Identification of Poppy Straws as a Special Source of Morphine in Chinese Municipal Wastewater

Abstract

Previous studies have predominantly focused on morphine for clinical use, codeine, and heroin as potential contributors, neglecting the possible contribution from poppy straws in Chinese traditional medicines. To determine the sources of morphine, this study collected influent samples from 150 wastewater treatment plants in 49 cities across the South and North of China for monitoring five substances, including morphine, codeine, 6-acetylmorphine, methadone, and tramadol. Positive matrix factorization (PMF) found that poppy straws (59.1%) and morphine for clinical use (28.5%) were identified as major contributors, while codeine (9.20%) and heroin (3.20%) contributed less. To validate the PMF results, a comparison was made with the International Narcotics Control Board (INCB) survey. The mass load of morphine derived from different sources, as determined by the INCB data survey, fell within the 95% confidence interval calculated by PMF, indicating consistency between the two surveys. Based on the PMF sources, morphine use from poppy straws and clinical purposes was calculated to be 11.8 mg/d/1000 inh and 9.55 mg/d/1000 inh, respectively. Consumption of codeine and heroin was estimated at 9.45 mg/d/1000 inh and 0.64 mg/d/1000 inh, respectively. The quantitative analysis of morphine sources in wastewater provides an accurate assessment of the four sources of morphine in Chinese wastewater.