Using wastewater analysis to estimate the prevalence of THC and CBD use in a population of Japan during and after the Covid-19 pandemic (2020–2023)

IF 2.5 3区医学 Q1 MEDICINE, LEGAL

Forensic science international Pub Date : 2025-10-15 DOI:10.1016/j.forsciint.2025.112687

Phong K. Thai , Qiuda Zheng , Nanami Yagishita , Zhe Wang , Hiroe Hara-Yamamura , Wayne Hall , Ryo Honda

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引用次数: 0

Abstract

Background

It is illegal to use cannabis products that contain THC in Japan but cannabidiol (CBD) can be legally used for medical purposes. There is a lack of objective evidence on the comparative prevalence of THC and CBD use in Japan. This pilot study used wastewater to estimate the prevalence use of those two substances in the population of a small town in Japan during and after the Covid-19 pandemic period.

Method

We conducted a longitudinal observational study. Wastewater samples were collected every week for every other two months from October 2020 to March 2023 from the inlet of a wastewater treatment plant serviced a town in Honshu Island, Japan with a population of approximately 120,000 people. Biomarkers of THC and CBD use in wastewater were measured during the monitoring period using liquid-liquid extraction and liquid chromatography-tandem mass spectrometry.

Results

The average estimated consumption of cannabis through the proxy of THC in the study population was 5 doses/1000 people/day. We observed a gradual increase of cannabis use from 2020 to 2023 by approximately 27 % per year. The prevalence of CBD use was similar to that of THC although CBD consumption could not be estimated in the absence of pharmacokinetic data.

Conclusions

The prevalence of THC use remained low in Japan compared to other countries despite a steady increase in recent years, but the use of CBD was much more common than in other countries. These findings provide evidence on the value of wastewater surveillance of drug use to differentiate between THC and CBD in Japan.

查看原文本刊更多论文

利用废水分析来估计在2019冠状病毒病大流行期间和之后（2020-2023年）日本人群中四氢大麻酚和CBD的使用情况。

背景：在日本，使用含有四氢大麻酚的大麻产品是非法的，但大麻二酚（CBD）可合法用于医疗目的。在日本，缺乏关于四氢大麻酚和CBD使用比较流行的客观证据。这项试点研究利用废水来估计在2019冠状病毒病大流行期间和之后，日本一个小镇人口中这两种物质的使用情况。方法：采用纵向观察研究。从2020年10月到2023年3月，每隔两个月每周从污水处理厂的入口收集废水样本，该污水处理厂为日本本州岛的一个城镇提供服务，人口约为12万。在监测期间，采用液-液萃取和液相色谱-串联质谱法测定废水中四氢大麻酚和CBD的生物标志物。结果：在研究人群中，通过四氢大麻酚的平均估计消费量为5剂/1000人/天。我们观察到，从2020年到2023年，大麻的使用量每年逐渐增加约27% %。CBD使用的流行程度与四氢大麻酚相似，尽管在缺乏药代动力学数据的情况下无法估计CBD的消费量。结论：尽管近年来日本四氢大麻酚的使用率稳步上升，但与其他国家相比，日本的四氢大麻酚使用率仍然较低，但CBD的使用比其他国家普遍得多。这些发现为在日本进行废水监测以区分四氢大麻酚和CBD的价值提供了证据。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Forensic science international 医学-医学：法

CiteScore

5.00

自引率

9.10%

发文量

285

审稿时长

49 days

期刊介绍： Forensic Science International is the flagship journal in the prestigious Forensic Science International family, publishing the most innovative, cutting-edge, and influential contributions across the forensic sciences. Fields include: forensic pathology and histochemistry, chemistry, biochemistry and toxicology, biology, serology, odontology, psychiatry, anthropology, digital forensics, the physical sciences, firearms, and document examination, as well as investigations of value to public health in its broadest sense, and the important marginal area where science and medicine interact with the law. The journal publishes: Case Reports Commentaries Letters to the Editor Original Research Papers (Regular Papers) Rapid Communications Review Articles Technical Notes.