Anthropogenic disturbances on distribution and sources of pharmaceuticals and personal care products throughout the Jinsha River Basin, China

Highlights

• Complex sources and distribution of PPCPs were studied along large-scale rural river.

• PPCPs were ubiquitous but present at relative low levels in the Jinsha River.

• Due to human habitation, PPCP distribution varied across the “Hu Huanyong” line.

• Land use index reflected major PPCP sources in less urbanized area.

• This study has implications for the PPCP management in rural areas worldwide.

Abstract

Pharmaceuticals and personal care products (PPCPs) are recognized as a group of emerging contaminants closely related to anthropogenic activities, which capture increasing attention worldwide. To evaluate the anthropogenic disturbances on PPCP distribution and sources, this study investigated the distribution and sources of 50 PPCPs along the 2300 km long Jinsha River and revealed different anthropogenic disturbances on PPCPs. Results showed that 40 out of the 50 PPCPs were ubiquitously detected among these river water samples, with the concentrations varied from less than 1 ng/L to more than 500 ng/L. Although most PPCPs concentrations were much lower in the Jinsha River than in highly developed rivers, the prevalence of PPCPs suggested the widespread use and improper disposal of PPCPs in the Jinsha River. The risk assessment also revealed that some PPCPs posed risks to aquatic organisms in the Jinsha River. Anthropogenic activities including human habitation and dam construction had different influence on PPCPs. PPCP distribution varied significantly across the “Hu Huanyong line”, indicating human habitation significantly influenced PPCP distribution. Dam construction was insignificant in altering PPCP distribution throughout the Jinsha River. Moreover, the land use index indicated degradation level of multiple lands related to anthropogenic activities and represented the major sources of PPCPs in the Jinsha River. Most PPCPs were correlated with anthropogenic lands, for example, antibiotics, analgesics, and endocrine disrupting chemicals mainly originated from artificial surfaces, whereas other PPCPs mainly originated from cultivated lands. Together, this study indicates the disturbances of multiple anthropogenic activities on PPCP distribution and sources along the Jinsha River, which contributes to PPCP management in rural areas.

Introduction

Pharmaceutical and personal care products (PPCPs) are a group of emerging contaminants that include prescription, nonprescription, and veterinary drugs as well as chemical ingredients of personal health and cleaning products (Boxall et al., 2012; Daughton, 2016). PPCPs have increasingly raised concerns since they are extensively used and continuously released into river ecosystems, and consequently cause a series of adverse effects including endocrine disruption, antibiotic resistance and even decline of biodiversity (Rosi-Marshall and Royer, 2012; Tijani et al., 2016). To assess and mitigate the human health and ecological risks of PPCPs, their sources and distribution patterns in river systems have been documented globally since the 1990s (Daughton, 2016). PPCPs enter river water primarily through wastewater treatment plants, and their contamination of river water is ubiquitous, with levels ranging from nano-to micrograms per liter (Aus et al., 2016; Burns et al., 2018; Wu et al., 2014). Despite some PPCPs are not inherently persistent in the environment, PPCPs are regarded as “pseudo-persistent” contaminants due to their sustained discharge and partial metabolism (Ellis, 2006; Ternes et al., 2004). These ubiquitous chemicals may lead to severe aquatic pollution worldwide with chronic exposure even at a low concentration (Peng et al., 2018; Santos et al., 2010; Wilkinson et al., 2017).

Anthropogenic activities play a critical role in PPCP contamination in the environment. Previous investigations indicated that the PPCP contamination was mainly associated with anthropogenic activities including the treatment and discharge of municipal sewage and industrial wastewater, livestock breeding, aquaculture, and landfill, leading to the presence of PPCPs in an aquatic environment (Xu et al., 2019; Yang et al., 2020). Meanwhile, different PPCP categories are variously related to different anthropogenic activities. For instance, therapeutic PPCPs have been generally considered to be related to the medical treatment level, and the elevated concentrations have been detected in the receiving water nearby hospitals (Spongberg et al., 2011). The agricultural activities, such as pesticide application, livestock rearing, and manure application, have been reported to release agricultural herbicides and pesticides into the aquatic environment (Fairbairn et al., 2015). However, most of previous studies have focused on a single class of PPCPs and associated anthropogenic activities, a comprehensive investigation was lack to establish the link between large class of PPCP categories with multiple anthropogenic activities, especially at large-scale watershed.

The Jinsha River is the upper reach of the Yangtze River in southwestern China. Most areas along this river are less urbanized, and it therefore serves as an important ecological barrier in China (Jun et al., 2013). Pollution in the Jinsha River deteriorates the downstream water quality of the Yangtze River and threatens both public health and ecosystems (Wang et al., 2015b). Since the Jinsha River Basin is large and located in a mountainous region (Zhou et al., 2018), sample collection is difficult, and its pollution condition has consequently been poorly investigated. Previous studies have revealed only heavy metal contamination, nutrients, and polycyclic aromatic hydrocarbon in some parts of the Jinsha River (Jun et al., 2003; Teng et al., 2011). However, the distribution of large PPCP classes along the entire Jinsha River Basin has not been explored. The Jinsha River has been subject to increasing anthropogenic activities, especially human habitation and dam construction, which may be regarded as potential sources of PPCPs. The Jinsha River originates in a pristine area and flows through the famous “Hu Huanyong line”, which delineates the striking difference in the distribution of China's population. With increasing human habitation, more PPCPs may be discharged into the river. The operation and management activities of hydropower stations might serve as another source of PPCPs, since these contaminants enter the environment through the activities of the staff in hydropower management station (Olsen et al., 2009). However, the influence of anthropogenic activities on PPCP distribution and sources along the Jinsha River remains unclear.

Land use patterns (including agricultural, urban, grassland and other land use) provides strong evidence of anthropogenic conditions along rivers, and land use can affect aquatic ecosystems via erosive processes (Likens and Bormann, 1974). As different PPCPs are discharged into rivers via multiple anthropogenic pathways (Liu and Wong, 2013), land use patterns may reflect the influence of multiple anthropogenic activities on PPCP composition, and may indicate potential PPCP sources in the river. Therefore, it is hypothesized that PPCP distribution and sources may be associated with land use patterns at large-scale watershed.

To test this hypothesis and address the abovementioned gap in knowledge, this study aimed to (1) provide an overview of the occurrence and concentrations of different PPCP categories in the surface water of the entire Jinsha River, (2) determine the impact of anthropogenic activities on PPCP distribution along the river, and (3) investigate PPCP sources (focusing on land use patterns) based on a statistical approach.