Endocrine disrupting chemicals accumulate in earthworms exposed to sewage effluent

Effect of the coexistence of endosulfan on the lindane biodegradation by Novosphingobium barchaimii and microbial enrichment cultures

Organochlorine pesticides, especially lindane and endosulfan, have been demonstrated to be both biodegradable and frequently coexistent, but their inhibitory effect has never been studied. In this study, we investigated the effect of endosulfan coexistence on lindane degradation to a lindane-degrading isolate, Novosphingobium barchaimii strain LL02, and mixed enrichment cultures from two different inocula. Our results of the lindane degradation batch experiments demonstrated that endosulfan concentration above 20 mg L^-1 causes significant inhibition to the lindane degradation efficiency of the strain LL02. Besides, the acidic conditions at pH 5.0 to 6.0 further decreased its lindane degradation rate constants by 57% compared to the neutral and alkaline conditions. For the mixed microbial cultures, the lindane degradation efficiency in the lindane/endosulfan co-contamination conditions decreased by 35.7%-50.7% compared to the lindane alone conditions. From our 16S rRNA amplicon sequencing results through the PacBio platform, most of the predominant bacteria in the lindane-enriched cultures were depressed in the lindane/endosulfan-enriched cultures. Moreover, bacteria of Burkholderia australis, Chujaibacter soli, Flavitalea flava, and one Rhodanobacteraceae bacterium were relatively highly abundant in the co-contamination enrichment cultures, suggesting their potential for lindane degradation under the endosulfan stress. Our results demonstrated that endosulfan coexistence causes inhibitory impacts on lindane biodegradation toward both lindane-degrading bacteria and mixed microbial cultures. The coexistence of multiple organochlorine pesticides on the biodegradation efficiencies should be carefully considered when applying bioremediation to remove organochlorine pesticide contamination.

Isolation of lindane- and endosulfan-degrading bacteria and dominance analysis in the microbial communities by culture-dependent and independent methods

　　Bioremediation for lindane and endosulfan removal is a cost-effective approach, but its effectiveness depends on the ability to isolate degrading functionalized microorganisms. Researchers have isolated many lindane and endosulfan degrading bacteria from enrichment cultures based on culture-dependent methods during the past decades. However, it is unknown whether the isolated bacteria can reflect the indigenous predominant degraders in enriching cultures. In this study, we compared the culture-dependent method with selective medium isolation with culture-independent method (PacBio SMRT sequencing of full-length 16S rRNA amplicon) to analyze the bacterial communities from four distinct lindane (LA1 and LC1) and endosulfan (EA1 and EC1) enrichment cultures. From all the isolates we harvested from lindane (63 isolates) and endosulfan (61 isolates) enrichment cultures, their BLAST alignment can only match 5.49 % and 4.32 % of the bacterial operational taxonomic units (OTUs), respectively. Rhodanbacter lindaniclasticus and Pandoraea thiooxydans were the rarely seen potential degrading representatives that were simultaneously enriched and isolated. This study is the first comparative analysis of microbial communities from lindane and endosulfan enrichment culture using culture-dependent and culture-independent methods. Our results suggested that developing a target-specific and efficient microbial isolation method is necessary to harvest and study representative degrading bacteria in the community.

Assessing potential indicator of endocrine-disrupting property of chemicals using soil invertebrates

Vitellogenin has been regarded as an acceptable indicator for evaluating the endocrine-disrupting property of chemicals using fish. However, the endocrine-disrupting property of chemicals has been rarely evaluated using soil species. This study aimed to find evidence that endocrine-disrupting chemicals (including the natural hormones estradiol and dihydrotestosterone) can affect the reproductive organs of earthworms. Earthworms were exposed to 17β-estradiol, dihydrotestosterone, bisphenol A, and methylparaben for seven days. The four EDCs inhibited normal oogenesis and maturation of oocytes in earthworm ovary, and dihydrotestosterone and bisphenol A were observed to damage earthworm seminal vesicle tissues and inhibit normal spermatogenesis. The evidence showed that the tested EDCs have an adverse effect on female and male reproductive systems of soil invertebrates. The results suggest that the evaluations of oogenesis and spermatogenesis in the ovary and seminal vesicles of earthworms are useful indicators for investigating the endocrine-disrupting property of chemicals. Additionally, our results encourage further studies on developing novel indicators using soil invertebrates to evaluate the effects of the toxicity of endocrine-disrupting chemicals on the soil ecosystem.

Lethal and long-term effects of landfill leachate on Eisenia andrei earthworms: Behavior, reproduction and risk assessment

Leachate is difficult to biodegrade, and presents variable physical, chemical and biological characteristics, as well as high toxicological potential for soil, groundwater and water bodies. In this context, untreated leachate toxicity was evaluated through acute and chronic exposures in Eisenia andrei earthworms. Physico-chemical leachate characterizations indicate a complex composition, with high organic matter (COD - 10,634 mg L^-1) and ammoniacal nitrogen (2388 mg L^-1) concentrations. Metals with carcinogenic potential, such as Cr, As and Pb, were present at 0.60, 0.14 and 0.01 μg L^-1, respectively and endocrine disrupting compounds were detected in estradiol equivalents of 660 ± 50 ng L^-1. Acute tests with Eisenia andrei indicated an LC₅₀ (72 h) of 1.3 ± 0.1 μL cm^-2 in a filter paper contact test and 53.9 ± 1.3 mL kg^-1 in natural soil (14 days). The EC₅₀ in a behavioral test was estimated as 31.6 ± 6.8 mL kg^-1, indicating an escape effect for concentrations ranging from 35.0 to 70.0 mL kg^-1 and habitat loss from 87.5 mL kg^-1 of leachate exposure. Chronic exposure (56 days) led to reproduction effects, resulting in a 4-fold decreased cocoon production and 7-fold juvenile decrease. This effect was mainly attributed to the possible presence of endocrine disrupting compounds. An estimated NOAEL of 1.7 mL L^-1 and LOAEL of 3.5 mL L^-1 were estimated for earthworms exposed to the assessed effluent. Extremely high-risk quotients (RQ ≥ 1) were estimated based on leachate application in irrigation. Thus, adequate municipal solid waste management is paramount, especially with regard to generated by-products, which can result in high toxicological risks for terrestrial organisms.

Development and application of a QuEChERS method with liquid chromatography-quadrupole time of flight-mass spectrometry for the determination of 50 wastewater-borne pollutants in earthworms exposed through treated wastewater

Soil-dwelling earthworms are valuable sentinels in soil pollution monitoring and, in case of wastewater reuse for agricultural irrigation, they are continuously exposed to a multitude of organic micro-pollutants. In the present work, an analytical methodology for the determination of 50 wastewater-borne pollutants in earthworms (Lumbricus terrestris) using a fast extraction and sensitive detection method was developed. In total, 17 protocols based on QuEChERS extraction methods were evaluated including the choice of extraction salt (EN vs Original) and the solvent pH as well as the cleanup type. EN with cleanup on Oasis PRiME HLB (P-16) provided the best overall performance. Compound quantification was accomplished by liquid chromatography-mass spectrometry on a QToF-MS system using the ultra-fast high-resolution multiple reaction monitoring (MRM^HR) mode. The method quantification limits ranged from 0.002 to 1.6 ng g^-1. In comparison to previously reported methods the present protocol afforded improved accuracy with recovery rates exceeding 80%. The validated method was applied to the analysis of 36 earthworm samples originating from laboratory experiments and fields that had been irrigated with treated wastewater. Among the eight analytes detected in field samples, the highest concentration levels were measured for gemfibrozil (13 ng g^-1) and caffeine (12 ng g^-1). To the best of our knowledge, this is the first report of the transfer of wastewater-borne contaminants to earthworms following irrigation under natural farming practices.

Cobalt-based ZIF coordinated hybrids with defective TiO2-x for boosting visible light-driven photo-Fenton-like degradation of bisphenol A

Designing heterostructure of photocatalyst as an efficient approach to boost visible light-driven photocatalytic degradation, we prepared a series of cobalt-based ZIF coordinated with defective TiO_2-x, denoted as B-TiO_2-x@ZIF-67 composites, through wrapping defective B-TiO_2-x on ZIF-67 for promoting photocatalytic degradation efficiency of biphenyl A. The B-TiO_2-x@ZIF-67 composites displayed superior photocatalytic performance to pure TiO_2-x or ZIF-67 because of faster separation of photogenerated charge carriers and more suitable redox potentials. Such a novel photo-Fenton-like system composed of B-TiO_2-x@ZIF-67/H₂O₂/visible light accelerated the peroxidative degradation of biphenyl An up to a removal efficiency of 95.30%, which is also higher than that of photocatalysis or Fenton-like reaction alone. In addition, the degradation efficiency of biphenyl A is unchanged after catalyst reuse of four cycles. Integrating the trapping experiments and electrochemical analysis, we found the oxygen vacancy on B-TiO_2-x capturing the electrons to promote the separation of photogenerated charges, meanwhile the Co(II) in the composite decomposed hydrogen peroxide (H₂O₂) to produce more •OH radical. Both of them mutually boosted the removal efficiency. Finally, feasible degradation pathways of biphenyl A were proposed based on the assay of LC-MS spectrometry. This strategy offers a novel insight into fabrication of Co-ZIF-based TiO_2-x materials and application to visible light-driven photocatalytic and Fenton-like degradation reaction.

Effects of organic mercury on Mytilus galloprovincialis hemocyte function and morphology

Abstract

Filter-feeding organisms accumulate xenobiotics and other substances in their tissues. They can be useful as sentinel organisms in biomonitoring of the marine compartment. Bivalve cellular immunity is ensured by phagocytosis and cytotoxic reactions carried out by hemocytes in a network with humoral responses. These can be affected by chemical contaminants in water that can be immunosuppressors also at a low concentration increasing the sensibility to pathogens. This work is an attempt to individuate cellular markers for pollution detection, investigating the effect of methylmercury (CH₃HgCl) at different concentrations on the activity and hemocyte morphology of the Mediterranean mussel, Mytilus galloprovincialis. We assessed the effect of three sub-lethal concentrations of the organometal on the cellular morphology, the efficacy of phagocytosis toward yeast cells, the alteration of the lysosomal membrane and the ability to release cytotoxic molecules. The results provide information on the alteration of hemocyte viability, modification of the morphological and cytoskeletal features and besides the cellular spreading, intrinsic ability of motile cells was used as a complementary investigation method. Exposure to the contaminant affected the percentage of phagocytosis and the phagocytosis index. Moreover, morphological and cytoskeleton alteration, caused by the pollutant, leads to reduced ability to incorporate the target and adhere to the substrate and the low ability of cells to retain neutral red could depend on the effects of methylmercury on membrane permeability. These results reinforce the use of the Mediterranean mussel as model for the evaluation of environmental quality in aquatic ecosystems integrating the novel information about hemocyte functions and morphology sensibility to organic mercury.

Graphic abstract

Insights Into the Biodegradation of Lindane (γ-Hexachlorocyclohexane) Using a Microbial System

Lindane (γ-hexachlorocyclohexane) is an organochlorine pesticide that has been widely used in agriculture over the last seven decades. The increasing residues of lindane in soil and water environments are toxic to humans and other organisms. Large-scale applications and residual toxicity in the environment require urgent lindane removal. Microbes, particularly Gram-negative bacteria, can transform lindane into non-toxic and environmentally safe metabolites. Aerobic and anaerobic microorganisms follow different metabolic pathways to degrade lindane. A variety of enzymes participate in lindane degradation pathways, including dehydrochlorinase (LinA), dehalogenase (LinB), dehydrogenase (LinC), and reductive dechlorinase (LinD). However, a limited number of reviews have been published regarding the biodegradation and bioremediation of lindane. This review summarizes the current knowledge regarding lindane-degrading microbes along with biodegradation mechanisms, metabolic pathways, and the microbial remediation of lindane-contaminated environments. The prospects of novel bioremediation technologies to provide insight between laboratory cultures and large-scale applications are also discussed. This review provides a theoretical foundation and practical basis to use lindane-degrading microorganisms for bioremediation.

Eco-friendly alginate encapsulated magnetic graphene oxide beads for solid phase microextraction of endocrine disrupting compounds from water samples

In the proposed method iron crosslinked alginate encapsulated magnetic graphene oxide beads were synthesized and used as an adsorbent for the microextraction of endocrine disrupting compounds from water samples and further analyzed by high performance liquid chromatography with ultraviolet detector. The beads were characterized using spectroscopic techniques, such as Fourier transform infra-red spectroscopy for the determination of different functional groups, Scanning electron microscopy for surface morphology, X-ray diffraction for phase determination and energy dispersive X ray spectroscopy for elemental composition. The results revealed that beads surface have functional groups of alginate and graphene oxide which are involved in π-π, n-πinteractions and hydrogen bonding for the bisphenol A and epichlorohydrin adsorption. The experimental conditions were studied for two endocrine disrupting compounds (Epichlorohydrin ad Bisphenol A) and at optimum conditions the adsorption capacity was 6.73 mgg^-1 for epichlorohydrin and 7.01 mgg^-1 for bisphenol A. The kinetic and equilibrium studies revealed that the adsorption process follow pseudo-second order kinetics and Langmuir equilibrium models. Analytical parameters were calculated for the microextraction of epichlorohydrin and bisphenol A. Limit of detection was 8.25 ngL^-1 and 13.99 ngL^-1 (n = 4) for epichlorohydrin and bisphenol A, respectively. Different solvents used for microextraction and maximum extraction of both endocrine disrupting compounds were obtained with methanol. The proposed method was applied to spiked samples and the recovery values were 97.17 ± 3.13% for epichlorohydrin and 99.46 ± 1.39% for bisphenol A. The magnetic graphene oxide encapsulated inside an alginate shows nontoxic green chemical with high extraction performance for toxic organic compounds in water treatment.

Context-specific behavioural changes induced by exposure to an androgenic endocrine disruptor

Pharmaceutical contaminants are being detected with increased frequency in organisms and ecosystems worldwide. This represents a major environmental concern given that various pharmaceuticals act on drug targets that are evolutionarily conserved across diverse taxa, are often persistent in the environment, and can bioconcentrate in organisms and bioaccumulate in food chains. Despite this, relatively little is known about the potential for pharmaceutical contaminants to affect animal behaviour, especially across multiple fitness-related contexts. Here, we investigated impacts of 21-day exposure of wild-caught male eastern mosquitofish (Gambusia holbrooki) to a field-realistic level of the veterinary pharmaceutical 17β-trenbolone-a growth-promoting steroid used extensively in beef production worldwide and a potent androgenic endocrine disruptor repeatedly detected in surface waters affected by livestock effluent run-off. First, we examined male boldness, activity, and exploratory behaviour in a novel environment (maze arena) and found no significant effect of 17β-trenbolone exposure. Second, the same males were tested in a reproductive assay for their tendency to associate with a stimulus (unexposed) female behind a partition. Exposed males exhibited reduced association behaviour, taking longer to first associate with, and spending less time within close proximity to, a female. Third, all males were assayed for sperm function (computer-assisted sperm analysis, sperm viability) or quantity (total sperm count) and, although no significant main effects of 17β-trenbolone were seen on sperm traits, exposure altered the relationship between male morphology and sperm function. Lastly, morphological traits were assessed and exposed males were found to have, on average, increased mass relative to length. In combination, these results demonstrate that exposure to a field-realistic level of 17β-trenbolone can produce subtle but important trait alterations in male fish-including context-specific behavioural changes, disruption of key sperm function trade-offs, and altered morphology-with potential impacts on exposed wildlife.

Comparative Endocrinology: Past, Present, and Future

Comparative endocrinology has traditionally focused on studies of the evolution of endocrine systems, regulation of hormone actions in animals, development of model systems, and the role of the environment in controlling hormone functions related to major life-history events. Comparative endocrinology also has made important contributions to basic research and clinical endocrinology. In recent years there has been a shift to a focus on anthropogenic chemical factors and their alteration of major life history events through endocrine disruption. During the 21st century, environmental comparative endocrinologists must play an important role in the identification and assessment of endocrine disruption on vertebrate and invertebrate animals and their environment as well as in monitoring remediation. All comparative biologists are encouraged to communicate their understanding of threats to biological systems to non-scientists to facilitate their understanding of the human impacts of various kinds of pollution and habitat destruction on wildlife and ecosystems as well as their long-term consequences.

Determination of the soil hazardous concentrations of bisphenol A using the species sensitivity approach

This study describes the determination of the species sensitivity distribution (SSD)-based soil hazardous contamination of bisphenol A for environmental risk assessment. We conducted a battery of bioassays, including acute assays using eight species from six different taxonomic groups and chronic assays using five species from four different taxonomic groups. We determined that our dataset satisfied Australia & New Zealand's guidelines for applying the SSD methodology. Finally, the chronic soil HC₅ and HC₅₀ values for bisphenol A were estimated to be 13.7 and 74.7mg/kg soil, respectively, for soil ecosystem protection against chronic exposure using the data generated from this and previous studies. Because the soil standard values of bisphenol A for protection of the soil ecosystem are not currently available, the HC values of bisphenol A that we suggested based on the SSD approach would be applied as fundamental data to establish soil standards of bisphenol A for soil ecosystem protection. To our knowledge, this is the first study reporting the soil hazardous concentration of bisphenol A for environmental risk assessment.

Pharmaceuticals in water, fish and osprey nestlings in Delaware River and Bay

Exposure of wildlife to Active Pharmaceutical Ingredients (APIs) is likely to occur but studies of risk are limited. One exposure pathway that has received attention is trophic transfer of APIs in a water-fish-osprey food chain. Samples of water, fish plasma and osprey plasma were collected from Delaware River and Bay, and analyzed for 21 APIs. Only 2 of 21 analytes exceeded method detection limits in osprey plasma (acetaminophen and diclofenac) with plasma levels typically 2-3 orders of magnitude below human therapeutic concentrations (HTC). We built upon a screening level model used to predict osprey exposure to APIs in Chesapeake Bay and evaluated whether exposure levels could have been predicted in Delaware Bay had we just measured concentrations in water or fish. Use of surface water and BCFs did not predict API concentrations in fish well, likely due to fish movement patterns, and partitioning and bioaccumulation uncertainties associated with these ionizable chemicals. Input of highest measured API concentration in fish plasma combined with pharmacokinetic data accurately predicted that diclofenac and acetaminophen would be the APIs most likely detected in osprey plasma. For the majority of APIs modeled, levels were not predicted to exceed 1 ng/mL or method detection limits in osprey plasma. Based on the target analytes examined, there is little evidence that APIs represent a significant risk to ospreys nesting in Delaware Bay. If an API is present in fish orders of magnitude below HTC, sampling of fish-eating birds is unlikely to be necessary. However, several human pharmaceuticals accumulated in fish plasma within a recommended safety factor for HTC. It is now important to expand the scope of diet-based API exposure modeling to include alternative exposure pathways (e.g., uptake from landfills, dumps and wastewater treatment plants) and geographic locations (developing countries) where API contamination of the environment may represent greater risk.

Bisphenol A in artificial soil: Effects on growth, reproduction and immunity in earthworms

The application of biosolids in agricultural fields is increasing annually. They contain not only nutrients but also xenobiotics, such as Bisphenol A (BPA). These compounds are not regulated in the use of biosolids in agriculture, which highlights the need to assess their effects on soil life, of which earthworms are most abundant of the animal representatives. In this study the effect of BPA on life-history parameters, such as mortality, growth and reproduction, and on immunity, is evaluated for Dendrobaena veneta and Eisenia fetida. Sublethal concentrations were evaluated by a modified OECD artificial soil test. Decline in growth with increasing concentration of BPA was detected during the first two weeks and the opposite effect for the next two, although these differences were only significant at the highest concentration. Reproduction traits were only significantly different for E. fetida, for which the number of juveniles decreased at higher concentrations, thus showing different sensitivity in both species. By using a contact test, the potentially harmful effect of direct contact with BPA was shown to be much higher than in soil (resembling natural) conditions. Finally, results indicate that BPA may not affect the immune system of these animals, at least in terms of coelomocyte viability.

Ecotoxicological assessment of soils polluted with chemical waste from lindane production: Use of bacterial communities and earthworms as bioremediation tools

An ecotoxicological survey of soils that were polluted with wastes from lindane (γ-HCH) production assessed the effects of organochlorine compounds on the metabolism of microbial communities and the toxicity of these compounds to a native earthworm (Allolobophora chlorotica). Furthermore, the bioremediation role of earthworms as facilitators of soil washing and the microbial degradation of these organic pollutants were also studied. Soil samples that presented the highest concentrations of ε-HCH, 2,4,6-trichlorophenol, pentachlorobenzene and γ-HCH were extremely toxic to earthworms in the short term, causing the death of almost half of the population. In addition, these soils inhibited the heterotrophic metabolic activity of the microbial community. These highly polluted samples also presented substances that were able to activate cellular detoxification mechanisms (measured as EROD and BFCOD activities), as well as compounds that were able to cause endocrine disruption. A few days of earthworm activity increased the extractability of HCH isomers (e.g., γ-HCH), facilitating the biodegradation of organochlorine compounds and reducing the intensity of endocrine disruption in soils that had low or medium contamination levels.

Multilevel ecotoxicity assessment of environmentally relevant bisphenol A concentrations using the soil invertebrate Eisenia fetida

Bisphenol A (BPA) presents a serious threat to soil ecosystems, yet its effects on soil-inhabiting organisms are mostly unexplored. Therefore, the impact of environmentally relevant BPA concentrations on a terrestrial model organism, the earthworm Eisenia fetida, was assessed. Animals were cutaneously exposed to 100nM and 10μM BPA up to 10days (10-d). Next, a battery of biomarkers was used for ecotoxicological evaluation on a cellular, tissue and behavioural level. HPLC analysis showed that after a 10-d exposure, BPA accumulation reached a maximum of 2.50μg BPA per g of wet tissue weight. On the cellular level, up to 3-d BPA exposure caused increased lipid oxidation indicating oxidative stress. Histopathological assessment of cell wall and ovaries after 7- and 10-d BPA exposure showed multiple abnormalities, i.e. hyperplasia of epidermis, increased body wall thickness and ovarian atrophy. Detection of these changes was facilitated by a newly proposed semi-quantitative scoring system. Finally, behavioural changes were detected after only 3days of exposure to 100nM BPA. Altogether, the presented multilevel toxicity evaluation indicates high sensitivity of earthworms to low BPA doses.

Fate of 17β-Estradiol as a model estrogen in source separated urine during integrated chemical P recovery and treatment using partial nitritation-anammox process

Recently, research on source separation followed by the treatment of urine and/or resource recovery from human urine has shown promise as an emerging management strategy. Despite contributing only 1% of the total volume of wastewater, human urine contributes about 80% of the nitrogen, 70% of the potassium, and up to 50% of the total phosphorus in wastewater. It is also a known fact that many of the micropollutants, especially selected estrogens, get into municipal wastewater through urine excretion. In this research, we investigated the fate of 17β-estradiol (E2) as a model estrogen during struvite precipitation from synthetic urine followed by the treatment of urine using a partial nitritation-anammox (PN/A) system. Single-stage and two-stage suspended growth PN/A configurations were used to remove the nitrogen in urine after struvite precipitation. The results showed an almost 95% phosphorous and 5% nitrogen recovery/removal from the synthetic urine due to struvite precipitation. The single and two stage PN/A processes were able to remove around 50% and 75% of ammonia and nitrogen present in the post struvite urine solution, respectively. After struvite precipitation, more than 95% of the E2 remained in solution and the transformation of E2 to E1 happened during urine storage. Most of the E2 removal that occurred during the PN/A process was due to sorption on the biomass and biodegradation (transformation of E2 to E1, and slow degradation of E1 to other metabolites). These results demonstrate that a combination of chemical and biological unit processes will be needed to recover and manage nutrients in source separated urine.

Detection of endocrine active substances in the aquatic environment in southern Taiwan using bioassays and LC-MS/MS

Endocrine active substances, including naturally occurring hormones and various synthetic chemicals have received much concern owing to their endocrine disrupting potencies. It is essential to monitor their environmental occurrence since these compounds may pose potential threats to biota and human health. In this study, yeast-based reporter assays were carried out to investigate the presence of (anti-)androgenic, (anti-)estrogenic, and (anti-)thyroid compounds in the aquatic environment in southern Taiwan. Liquid chromatography tandem mass spectrometry (LC-MS/MS) was also used to measure the environmental concentrations of selected endocrine active substances for assessing potential ecological risks and characterizing contributions to the endocrine disrupting activities. Bioassay results showed that anti-androgenic (ND-7489 μg L(-1) flutamide equivalent), estrogenic (ND-347 ng L(-1) 17β-estradiol equivalent), and anti-thyroid activities were detected in the dissolved and particulate phases of river water samples, while anti-estrogenic activities (ND-10 μg L(-1) 4-hydroxytamoxifen equivalent) were less often found. LC-MS/MS analysis revealed that anti-androgenic and estrogenic contaminants, such as bisphenol A, triclosan, and estrone were frequently detected in Taiwanese rivers. In addition, their risk quotient values were often higher than 1, suggesting that they may pose an ecological risk to the aquatic biota. Further identification of unknown anti-androgenic and estrogenic contaminants in Taiwanese rivers may be necessary to protect Taiwan's aquatic environment.

Exposure to 17β-Oestradiol Induces Oxidative Stress in the Non-Oestrogen Receptor Invertebrate Species Eisenia fetida

Background

The environmental impacts of various substances on all levels of organisms are under investigation. Among these substances, endocrine-disrupting compounds (EDCs) present a threat, although the environmental significance of these compounds remains largely unknown. To shed some light on this field, we assessed the effects of 17β-oestradiol on the growth, reproduction and formation of free radicals in Eisenia fetida.

Methodology/Principal Findings

Although the observed effects on growth and survival were relatively weak, a strong impact on reproduction was observed (50.70% inhibition in 100 μg/kg of E₂). We further demonstrated that the exposure of the earthworm Eisenia fetida to a contaminant of emerging concern, 17β-oestradiol (E₂), significantly affected the molecules involved in antioxidant defence. Exposure to E₂ results in the production of reactive oxygen species (ROS) and the stimulation of antioxidant systems (metallothionein and reduced oxidized glutathione ratio) but not phytochelatins at both the mRNA and translated protein levels. Matrix-assisted laser desorption/ionization (MALDI)-imaging revealed the subcuticular bioaccumulation of oestradiol-3,4-quinone, altering the levels of local antioxidants in a time-dependent manner.

Conclusions/Significance

The present study illustrates that although most invertebrates do not possess oestrogen receptors, these organisms can be affected by oestrogen hormones, likely reflecting free diffusion into the cellular microenvironment with subsequent degradation to molecules that undergo redox cycling, producing ROS, thereby increasing environmental contamination that also perilously affects keystone animals, forming lower trophic levels.

Impact of treated wastewater on organismic biosensors at various levels of biological organization

Relating the treated wastewater quality and its impact on organismic biosensors (Prussian carp, Carassius gibelio and earthworm, Eisenia fetida) was the main objective of the study. The impact on health status of fish living downstream, microbiological contamination and antimicrobial resistance, fish tissue structure, blood biochemistry, oxidative stress, genotoxic effects, as well as multixenobiotic resistance mechanism (MXR) was assessed. Treated wastewater discharged from the WWTP modified the environmental parameters and xenobiotic concentrations of the receiving surface waters. Potential bacterial pathogens from fish and respective waters were found in relatively low numbers, although they comprised aeromonads with a zoonotic potential. High resistance profiles were determined towards the tested antimicrobial compounds, mostly sulfamethoxazole and erythromycin. Histopathology primarily revealed gill lamellar fusion and reduction of interlamellar spaces of effluent fish. A significant increase in plasma values of urea, total proteins, albumins and triglycerides and a significant decrease in the activity of plasma superoxide dismutase were noted in carp from the effluent-receiving canal. Micronucleus test did not reveal significant differences between the examined groups, but a higher frequency of erythrocyte nuclear abnormalities was found in fish sampled from the effluent-receiving canal. Earthworms indicated to the presence of MXR inhibitors in water and sludge samples, thus proving as a sensitive sentinel organism for environmental pollutants. The integrative approach of this study could serve as a guiding principle in conducting evaluations of the aquatic habitat health in complex bio-monitoring studies.

Behavioural and physiological responses of birds to environmentally relevant concentrations of an antidepressant

Many wildlife species forage on sewage-contaminated food, for example, at wastewater treatment plants and on fields fertilized with sewage sludge. The resultant exposure to human pharmaceuticals remains poorly studied for terrestrial species. On the basis of predicted exposure levels in the wild, we administered the common antidepressant fluoxetine (FLUOX) or control treatment via prey to wild-caught starlings (Sturnus vulgaris) for 22 weeks over winter. To investigate responses to fluoxetine, birds were moved from their group aviaries into individual cages for 2 days. Boldness, exploration and activity levels showed no treatment effects but controls and FLUOX birds habituated differently to isolation in terms of the concentration of corticosterone (CORT) metabolites in faeces. The controls that excreted higher concentrations of CORT metabolites on day 1 lost more body mass by day 2 of isolation than those which excreted lower levels of CORT metabolites. CORT metabolites and mass loss were unrelated in FLUOX birds. When we investigated the movements of birds in their group aviaries, we found the controls made a higher frequency of visits to food trays than FLUOX birds around the important foraging periods of sunrise and sunset, as is optimal for wintering birds. Although individual variability makes interpreting the sub-lethal endpoints measured challenging, our data suggest that fluoxetine at environmentally relevant concentrations can significantly alter behaviour and physiology.

Medicating the environment: assessing risks of pharmaceuticals to wildlife and ecosystems

Global pharmaceutical consumption is rising with the growing and ageing human population and more intensive food production. Recent studies have revealed pharmaceutical residues in a wide range of ecosystems and organisms. Environmental concentrations are often low, but pharmaceuticals typically are designed to have biological effects at low doses, acting on physiological systems that can be evolutionarily conserved across taxa. This Theme Issue introduces the latest research investigating the risks of environmentally relevant concentrations of pharmaceuticals to vertebrate wildlife. We take a holistic, global view of environmental exposure to pharmaceuticals encompassing terrestrial, freshwater and marine ecosystems in high- and low-income countries. Based on both field and laboratory data, the evidence for and relevance of changes to physiology and behaviour, in addition to mortality and reproductive effects, are examined in terms of the population- and community-level consequences of pharmaceutical exposure on wildlife. Studies on uptake, trophic transfer and indirect effects of pharmaceuticals acting via food webs are presented. Given the logistical and ethical complexities of research in this area, several papers focus on techniques for prioritizing which compounds are most likely to harm wildlife and how modelling approaches can make predictions about the bioavailability, metabolism and toxicity of pharmaceuticals in non-target species. This Theme Issue aims to help clarify the uncertainties, highlight opportunities and inform ongoing scientific and policy debates on the impacts of pharmaceuticals in the environment.

Commentary: Plastic ocean and the cancer connection: 7 questions and answers

A plethora of recent scientific reports testifies to challenges the world is facing from an ever-increasing marine plastic pollution. Toxicological concerns have been put forward, but possible links between the now ubiquitous synthetic polymers and human as well as wildlife cancers remain to be investigated. Hence, this commentary which addresses seven questions. Given numerous uncertainties on the factual impacts of plastics, we should embark on empirical studies into the validity of biologically plausible links between plastic residues and cancers and concomitantly consider ways to reduce plastics in the world within and around us.

Impacts of Pharmaceuticals on Terrestrial Wildlife

Essentially ubiquitous in our environment, residues of human and veterinary pharmaceuticals somewhat paradoxically represent an emerging and increasing risk to wild biota. Whilst in recent years a great deal of analytical effort has been expended to quantify the presence of many pharmaceutical contaminants, especially in freshwater systems, our real understanding of the risks posed to most clades of wildlife, aquatic and terrestrial alike, still lags behind. In particular, relevant field-based studies regarding possible chronic impacts in higher terrestrial wildlife (birds, mammals, reptiles, etc.) remain all too scarce. Yet, for example, over the past two decades Old World Gyps vultures on the Indian subcontinent have been virtually extirpated due to non-target exposure to a single synthetic pharmaceutical compound, diclofenac (a non-steroidal anti-inflammatory drug). Here, we highlight and discuss the myriad possible exposure routes to terrestrial wildlife, consider the analytical and monitoring approaches that are already in use or that could be used in future research, and reflect upon a selection of legislative approaches currently being applied to identified terrestrial impacts. Finally, with the ultimate aim of encouraging further applied ecotoxicology-based research in this emerging field, we highlight several priorities for future inquiry, with special emphasis on non-target effects in previously overlooked but potentially vulnerable or highly representative clades of wildlife exposed within environmentally relevant, real-world scenarios.

Global Assessment of Bisphenol A in the Environment: Review and Analysis of Its Occurrence and Bioaccumulation

Because bisphenol A (BPA) is a high production volume chemical, we examined over 500 peer-reviewed studies to understand its global distribution in effluent discharges, surface waters, sewage sludge, biosolids, sediments, soils, air, wildlife, and humans. Bisphenol A was largely reported from urban ecosystems in Asia, Europe, and North America; unfortunately, information was lacking from large geographic areas, megacities, and developing countries. When sufficient data were available, probabilistic hazard assessments were performed to understand global environmental quality concerns. Exceedances of Canadian Predicted No Effect Concentrations for aquatic life were >50% for effluents in Asia, Europe, and North America but as high as 80% for surface water reports from Asia. Similarly, maximum concentrations of BPA in sediments from Asia were higher than Europe. Concentrations of BPA in wildlife, mostly for fish, ranged from 0.2 to 13 000 ng/g. We observed 60% and 40% exceedences of median levels by the US Centers for Disease Control and Prevention's National Health and Nutrition Examination Survey in Europe and Asia, respectively. These findings highlight the utility of coordinating global sensing of environmental contaminants efforts through integration of environmental monitoring and specimen banking to identify regions for implementation of more robust environmental assessment and management programs.

Acute toxicological effects on the earthworm Eisenia fetida of 18 common pharmaceuticals in artificial soil

Following soil applications of recycled water and biosolids, pharmaceutical residues can eventually enter the terrestrial environment. In vitro and in vivo assays have largely focused on the acute ecotoxicity of these compounds in aquatic systems. However, studies on the ecotoxicological effects of pharmaceuticals in soil biota are especially scarce. The aim of this study was to investigate the acute toxicity of 18 pharmaceuticals (4 NSAIDs, 5 blood lipid-lowering agents, 6 β-blockers and 3 antibiotics) that are usually found in the environment by using an Eisenia fetida bioassay. In addition, the presence of these pharmaceuticals in artificial soil was verified at the end of the test. Our results indicate that seven of the studied drugs cause acute adverse effects in E. fetida, in particular, the NSAIDs and the blood lipid-lowering agents. Ibuprofen (LC50=64.80 mg/kg) caused the highest acute toxicity for all tested compounds, followed by diclofenac (LC50=90.49 mg/kg) and simvastatin (LC50=92.70 mg/kg). Other tested pharmaceuticals from NSAIDs and blood lipid-lowering families have toxicity effects, from a LC50=140.87 mg/kg for gemfibrozil to 795.07 mg/kg for lovastatin. Atorvastatin, bezafibrate, β-blockers and antibiotics showed no detectable lethality in E. fetida. The four NSAIDs showed evidence of modification of their original chemical structure after 14 days so the detected toxicity may be due to the original product as well as their degradation products. The three blood lipid-lowering agents seem to be more stable in soil. From an environmental perspective, the lethal concentrations of the tested drugs are much greater than those reported in wastewater and biosolids, therefore acute toxic effects may be improbable. However, little is known about the accumulation of these substances in soils after regular applications, so accumulative and chronic effects cannot be excluded. Moreover, more studies are needed to determine the role of the degradation products of these pharmaceuticals on terrestrial toxicity.

Detection and drivers of exposure and effects of pharmaceuticals in higher vertebrates

Pharmaceuticals are highly bioactive compounds now known to be widespread environmental contaminants. However, research regarding exposure and possible effects in non-target higher vertebrate wildlife remains scarce. The fate and behaviour of most pharmaceuticals entering our environment via numerous pathways remain poorly characterized, and hence our conception and understanding of the risks posed to wild animals is equally constrained. The recent decimation of Asian vulture populations owing to a pharmaceutical (diclofenac) offers a notable example, because the exposure route (livestock carcasses) and the acute toxicity observed were completely unexpected. This case not only highlights the need for further research, but also the wider requirement for more considered and comprehensive 'ecopharmacovigilance'. We discuss known and potential high risk sources and pathways in terrestrial and freshwater ecosystems where pharmaceutical exposure in higher vertebrate wildlife, principally birds and mammals, may occur. We examine whether approaches taken within existing surveillance schemes (that commonly target established classes of persistent or bioaccumulative contaminants) and the risk assessment approaches currently used for pesticides are relevant to pharmaceuticals, and we highlight where new approaches may be required to assess pharmaceutical-related risk.

Prenatal exposure to low doses of atrazine affects mating behaviors in male guppies

Performing appropriate mating behaviors is crucial to male reproductive success, especially in species where mating is predominantly via female mate choice. Mating behaviors are hormonally regulated and may be sexually selected traits: courtship displays are selected via mate choice, while forced copulations and aggressive behaviors are selected for via intrasexual competition. Endocrine disrupting compounds interfere with proper hormonal functioning in exposed animals. Exposures during developmentally crucial life stages can have irreversible effects lasting through adulthood. I tested the effects of prenatal exposure to environmentally relevant doses of a commonly used herbicide, atrazine (1 and 13.5μg/L) on mating behaviors in male guppies. Guppies were used as a model organism to test the effects of atrazine exposure on wildlife reproductive health. Adult female guppies were mated and exposed to the treatments throughout the gestation period, and offspring born to them were raised without further treatment. At adulthood, the males were tested for the effects of prenatal exposure on their mating behaviors such as courtship displays, gonopodium swings, forced copulatory attempts, and competitive and aggressive behaviors towards rivals who were not exposed to atrazine. I also tested female preference for treated males compared to control males. Atrazine-exposed males were less likely to perform the mating behaviors, and performed them less frequently, than control males. Atrazine exposure also made males less aggressive towards rivals. Females preferred untreated males over atrazine-treated males. In all cases, a non-monotonic pattern was seen, highlighting the significance of low-dose exposures.

Persistence of estrogenic activity in soils following land application of biosolids

Estrogenic compounds may enter the environment when biosolids are applied to land. In the present study, soil samples were collected over 4 mo from a field trial following addition of biosolids. The recombinant yeast estrogen screen bioassay identified estrogenic activity in the soil at all sampling times to concentrations up to 2.3 µg 17β-estradiol equivalency/kg. The present results indicate the potential for estrogenic compounds to persist in soil following biosolids application.

Development of an in vitro thin-film solid-phase microextraction method to determine the bioavailability of xenoestrogens in soil

Biosolids applied to agricultural fields, parks, and other areas represent significant sources of estrogen-like endocrine disrupting compound (EEDC) inputs to soil. It is important to determine the bioavailability of EEDCs in soil to inform risk assessment concerning their environmental presence; Eisenia fetida (earthworms) are typically used in traditional in vivo bioavailability experiments. The development of an in vitro bioavailability method will decrease time, expense, and use of solvents in future analyses. A thin-film solid-phase microextraction (TF-SPME) method for determining the bioavailability of several EEDCs detected in biosolids was developed and optimized. It was found that the TF-SPME method could be used to calculate equilibrium porewater concentrations of diethylhexyl phthalate, bisphenol A, benzophenone, and triclosan at environmentally relevant concentrations in artificial soil within 88 min. The potential and limitations of using TF-SPME-generated porewater concentrations to predict E. fetida tissue concentrations are discussed.

Comparison of multiple API techniques for the simultaneous detection of microconstituents in water by on-line SPE-LC-MS/MS

This study described a fully automated method using on-line solid phase extraction of large volume injections coupled with high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS) to simultaneously detect a group of recalcitrant microconstituents (pharmaceuticals and personal care products, steroid hormones and sterols) in aqueous matrices. Samples (1 mL to 20 mL) were loaded to the preconcentration column at 1 mL/min, and the column was washed with 1000 μL of 25% methanol in LC/MS water to remove polar and ionic interferences before LC-MS/MS analysis. Three different atmospheric pressure ionization (API) techniques, including photoionization (APPI) with four different dopants (acetone, anisole, chlorobenzene and toluene), heated electrospray ionization (HESI) and atmospheric pressure chemical ionization (APCI), were evaluated on the basis of method detection limits (MDLs) and recoveries from different aqueous matrixes. Results indicated that APPI with toluene as dopant was the most sensitive ionization method for the majority of the analytes. When using 5 mL of sample, MDLs for pharmaceuticals and personal care products, including carbamazepine, DEET, caffeine, naproxen, acetaminophen and primidone, were between 0.3 ng/L and 15 ng/L. MDLs of hormones, including testosterone, equilenin, progesterone, equilin, 17β-estradiol, 17α-ethynylestradiol, estrone, androsterone, mestranol and estriol, were between 1.2 ng/L and 37 ng/L. The combination of APPI with dopant allowed the detection of two difficult to ionize fecal related sterols, such as coprostan-3-ol and coprostan-3-one with MDLs of 5.4 ng/L and 11 ng/L, respectively. Calculated MDLs are more than adequate for analysis of wastewater using 1 to 5 mL sample size and for surface waters using up to 20 mL sample size.

Earthworm bioassays and seedling emergence for monitoring toxicity, aging and bioaccumulation of anthropogenic waste indicator compounds in biosolids-amended soil

Land application of biosolids (treated sewage sludge) can be an important route for introducing xenobiotic compounds into terrestrial environments. There is a paucity of available information on the effects of biosolids amendment on terrestrial organisms. In this study, the influence of biosolids and biosolids aging on earthworm (Eisenia fetida) reproduction and survival and lettuce (Lactuca sativa) seedling emergence was investigated. Earthworms were exposed to soils amended with varying quantities of biosolids (0, 1, 2, 3, or 4% dry mass). To investigate the influence of biosolids aging, the biosolids used in the study were aged for differing lengths of time (2 or 8 weeks) prior to exposure. All of the adult earthworms survived in the biosolids-amended soils at all concentrations that were aged for 2 weeks; however, only 20% of the adults survived in the soil amended with the highest concentration of biosolids and aged for 8 weeks. Reproduction as measured by mean number of juveniles and unhatched cocoons produced per treatment correlated inversely with biosolids concentration, although the effects were generally more pronounced in the 8-week aged biosolids-soil samples. Latent seedling emergence and reduced seedling fitness correlated inversely with biosolids concentration, but these effects were tempered in the 8-week aged versus the 2-week aged soil-biosolids mixtures. Anthropogenic waste indicator compounds (AWIs) were measured in the biosolids, biosolids-soil mixtures, and earthworm samples. Where possible, bioaccumulation factors (BAFs) were calculated or estimated. A wide variety of AWIs were detected in the biosolids (51 AWIs) and earthworm samples (≤19 AWI). The earthworms exposed to the 8-week aged biosolids-soil mixtures tended to accumulate greater quantities of AWIs compared to the 2-week aged mixture, suggesting that the bioavailability of some AWIs was enhanced with aging. The BAFs for a given AWI varied with treatment. Notably large BAFs were determined for some AWIs. For example, the maximum BAF determined for para-cresol, methyl salicylate, bisphenol-A, and cholesterol was greater than 100 in some treatments.

Tissue-specific uptake and bioconcentration of the oral contraceptive norethindrone in two freshwater fishes

The environmental presence of the oral contraceptive norethindrone (NET) has been reported and shown to have reproductive effects in fish at environmentally realistic exposure levels. The current study examined bioconcentration potential of NET in fathead minnow (Pimephales promelas) and channel catfish (Ictalurus punctatus). Fathead minnows were exposed to 50 μg/l NET for 28 days and allowed to depurate in clean water for 14 days. In a minimized 14-day test design, catfish were exposed to 100 μg/l NET for 7 days followed by 7-day depuration. In the fathead test, tissues (muscle, liver, and kidneys) were sampled during the uptake (days 1, 3, 7, 14, and 28) and depuration (days 35 and 42) phases. In the catfish test, muscle, liver, gill, brain, and plasma were collected during the uptake (days 1, 3, and 7) and depuration (day 14) stages. NET tissue levels were determined by gas chromatography-mass spectrometry (GC-MS). Accumulation of NET in tissues was greatest in liver followed by plasma, gill, brain, and muscle. Tissue-specific bioconcentration factors (BCFs) ranged from 2.6 to 40.8. Although NET has been reported to elicit reproductive effects in fish, the present study indicated a low potential to bioconcentrate in aquatic biota.

Environmentally realistic exposure to the herbicide atrazine alters some sexually selected traits in male guppies

Male mating signals, including ornaments and courtship displays, and other sexually selected traits, like male-male aggression, are largely controlled by sex hormones. Environmental pollutants, notably endocrine disrupting compounds, can interfere with the proper functioning of hormones, thereby impacting the expression of hormonally regulated traits. Atrazine, one of the most widely used herbicides, can alter sex hormone levels in exposed animals. I tested the effects of environmentally relevant atrazine exposures on mating signals and behaviors in male guppies, a sexually dimorphic freshwater fish. Prolonged atrazine exposure reduced the expression of two honest signals: the area of orange spots (ornaments) and the number of courtship displays performed. Atrazine exposure also reduced aggression towards competing males in the context of mate competition. In the wild, exposure levels vary among individuals because of differential distribution of the pollutants across habitats; hence, differently impacted males often compete for the same mates. Disrupted mating signals can reduce reproductive success as females avoid mating with perceptibly suboptimal males. Less aggressive males are at a competitive disadvantage and lose access to females. This study highlights the effects of atrazine on ecologically relevant mating signals and behaviors in exposed wildlife. Altered reproductive traits have important implications for population dynamics, evolutionary patterns, and conservation of wildlife species.

Photolysis kinetics and influencing factors of bisphenol S in aqueous solutions

The photodegradation of bisphenol S (BPS) in aqueous solutions was studied under different conditions. Photolysis and kinetics were investigated, as were the photolysis mechanism and the influences of initial pH value, light source, and environmental substances in water. The results showed that the photolysis of BPS occurred under UV light, and the rate increased with light source intensity. The photolysis of 5.0-50.0 mg/L BPS in water followed first-order kinetics: the rate was gamma = 0.0161C(BPS) under a 40-W UV-lamp, and the degradation half-life was 43.1 min. Due to its absorption of light, direct photolysis of BPS was a predominant pathway for BPS but was not obviously affected by reactive oxygen species. The results confirmed that the photolysis rates of BPS in alkaline water solution were faster than those in acidic and neutral water solution because of the ionization of BPS. The photodegradation rate of BPS increased in the presence of chloride and ferric ions, while the rate was inhibited by nitrate and phosphate in aqueous solution.

Vermistabilization of sewage sludge (biosolids) by earthworms: converting a potential biohazard destined for landfill disposal into a pathogen-free, nutritive and safe biofertilizer for farms

Earthworms feed readily upon sludge components, rapidly converting them into vermicompost, reduce the pathogens to safe levels and ingest the heavy metals. Volume is significantly reduced from 1 m³ of wet sludge (80% moisture) to 0.5 m³ of vermicompost (30% moisture). Earthworms have real potential both to increase the rate of aerobic decomposition and composting of organic matter and also to stabilize the organic residues in the sludge--removing the harmful pathogens (by devouring them and also by discharge of antibacterial coelomic fluid) and heavy metals (by bio-accumulation). They also mineralize the essential nutrients nitrogen, phosphorus and potassium from the sludge. It may not be possible to remove toxic substances completely, but at least change the 'chemical make-up' of the sludge to make it harmless to the soil and enable its use as a nutritive organic fertilizer. This method has been found to comply with grade A standards for sludge stabilization.

Anthropogenic pollutants: a threat to ecosystem sustainability?

Pollutants, including synthetic organic materials and heavy metals, are known to adversely affect physiological systems in all animal species studied to date. While many individual chemicals can perturb normal functions, the combined actions of multiple pollutants are of particular concern because they can exert effects even when each individual chemical is present at concentrations too low to be individually effective. The biological effects of pollutants differ greatly between species reflecting differences in the pattern of exposure, routes of uptake, metabolism following uptake, rates of accumulation and sensitivity of the target organs. Thus, understanding of the effects of pollutants on wildlife and ecosystems will require detailed study of many different species, representing a wide range of taxa. However, such studies can be informed by knowledge obtained in more controlled conditions which may indicate likely mechanisms of action and suitable endpoint measurements. Responses may be exacerbated by interactions between the effects of pollutants and environmental stressors, such as under-nutrition or osmotic stresses and so changes in such variables associated with climatic changes may exacerbate physiological responses to pollutant burdens.

Detection of endocrine disrupting chemicals in aerial invertebrates at sewage treatment works

Endocrine disrupting chemicals (EDCs) constitute a diverse group of chemical compounds which can alter endocrine function in exposed animals. Whilst most studies have focussed on exposure of wildlife to EDCs via aquatic routes, there is the potential for transfer into the terrestrial food chain through consumption of contaminated prey items developing in sewage sludge and waste water at sewage treatment works. In this study, we determine levels of EDCs in aerial insects whose larval stages develop on percolating filter beds at sewage treatment works. We compare absolute concentrations of known EDCs with those collected from aquatic environments not exposed to sewage effluent outflow. Our findings document for the first time that aerial invertebrates developing on sewage filter beds take up a range of chemicals thought to be incorporated from the sewage effluent, which act as endocrine disruptors. For two synthetic chemicals (17alpha-ethinylestradiol and butylated hydroxy aniline), concentrations were significantly higher in insects captured around percolating filter beds than sites over 2 km from the nearest sewage works. A number of species of insectivorous bats and birds, some of which are declining or threatened, use sewage works as principle foraging sites. We calculate approximate exposure levels for a species of bat known to forage within sewage works and suggest that further research is warranted to assess the ecological implications of consuming contaminated invertebrate prey.

Sustainable risk management of emerging contaminants in municipal wastewaters

The presence of emerging contaminants in municipal wastewaters, particularly endocrine-disrupting compounds such as oestrogenic substances, has been the focus of much public concern and scientific attention in recent years. Due to the scientific uncertainty still surrounding their effects, the Precautionary Principle could be invoked for the interim management of potential risks. Therefore, precautionary prevention risk-management measures could be employed to reduce human exposure to the compounds of concern. Steroid oestrogens are generally recognized as the most significant oestrogenically active substances in domestic sewage effluent. As a result, the UK Environment Agency has championed a 'Demonstration Programme' to investigate the potential for removal of steroid oestrogens and alkylphenol ethoxylates during sewage treatment. Ecological and human health risks are interdependent, and ecological injuries may result in increased human exposures to contaminants or other stressors. In this context of limiting exposure to potential contaminants, examining the relative contribution of various compounds and pathways should be taken into account when identifying effective risk-management measures. In addition, the explicit use of ecological objectives within the scope of the implementation of the EU Water Framework Directive poses new challenges and necessitates the development of ecosystem-based decision tools. This paper addresses some of these issues and proposes a species sensitivity distribution approach to support the decision-making process related to the need and implications of sewage treatment work upgrade as risk-management measures to the presence of oestrogenic compounds in sewage effluent.