RESUMEN
Pharmaceutical residues end up in surface waters, impacting drinking water sources and contaminating the aquatic ecosystem. Pharmacists can play a role in reducing pharmaceutical residues, yet this is often not addressed in pharmacy undergraduate education. Therefore, we developed the educational module "Reducing Pharmaceuticals in Water" for pharmacy students; this was integrated in our pharmacy simulation game for third year Master of Pharmacy students at the University of Groningen. In this study, we aim to evaluate the effects of the module on students' knowledge of pharmaceutical residues in water, to describe students' experiences in taking the module, and to explore their attitudes towards green pharmacy education in general. This mixed-methods study included quantitative measurements, before and after students took the module (intervention group) and in a control group which did not receive the module. Data were collected between February 2023 and June 2023. Overall, 29 students took the module and 36 students were in the control group. The knowledge score of students in the intervention group (N = 29) increased significantly from 9.3 to 12.9 out of 22 (p < 0.001). The knowledge score of the students in the control group was (8.9 out of 22). Students found the e-learning and the patient cases the most exciting part of this module. Students also recognized the need to including environmental issues in pharmacy education. In conclusion, the module contributes towards improved knowledge and increased awareness of the impact of pharmaceuticals found in water. It represents a promising strategy to strengthen pharmacist's role in mitigating the amount and the effect of pharmaceuticals on water and the environment in the future.
RESUMEN
There are more than 3,500 active pharmaceutical ingredients (APIs) on the global market for human and veterinary use. Residues of these APIs eventually reach the aquatic environment. Although an environmental risk assessment (ERA) for marketing authorization applications of medicinal products is mandatory in the European Union since 2006, an ERA is lacking for most medicines approved prior to 2006 (legacy APIs). Since it is unfeasible to perform extensive ERA tests for all these legacy APIs, there is a need for prioritization of testing based on the limited data available. Prioritized APIs can then be further investigated to estimate their environmental risk in more detail. In this study, we prioritized more than 1,000 APIs used in Europe based on their predicted risk for aquatic freshwater ecosystems. We determined their risk by combining an exposure estimate (Measured or Predicted Environmental Concentration; MEC or PEC, respectively) with a Predicted No Effect Concentration (PNEC). We developed several procedures to combine the limited empirical data available with in silico data, resulting in multiple API rankings varying in data needs and level of conservativeness. In comparing empirical with in silico data, our analysis confirmed that the PEC estimated with the default parameters used by the European Medicines Agency often - but not always - represents a worst-case scenario. Comparing the ecotoxicological data for the three main taxonomic groups, we found that fish represents the most sensitive species group for most of the APIs in our list. We furthermore show that the use of in silico tools can result in a substantial underestimation of the ecotoxicity of APIs. After combining the different exposure and effect estimates into four risk rankings, the top-ranking APIs were further screened for availability of ecotoxicity data in data repositories. This ultimately resulted in the prioritization of 15 APIs for further ecotoxicological testing and/or exposure assessment.
Asunto(s)
Monitoreo del Ambiente , Contaminantes Químicos del Agua , Animales , Humanos , Monitoreo del Ambiente/métodos , Ecosistema , Medición de Riesgo/métodos , Peces , Preparaciones Farmacéuticas , Contaminantes Químicos del Agua/análisisRESUMEN
Environmental risks of human pharmaceutical products should be made transparent and mitigated as far as possible. We propose to apply a risk mitigation scheme to the marketing authorisation of human medicinal products which is pragmatic and tailored, and thus will not increase the burden to regulators and industry too much. This scheme takes into account increasing knowledge and accuracy of the environmental risk estimates, applying preliminary risk mitigation when risks are determined based on model estimates, and definitive, more strict and far-reaching risk mitigation when risks are based on actual measured environmental concentrations. Risk mitigation measures should be designed to be effective, proportional, easy to implement, and in line with current (other) legislation, as well as not being a burden to the patient/health care professionals. Furthermore, individual risk mitigation measures are proposed for products showing environmental risks, while general risk mitigation measures can be applied to all products to reduce the overall burden of pharmaceuticals in the environment. In order to effectively mitigate risk, linking marketing authorisation legislation to environmental legislation is essential.
Asunto(s)
Preparaciones Farmacéuticas , HumanosRESUMEN
One of the flagship actions of the Pharmaceutical Strategy for Europe is to address environmental challenges associated with pharmaceutical use. This includes strengthening the Environmental Risk Assessment (ERA) at marketing authorisation (MA) of pharmaceuticals, and revision of the pharmaceutical legislation where needed. The overall aim of an ERA should be to enable comprehensive and effective identification and management of environmental risks of pharmaceuticals without affecting the availability of pharmaceuticals to patients. As experts in the evaluation of ERAs of human medicinal products submitted by pharmaceutical industries (Applicants), we have summarized the current status of the ERA and suggest legislative changes to improve environmental protection without affecting availability. Six regulatory goals were defined and discussed, including possible ways forward: 1) mandatory ERAs in accordance to the EMA guideline at the time of the MA, 2) enforcement of risk mitigation measures including re-evaluation of the ERA, 3) facilitated exchange of environmental data between pharmaceutical and environmental legislations, 4) substance-based assessments, 5) transparency of data, and 6) a catching-up procedure for active pharmaceutical ingredients that lack an ERA. These legislative proposals can be considered as prerequisites for a harmonised assessment and effective management of environmental risks and hazards of human pharmaceuticals.
Asunto(s)
Industria Farmacéutica , Monitoreo del Ambiente , Humanos , Monitoreo del Ambiente/métodos , Europa (Continente) , Medición de Riesgo , Preparaciones FarmacéuticasRESUMEN
Medicines are essential to human health but can also impact the aquatic and terrestrial environment after use by patients and release via excreta into wastewater. We highlight the need for a GREENER approach to identify and meet important environmental criteria, which will help reduce the impact of medicinal residues on the environment. These criteria include effect reduction by avoiding nontarget effects or undesirable moieties, exposure reduction via lower emissions or environmental (bio)degradability, no PBT (persistent, bioaccumulative, and toxic) substances, and risk mitigation. With all of these criteria, however, patient health is of primary importance as medicines are required to be safe and efficacious for treating diseases. We discuss the feasibility of including these criteria for green by design active pharmaceutical ingredients in the process of drug discovery and development and which tools or assays are needed to accomplish this. The integrated GREENER approach can be used to accelerate discussions about future innovations in drug discovery and development.
RESUMEN
AIMS: Sewage treatment effluent with pharmaceutical residues is discharged into surface waters, raising societal concerns. The aim of this paper is to describe the Dutch chain approach on medicinal residues in water that has been implemented by the Dutch government. We show how stakeholders from both the health and water sectors have got actively involved. Within this chain approach, source measures as well as end-of-pipe measures are identified and, where feasible and effective, implemented. METHODS: Descriptive paper on the Dutch chain approach. RESULTS: Getting the water and health care sectors to talk with each other instead of about each other was the key accomplishment. Comprehension of each other's viewpoints, terminology, policy goals and span of control, was pivotal in setting shared goals, creating perspective about possible measures and actually taking (joint) action. Together, stakeholders agreed to act within their own possibilities, without pointing at others, and to focus on pragmatic measures. In this article, we provide examples of measures taken, pilot projects performed, and of measures that were not implemented. Besides this, we discuss the most important barriers encountered during this process and how they were overcome. CONCLUSION: The issue of pharmaceuticals in the environment is a wicked problem, which makes it necessary to work together with many stakeholders on possible solutions, avoiding paralysis by complexity. Most importantly, stakeholders need to invest in mutual understanding, keep an open communication, and feel invited to bring in solutions for their part of the chain.
Asunto(s)
Ambiente , Agua , Humanos , Preparaciones FarmacéuticasRESUMEN
Environmental quality standards (EQSs) for 3 pharmaceuticals in surface water were derived: carbamazepine (epilepsy), metoprolol (heart failure), and metformin (diabetes). In recent years, these pharmaceuticals have been detected frequently in Dutch surface waters. The proposed standards are based on ecotoxicity data from national and European authorization dossiers and additional information obtained from open literature. The methods used are in accordance with the methodology of the Water Framework Directive and national frameworks for risk limit derivation. Only the exposure route regarding direct ecotoxic effects on ecosystems could be taken into account for deriving EQSs. The exposure route of secondary poisoning of fish-eating animals was not triggered, and not enough data were available or accessible to derive an EQS for the exposure of humans due to consumption of fish. Monitoring data for surface waters worldwide show that the proposed quality standards for carbamazepine may be exceeded. It could be expected that when carbamazepine use increases or effluents are diluted less during dry seasons, standards will be exceeded more often.
Asunto(s)
Carbamazepina/análisis , Monitoreo del Ambiente , Metformina/análisis , Metoprolol/análisis , Contaminantes Químicos del Agua/análisis , Calidad del Agua/normas , Carbamazepina/toxicidad , Ecosistema , Ecotoxicología , Metformina/toxicidad , Metoprolol/toxicidad , Pruebas de Toxicidad Aguda , Pruebas de Toxicidad CrónicaRESUMEN
Predicted-no-effect concentrations (PNECs) and environmental quality standards (EQSs) are derived in a large number of legal frameworks worldwide. When deriving these safe concentrations, it is necessary to evaluate the reliability and relevance of ecotoxicity studies. Such evaluation is often subject to expert judgment, which may introduce bias and decrease consistency when risk assessors evaluate the same study. The Criteria for Reporting and Evaluating Ecotoxicity Data (CRED) project attempts to address this problem. It aims to improve the reproducibility, transparency, and consistency of reliability and relevance evaluations of aquatic ecotoxicity studies among regulatory frameworks, countries, institutes, and individual assessors. In the present study, the CRED evaluation method is presented. It includes a set of 20 reliability and 13 relevance criteria, accompanied by extensive guidance. Risk assessors who participated in the CRED ring test evaluated the CRED evaluation method to be more accurate, applicable, consistent, and transparent than the often-used Klimisch method. The CRED evaluation method is accompanied by reporting recommendations for aquatic ecotoxicity studies, with 50 specific criteria divided into 6 categories: general information, test design, test substance, test organism, exposure conditions, and statistical design and biological response. An ecotoxicity study in which all important information is reported is more likely to be considered for regulatory use, and proper reporting may also help in the peer-review process.
Asunto(s)
Monitoreo del Ambiente/normas , Proyectos de Investigación/normas , Contaminantes Químicos del Agua/toxicidad , Ambiente , Cooperación Internacional , Reproducibilidad de los Resultados , Medición de RiesgoRESUMEN
Hexachlorobenzene (HCB) is a priority hazardous substance within the Water Framework Directive (WFD). For aquatic systems, the European Commission has derived quality standards (QS) for HCB in biota. However, in some countries a preference may exist for QS based on water concentrations. The conversion of biota QS into water QS can be done by dividing the quality standard for biota by a reliable bioaccumulation factor (BAF) or by the product of the bioconcentration factor (BCF) and the biomagnification factor (BMF) (BCF × BMF). An extensive literature review of HCB bioaccumulation was performed, and data on bioaccumulation, biomagnification and bioconcentration, both from the field and the laboratory, were assessed for their usefulness to recalculate biota standards into water standards. The evaluation resulted in 10 reliable values for field BAFs, with a geometric mean of 221 000 L/kg (5% lipid-normalized). Bioaccumulation factor measurements show a high variation of more than 1 order of magnitude. At lower trophic levels (algae, small zooplankton), accumulation of HCB already exceeds expected accumulation through equilibrium partitioning by far. This affects BAFs at higher trophic levels as well. Moreover, observed BAF values for HCB in fish cannot be easily explained from the age of the fish, but there is a significant increase with trophic level. Reliable values for laboratory BCFs for fish were retrieved from literature, partly with water-based exposure and partly with dietary exposure. The 5% lipid-normalized BCF of all these data is 12 800 L/kg. Regarding biomagnification, a number of reliable BMF and trophic magnification factor values, mostly determined in the field, were retrieved. From these data, an overall BMF of 3 per trophic level can be deduced. When comparing BCF values for fish multiplied by the BMF (12 800 × 3 = 38 400 L/kg) to the observed BAF values for fish (geometric mean 238 000 L/kg), there appears to be a large gap. Thus, the uncertainties surrounding values for bioaccumulation of HCB are high. Although the confidence in laboratory BCFs is higher, these data seem to be not relevant for small fish in the field. This makes it difficult to obtain a reliable BAF or BCF × BMF value to recalculate biota standards into water standards. On the other hand, biota concentrations in the field show a high variability that also hampers comparison with a fixed limit such as a quality standard. Thus, compliance checking using biota in the field means that a relatively large amount of fish will have to be used to obtain a reliable estimate. The following "tiered approach" is suggested: 1) calculate a water quality standard, using the BAF value that is most relevant for the trophic level to be protected, and 2) if this standard is exceeded in the field, sample representative biota in the field and compare concentrations of HCB in biota and water with their respective standards in a weight of evidence approach for compliance checking. In this way, unnecessary biota sampling can be avoided for reasons of efficiency and animal welfare.
Asunto(s)
Unión Europea , Hexaclorobenceno/metabolismo , Contaminantes Químicos del Agua/metabolismo , Calidad del Agua/normas , Animales , Peces/metabolismoRESUMEN
There is no uniform Persistent, Bioaccumulative, Toxic (PBT) or very Persistent, very Bioaccumulative (vPvB) assessment of chemicals in Europe, as the various regulatory frameworks use only limited or dissimilar PBT assessments, or none at all. The European REACH Regulation requires a PBT/vPvB assessment for all chemical substances that are produced within or imported into the EU in amounts exceeding 10 tonnes per year, using the criteria as described in REACH Annex XIII. However, not all substances on the EU market need to be screened according to these criteria under REACH. For a number of substances, such as those imported or produced in lower volumes, there is no REACH requirement, and for human and veterinary medicinal products, biocides, plant protection products, and food and feed additives, other EU legislation is in force to regulate their marketing and use. Compounds may also be screened for PBT properties within international agreements, such as the Oslo Paris Convention (OSPAR), the IMO Ballast Water Management Convention, the UNECE POP Protocol, and the UNEP Stockholm Convention on Persistent Organic Pollutants (POPs), which all have their own set of PBT or POP criteria. This study compares the PBT/vPvB assessment under REACH with PBT or POP assessments performed within other regulatory frameworks. Attention is paid to the process of PBT/vPvB/POP identification and which legislative steps can be taken if the PBT/vPvB/POP status is assigned. In addition to the different PBT or POP criteria of the various frameworks, descriptions of these criteria and approaches for application of weight of evidence also vary. Some EU frameworks still refer to the criteria in the former Technical Guidance Documents (TGD) of 2003, which preceded REACH. Although differences between the old TGD criteria and those in the REACH Annex XIII are small, this does cause dissimilarities among the frameworks. The risk management follow-up of a PBT or vPvB identification, which may include a socio economic analysis, also depends on the legal framework and the specific conditions under which a substance is used. Irrespective of the framework in which a substance is used, individual European Member States may propose a substance evaluation for PBT or vPvB identification under REACH. However, authorization is only possible for uses of PBT substances that are not covered by their regular framework but are registered under REACH. How socio-economic criteria should be weighed against PBT/vPvB properties and environmental risks in authorizing or restricting the use of PBT/vPvB substances is often not specified. Thus, although the goal of restricting or banning the use of PBT/vPvB substances is shared among all EU-based regulatory frameworks, there are many differences in how to achieve this goal. These differences create a challenge to harmonize the PBT/vPvB assessment of substances, not only regarding technical criteria, but also regarding regulatory follow-up.
Asunto(s)
Política Ambiental , Contaminantes Ambientales/clasificación , Contaminación Ambiental/legislación & jurisprudencia , Unión Europea , Regulación Gubernamental , Toma de Decisiones , Exposición a Riesgos Ambientales/prevención & control , Monitoreo del Ambiente , Contaminantes Ambientales/química , Contaminantes Ambientales/toxicidad , Contaminación Ambiental/análisis , Contaminación Ambiental/prevención & control , Medición de RiesgoRESUMEN
Regime shifts in shallow lakes may significantly affect partitioning of sediment-bound hydrophobic organic chemicals (HOCs) such as polychlorobiphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH). In replicated experimental model ecosystems mimicking the alternative stable states 'macrophyte-dominated' and 'suspended solid - phytoplankton dominated', we tested the effects of macrophytes and benthivorous fish presence on mass distribution and bioaccumulation of hexachlorobenzene, PCBs and PAHs. HOC mass distributions and lipid-normalized concentrations in sediment (Soxhlet- and 6-h Tenax-extractable), suspended solids, macrophytes, periphyton, algae, zooplankton, invertebrates and carp revealed that mobile, i.e. less hydrophobic or less aged HOCs were more susceptible to ecological changes than their sequestered native counterparts. Macrophytes were capable of depleting considerable percentages of the bioavailable, fast desorbing HOC fractions in the sediment upper (bioactive) layer, but did not have a significant diluting effect on lipid-normalized HOC concentrations in carp. Carp structured invertebrate communities through predation and stimulated partitioning of HOCs to other system compartments by resuspending the sediment. These results show that shifts in ecosystem structure have clear effects on fate, risks and natural attenuation of sediment-bound organic contaminants.
Asunto(s)
Ecosistema , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/metabolismo , Animales , Interacciones Hidrofóbicas e Hidrofílicas , Invertebrados/metabolismo , Fitoplancton/metabolismo , Bifenilos Policlorados/análisis , Bifenilos Policlorados/metabolismo , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/metabolismoRESUMEN
The predictive power of bioaccumulation models may be limited when they do not accountfor strong sorption of organic contaminants to carbonaceous materials (CM) such as black carbon, and when they do not include metabolic transformation. We tested a food web accumulation model, including sorption to CM, on data from a model ecosystem experiment with historically contaminated sediment. In combination with measured CM contents of the sediment, the model gave good fits for the biota that are known not to metabolize PAHs (macrophytes, periphyton, floating algal biomass). The same model was applied to invertebrates and fish but now with optimization of their metabolic transformation rates (k(m)). For fish, these rates correlated empirically with log K(OW): Log k(m) = -0.8 log K(OW) + 4.5 (r2 adj = 0.73). For invertebrates, log k(m) did not correlate with logK(OW). Sensitivity analysis revealed that the model output is highly sensitive to sediment CM content and sorption parameters, moderately sensitive to metabolic transformation rates, and slightly sensitive to lipid fraction of the organism and diet-related parameters. It is concluded that CM-inclusive models yield a better assessment of accumulation than models without sorption to CM. Furthermore, inclusion of CM in a model enables metabolic transformation rates to be calculated from the remaining overestimation in the model results when compared to measured data.
Asunto(s)
Algoritmos , Monitoreo del Ambiente , Cadena Alimentaria , Hidrocarburos Policíclicos Aromáticos/farmacocinética , Contaminantes del Suelo/farmacocinética , Contaminantes Químicos del Agua/farmacocinética , Adsorción , Animales , Biotransformación , Peces , Sedimentos Geológicos/química , Invertebrados , Modelos Teóricos , Hidrocarburos Policíclicos Aromáticos/química , Análisis de Regresión , Contaminantes del Suelo/química , Contaminantes Químicos del Agua/químicaRESUMEN
Model estimations of bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) have been higher than field or laboratory data. This has been explained by strong sorption to black carbon (BC). In this paper, eight previously published bioaccumulation datasets were reinterpreted in terms of additional BC sorption. Biota--Solids Accumulation Factors (BSAFs) of PAHs typically decreased by 1-2 orders of magnitude and were better in line with field data in marine, fresh water, and terrestrial ecosystems. Probabilistic BC-inclusive modeling showed that if BC content is not accurately known, uncertainty in BSAFs is 2-3 orders of magnitude (90 percentile confidence interval) due to uncertainty in the BC sorption term. When BC contents are measured, the deviation between model estimations and field measurements reduces to about a factor of 3. This implies that including routine measurements of BC contents is crucial in improving risk estimations of PAHs.
Asunto(s)
Hidrocarburos Policíclicos Aromáticos/química , Hollín/química , Adsorción , Ecosistema , Contaminación Ambiental/prevención & control , Modelos Teóricos , Sensibilidad y EspecificidadRESUMEN
It is not clear whether sequestration or aging of organic chemicals like polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) limits accumulation in higher levels of aquatic food chains. Therefore, the effect of aging on accumulation was studied in 1(-m3) model ecosystems that mimicked fish-dominated, macrophyte-dominated, and fish- and macrophyte-dominated shallow lakes. Also treatments without fish and macrophytes were included. General characteristics, biomasses, total (Soxhlet-extractable), and labile (6-h Tenax-extractable) PCB and PAH concentrations in sediment and biota were monitored over time. Accumulation data for PCB 28, PCB 149, and fluoranthene (native to the sediment taken from the field) were compared to those for spiked analogues PCB 29, PCB 155, and fluoranthene-d10. Labile fractions for spiked compounds were higher than for their native analogues and decreased over time, suggesting sequestration in the sediment. In the majority of cases, 6-h Tenax-extractable concentrations correlated better with concentrations in biota than Soxhlet-extractable concentrations. Ecosystem structure affected food web accumulation, but replicate variability was too high to detect clear treatment effects. Differences in accumulation between spiked compounds and their native analogues indicated an effect of aging for invertebrates, macrophytes, and benthivorous fish. Thus, aging may translate directly into reduced uptake at higher trophic levels.
Asunto(s)
Ecosistema , Monitoreo del Ambiente/estadística & datos numéricos , Cadena Alimentaria , Agua Dulce/análisis , Sedimentos Geológicos/análisis , Modelos Teóricos , Bifenilos Policlorados/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Análisis de Varianza , Animales , Carbono/análisis , Peces/metabolismo , Invertebrados/metabolismo , Plantas/metabolismo , Bifenilos Policlorados/farmacocinética , Hidrocarburos Policíclicos Aromáticos/farmacocinética , Zooplancton/metabolismoRESUMEN
Ecological factors may play an important role in the bioaccumulation of polychlorobiphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Geochemical and bioaccumulation behavior of these chemicals also appears to be related to the presence of black carbon (BC) in sediment. In situ PCB and PAH biota to sediment accumulation factors (BSAF) for benthic invertebrates, as well as 6h Tenax-extractable (fast-desorbing) concentrations and lake characteristics (including BC in sediment), were determined for different seasons in chemically similar but ecologically different lakes (fish-dominated turbid, algae-dominated turbid, and macrophyte-dominated). BSAFs could be explained with a model including a term for Freundlich sorption to BC and a term for uptake from fast-desorbing concentrations in ingested sediments. Freundlich coefficients for in situ sorption to BC (KF) were calculated from slow desorbing fractions and BC contents and agreed well with literature values for KF. Furthermore, in contrast to BSAFs based on total extracted concentrations, Tenax-based BSAF showed a strong positive correlation with log Kow. We therefore argue that BC caused slow desorption and limited BSAFs in these lakes. Seasonal and lake effects on BSAFs were detected, while the differences between oligochaetes and other invertebrates were small for PCBs and within a factor of 10 for PAHs. BSAFs for pyrogenic PAHs were much lower than for PCBs, which was explained by stronger sorption to BC and lesser uptake from ingested sediment.
Asunto(s)
Sedimentos Geológicos/química , Bifenilos Policlorados/farmacocinética , Hidrocarburos Policíclicos Aromáticos/farmacocinética , Contaminantes Químicos del Agua/farmacocinética , Adsorción , Animales , Disponibilidad Biológica , Invertebrados , Bifenilos Policlorados/química , Hidrocarburos Policíclicos Aromáticos/química , Estaciones del Año , Abastecimiento de AguaRESUMEN
It is unclear whether accumulation of sediment-bound chemicals in benthivorous fish depends on the degree of sequestration in the sediment like it does for invertebrates. Here, we report on the potential of slow and fast desorbing sediment-bound polychlorobiphenyl (PCB) fractions for accumulation in carp (Cyprinus carpio) in lake enclosures treated with different nutrient doses. Routes of PCB uptake were quantitatively evaluated for 15 PCBs (log Kow range 5.6-7.8) using model analysis. Fast-desorbing PCB fractions in the sediment were defined as the ratio of 6-h Tenax-extractable to (total) Soxhlet-extractable concentrations. These fractions varied between 4 and 22% and did not show a clear trend with log Kow. However, bioaccumulation of PCBs in carp correlated much better with Tenax-extractable concentrations than with total-extractable concentrations. Nutrient additions in the enclosures had a positive effect on PCB accumulation. Model results showthat PCB uptake in carp can be explained from (1) uptake through invertebrate food, (2) uptake from fast-desorbing fractions in ingested sediments, and (3) uptake from water, where PCBs are in partitioning equilibrium with fast-desorbing fractions. The main implication of this research is that fast-desorbing PCB fractions in sediments have great predictive potential for bioaccumulation in benthivorous fish.
Asunto(s)
Carpas/metabolismo , Sedimentos Geológicos/química , Bifenilos Policlorados/análisis , Contaminantes Químicos del Agua/análisis , Adsorción , Animales , Disponibilidad Biológica , Cadena Alimentaria , Agua Dulce , Invertebrados/química , Invertebrados/metabolismo , Modelos Biológicos , Países Bajos , Bifenilos Policlorados/química , Bifenilos Policlorados/metabolismo , Polímeros , Reproducibilidad de los ResultadosRESUMEN
Benthic communities in floodplain lake ecosystems are often exposed to varying levels of both food and toxicants. Inhibition through toxicants of sensitive species and stimulation through increased amounts of food of opportunistic species have been observed in separate studies. The aim of this study was therefore to assess the responses of benthic invertebrates to combined food and contamination input. Hence, seven floodplain lakes located along the River Waal, The Netherlands, with different levels of food (being either phytoplankton or macrophyte dominated) and toxicants were selected. The responses of the sensitive mayfly Ephoron virgo and the opportunistic midge Chironomus riparius to these sediments were assessed in 10-d growth bioassays with both species and a 28-d emergence experiment with C. riparius. A decrease in both survival and growth of E. virgo was observed with increasing contaminant levels. In contrast, C. riparius responded to the food quantity and quality in the sediments in spite of the toxicants present. Therefore, we conclude that the midge C. riparius is not a suitable test organism for the assessment of sediment toxicity. Alternatively, it proved to be an appropriate test organism to determine the nutritional value of sediments. The mayfly E. virgo turned out to be a much more appropriate test organism for sediment toxicity bioassays because it responds to the toxicant levels in the sediments rather than to the nutritional value. Our results demonstrate that the trophic state of an ecosystem (macrophyte or plankton dominated) influences the ecological risk of toxicants to benthic invertebrates in a species-specific way. It is concluded that not the toxicant load but the combination of food and contaminants determines the persistence of benthic invertebrates and therewith the benthic invertebrate composition in complexly polluted ecosystems.