Article pubs.acs.org/est
Psychoactive Pharmaceuticals in Sludge and Their Emission from Wastewater Treatment Facilities in Korea Bikram Subedi,† Sunggyu Lee,‡ Hyo-Bang Moon,‡ and Kurunthachalam Kannan*,† †
Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O. Box 509, Albany, New York 12201-0509, United States ‡ Department of Marine Sciences and Convergent Technology, College of Science and Technology, Hanyang University, Ansan 426-791, Republic of Korea S Supporting Information *
ABSTRACT: Concern over the occurrence of pharmaceuticals and their metabolites in the environment is mounting due to the potential adverse effects on nontarget organisms. This study draws upon a nationwide survey of psychoactive pharmaceuticals (i.e., antischizophrenics, anxiolytics, and antidepressants) in sludge from 40 representative wastewater treatment plants (WWTPs) that receive domestic, industrial, or mixed (domestic plus industrial) wastewaters in Korea. A total of 16 psychoactive pharmaceuticals (0.12−460 ng/g dry weight) and nine of their metabolites (0.97−276 ng/g dry weight) were determined in sludge. The median concentrations of psychoactive drugs in sludge from domestic WWTPs were 1.2−3.2 times higher than the concentrations found in WWTPs that receive combined domestic and industrial wastewaters. Among the psychoactive drugs analyzed, the median environmental emission rates of alprazolam (APZ) and carbamazepine (CBZ) through domestic WWTPs (both sludge and effluent discharges combined) were calculated to be ≥15.5 μg/capita/day, followed by quetiapine (QTP; 8.51 μg/ capita/day), citalopram (CLP; 5.45 μg/capita/day), and venlafaxine (VLF; 3.59 μg/capita/day). The per-capita emission rates of some of the metabolites of psychoactive drugs through WWTP discharges were higher than those calculated for parent compounds. Significant correlations (ρ = 0.432−0.780, p < 0.05) were found between the concentrations of typically coprescribed antischizophrenics and antidepressants in sludge. Multiple linear regression analysis of measured concentrations of drugs in sludge revealed that several WWTP parameters such as treatment capacity, population-served, sludge production rate, composition of wastewater (domestic versus industrial), and hydraulic retention time can affect the concentrations of psychoactive drugs in sludge.
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INTRODUCTION Pharmaceuticals that are designed and administered for biological or physiological effects in humans and/or animals are excreted, either unchanged or metabolized, down the drain and eventually reach wastewater treatment plants (WWTPs).1−3 Incomplete removal of pharmaceuticals in WWTPs can result in the introduction of these bioactive chemicals into the aquatic environment. In WWTPs, sorption to sludge plays a significant role in the removal of pharmaceuticals from the aqueous phase. The sludge is used in the production of biosolids, which are applied as fertilizers in agriculture. This process can reintroduce pharmaceuticals and their metabolites into the terrestrial environment.4,5 Thus, biosolids can act as reservoirs or sinks for pharmaceuticals.6 The U.S. National Research Council reported a lack of information on pharmaceuticals in biosolids and recommended the need for further research on bioactive chemicals in sludge.7 The U.S. Environmental Protection Agency (EPA) has estimated that ∼8 × 106 tons of dry biosolids are applied as a fertilizer in agriculture in the United States annually.8 The proportion of biosolids applied in agriculture has increased from 36% in 1988 to ∼55% in 2004 of the total production.8,9 In 14 Western European countries, ∼2.5× 106 tons of dry © 2013 American Chemical Society
biosolids (38% of total) are applied as a fertilizer in agriculture every year.10 Psychoactive pharmaceuticals such as antischizophrenics, sedatives−hypnotics−anxiolytics (including antiepileptics), and antidepressants are among the most widely prescribed pharmaceuticals globally; 15 of these drugs are among the 200 most-prescribed drugs in the United States.11 Psychoactive pharmaceuticals such as APPZ (in 2002) and QTP (in 1997) were ranked ≤4 and ≤100, respectively, among the mostprescribed pharmaceuticals in the United States in 2011−2013 (http://www.drugs.com/stats). The global annual production of APZ, DZP, OxZP, and LZP were 7 (2006), 76 (1990− 1999), 12 (2006), and 25 tons (2006), respectively.12 Despite this high-volume production and consumption, little is known about the occurrence of psychoactive pharmaceuticals in environmental matrices. Antipsychotics have been reported in drinking water,13 surface water,14 river water,15 WWTP discharges,16−18 and hospital effluents16 at ng/L to μg/L levels. Received: Revised: Accepted: Published: 13321
September 16, 2013 October 21, 2013 October 28, 2013 October 28, 2013 dx.doi.org/10.1021/es404129r | Environ. Sci. Technol. 2013, 47, 13321−13329
Environmental Science & Technology
Article
Sample Collection and Preparation. A total of 40 sludge samples were collected from WWTPs in South Korea during July through October 2011. WWTPs were selected to represent various regions (four cities and seven provinces), watersheds (four rivers and three seas), treatment capacity (WTC: 1048− 957 782 m3/day), and population-served (IE: 128−3 622 800). On the basis of the proportion of industrial water inflow, WWTPs were categorized as domestic (WWTPD = 0−3% industrial wastewater), mixed (WWTPM = 20−60%), and industrial (WWTPI >70%). The major sources of influent, WTC (m3/day), IE, sludge production rate (ASP: tons/year), proportion of industrial wastewater (IWW: %), and hydraulic retention time (HRT: h) of the studied WWTPs are provided in Table S1 of the Supporting Information. The sludge samples were collected from each WWTP on three different days, pooled, and homogenized to obtain representative samples. All samples were collected in precleaned polypropylene bottles, shipped to the laboratory in Albany, New York, in dry ice, and stored in a freezer at −20 °C until extraction. Sludge samples were analyzed by following the method described earlier, with some modifications.35 Briefly, ∼0.1 g of freeze-dried sludge samples were spiked with a mixture of internal standards (25 ng) and allowed to equilibrate for ∼30 min at room temperature. Spiked sludge samples were vortexmixed for 1 min and extracted with 6 mL of methanol:water mixture (5:3 v/v) using an ultrasonic bath (Branson Ultrasonics 3510R-DTH; Danbury, CT) for 30 min. Extracts were centrifuged at 4500 rpm for 5 min (Eppendorf Centrifuge 5804, Hamburg, Germany), the supernatant was collected in a polypropylene tube, and the extraction was repeated. The extracts were combined and concentrated to ∼1 mL under a gentle stream of nitrogen. The concentrated extract was diluted with milli-Q water to ∼6 mL and purified by passage through Oasis HLB 6 cc (200 mg; Waters, Milford, MA) cartridges. Prior to use, the cartridges were conditioned with 3 mL of methanol and 3 mL of milli-Q water; the extracts were loaded at ∼1 mL/min. Cartridges were allowed to dry for ∼30 min under vacuum and eluted with 2 × 5 mL of methanol. The eluent was concentrated to ∼500 μL under a gentle stream of nitrogen at 35 °C, using a TurboVap Evaporator (Zymark, Inc., MA). The final volume of the extract was adjusted to 1 mL in an amber glass vial, and 10 μL of the extract was injected into HPLC-MS/MS. Instrumental Analysis. Target chemicals were analyzed using an API 2000 electrospray triple quadrupole mass spectrometer (ESI-MS/MS; Applied Biosystems, Foster City, CA), interfaced with an Agilent 1100 Series HPLC system (Agilent Technologies, Santa Clara, CA). The analytes were separated using a Hypersil Gold column (150 mm × 2.1 mm, 3 μm) (Thermo Scientific, Chelmsford, MA). Methanol and water (0.1% formic acid) were used as mobile phases; a description of the gradient flow is presented in Table S2 of the Supporting Information. Target analytes were determined by multiple-reaction monitoring (MRM) in positive ionization mode. Detailed information on the MS/MS transitions is provided in the Supporting Information (Table S3). The quantitation of pharmaceuticals was based on the isotope dilution method. However, metabolites were quantified using the internal standards of the corresponding parent compound (due to the lack of labeled standards available for the metabolites), and BPP was quantified using VLF-D8. The concentrations of metabolites and BPP were not corrected for the recoveries of corresponding internal standards. Seven to
However, studies on the occurrence of psychoactive pharmaceuticals and their metabolites in biosolids are limited.19 Concentrations of a few psychoactive pharmaceuticals have been reported in biosolids from the United States,20 Canada,5 and France.21 Recent studies have reported the dissipation of psychoactive pharmaceuticals in agricultural soils22 and the uptake of these chemicals by plants.23 Biotransformation and bioaccumulation of psychoactive drugs in soil-dwelling organisms also have been reported.24 Nevertheless, concentrations and profiles of a wide range of psychoactive drugs, such as APPZ, QTP, LZP, and their metabolites, such as DAAPZ, NQTP, NSTL, NDZP, and DCLP, have not been reported in biosolids. Little is known about the toxicity of psychoactive pharmaceuticals on nontarget organisms.25 The physiological processes that are controlled by serotonin, such as reproduction, swimming, and feeding behavior in fish, induction of spawning in bivalves, and swimming behavior in annelids, were altered from exposure to psychoactive drugs such as STL and DZP.26,27 The EC50 levels of DZP in daphnia, algae, and fish were 2, 5.5, and 28 mg/L, respectively.28 In Japanese medaka (Oryzias latipes), egg production decreased after exposure to 0.5 mg/L of PPN.29 Some psychoactive drugs that are excreted unchanged or as metabolites can be pharmacologically equipotent.30−32 For example, 10,11-epoxycarbamazepine, a metabolite of CBZ, has a mechanism of toxicity similar to CBZ.33 Therefore, monitoring of active metabolites of pharmaceuticals in biosolids is essential for a complete understanding of potential risks.34 This is the first nationwide study to identify the occurrence of psychoactive pharmaceuticals and their select metabolites in sludge from WWTPs in Korea. The psychoactive pharmaceuticals and their select metabolites were determined in sludge from WWTPs that receive industrial and domestic wastes. The environmental emissions of the psychoactive drugs through the discharge of sludge and wastewater effluent were calculated. Environmental emission rates were estimated based on the concentrations determined in sludge, and the concentrations estimated for effluents were based on the reported sludge-water partition ratios of target compounds. Finally, factors affecting the concentrations of psychoactive drugs in sludge were investigated by multiple linear regression analysis of WWTP parameters such as treatment capacity, population-served, sludge production rate, composition of waste (industrial versus domestic), and hydraulic retention time.
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MATERIALS AND METHODS Reagents and Chemicals. Standard stock solutions (100 or 1000 μg/mL) of individual pharmaceuticals, VLF, BPP, STL, NSTL, DZP, NDZP, OxZP, DPH, APZ, AHA, CLP, DCLP, LZP, QTP, NQTP, APPZ, DAPPZ, CBZ, CPG, CPGA, and PPN-D7, were purchased from Cerilliant (Round Rock, TX). Isotope-labeled standards, VLF-D6, STL-D3, DZP-D5, DPH-D3, APZ-D5, CLP-D6, LZP-D4, QTP-D8 hemifumarate, APPZ-D8, and CBZ-D10, also were purchased from Cerilliant. PPN, DTZ, VPM, CFI, NVP, and CFI-13C3 were purchased from SigmaAldrich (St. Louis, MO). DPMA was purchased from Enamine (Monmouth, NJ) and DTZ-D3, VPM-D6, CPG-D4, and DAD from Santa Cruz Biotechnology, Inc. (Dallas, TX). Purity of all of the standards was ≥95%. Formic acid (98.2%) was from Sigma-Aldrich. Ultrapure water was prepared with the milli-Q ultrapure system (Barnstead International, Dubuque, IA). All standard stock solutions were stored at −20 °C. 13322
dx.doi.org/10.1021/es404129r | Environ. Sci. Technol. 2013, 47, 13321−13329
Environmental Science & Technology
Article
Table 1. Concentration of Select Psychoactive Pharmaceuticals and Their Metabolites in Sludge from Korean WWTPs (ng/g dry wt)a industrial WWTP analyte
LOQ
antischizophrenics aripiprazole (APPZ) 0.5 dehydro-aripiprazole 0.5 (DAPPZ) quetiapine (QTP) 0.5 norquetiapine 5.0 (NQTP) sedatives−hypnotics−anxiolytics lorazepam (LZP) 0.5 alprazolam (APZ) 5.0 α-hydroxy alprazolam 5.0 (AHA) diazepam (DZP) 1.0 oxazepam (OXZP) 1.0 nordiazepam (NDZP) 1.0 carbamazepine 1.0 (CBZ) antidepressants venlafaxine (VLF) 0.1 bupropion (BPP) 0.5 sertraline (STL) 1.0 norsetraline (NSTL) 10 citalopram (CLP) 1.0 N-desmethyl 20 citalopram (DCLP) antihypertensions propranolol (PPN) 1.0 diltiazem (DTZ) 1.0 desacetyl diltiazem 0.5 (DAD) verapamil (VPM) 0.5 norverapamil (NVP) 0.5 antiplatelet clopidogrel (CPG) 1.0 clopidogrel carboxylic 1.0 acid (CPGC) antihistamine diphenhydramine 0.5 (DPH) 2-(diphenylmethoxy) 5.0 acetic acid (DPMA) stimulant caffeine (CFI) 5.0 a
df
mean
median
mixed WWTP range
0/15 0/15
domestic WWTP
df
mean
median
range
df
mean
median
7/9 4/9
4.17 1.39
2.69 1.42
1.08−8.14
