Caffeine in surface and wastewaters in Barbados, West Indies

Temporal Analysis of Pharmaceuticals as Emerging Contaminants in Surface Water and Wastewater Samples: A Case Study

Pharmaceuticals in the environment are a global concern, with studies in all continents highlighting their widespread occurrence and potential ecological impacts, revealing their presence, fate, and associated risks in aquatic ecosystems. Despite typically occurring at low concentrations (ranging from ng/L to µg/L), advancements in analytical methods and more sensitive equipment have enabled the detection of a higher number of pharmaceuticals. In this study, surface and wastewater samples were extracted using solid phase extraction and analyzed using ultra-high-performance liquid chromatography with tandem mass spectrometry. Among the therapeutic classes investigated, nonsteroidal anti-inflammatory drugs/analgesics, antibiotics, and psychiatric drugs showed a higher number of detected pharmaceuticals. Concentrations ranged from below method detection limit ( Collapse

Key Words

• liquid chromatography
• mass spectrometry
• overtime analysis
• pharmaceuticals
• public health
• surface and wastewater samples

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MESH Headings Collapse

Grants

• UIDB/50006/2020 Fundação para a Ciência e Tecnologia
• UIDP/50006/2020 Fundação para a Ciência e Tecnologia
• LA/P/0008/2020 Fundação para a Ciência e Tecnologia
• PTDC/QUI-QAN/3899/2021 Fundação para a Ciência e Tecnologia
• PTDC/EAM-AMB/2023/2021 Fundação para a Ciência e Tecnologia
• MTS/SAS/0077/2020 Fundação para a Ciência e Tecnologia
• P223RT0141/ENOTTA-CA21147 Ibero-American Program on Science and Technology (CYTED) & European Cooperation in Science and Technology (COST)
• 101003777 Fundação para a Ciência e a Tecnologia (FCT) BiodivRestore Joint Call 2020-2021 - European Union's Horizon 2020 research and innovation programme

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Affiliation(s)

Paula Paíga REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Luísa Correia-Sá REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Manuela Correia REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Sónia Figueiredo REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)
Joana Vieira Águas do Centro Litoral, SA, Grupo Águas de Portugal, ETA da Boavista, Avenida Dr. Luís Albuquerque, 3030-410 Coimbra, Portugal; (J.V.)
Sandra Jorge Águas do Centro Litoral, SA, Grupo Águas de Portugal, ETA da Boavista, Avenida Dr. Luís Albuquerque, 3030-410 Coimbra, Portugal; (J.V.)
Jaime Gabriel Silva Águas do Douro e Paiva, SA, Grupo Águas de Portugal, Rua de Vilar, 235 5°, 4050-626 Porto, Portugal; Departamento de Engenharia Civil, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal
Cristina Delerue-Matos REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4249-015 Porto, Portugal; (L.C.-S.); (M.C.); (S.F.)

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Microbial metabolism of caffeine and potential applications in bioremediation

With increasing global consumption of caffeine-rich products, such as coffee, tea, and energy drinks, there is also an increase in urban and processing waste full of residual caffeine with limited disposal options. This waste caffeine has been found to leach into the surrounding environment where it poses a threat to microorganisms, insects, small animals, and entire ecosystems. Growing interest in harnessing this environmental contaminant has led to the discovery of 79 bacterial strains, eight yeast strains, and 32 fungal strains capable of metabolizing caffeine by N-demethylation and/or C-8 oxidation. Recently observed promiscuity of caffeine-degrading enzymes in vivo has opened up the possibility of engineering bacterial strains capable of producing a wide variety of caffeine derivatives from a renewable resource. These engineered strains can be used to reduce the negative environmental impact of leached caffeine-rich waste through bioremediation efforts supplemented by our increasing understanding of new techniques such as cell immobilization. Here, we compile all of the known caffeine-degrading microbial strains, discuss their metabolism and related enzymology, and investigate their potential application in bioremediation.

Pharmaceuticals, hazard and ecotoxicity in surface and wastewater in a tropical dairy production area in Latin America

Pharmaceuticals comprise a complex group of emerging pollutants. Despite the significant number of pharmaceuticals used in veterinary medicine, the input of these compounds into the environment due to livestock activities has been scarcely described. This work assays for the first time in Central America the occurrence of pharmaceuticals in farm wastewater in an area devoted to dairy production, and in the surrounding surface waters. Among 69 monitored pharmaceuticals, a total of eight compounds were detected in wastewater samples collected from seven dairy farms after three sampling campaigns. Six pharmaceuticals were considered either of high (albendazole, lovastatin and caffeine) or intermediate estimated hazard (ciprofloxacin, acetaminophen and ketoprofen) based on the HQ approach, while 26% of the samples were considered of high estimated hazard according to the cumulative ∑HQ approach. Similarly, when ecotoxicological tests were applied, all the samples showed some level of toxicity towards Daphnia magna, and most samples towards Vibrio fischeri and Lactuca sativa. Fourteen pharmaceuticals were detected in surface water samples collected in the surroundings of the dairy production farms, including rural and urban areas. Seven out of these compounds showed high estimated risk (risperidone, diphenhydramine, trimethoprim, fluoxetine, ofloxacin, caffeine and ibuprofen), while three (gemfibrozil, ciprofloxacin and cephalexin) exhibited intermediate estimated risk. In a similar worrisome way, 27% of these samples were estimated to pose high environmental risk according to the pharmaceutical content. Despite being nontoxic for D. magna or V. fischeri, frequent inhibition (>20%) of GI in L. sativa was determined in 34% of surface water samples; such findings raise concern on the apparent inceptive environmental pollution and risk within the area. According to the pharmaceutical content patterns in both kinds of studied matrices, no clear evidence of significant contamination in surface water due to livestock activities could be retrieved, suggesting a main role of urban influence.

International Comparison, Risk Assessment, and Prioritisation of 26 Endocrine Disrupting Compounds in Three European River Catchments in the UK, Ireland, and Spain

Endocrine-disrupting compounds (EDCs) constitute a wide variety of chemistries with diverse properties that may/can pose risks to both humans and the environment. Herein, a total of 26 compounds, including steroids, flame retardants, and plasticizers, were monitored in three major and heavily urbanized river catchments: the R. Liffey (Ireland), the R. Thames (UK), and the R. Ter (Spain), by using a single solid-phase extraction liquid chromatography-mass spectrometry (SPE-LC-MS/MS) method. Occurrence and frequency rates were investigated across all locations over a 10-week period, with the highest concentration obtained for the flame retardant tris(2-chloroethyl) phosphate (TCEP) at 4767 ng∙L-1 in the R. Thames in Central London. Geographical variations were observed between sites and were partially explained using principal component analysis (PCA) and hierarchical cluster analysis (HCA). In particular, discrimination between the R. Ter and the R. Thames was observed based on the presence and concentration of flame retardants, benzotriazole, and steroids. Environmental risk assessment (ERA) across sites showed that caffeine, a chemical marker, and bisphenol A (BPA), a plasticizer, were classified as high-risk for the R. Liffey and R. Thames, based on relative risk quotients (rRQs), and that caffeine was classified as high-risk for the R. Ter, based on RQs. The total risks at each location, namely ΣRQriver, and ΣrRQriver, were: 361, 455, and 723 for the rivers Liffey, Thames, and Ter, respectively. Caffeine, as expected, was ubiquitous in all 3 urban areas, though with the highest RQ observed in the R. Ter. High contributions of BPA were also observed across the three matrices. Therefore, these two compounds should be prioritized independently of location. This study represents a comprehensive EDC monitoring comparison between different European cities based on a single analytical method, which allowed for a geographically independent ERA prioritization to be performed.

Recent Advances in Electrochemical Sensors for Caffeine Determination

The determination of target analytes at very low concentrations is important for various fields such as the pharmaceutical industry, environmental protection, and the food industry. Caffeine, as a natural alkaloid, is widely consumed in various beverages and medicines. Apart from the beneficial effects for which it is used, caffeine also has negative effects, and for these reasons it is very important to determine its concentration in different mediums. Among numerous analytical techniques, electrochemical methods with appropriate sensors occupy a special place since they are efficient, fast, and entail relatively easy preparation and measurements. Electrochemical sensors based on carbon materials are very common in this type of research because they are cost-effective, have a wide potential range, and possess relative electrochemical inertness and electrocatalytic activity in various redox reactions. Additionally, these types of sensors could be modified to improve their analytical performances. The data available in the literature on the development and modification of electrochemical sensors for the determination of caffeine are summarized and discussed in this review.

Consumption trends of pharmaceuticals and psychoactive drugs in Latvia determined by the analysis of wastewater

Wastewater-based epidemiology (WBE) was applied to evaluate seasonal variations of the consumption of pharmaceuticals (i.e. antibiotics, NSAIDs, antiepileptics, antihypertensives and others), caffeine, alcohol and nicotine in Latvia throughout 2021. In addition, weekly variation of caffeine, nicotine and alcohol consumption was investigated. Pronounced seasonality was observed in the consumption of antibiotics and decongestants, as well as caffeine, nicotine and alcohol. Correlation with COVID-19 statistics was observed in the case of macrolide antibiotics and antiasthmatic salbutamol. Comparison of the estimated consumption values obtained using the WBE approach and the statistics revealed that the majority of compounds data are in good agreement except angiotensin II receptor blocker group antihypertensives where the most overestimated consumption values were observed.

Will extreme weather events influence the toxic impacts of caffeine in coastal systems? Comparison between two widely used bioindicator species

In the recent years, marine heatwaves (MHWs) have caused devastating impacts on marine life. The understanding of the combined effects of these extreme events and anthropogenic pollution is a vital challenge. In particular, the combined effect of MHWs on the toxicity of pharmaceuticals to aquatic life remains unclear. To contribute to these issues, the main goal of the present investigation was to evaluate how MHWs may increase caffeine (CAF) toxicity on the clam Ruditapes philippinarum and the mussel Mytilus galloprovincialis. Bioaccumulation levels and changes on oxidative stress, metabolic capacity and neurotoxic status related biomarkers were investigated. The obtained results revealed the absence of CAF accumulation in both species. However, the used contaminant generated in both bivalve species alteration on neurotransmission, detoxification mechanisms induction as well as cellular damage. The increase of antioxidant defence mechanisms was complemented by an increase of metabolic activity and decrease of energy reserves. The obtained results seemed magnified under a simulated MHWs, suggesting to a climate-induced toxicant sensitivities' response. On this perspective, understanding of how toxicological mechanisms interact with climate-induced stressors will provide a solid platform to improve effect assessments for both humans and wildlife.

Caffeine as a contaminant of concern: A review on concentrations and impacts in marine coastal systems

Caffeine has been identified as emerging contaminant of concern due to its widespread occurrence in the aquatic environment and potential to be biologically active. Recently, these concerns have been translated in an increasing research on its occurrence and effects on biota. However, there is still a limited knowledge on seawater matrices and the implications of caffeine presence in coastal and marine ecosystems are not fully known. The present review aims to fill these knowledge gaps, analysing the existing literature regarding the occurrence, effects and potential risks of caffeine residues to coastal ecosystems, contributing to the risk assessment of this psychoactive drug in the aquatic environment. The analysed literature reported caffeine concentrations in the coastal ecosystems, raising high concerns about the potential adverse impacts on the ecological safety and human health. Caffeine has been found in tissues from coastal and marine biota including microalgae, coral reefs, bivalves and fish due to bioaccumulation after chronic, long-term exposures in a contaminated environment. Additionally, caffeine residues had been demonstrated to have adverse impacts on aquatic organisms, at environmentally realistic concentrations, inducing oxidative stress and lipid peroxidation, neurotoxicity, changing energy reserves and metabolic activity, affecting reproduction and development and, in some cases, causing mortality. Considering the increasing adverse impacts of caffeine pollution in the coastal environment, this review highlights the urgent need to minimize the increasing load of caffeine to the aquatic ecosystems; being imperative the implementation of scientific programs and projects to classify effectively the caffeine as a high-priority environmentally hazardous emerging pollutant.

Spatio-temporal distribution of pharmaceutically active compounds in the River Cauvery and its tributaries, South India

Pharmaceutically active compounds (PhACs) present in the environment are a great threat to human well-being and the ecosystem. Eventhough recognized as the pharmacy of the world", studies addressing the distribution of PhACs in the Indian environment are scarce. Hence, in the current study, selected PhACs, heavy metals (HMs), and physicochemical parameters (PCPs) were measured from the surface waters of the River Cauvery during the pre- and post-monsoon. PhACs such as caffeine, carbamazepine, and diclofenac were detected in most samples, whereas topiramate, ibuprofen, and verapamil were found only in few stations. In contrast, the distribution of ciprofloxacin, atenolol, and isoprenaline was strongly influenced by the seasonal pattern (p < 0.05). PhACs such as loperamide, glafenine, erythromycin, and gemfibrozil were not detected during the study. Distribution of PhACs based on average concentration (ng/L) are, CBZ (205.62) > CAF (114.09) > DCF (28.51) > CIP (25.23) > ATL (18.86) > IPL (13.91) > PPL (11.26) > TCS (10.39) > IBF (7.34) > TPT (3.09) > VPL (1.16). Bivariate and multivariate statistical analyses have revealed a positive correlation expressed by the majority of the PhACs with PCPs (COD, TOC), nutrients (TN, TP), and HMs (Pb, Mn, Ni) in the range from 0.540** to 0.961**(p < 0.01). Whereas, DO revealed negative correlation with most of the parameters in the range from -0.559** to -0.831** (p < 0.01). A high average concentration of PhACs was recorded in the upstream (52.08 ng/L) and wastewater discharge points (55.60 ng/L). Further, the environmental risk assessment study has identified the higher risk exhibited by TCS (RQ: 3.29) and CAF (RQ: 38.82) on algae and Daphnia respectively. The study portrays the distribution of emerging contaminants in the River Cauvery and its tributaries and also delivers preliminary data about the distribution of isoprenaline, topiramate, verapamil, and perindopril in the Indian freshwater system.

Chironomus sancticaroli generation test applied to chemical contaminants and freshwater sediment samples

The use of ecotoxicological bioassays has been increasing due to the importance of understanding the effects of substances on biota and to help environmental agencies determine water and sediment qualities. The use of Chironomus sp. in laboratory bioassays is extensive, but there is still a lack of studies regarding the application of extended ecotoxicological tests, which evaluate different population generation responses and show a detailed impact on their development. The present study investigated the response of Chironomus sancticaroli, a Brazilian endemic insect, to 17α-ethinylestradiol hormone, caffeine anhydrous, LAS (linear alkylbenzene sulfonate), and environmental samples (sediments) in relation to wing length, fecundity, and larval length over three generations. Statistically, differences for all contaminants between P (parental), F1, and F2 generations (p ≤ 0.05) were observed, indicating that in the environment, the organism may be negatively affected when exposed to contaminants in successive generations. Different ecological responses were also noted in comparison to classic acute (96h) and chronic (10 days) ecotoxicological tests using Chironomus sancticaroli. Our results highlight that the generation test can present more detailed results regarding the effects of stressors on the organism's life cycle than do the classic bioassays.

Environmental knowledge, behaviors, and attitudes regarding caffeine consumption among Chinese university students from the perspective of ecopharmacovigilance

Caffeine is considered the most representative pharmaceutical emerging contaminant (PEC) because of its ubiquity, high environmental abundance, uncovered ecological risks, and its indicator property for anthropogenic environmental inputs of PECs. Ecopharmacovigilance (EPV) targeting caffeine has been proposed as an optimized measure for the control of caffeine pollution sources and the related anthropogenic behaviors from the perspective of pharmacy administration. This cross-sectional study was conducted to evaluate the environmental knowledge, behaviors, and attitudes regarding caffeine consumption among university students, one of the groups with high caffeine consumption, from an EPV perspective. Three hundred and seven usable survey instruments were acquired. The mean score for environmental knowledge about caffeine consumption was 3.66 out of a total of 7. The consumption frequency of caffeinated drinks, food, or drugs among student respondents was low. Throwing away in "household garbage" was an important disposal mechanism for unconsumed caffeinated products. Most students showed positive attitudes and strong intentions toward caffeine pollution control from the perspective of targeted EPV. These data suggested high acceptance of EPV program targeting caffeine among university students. However, more should be done to enhance their related knowledge, and some strengthening interventions for the effective removal of residual caffeine in garbage are needed.

Rapid remediation of pharmaceuticals from wastewater using magnetic Fe3O4/Douglas fir biochar adsorbents

Modification of commercially available Douglas fir biochar (BC) by iron oxide nanoparticle precipitation from aqueous Fe²⁺/Fe³⁺ salt solutions upon NaOH treatment generated a hybrid adsorbent (MBC) that removed three common emerging aqueous contaminants, a stimulant (caffeine) and two anti-inflammatory drugs (ibuprofen and acetylsalicylic acid) through batch sorption. Fe₃O₄ particles (12.3 ± 7.1 nm diameter fundamental particles with aggregates 1-17 μm diameter) dispersed on the biochar surface provided magnetization and created new adsorption sites for the contaminant uptake. These smaller quasi-spherical, octahedral Fe₃O₄ particles as well as the spindle-like Fe₂O₃ particles were observed with scanning electron microscopy (SEM) images of MBC, and the composition was confirmed by X-ray powder diffraction (XRD). Adsorption features were evaluated using Langmuir and Freundlich isotherm models. The Langmuir adsorption capacities on MBC at 35 °C have increased from 24.6 ± 0.4 to 75.1 ± 1.8 mg/g for caffeine, 17.5 ± 0.4 to 39.9 ± 1.2 mg/g for ibuprofen and 106.2 ± 2.8 to 149.9 ± 4.5 mg/g for acetylsalicylic acid after Fe₃O₄ modification. Fast adsorption resulted in equilibrium within 5 min. MBC has potential as a low cost, green adsorbent for pharmaceutical mitigation from water with high adsorption capacities and fast kinetics. The Douglas fir biochar is a byproduct waste from a syn-gas from wood production process covering its production costs.

Effective photocatalytic removal of selected pharmaceuticals and personal care products by elsmoreite/tungsten oxide@ZnS photocatalyst

In this study, elsmoreite/tungsten oxide is used to form a heterojunction with ZnS-containing industrial waste. The effect of the elsmoreite/tungsten oxide content on photocatalytic activity of ZnS using the different ratios of ZnS:Na₂WO₄ in the synthesis solution is estimated. The initial ZnS:Na₂WO₄ ratio leads to the formation of hexagonal WO₃∙0.33H₂O on the surface of ZnS. A further increase in the ZnS:Na₂WO₄ ratio results in the domination of cubic WO₃∙0.5H₂O over hexagonal WO₃. The ultraviolet-visible (UV-Vis) diffuse reflectance spectra of elsmoreite/tungsten oxide@ZnS composite photocatalysts show that the absorption onset shifts monotonously towards lower wavelengths from 450 nm to 400 nm. The microrods of hexagonal WO₃ and {111}-truncated submicron-sized crystals of WO₃∙0.5H₂O are grown on the ZnS surface. The transmission electron microscopy (TEM) results confirm the formation of a heterojunction between elsmoreite/tungsten oxide and ZnS. The photocatalytic activities of elsmoreite/tungsten oxide@ZnS composite photocatalysts are evaluated for the degradation of selected pharmaceuticals and personal care products (PPCPs): metoprolol - Mt, triclosan - TCS, and caffeine - CAF both in single and in mixture solutions. The elsmoreite/tungsten oxide@ZnS photocatalysts degrade 50% of Mt, 70% TCS, and 60% CAF in single solution and 35% of Mt, 20% of CAF, and 20% of TCS in mixture solution. Hydrated Mt and TCS are preferably adsorbed on the surface of WO₃∙0.5H₂O (111), and CAF has better affinity to the surface of WO₃. The elsmoreite/tungsten oxide@ZnS photocatalysts show a good reusability. Hydroxyl radicals (^•OH) and photogenerated holes (h⁺) are involved in the photocatalytic removal of Mt, while only h⁺ is involved in the photocatalytic removal of TCS. Interestingly, none of the above-mentioned species is involved in the photocatalytic removal of CAF. Also, nontoxic CAF is mainly degraded into intermediates with higher toxicity. The toxicity of the photocatalytically treated model wastewater in the mixture solution, tested with Vibrio fischeri, is much lower than that in the single solution.

Enhanced Photocatalytic Degradation of Caffeine Using Titanium Dioxide Photocatalyst Immobilized on Circular Glass Sheets under Ultraviolet C Irradiation

This work presents the development of titanium dioxide (TiO2) film immobilized on circular glass sheets for photocatalytic degradation of caffeine under ultraviolet C (UVC) irradiation. TiO2 was synthesized through the ultrasonic-assisted sol–gel method and immobilized on circular glass sheets by the doctor blade technique. Polyvinylpyrrolidone (PVP) was used to mix with the TiO2 precursor solution to enhance film adhesion on the glass surface. TiO2 film was mainly composed of anatase phase with a small amount of rutile phase. Caffeine removal was found to increase with increasing irradiation time. Caffeine (20 mg/L) in the synthetic wastewater could not be detected after 3 h of UVC irradiation. The reaction rate of caffeine degradation followed the pseudo-first-order model. The concentrated caffeine solutions required a longer irradiation time for degradation. The used TiO2-coated glass sheets could be easily separated from the treated wastewater and reusable. The caffeine removal efficiency of TiO2-coated glass sheets in each cycle maintained a high level (~100%) during fifteen consecutive cycles.

Monitoring pharmaceuticals in the aquatic environment using enzyme-linked immunosorbent assay (ELISA)-a practical overview

The presence of pharmaceuticals, which are considered as contaminants of emerging concern, in natural waters is currently recognized as a widespread problem. Monitoring these contaminants in the environment has been an important field of research since their presence can affect the ecosystems even at very low levels. Several analytical techniques have been developed to detect and quantify trace concentrations of these contaminants in the aquatic environment, namely high-performance liquid chromatography, gas chromatography, and capillary electrophoresis, usually coupled to different types of detectors, which need to be complemented with time-consuming and costly sample cleaning and pre-concentration procedures. Generally, the enzyme-linked immunosorbent assay (ELISA), as other immunoassay methodologies, is mostly used in biological samples (most frequently urine and blood). However, during the last years, the number of studies referring the use of ELISA for the analysis of pharmaceuticals in complex environmental samples has been growing. Therefore, this work aims to present an overview of the application of ELISA for screening and quantification of pharmaceuticals in the aquatic environment, namely in water samples and biological tissues. The experimental procedures together with the main advantages and limitations of the assay are addressed, as well as new incomes related with the application of molecular imprinted polymers to mimic antibodies in similar, but alternative, approaches. Graphical Abstract.

Monitoring survey of caffeine in surface waters (Lis River) and wastewaters located at Leiria Town in Portugal

Investigation during 11-month period was performed to study the presence of caffeine in the Lis River in Leiria Town in Portugal, and a monitoring during 9-month period was realized to check the contribution of the human pollution of two wastewater treatment plants (WWTPs) that discharge their effluents to the studied river. The samples were collected in five sampling points along the river and in two influents and two effluents of the studied WWTPs. Caffeine was detected in all ninety-one collected samples. The caffeine concentration ranged from 25.3 to 321 ng/L in the river samples, from 112 to 1927 ng/L in the WWTP effluents, and from 9478 to 83,901 ng/L in the WWTP influents. The highest concentration in the river was detected in the two sampling points located after the effluent discharge points and reached 315 and 321 ng/L. Risk assessment was performed for three trophic levels using the risk quotient calculation and revealed that caffeine do not cause toxic effect on Daphnia magna and on fish but could be possibly toxic to algae. The results proved that caffeine can be an effective indicator of human-born pollution.

Micropollutants related to human activity in groundwater resources in Barbados, West Indies

Several micropollutants, including caffeine, artificial sweeteners, pharmaceuticals, steroid hormones and a current-use pesticide were analyzed in water samples collected from five groundwater pumping stations in Barbados. The presence of caffeine and three artificial sweeteners (i.e. acesulfame, sucralose, saccharin) in groundwater samples indicated that groundwater was being contaminated by infiltration of wastewater into the karst aquifer. An estrogen (i.e. estrone), three pharmaceuticals (i.e. carbamazepine, trimethoprim, ibuprofen) and a transformation product of the fungicide, chlorothalonil (i.e. 4-hydroxychlorothalonil) were also detected at ng/L concentrations in groundwater collected from two or more pumping sites. The concentrations of carbamazepine and trimethoprim were correlated with the concentrations of caffeine (R² values of 0.70 to 0.80), indicating pharmaceutical contamination of groundwater by infiltration from domestic wastewater. The concentrations of caffeine were generally higher in groundwater samples collected in June during the wet season relative to the concentrations in samples collected in February during the dry season, indicating that infiltration of contaminants is higher during periods of heavy rainfall. Rapid rates of degradation and relatively slow rates of infiltration may explain why several target analytes were not detected in groundwater. Elevated concentrations of 4-hydroxychlorothalonil > 0.1 μg/L in samples collected at two of the monitoring sites warrant further studies on the sources and the distribution of this compound and other pesticides used in agriculture and for turf-treatment (e.g. golf courses). Overall, more data are needed in order to implement mitigation strategies that are effective in reducing chemical contamination in groundwater in Barbados.

Pharmaceuticals, illicit drugs and their metabolites in fish from Argentina: Implications for protected areas influenced by urbanization

Because an understanding of aquatic bioaccumulation of human pharmaceuticals in Latin America is limited, this area was recently identified as a priority environmental quality research need. We examined bioaccumulation of twenty-seven pharmaceuticals, illicit drugs and their metabolites in muscle, liver and gills of multiple fish species (Rhamdia quelen, Hypostomus commersoni, Hoplias lacerdae, Prochilodus lineatus) from an urban river receiving wastewater discharges (Paraná) and a lotic system (Acaraguá) without direct wastewater sources, which runs through a protected area. All samples were analyzed using isotope-dilution liquid chromatography-tandem mass spectrometry. Caffeine, which was detected up to 13 μg/kg, and antibiotics were consistently detected in all fish. Among antibiotics, erythromycin was ubiquitous (0.7-5.6 μg/kg) but its tissue concentrations were lower than levels of sulfamethoxazole, sulfathiazole and trimethoprim (0.9-5.5 μg/kg), which are used in human medicine, aquaculture and livestock. Erythromycin bioaccumulation in fish is reported here from Argentina for the first time, though levels of antibiotics in edible muscles of these species were lower than the maximum residue limits for human consumption. We observed norfluoxetine, the primary active metabolite of the antidepressant fluoxetine, ranging from 1.1-9.1 μg/kg in fish. We further identified benzoylecgonine, a primary metabolite of cocaine, in fish from both study systems, representing the first observation an illicit drug or associated metabolites bioaccumulation in aquatic life from Argentina. Interestingly, high pharmaceutical levels were observed in fish from the Acaraguá river suggesting their transport into the protected area, from the surrounding lands. Though fish from the Paraná river were sampled near WWTP discharges, pharmaceutical concentrations may have been reduced by hydrological and other environmental conditions, and biological differences among species. These findings, which observed bioaccumulation of select pharmaceuticals, their metabolites and illicit drugs in wild fish sampled inside a protected area, highlight the importance of developing an advanced understanding of urban influences on inland protected watersheds.

Semi-continuous pharmaceutical and human tracer monitoring by POCIS sampling at the watershed-scale in an agricultural rural headwater river

Pharmaceutical monitoring (37 pharmaceuticals and 3 human tracers) was conducted in a headwater streams in southwest France, an area characterized by a low population density with an elderly population (30% > 60 years old) and extensive agriculture (cow cattle breeding). Polar Organic Chemical Integrative Sampler (POCIS) were exposed for 14-day consecutive periods in 2016 at three sampling points. Three human wastewater tracers and 20 pharmaceuticals commonly used for human and/or cattle were quantified in headwaters. Succession of small Wastewater Treatment Plant (WWTP), non-collective sanitation, discharges of untreated effluents as well as the river ability to dilute discharged wastewater, mainly explain the pharmaceuticals and human tracers concentrations. Pharmaceutical loads were time-dependent and were higher during cold season due to increase of pharmaceutical consumption. In contrast, better degradation and/or sorption onto river biofilms in warm season induced the decrease of headwater pharmaceutical content. The headwaters streams were contaminated by compounds found in other type of watershed, but β-blocker were the compounds quantified in higher concentration with frequencies of 100%, which was consistent with the elderly population living in the watershed. Specific compounds (sulfamerazine and sulfamethoxazole) used to cattle medical care were detected in waters, but at a low content.

Contaminants of Emerging Concern in Wastewaters in Barbados, West Indies

There have been few reports in the peer-reviewed literature on the levels of contaminants of emerging concern (CECs) in municipal wastewater from the Caribbean region. In this study of wastewater collected from two wastewater treatment plants in Barbados, caffeine and ibuprofen were detected at µg/L concentrations, whereas two steroid hormones (i.e. androstenedione, estrone) and several prescription pharmaceuticals were detected at ng/L concentrations. Among drugs of abuse, benzoylecgonine (i.e. metabolite of cocaine), MDMA (i.e. Ecstasy) and MDA (i.e. 3,4-methylenedioxyamphetamine) were present at the highest concentrations in untreated wastewater. Overall, these data show that there is potential impact in the marine environment in Barbados from CECs discharged into the coastal zone.

Contaminants of emerging concern in surface waters in Barbados, West Indies

Contaminants of emerging concern (CECs), including pharmaceuticals, artificial sweeteners, steroid hormones, and current-use pesticides have been detected in surface waters around the world, but to date, there have been no reports in the peer-reviewed literature on the levels of these classes of contaminants in freshwater resources in the Caribbean region. In the present study, multi-residue solid phase extraction (SPE) and liquid chromatography with tandem mass spectroscopy (LC-MS/MS) were used to analyze grab samples of surface waters collected from five different watersheds in Barbados, West Indies. The artificial sweeteners (AS), acesulfame, cyclamate, saccharin, and sucralose were widely detected in the watersheds, indicating contamination from domestic wastewater, and the concentrations of these chemical tracers in water were correlated with the concentrations of the non-prescription pharmaceutical, ibuprofen (R ² values of 0.4-0.6). Surprisingly, the concentrations of another chemical tracer of domestic wastewater, caffeine were not correlated with ibuprofen or AS concentrations. Several other prescription pharmaceuticals and the steroid hormones, estrone and androstenedione, were detected in selected watersheds at low ng/L concentrations. The fungicide, chlorothalonil was widely detected in surface waters at low (< 10 ng/L) concentrations, but the levels of this pesticide were not correlated with the concentrations of the other target analytes, indicating that the source of this pesticide is not domestic wastewater. An informal survey of disposal practices for out of date or unused drugs by pharmacies in Barbados indicated that disposal into trash destined for the landfill and flushing down the sink might be significant sources of contamination of water resources by pharmaceuticals.

Caffeine impacts in the clam Ruditapes philippinarum: Alterations on energy reserves, metabolic activity and oxidative stress biomarkers

Caffeine is known to be one of the most consumed psychoactive drugs. For this reason, caffeine is continuously released into the environment with potential impacts on inhabiting organisms. The current study evaluated the biochemical alterations induced in the clam species Ruditapes philippinarum after exposure for 28 days to caffeine (0.5, 3.0 and 18.0 μg/L). The results obtained showed that, with the increasing caffeine concentrations, an increase in clams defense mechanisms (such as antioxidant and biotransformation enzymes activity) was induced which was accompanied by an increase in protein content. Nevertheless, although an increase on defense mechanisms was observed, clams were not able to prevent cells from lipid peroxidation that increased with the increase of caffeine concentration. Furthermore, with the increase of exposure concentrations, clams increased their metabolic activity (measured by electron transport activity), reducing their energy reserves (glycogen content), to fight against oxidative stress. Overall, the present study demonstrated that caffeine may impact bivalves, even at environmentally relevant concentrations, inducing oxidative stress in organisms. The present study is an important contribution to address knowledge gaps regarding the impacts of long-term exposures to pharmaceuticals since most of the studies assessed the effects after acute exposures, most of them up to 96 h.