Occurrence of pharmaceuticals and cocaine in a Brazilian coastal zone

Highlights

• Pharmaceuticals and cocaine were assessed in a subtropical coastal zone

• Acetaminophen, caffeine, diclofenac, ibuprofen, losartan and valsartan were quantified

• Ibuprofen showed highest concentration in order of μg·L^− 1

• Cocaine and benzoylecgonine were both quantified in all of the samples

Abstract

The present study determined environmental concentrations of pharmaceuticals, cocaine, and the main human metabolite of cocaine in seawater sampled from a subtropical coastal zone (Santos, Brazil). The Santos Bay is located in a metropolitan region and receives over 7367 m³ of wastewater per day. Five sample points under strong influence of the submarine sewage outfall were chosen. Through quantitative analysis by LC–MS/MS, 33 compounds were investigated. Seven pharmaceuticals (atenolol, acetaminophen, caffeine, losartan, valsartan, diclofenac, and ibuprofen), an illicit drug (cocaine), and its main human metabolite (benzoylecgonine) were detected at least once in seawater sampled from Santos Bay at concentrations that ranged from ng·L^− 1 to μg·L^− 1. In light of the possibility of bioaccumulation and harmful effects, the high concentrations of pharmaceuticals and cocaine found in this marine subtropical ecosystem are of environmental concern.

Introduction

As the world's population grows and becomes more concentrated in coastal zones, marine ecosystems become further exposed to both treated and untreated wastewater discharges composed of a mixture of emerging contaminants that includes bioactive compounds.

Drugs consumption is often associated with longevity and stressful lives, particularly in urban areas. Advances in medicine, the significant growth of chemistry and pharmaceutical companies, and changes in social conditions have all led to the more widespread use of pharmaceuticals and psychotropic substances (Borova et al., 2014).

In recent years, pharmaceuticals and personal care products (PPCPs) have been considered emerging contaminants of great concern to environmental protection agencies, such as the USEPA and Environment Canada (USEPA – United States Environmental Protection Agency, 2010, Environment Canada, 2011). As reported by Petrie et al. (2015), the presence of PPCPs in the environment is mainly attributed to the discharge of wastewater from WWTPs because conventional processes are not designed to remove such compounds, resulting in their discharge to receiving surface waters including rivers, lakes and coastal waters. There is accumulating evidence that domestic sewage carries PPCPs and illicit drugs into aquatic ecosystems, even after passing through wastewater processing facilities (Zuccato et al., 2008, Terzic et al., 2010, Gilbert, 2011, Baker et al., 2012, Baker and Kasprzyk-Hordern, 2013, Borova et al., 2014, Zenobio et al., 2015).

Most of the efforts to assess PPCPs occurrence and potential impacts on non-target organisms in aquatic environments have been focused in freshwater rivers and streams heavily impacted by wastewater effluent. However, because urban estuarine and marine environments typically receive inputs of complex mixtures of chemical contaminants from a variety of sources, including numerous municipal and industrial wastewater outfalls, characterization of PPCP concentrations in these environments is also important (Klosterhaus et al., 2013). A large number of analytical methodologies are available for their determination in surface waters, and recent trends are focused toward the development and application of generic methods that permit simultaneous analysis of multiclass compounds, including acidic, neutral, and basic pharmaceuticals (Gros et al., 2009).

Previous studies have observed PPCPs, as well as illicit drugs and their metabolites in marine environments (Maranho et al., 2015a, Klosterhaus et al., 2013, Fang et al., 2012, Weigel et al., 2002, Weigel et al., 2004). Such compounds have been found at low concentrations in surface waters (ng·L^− 1), but they are continually released into ecosystems. This steady flow contributes to their persistence and potential adverse effects (Andreu et al., 2016, Alygizakis et al., 2016). Concerning specifically illicit drugs and their breakdown products, occurrences in regions of production and use and areas with insufficient wastewater treatment are not well studied (Rosi-Marshall et al., 2015).

In light of the lack of data on the occurrence of pharmaceuticals and illicit drugs in tropical coastal zones, the main objective of this study was to measure the presence of 33 emerging contaminants, including pharmaceuticals, cocaine, and its main metabolite benzoylecgonine in water samples from the Santos Bay (São Paulo, Brazil).