in the WBE literature. This is problematic because the geographical extents of wastewater catchments and census area units rarely align perfectly with each other and exist at different spatial scales. This complicates efforts to estimate the number of people serviced by WWTPs in these census area units. This study compared four geospatial methods to combine wastewater catchment areas and census area units to calculate the census population size of wastewater treatment plants. These methods were applied nationally to WWTPs across New Zealand. Population estimates varied by up to 73 % between the methods, which could skew comparisons of per capita wastewater loads between sites. Variability in population estimates (relative standard deviation, RSD) was significantly higher in smaller catchments (rs = -0.727, P < .001), highlighting the importance of method selection in smaller sites. Census population estimates were broadly similar to those provided by wastewater operators, but significant variation was observed for some sites (ranging from 42 % lower to 78 % higher, RSD = 262 %). We present a widely applicable method to calculate population size from census, which involves disaggregating census area units by individual properties. The results reinforce the need for transparent reporting to maintain confidence in the comparison of WBE across sites and studies.

Magnetic solid-phase extraction based on polydopamine-coated magnetic nanoparticles for rapid and sensitive analysis of eleven illicit drugs and metabolites in wastewater with the aid of UHPLC-MS/MS

The quantification of illicit drugs in wastewater has become a valuable tool for monitoring illicit drug abuse. The commonly utilized methods for detecting drugs in wastewater require a substantial sample volume, extended pretreatment durations, and intricate procedures. This study first employed polydopamine-coated magnetic nanocomposites as adsorbents for magnetic solid-phase extraction, combined with UPLC-MS/MS, to simultaneously determine the concentrations of eleven common illicit drugs in wastewater. The synthesis process for Fe3O4@PDA is straightforward and high-yield. Benefiting from the strong magnetic response, good dispersibility, and abundant binding sites of the prepared nanocomposites, the extraction of illicit drugs from wastewater could be achieved in just 15 min. The method exhibited satisfactory limits of quantitation (ranging from 5 to 10 ng/L), commendable accuracy (ranging from 90.59 % to 106.80 %), good precision (with RSDs below 10 %), and less sample consumption (only 1 mL). The efficacy of this method was successfully validated through its application to actual wastewater samples collected from ten wastewater treatment plants. The results indicated that morphine, codeine, methamphetamine, and ketamine were the predominant illicit drugs present in the samples. The method developed is able to meet the needs of common illicit drug monitoring and high-throughput analysis requirements.

In five wastewater treatment plants in Xinjiang, China: Removal processes for illicit drugs, their occurrence in receiving river waters, and ecological risk assessment

Residues of illicit drugs are frequently detected in wastewater, but data on their removal efficiency by wastewater treatment plants (WWTPs) and the ecological risks to the aquatic environment are lacking in this study. The research evaluates the residues, mass load, drug removal efficiency, and risk assessment of illicit drugs in WWTPs and aquatic environments (lakes) in Xinjiang, China. Initially, the concentration (incidence) and mass load of 10 selected illicit drugs were analyzed through wastewater analysis. The detected substances included methamphetamine (METH), morphine (MOR), 3,4-methylenedioxy methamphetamine (MDMA), methadone (MTD), cocaine (COC), benzoylecgonine (BE), ketamine (KET), and codeine (COD), with concentrations ranging from 0.11 ± 0.01 ng/L (methadone) to 48.26 ± 25.05 ng/L (morphine). Notably, morphine (59.74 ± 5.82 g/day) and methamphetamine (41.81 ± 4.91 g/day) contributed significantly to the WWTPs. Next, the drug removal efficiency by different sewage treatment processes was ranked as follows: Anaerobic-Oxic (A/O) combined Membrane Bio-Reactor (MBR) treatment process > Oxidation ditch treatment process > Anaerobic-Anoxic-Oxic (A2/O) treatment process > Anaerobic-Anoxic-Oxic combined Membrane Bio-Reactor treatment process. Finally, the research reviewed the concentration and toxicity assessments of these substances in the aquatic environment (lakes). The results indicated that Lake1 presented a medium risk level concerning the impact of illicit drugs on the aquatic environment, whereas the other lakes exhibited a low risk level. As a result, it is recommended to conduct long-term monitoring and source analysis of illicit drugs, specifically in Lake1, for further investigation. In conclusion, to enhance the understanding of the effects of illicit drugs on the environment, future research should expand the list of target analytes.

Magnetic Liposomes Infused with GPCR-Expressing Cell Membrane for Targeted Extraction Using Minimum Organic Solvent: An Investigative Study of Trace THC in Sewage

Trace analysis of lipophilic substances in complex environmental, food, or biological matrices has proven to be a challenge, on account of their high susceptibility to adsorption by particulate matter and liquid-solid interfaces. For this purpose, liquid-liquid extraction (LLE) is often employed as the separation method, which uses water-immiscible organic solvents. As an alternative, magnetic solid-phase extraction (MSPE) allows for adsorption, separation, and recovery of analytes from large volumes of aqueous samples with minimum usage of organic solvents. However, the poor selectivity hampers its performance in various scenarios, especially in sewage samples where complicated and unpredictable interference exists, resulting in block of the active adsorption sites of the sorbent. To this end, we propose receptor-affinity MSPE employing magnetic liposomes decorated with cell membranes expressing G-protein-coupled receptor as the sorbents. Application of the novel sorbent CM@Lip@Fe infused with CB1 cannabinoid receptors was demonstrated for the targeted extraction and enrichment of tetrahydrocannabinol from sewage matrix. Thanks to the high affinity and molecular selectivity of the ligand-receptor interactions, a limit of quantitation of 5.17 ng/L was achieved coupled with HPLC-MS/MS in unfiltered raw sewage, featuring minimum usage of organic solvents, fivefold enhanced sensitivity, low sorbent dosage (75 mg/L of sewage), and high efficiency as major advantages over conventional LLE. This work establishes a framework for efficient separation of specific molecules from complex media, thus promising to extend and refine standard LLE as the clean-up procedure for trace analysis.