Occurrence and risk assessment of pharmaceuticals and personal care products and endocrine disrupting chemicals in reclaimed water and receiving groundwater in China

Oxidation of β-blockers by birnessite: Kinetics, mechanism and effect of metal ions

Manganese dioxides are ubiquitous in natural waters, soils, and sediments and play an important role in oxidative transformation of organic pollutants. This work presents the kinetics of the oxidation of selected β-blockers, betaxolol, metoprolol, and atenolol by birnessite (δ-MnO₂) as a function of concentration of the β-blocker, dosage of δ-MnO₂, and solution pH. The values of pseudo-first-order rate constants (k_obs) of β-blockers decreased in the order betaxolol > atenolol > metoprolol, which was positively correlated with their acid dissociation constants (K_a). Effect of series of metal ions (Fe³⁺, Cr³⁺, Al³⁺, Pb²⁺, Cu²⁺, Zn²⁺, Ni²⁺, Cd²⁺, Mg²⁺, and Ca²⁺) on the degradation of β-blockers by δ-MnO₂ was systematically examined. All of these metal ions inhibited the oxidation reaction under the same constant ionic strength. The inhibition efficiency was positively correlated with the logarithm of stability constant of metal ions in aqueous solution (logK_MeOH). By LC-ESI-MS/MS analyses, the oxidation of β-blockers primarily involved hydroxylation and cleavage of the parent molecules to the short branched chain compounds. An electron transfer mechanism for the oxidation of β-blockers by δ-MnO₂ was proposed. The oxidation was initiated by the electron transfer from the nonbonding electrons on nitrogen (N-electrons) of β-blockers to δ-MnO₂, followed by transformation of radical intermediates. These findings will help to understand the oxidation processes of β-blockers and predict the effect of metal ions on the removal of pollutants by δ-MnO₂ in the environment.

Targeted eco-pharmacovigilance for ketoprofen in the environment: Need, strategy and challenge

Implementing "targeted" eco-pharmacovigilance(EPV) which focuses on individual or specific pharmaceuticals on a prioritised basis is a feasible, economical and customized approach to reduce the environmental concentrations and risks of pharmaceuticals. Non-steroidal anti-inflammatory drugs(NSAIDs) remaining in environment are a kind of priority hazard substances, due to a notable case that diclofenac residues caused the loss of more than 99% of vultures across the Indian sub-continent. Ketoprofen, as another widely used NSAID with comparable or even higher global consumption than diclofenac, in the environment has been shown to present a potential risk to non-target terrestrial and aquatic species. Based on the review of 85 articles reporting the analyses of ketoprofen residues in environment since 2010, we found that this NSAID frequently present in various environmental compartments around the world. Therefore, it is urgent to implement EPV targeting ketoprofen pollution. Here, we provide some recommendations for implementing the targeted EPV for ketoprofen, including: Closely monitoring ketoprofen in the natural environment; Reducing the residues of ketoprofen through source control; Encouraging urine source separation and treatment; Limiting the application of veterinary ketoprofen; Designing and constituting a framework system of targeted EPV. But some challenges, such as ambiguity in the accountability of the main bodies responsible for continued monitoring of ketoprofen residues, the lack of optimized urine source separation scenarios and procedure, the need for detailed design and application schemes of the framework system of targeted EPV, etc. should be addressed.

Implementing ecopharmacovigilance (EPV) from a pharmacy perspective: A focus on non-steroidal anti-inflammatory drugs

Environmental experts have made great efforts to control pharmaceutical pollution. However, the control of emerged environmental problems caused by medicines should draw more attention of pharmacy and pharmacovigilance researchers. Ecopharmacovigilance (EPV) as a kind of pharmacovigilance for the environment is recognized worldwide as crucial to minimize the environmental risk of pharmaceutical pollutants. But continuing to treat the pollution of pharmaceuticals as a group of substances instead of targeting individual pharmaceuticals on a prioritized basis will lead to a significant waste of resources. Considering vulture population decline caused by non-steroidal anti-inflammatory drugs (NSAIDs) residues, we presented a global-scale analysis of 139 reports of NSAIDs occurrence across 29 countries, in order to provide a specific context for implementing EPV. We found a heavy regional bias toward research in Europe, Asia and America. The top 5 most frequently studied NSAIDs included ibuprofen, diclofenac, naproxen, acetaminophen and ketoprofen. The profile of NSAIDs was dominated by acetaminophen in wastewater influents and effluents. Ibuprofen was the most abundant NSAID in surface water. Only 9 NSAIDs were reported in groundwater samples. And majority of NSAIDs were detected in solid matrices at below 1μg/g except for ketoprofen, diclofenac and ibuprofen. From a pharmacy perspective, we get some implication and propose some management practice options for EPV implementation. These include: Further popularizing and applying the concept of EPV, together with developing relevant regulatory guidance, is necessary; More attention should be paid to how to implement EPV for the pollution control of older established drugs; Triggering "a dynamic watch-list mechanism" in conjunction with "source control"; Implementing targeted sewage treatment technologies and strengthening multidisciplinary collaboration; Pharmaceutical levels in aquatic organisms as biological indicators for monitoring pharmaceutical pollution within the water environment; Upgrading drinking water treatment plants with the aim of removing pharmaceutical residues; Paying more attention to EPV for pharmaceuticals in solid matrices.

Toxicity study of reclaimed water on human embryonic kidney cells

The importance of evaluating the toxic effects associated with the use of reclaimed water has been increasing. The purpose of this research was to investigate the cytotoxicity and molecular toxicity of reclaimed water on the human embryonic kidney 293 (HEK293) cells. The culture medium was synthesized using the reclaimed water samples. Wastewater treatment plant influent (WTI) and effluent (WTE), containing micropollutants at the nanogram per liter level, decreased cell proliferation (93.4-98.9% and 91.5-96.6% of the control, respectively) and increased cell damage (103.6-117.5% and 100.7-109% of the control, respectively) at all exposure times, except for a decrease in cell damage observed after an 8-h exposure to WTE. Membrane bioreactor permeate (MBRP) increased cell proliferation (102.1-106.7% of the control) and decreased cell damage at 8 and 12 h (92.4 and 98.4% of the control, respectively), but slightly increased cell damage at 24 h and later time points (101.1-104.9% of the control). All three water samples induced cell apoptosis (120.9-123.4% of the control). They also affected the expression of cell-cycle regulatory proteins (p16^INK4a, p27^Kip1, cyclin-dependent kinases 2 and 4, cyclin D1, and cyclin E) and apoptosis-related regulatory proteins (p-JNK, Bcl-2, caspase-9, and caspase-3). In conclusion, all three water samples showed cytotoxicity and molecular toxicity in the HEK293 cells, and the results of the cell-cycle and apoptosis regulatory protein expression after WTI and WTE treatments were consistent with the results of the cytotoxicity.

Occurrence of pharmaceutical, recreational and psychotropic drug residues in surface water on the northern Antarctic Peninsula region

Human presence in the Antarctic is increasing due to research activities and the rise in tourism. These activities contribute a number of potentially hazardous substances. The aim of this study is to conduct the first characterisation of the pharmaceuticals and recreational drugs present in the northern Antarctic Peninsula region, and to assess the potential environmental risk they pose to the environment. The study consisted of a single sampling of ten water samples from different sources, including streams, ponds, glacier drains, and a wastewater discharge into the sea. Twenty-five selected pharmaceuticals and 21 recreational drugs were analysed. The highest concentrations were found for the analgesics acetaminophen (48.74 μg L^-1), diclofenac (15.09 μg L^-1) and ibuprofen (10.05 μg L^-1), and for the stimulant caffeine (71.33 μg L^-1). All these substances were detected in waters that were discharged directly into the ocean without any prior purification processes. The hazard quotient (HQ) values for ibuprofen, diclofenac and acetaminophen were far in excess of 10 at several sampling points. The concentrations of each substance measured and used as measured environmental concentration values for the HQ calculations are based on a one-time sampling. The Toxic Unit values indicate that analgesics and anti-inflammatories are the therapeutic group responsible for the highest toxic burden. This study is the first to analyse a wide range of substances and to determine the presence of pharmaceuticals and psychotropic drugs in the Antarctic Peninsula region. We believe it can serve as a starting point to focus attention on the need for continued environmental monitoring of these substances in the water cycle, especially in protected regions such as the Antarctic. This will determine whether pharmaceuticals and recreational drugs are hazardous to the environment and, if so, can be used as the basis for risk-assessment studies to prioritise the exposure to risk.

Endocrine disrupting compounds in drinking water supply system and human health risk implication

To date, experimental and epidemiological evidence of endocrine disrupting compounds (EDCs) adversely affecting human and animal populations has been widely debated. Notably, human health risk assessment is required for risk mitigation. The lack of human health risk assessment and management may thus unreliably regulate the quality of water resources and efficiency of treatment processes. Therefore, drinking water supply systems (DWSSs) may be still unwarranted in assuring safe access to potable drinking water. Drinking water supply, such as tap water, is an additional and crucial route of human exposure to the health risks associated with EDCs. A holistic system, incorporating continuous research in DWSS monitoring and management using multi-barrier approach, is proposed as a preventive measure to reduce human exposure to the risks associated with EDCs through drinking water consumption. The occurrence of EDCs in DWSSs and corresponding human health risk implications are analyzed using the Needs, Approaches, Benefits, and Challenges (NABC) method. Therefore, this review may act as a supportive tool in protecting human health and environmental quality from EDCs, which is essential for decision-making regarding environmental monitoring and management purposes. Subsequently, the public could have sustainable access to safer and more reliable drinking water.

Effects of acetylacetone on the photoconversion of pharmaceuticals in natural and pure waters

Acetylacetone (AcAc) has proven to be a potent photo-activator in the degradation of color compounds. The effects of AcAc on the photochemical conversion of five colorless pharmaceuticals were for the first time investigated in both pure and natural waters with the UV/H₂O₂ process as a reference. In most cases, AcAc played a similar role to H₂O₂. For example, AcAc accelerated the photodecomposition of carbamazepine, oxytetracycline, and tetracycline in pure water. Meanwhile, the toxicity of tetracyclines and carbamazepine were reduced to a similar extent to that in the UV/H₂O₂ process. However, AcAc worked in a way different from that of H₂O₂. Based on the degradation kinetics, solvent kinetic isotope effect, and the inhibiting effect of O₂, the underlying mechanisms for the degradation of pharmaceuticals in the UV/AcAc process were believed mainly to be direct energy transfer from excited AcAc to pharmaceuticals rather than reactive oxygen species-mediated reactions. In natural waters, dissolved organic matter (DOM) played a crucial role in the photoconversion of pharmaceuticals. The role of H₂O₂ became negligible due to the scavenging effects of DOM and inorganic ions. Interestingly, in natural waters, AcAc first accelerated the photodecomposition of pharmaceuticals and then led to a dramatic reduction with the depletion of dissolved oxygen. Considering the natural occurrence of diketones, the results here point out a possible pathway in the fate and transport of pharmaceuticals in aquatic ecosystems.

Degradation of chloramphenicol by potassium ferrate (VI) oxidation: kinetics and products

The oxidation of chloramphenicol (CAP) by potassium ferrate (VI) in test solution was studied in this paper. A series of jar tests were performed at bench scale with pH of 5-9 and molar ratio [VI/CAP] of 16.3:1-81.6:1. Results showed that raising VI dose could improve the treatment performance and the influence of solution pH was significant. VI is more reactive in neutral conditions, presenting the highest removal efficiency of CAP. The rate law for the oxidation of CAP by VI was first order with respect to each reactant, yielding an overall second-order reaction. Furthermore, five oxidation products were observed during CAP oxidation by VI. Results revealed that VI attacked the amide group of CAP, leading to the cleavage of the group, while benzene ring remained intact.

Detection and quantification of acidic drug residues in South African surface water using gas chromatography-mass spectrometry

A method was optimized for derivatization, separation, detection and quantification of salicylic acid, acetylsalicylic acid, nalidixic acid, ibuprofen, phenacetin, naproxen, ketoprofen, meclofenamic acid and diclofenac in surface water using gas chromatography-mass spectrometry. For most of the acidic drugs, recovery was in the range 60-110% and the percent standard deviation was below 15% for the entire method, with limits of detection ranging from 0.041 to 1.614 μg L^-1. The developed method was applied in the analysis of acidic drugs in Umgeni River system, KwaZulu-Natal South Africa. All of the selected acidic drugs were detected and quantified, their concentration in Umgeni River system ranged from 0.0200 to 68.14 μg L^-1.

Adsorptive removal of aqueous bezafibrate by magnetic ferrite modified carbon nanotubes

MFe₂O₄/CNTs were synthesized and successfully applied for the removal of aqueous bezafibrate. The adsorption behavior and mechanism were elucidated in detail.

Occurrence, distribution and risk assessment of suspected endocrine-disrupting chemicals in surface water and suspended particulate matter of Yangtze River (Nanjing section)

The occurrence and distribution of eight selected endocrine-disrupting chemicals were investigated in samples of surface water and suspended particulate matter (SPM) in Nanjing section of Yangtze River over a year (the flow period, the wet period and the dry period). All target compounds were detected at least once in surface water with 4-tert-butylphenol (4-TBP), nonyphenol (NP) and bisphenol A (BPA) as the dominant compounds, with concentrations in the range of 225-1121ng/L, 1.4-858ng/L and 1.7-563ng/L, respectively. Except for December, all selected compounds for the other sampling times were not found in all sampling points. NP (mean concentration 69.8µg/g) and BPA (mean concentration 51.8µg/g) were also the dominant estrogens in SPM. In addition, the highest total compounds concentrations were found in December in both phases, which could be due to the low flow conditions and temperature during this season. Meanwhile, a significant positive correlation was found between the total compounds concentrations in the water phase and those in SPM phase. Risk assessment based on the calculated risk quotients (RQ) showed that low and moderate risk for the aquatic environment from presence of the target compounds at all sampling points with exception of 4-TBP and NP which might pose a high risk to aquatic organisms.

Screening of 1300 organic micro-pollutants in groundwater from Beijing and Tianjin, North China

Groundwater contamination in China has become a growing public concern because of the country's rapid economic development and dramatically increasing fresh water demand. However, there is little information available on groundwater quality, particularly with respect to trace organic micro-pollutants contamination. This study was undertaken to investigate the occurrence of 1300 pollutants at 27 groundwater sites in Beijing and Tianjin, North China. Seventy-eight chemicals (6% of the targeted compounds) were detected in at least one sampling point; observed chemicals included polycyclic aromatic hydrocarbons (PAHs), pesticides, plasticizers, antioxidants, pharmaceuticals and other emerging compounds. Chemicals with a frequency of detection over 70% were 2-ethyl-1-hexanol (median concentration 152 ng L^-1), benzyl alcohol (582 ng L^-1), 2-phenoxy-ethanol (129 ng L^-1), acetophenone (74 ng L^-1), pentamethylbenzene (51 ng L^-1), nitrobenzene (40 ng L^-1) and dimethyl phthalate (64 ng L^-1). Pesticides with concentrations exceeding the EU maximum residual limits (MRL) of 0.1 μg L^-1 were 1,4-dichlorobenzene, oxadixyl, diflubenzuron, carbendazim, diuron, and the E and Z isomers of dimethomorph. Naphthalene and its 7 alkylated derivatives were widely observed at maximum concentration up to 30 μg L^-1, which, although high, is still below the Australian drinking water guidelines of 70 μg L^-1. The risk assessment indicated there is no human health risk through the oral consumption from most wells, although there were four wells in which total seven compounds were found at the concentrations with a potential adverse health effects. This work provides a wide reconnaissance on broad spectrum of organic micro-contaminants in groundwater in North China.

Function of a landscape lake in the reduction of biotoxicity related to trace organic chemicals from reclaimed water

The storage of water in a landscape lake can act as a buffer zone between reclaimed water production and reuse, but there is still uncertainty about the variation of water quality and toxic effects during the open-storage process. In this study, long-term sample collection, chemical analyses and biotoxicity assessments were conducted on reclaimed water before and after open storage in a landscape lake. The organic contents, in terms of chemical oxygen demand and total organic carbon, were found to be slightly higher in the lake water than that in the reclaimed water, but substantial reduction of the total concentration of 52 trace organic chemicals was obtained and microorganism toxicity, phytotoxicity, aquatic vertebrate toxicity and genotoxicity, were significantly weakened after open storage. Furthermore, the total risk quotient (RQTotal) decreased from 5.12 (potential ecological risk level) in the reclaimed water to 0.18 (negligible ecological risk level) in the lake water. The removal of chlorpyrifos, dichlorphos and tetracycline was identified as the main reason for biotoxicity reduction after open storage. The seminatural environment of the landscape lake would have provided a favorable condition for the decay of toxic trace organic chemicals so that the stored water turned to be safer for further reuse.

Parent and conjugated estrogens and progestagens in surface water of the Santa Ana River: Determination, occurrence, and risk assessment

The present study investigated the occurrence of 13 parent and conjugated estrogens and progestagens in surface water of the Santa Ana River. With the exception of the synthetic hormones 17α-ethynylestradiol and mestranol, other compounds were detected at least twice at 10 representative sites, with the ubiquitous estrone (E1) and 17β-estradiol-3-sulfate as the dominant compounds quantified (0.24-6.37 ng/L and 0.49-9.25 ng/L, respectively). Sites near dairy farms exhibited high levels of conjugates, whereas those close to a sewage treatment plant (STP) effluent outlet displayed relatively high concentrations of E1. Principle component analysis coupled with multiple linear regression revealed dairy farms and the STP as the 2 significant contamination sources, accounting for 69.9% and 31.1% of the total hormone burden, respectively. Risk assessment results suggested E1 and 17β-estradiol (E2) as the 2 hormones with the largest risks to aquatic organisms, and which combined, contributed >90% of the total estrogenicity. Most of the sites investigated showed that E1 and E2 posed a medium risk (0.1 < risk quotient < 1), whereas each induced a high risk (risk quotient >1) at sites severely impacted by the STP and dairy farms. These results suggest that river health would benefit from effective treatment of waste at the STP and dairy farms prior to discharge. Environ Toxicol Chem 2016;35:2657-2664. © 2016 SETAC.

Screening determination of pharmaceutical pollutants in different water matrices using dual-channel capillary electrophoresis coupled with contactless conductivity detection

In this study, the employment of purpose-made dual-channel compact capillary electrophoresis (CE) instrument with capacitively coupled contactless conductivity detection (C(4)D) as a simple and inexpensive solution for screening determination of various pharmaceutical pollutants frequently occurring in surface water and hospital wastewater in Hanoi, Vietnam is reported. Five negatively charged pharmaceutically active compounds, namely ibuprofen, diclofenac, bezafibrate, ketoprofen and mefenamic acid were determined using the first channel whereas three positively charged ones, namely diphenhydramine, metoprolol and atenolol were determined with the second channel of the CE-C(4)D instrument. Two different background electrolytes (BGEs) were used in these two CE channels independently. The best detection limits achieved were in the range of 0.2-0.8mg/L without sample pre-concentration. Enrichment factors up to 200 were obtainable with the inclusion of a solid phase extraction step. Good agreement between results obtained from CE-C(4)D and those with the standard confirmation method (HPLC-DAD) was achieved, with correlation coefficients higher than 0.98.

Phenolic endocrine disrupting chemicals in an urban receiving river (Panlong river) of Yunnan-Guizhou plateau: Occurrence, bioaccumulation and sources

The objectives of this study were to track the occurrence, bioaccumulation and sources of phenolic endocrine disrupting chemicals (EDCs) in a representative urban river (Panlong River) of Yunnan-Guizhou Plateau. It provided more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environments. Phenolic EDCs, such as nonylphenol-di-ethoxylate (NP2EO), nonylphenol-mono-ethoxylate (NP1EO), 4-nonylphenol (4-NP), bisphenol A (BPA), 4-cumylphenol (4-CP) and 4-tert-octylphenol (4-t-OP), were ubiquitously present in Panlong River. The distribution of phenolic EDCs in the water and sediment tended to assume a shape like an inverted letter "W". The residual levels of phenolic EDCs increased dramatically in certain areas. The concentrations of NP2EO, NP1EO, 4-NP, BPA, 4-CP, 4-t-OP and the total phenolic EDCs (ΣPEDCs) were up to 202, 154, 17, 79, 3.3, 4.6 and 429 ng/L in water, and were up to 352, 316, 124, 18, 14, 4.8 and 813 ng/g in sediment, respectively. However, the concentrations of 4-NP, BPA, 4-CP, 4-t-OP and ΣPEDCs in the three predominant fish species (Carassius auratus, Cyprinus carpio and Anabarilius alburnops) were up to 63, 113, 12, 14 and 201 ng/g, respectively. Distribution characteristics of phenolic EDCs in water were significantly similar to those found in sediment, but different in fish. Occurrence, bioaccumulation and sources of phenolic EDCs were mainly subjected to the distribution characteristics of industry, agriculture and residential areas in Panlong catchment. Moreover, the bioconcentration factors (BCFs) were closely related to the octanol-water partition coefficients (log K(ow)) of phenolic EDCs. Without direct input, the redissolution of phenolic EDCs from sediments seems conceivable. The concentrations of phenolic EDCs in the sections of urban areas were remarkably higher than those in suburban sections, since there could exist a potential risk to aquatic organisms and even to human.

A review of the influence of treatment strategies on antibiotic resistant bacteria and antibiotic resistance genes

Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARG) in the aquatic environment have become an emerging contaminant issue, which has implications for human and ecological health. This review begins with an introduction to the occurrence of ARB and ARG in different environmental systems such as natural environments and drinking water resources. For example, ARG or ARB with resistance to ciprofloxacin, sulfamethoxazole, trimethoprim, quinolone, vancomycin, or tetracycline (e.g., tet(A), tet(B), tet(C), tet(G), tet(O), tet(M), tet(W), sul I, and sul II) have been detected in the environment. The development of resistance may be intrinsic, may be acquired through spontaneous mutations (de novo), or may occur due to horizontal gene transfer from donor bacteria, phages, or free DNA to recipient bacteria. An overview is also provided of the current knowledge regarding inactivation of ARB and ARG, and the mechanism of the effects of different disinfection processes in water and wastewater (chlorination, UV irradiation, Fenton reaction, ozonation, and photocatalytic oxidation). The effects of constructed wetlands and nanotechnology on ARB and ARG are also summarized.