Elsevier

Science of The Total Environment

Volume 636, 15 September 2018, Pages 975-984
Science of The Total Environment

Pharmaceutically active compounds in the Xiangjiang River, China: Distribution pattern, source apportionment, and risk assessment

https://doi.org/10.1016/j.scitotenv.2018.04.267Get rights and content

Highlights

  • First investigation of categories of PhACs on the Xiangjiang River

  • Urban areas were heavier impacted by pharmaceuticals than rural areas.

  • Distribution of PhACs was closely related to the temperature and NH3-N.

  • Domestic sewage was the major contribution of PhACs on the surface water.

  • Both single and mixture risk approaches were used to evaluate the aquatic risks.

Abstract

The occurrence of 36 pharmaceutically active compounds in surface water of the Xiangjiang River was investigated in two seasons (n = 38). Twenty-five of these compounds were detected, with cefotaxime (maximum concentration 830 ng L−1) the most abundant compound followed by amoxicillin (maximum concentration 710 ng L−1). The spatiotemporal distribution was observed; indicating that pollution hotspots were mostly located in economically developed and densely populated regions such as Changsha City. Lower concentrations were found in summer than winter, which may be attributed to the dilution effect of a flood event and higher water temperatures. The distribution of pharmaceuticals was significantly correlated with temperature and ammonia nitrogen content. A principal component analysis-multiple linear regression model estimated that domestic sewage was the main source of pharmaceuticals, although the source composition varied among different sampling sites. Risk assessment was conducted using both individual and mixture models for preliminary identification of potential hazards. Sulfamethoxazole, clarithromycin, and azithromycin posed a high risk to algae, while sulfamethoxazole, trimethoprim, and erythromycin-H2O showed a medium risk to invertebrates. Moreover, the mixture risk quotients calculated using a concentration addition model ranged from 0.31 to 9.60 in winter, and from 0.06 to 0.61 in summer, indicating a potential risk to the aquatic environment. This study provides scientific support to policy-makers to establish contaminant management priorities and enriches the global data on emerging contaminants.

Introduction

River systems often serve as important drinking water sources; simultaneously, they are among the most vulnerable water bodies due to natural and anthropogenic activities (Zhang et al., 2010). As reported in a worldwide study, over 65% of the rivers in the world are polluted (Vorosmarty et al., 2010). Emerging contaminants, especially pharmaceutically active compounds (PhACs), which were widely used in agricultural practices, as veterinary additives, and in human health care (Barceló and Petrovic, 2007), heavily impact water quality.

Even at trace levels, PhACs exhibit undesired biologically active effects on non-target organisms (Zhou et al., 2016). For example, ciprofloxacin may interfere with the photosynthesis pathway of higher plants, leading to morphological abnormalities or growth inhibition (Aristilde et al., 2010). Diclofenac also has high antiovulatory effects on aquatic vertebrates (Yokota et al., 2015). In addition, previous studies have provided evidence that the prevalence of antibiotics in water bodies was strongly correlated with the population of antibiotic-resistant bacteria and they can also promote the generation of antibiotic resistance genes (Jiang et al., 2013; Varela et al., 2014; Zhang et al., 2014). These genes could be shared between microorganisms, animals, and even to humans, through horizontal gene transfer (Liu and Wong, 2013).

There is a knowledge gap regarding the environmental implications of chemical mixtures since most risk assessments have been based on individual compound (Ding et al., 2017). It should be noted that PhACs are unlikely to exist as independent constituents, a broad range are applied in combination at any real sites (Lopez-Serna et al., 2012; Paiga et al., 2016), engendering a serious mixture effect referred to as the “cocktail effect” (Du et al., 2017). Backhaus and Faust (2012) introduced a tiered assessment approach, which introduces first tier screening for chemical mixtures to determine whether more elaborate mixture risk assessment is needed. Since then, certain studies have paid close attention to the environmental implications of chemical mixtures (Backhaus and Karlsson, 2014; Liu et al., 2015; Yao et al., 2017).

To date, several studies have focused on the occurrence of PhACs in the estuary (Yan et al., 2015; Zhao et al., 2017), central and lower areas of the Yangtze River (Wu et al., 2014). These studies give rise to concerns over the potential effects of pharmaceuticals in drinking water sources. However, data that characterize the sources, exposure, and effects of pharmaceuticals in this area are still very limited. In addition, tributaries can be important contributions to pollution in the main stream. To our knowledge, no study has ever systematically addressed the pharmaceutical contaminants in the Xiangjiang River, which is a main tributary of the Yangtze River. The Xiangjiang River is 856 km in length with a catchment area of 94,660 km2, of which 90.2% is located in the Hunan Province. >40 million people live along the river bank. It is an important water resource for drinking, irrigation, industry, fisheries, and transportation. It is also the most important economic belt in the Hunan Province, and is responsible for 70% of the gross domestic product (GDP) of the province. However, water pollution in the Xiangjiang River is markedly exacerbated by increasing population, booming economy, and accelerated urbanization during recent years (Xie, 2016).

In this context, this study focused on the spatiotemporal distribution of multi-residue PhACs, which are frequently used for human and animal purposes in proximity to the Xiangjiang River. The linkages between PhAC concentrations and water quality parameters were explored. Potential pollution sources were also interpreted based on the concentration profile. In addition, both the single compound ecological risks and the mixture risks were evaluated for the aquatic environment. This work will serve to enrich the inventories of pharmaceutical pollution on a global scale, elucidate whether aquatic organisms are at risk, and help identify potential PhAC sources in the study region.

Section snippets

Chemicals and reagents

Thirty-six PhACs with high purity grade (>98%) and obtained from Dr. Ehrenstorfer GmbH (Augsburg, Germany), were selected as the targets in this study. Detailed information on the physico-chemical properties is provided in Table S1. Surrogate standards (purity > 99%), including sulfamethoxazole-D4, sulfamethazine-D4, ciprofloxacin-D8, ibuprofen-D3, roxithromycin-D7, and thiabendazole-D4, were purchased from Toronto Research Chemicals (Oakville, Canada), and meclocycline was obtained from

Occurrence and concentrations of PhACs

Among the 36 investigated compounds, 25 of them were detected during the two sampling campaigns, indicating their ubiquitous presence in the Xiangjiang River. The compounds which were not detected or concentrations below the MDL in all samples are not discussed in this study. These include sulfathiazole, sulfamerazine, sulfaquinoxaline, difloxacin, pefloxacin, tetracycline, chlortetracycline, doxycycline, tylosin, naproxen, and ketoprofen.

As shown in Table 1, the mean concentrations of PhACs in

Conclusion

In this study, the first investigation of the seasonal variation and spatial distribution of 36 PhACs was conducted on the Xiangjiang River. Twenty-five compounds were detected with concentrations ranging from ND to 830 ng L−1 (cefotaxime). Pharmaceutical contaminant levels were moderate compared with previously reported data on a global scale. Higher temperature and the dilution effect of stream flow in summer could be responsible for the dramatic seasonal variation of most compounds (p

Acknowledgement

This work was financially supported by the Special Fund for Agro-scientific Research in the Public Interest (No. 201503108) and Science & Technology Project of Hunan Province (No. 2017WK2091).

References (61)

  • J.J. Jiang et al.

    Source contributions and mass loadings for chemicals of emerging concern: Chemometric application of pharmaco-signature in different aquatic systems

    Environ. Pollut.

    (2016)
  • Y. Kim et al.

    Effect of runoff discharge on the environmental levels of 13 veterinary antibiotics: a case study of Han River and Kyungahn Stream, South Korea

    Mar. Pollut. Bull.

    (2016)
  • C.I. Kosma et al.

    Occurrence and removal of PPCPs in municipal and hospital wastewaters in Greece

    J. Hazard. Mater.

    (2010)
  • K. Kummerer

    Antibiotics in the aquatic environment-a review-part I

    Chemosphere

    (2009)
  • G.M. Lalumera et al.

    Preliminary investigation on the environmental occurrence and effects of antibiotics used in aquaculture in Italy

    Chemosphere

    (2004)
  • W. Li et al.

    Occurrence of antibiotics in water, sediments, aquatic plants, and animals from Baiyangdian Lake in North China

    Chemosphere

    (2012)
  • N. Li et al.

    Occurrence, seasonal variation and risk assessment of antibiotics in the reservoirs in North China

    Chemosphere

    (2014)
  • J.L. Liu et al.

    Pharmaceuticals and personal care products (PPCPs): a review on environmental contamination in China

    Environ. Int.

    (2013)
  • J. Liu et al.

    Occurrence, bioaccumulation and risk assessment of lipophilic pharmaceutically active compounds in the downstream rivers of sewage treatment plants

    Sci. Total Environ.

    (2015)
  • R. Lopez-Serna et al.

    Occurrence and distribution of multi-class pharmaceuticals and their active metabolites and transformation products in the Ebro river basin (NE Spain)

    Sci. Total Environ.

    (2012)
  • V. Osorio et al.

    Concentration and risk of pharmaceuticals in freshwater systems are related to the population density and the livestock units in Iberian Rivers

    Sci. Total Environ.

    (2016)
  • P. Paiga et al.

    Presence of pharmaceuticals in the Lis river (Portugal): sources, fate and seasonal variation

    Sci. Total Environ.

    (2016)
  • H. Pan et al.

    A comprehensive analysis of heavy metals in urban road dust of Xi'an, China: contamination, source apportionment and spatial distribution

    Sci. Total Environ.

    (2017)
  • A.K. Sarmah et al.

    A global perspective on the use, sales, exposure pathways, occurrence, fate and effects of veterinary antibiotics (VAs) in the environment

    Chemosphere

    (2006)
  • A.R. Varela et al.

    Insights into the relationship between antimicrobial residues and bacterial populations in a hospital-urban wastewater treatment plant system

    Water Res.

    (2014)
  • C. Wu et al.

    Occurrence of pharmaceuticals and personal care products and associated environmental risks in the central and lower Yangtze river, China

    Ecotoxicol. Environ. Saf.

    (2014)
  • W.H. Xu et al.

    Determination of selected antibiotics in the Victoria Harbour and the Pearl River, South China using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

    Environ. Pollut.

    (2007)
  • H. Xu et al.

    Assessing the influence of rain gauge density and distribution on hydrological model performance in a humid region of China

    J. Hydrol.

    (2013)
  • C. Yan et al.

    Selected emerging organic contaminants in the Yangtze Estuary, China: a comprehensive treatment of their association with aquatic colloids

    J. Hazard. Mater.

    (2015)
  • Y.Y. Yang et al.

    Suitability of pharmaceuticals and personal care products (PPCPs) and artificial sweeteners (ASs) as wastewater indicators in the Pearl River Delta, South China

    Sci. Total Environ.

    (2017)
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