Fate and environmental risks of 40 pharmaceutically active compounds in the Pearl River basin

The PhACs have attracted massive attention due to their large quantity of consumption, continuous discharge, and ecological risk to aquatic organisms in the receiving aquatic environments. The Pearl River basin serves as an important source of drinking water for many cities in southern China. Prof. Bin Yang from the South China Normal University and their team members have worked jointly and comprehensively investigated the occurrence, fate, and environmental risk of 40 pharmaceutically active compounds (PhACs) from surface waters and sediments in the Beijiang River, Xijiang River, and Maozhou River of the Pearl River basin, South China. Major classes of PhACs in this study included NSAIDs, antidepressants, anxiolytics, and antihypertension drugs. In addition, the seasonal and temporal variations in the concentrations of these PhACs among and between different rivers, along with the environmental risk were evaluated.

Their analysis is published in the journal Frontiers of Environmental Science & Engineering on April 15, 2023.

Pharmaceutically active compounds (PhACs) are widely used in humans and veterinaries to prevent, diagnose, and treat diseases. Major groups of the PhACs include nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, anxiolytics, and hypertension medicines. Most of these drugs have been regarded as emerging organic contaminants in aquatic ecosystems. The PhACs have been frequently detected in surface waters throughout the world at concentrations range of ng/L to μg/L over the past decades. The primary sources of PhACs to aquatic environments are effluents from the wastewater treatment plants (WWTPs), wastewaters from livestock and poultry industries, and sewage wastewater containing optionally disposal of expired or unused drugs.

Among the PhACs, NSAIDs are one of the most frequently used pharmaceuticals globally, and listed among the top 10 persistent pollutants. Widely detected NSAIDs in aquatic environments include ibuprofen, diclofenac, naproxen, ketoprofen, and salicylic acid. Meanwhile, psychotropic pharmaceuticals (PPhs) are widely consumed in the developed countries. Antidepressants and anxiolytics are the most widely detected PPhs in aquatic environments. Numerous studies have shown that many PhACs are toxic to aquatic organisms. Therefore, the environmental risk of PhACs cannot be simply ignored.

The Pearl River basin serves as an important source of drinking water for many cities in southern China. Previous research on the pollution of PhACs in the Pearl River basin has been conducted with one or two sampling campaigns along one main stream with recognized sources of PhACs contamination. This approach could not provide a complete understanding on variations in the frequency of occurrence and the environmental risk of PhACs. Moreover, data on PhACs for multiple rivers in the Pearl River basin by one sampling campaign in each of two seasons in a year are of relatively paucity. The work of Professor Bin Yang's team fills this gap.

In this study, the research team found the average concentrations of detected PhACs in surface waters and sediments ranged from 0.17 to 19.1 ng/L and 0.10 to 10.4 ng/g, respectively. Meanwhile, PhACs concentration in surface waters and sediments varied greatly among and within the Beijiang River, Xijiang River, and Maozhou River. The largest annual flux of PhACs of the Xijiang River and Beijiang River was more than 11 000 kg per annum, whereas only 25.7 kg/a in the Maozhou River. In addition, the estimated emissions of PhACs in the Beijiang River, Xijiang River, and Maozhou River ranged respectively from 0.28 to 4.22 kg/a, 0.12 to 6.72 kg/a, and 6.66 to 91.0 kg/a, and the backestimated usage varied with a range from 12.0 to 293 kg/a, 6.79 to 944 kg/a, 368 to 17 459 kg/a. Moreover, the emissions of PhACs showed a close relationship with the gross domestic product (GDP) of each city along the Pearl River. The environmental risk assessment suggested that diazepam and ibuprofen had a moderate risk in this region.

This study has revealed that PhACs are ubiquitous in the surface waters and sediments of the three major rivers of the Pearl River basin. The concentrations of commonly detected PhACs are comparable to those detected in many other river basins in China, and lower than in other countries. Meanwhile, there is a distinctive spatial and seasonal variation in PhACs occurrence profiles within and among the three river basins. This study can provide important data on the fate and environmental assessment of the PhACs in the Pearl River basin. It is pointed out that a multiple-year monitoring the pollution of PhACs is necessary for a complete understanding of the risk of PhACs in the Pearl River basin.

###

About Higher Education Press

Founded in May 1954, Higher Education Press Limited Company (HEP), affiliated with the Ministry of Education, is one of the earliest institutions committed to educational publishing after the establishment of P. R. China in 1949. After striving for six decades, HEP has developed into a major comprehensive publisher, with products in various forms and at different levels. Both for import and export, HEP has been striving to fill in the gap of domestic and foreign markets and meet the demand of global customers by collaborating with more than 200 partners throughout the world and selling products and services in 32 languages globally. Now, HEP ranks among China's top publishers in terms of copyright export volume and the world's top 50 largest publishing enterprises in terms of comprehensive strength.

The Frontiers Journals series published by HEP includes 28 English academic journals, covering the largest academic fields in China at present. Among the series, 12 have been indexed by SCI, 6 by EI, 2 by MEDLINE, 1 by A&HCI. HEP's academic monographs have won about 300 different kinds of publishing funds and awards both at home and abroad.

About Frontiers of Environmental Science & Engineering

Frontiers of Environmental Science & Engineering (FESE) is the leading edge forum for peer-reviewed original submissions in English on all main branches of environmental disciplines. FESE welcomes original research papers, review articles, short communications, and views & comments. All the papers will be published within 6 months since they are submitted. The Editors-in-Chief are Prof. Jiuhui Qu from Tsinghua University, and Prof. John C. Crittenden from Georgia Institute of Technology, USA. The journal has been indexed by almost all the authoritative databases such as SCI, Ei, INSPEC, SCOPUS, CSCD, etc.