Long-term Monitoring Of Urban Methamphetamine Abuse Based On Municipal Wastewater Analysis

According to the Annual Report on Drug Situation in China,the proportion of synthetic illicit drug abusers among all drug abusers has increased from 28%in 2010 to 60.5%in 2016.Methamphetamine(METH)has become the most serious abused drug in China.The abuse of METH not only does harm to people's health,but also has negative effects on social security and economic development.In this study,wastewater-based epidemiology has been applied to the long-term monitoring of METH abuse in Dalian from 2015 to 2017.Wastewater samples were collected from 11 Wastewater Treatment Plants(WWTPs)over the period.The concentrations of METH and its metabolite amphetamine(AMP)in wastewater samples were analyzed and spatial and temporal profile of METH abuse were back calculated.The concentrations of METH in wastewater samples have showed an overall downward trend.It remained stable between 2015 and 2016 with concentration 409±235 ng/L and 523±549 ng/L,respectively.Then it decreased significantly to only 188±187 ng/L in 2017.The figure for AMP has witnessed an upward trend from 9.44±3.25 ng/L in 2015 to 14.3±15.2 ng/L in 2016 and 34.4±33.8 ng/L in 2017.The source of AMP and METH in wastewater was distinguished that the AMP and METH were from illegal abuse with less than 1%potential impact of legal source.The population estimation model has been conducted by using ammonia nitrogen(NH4-N)population,cotinine(COT)population,and design capacity and flow rate.The consumption of METH was calculated based on the population estimation.Average METH consumption showed a stable level from 2015(457±134 ?g/day)to 2016(454±328 ?g/day),followed by a significant decline in 2017(220±220 ?g/day).It is estimated that the total amount of METH abuse in Dalian was about 1310 kg in 2015-2016,while it declined to 633 kg in 2017.Meanwhile the estimated number of METH abusers was about 86,000 in 2015-2016 and 41,500 in 2017.The results showed that the trend of MTEH abuse has been controlled effectively and efficiently by the government policies,such as online supervise system on drug abusers,anti-drug education on teenagers,crack-down on criminal forces and the control plan of precursor drugs.Monte Carlo simulation was used to calculate the uncertainty and sensitivity of the consumption and prevalence rate of METH during the sampling period in Dalian.The results show that the uncertainty of the final result is mainly due to individual difference of METH abusers,which means population model used in wastewater analysis can effectively reduce the uncertainty of the final result in the long-term monitoring of addictive substances abuse.Meanwhile it also has the advantages of real-time,time-saving,and giving the objective and accurate results.