Aquatic biota as potential biological indicators of the contamination,bioaccumulation and health risks caused by organochlorine pesticides in a large,shallow Chinese lake (Lake Chaohu)

Aquatic biota have long been recognized as bioindicators of the contamination caused by hydrophobic organic contaminants (HOCs) in aquatic environments. The primary purpose of the present study is to identify which species of aquatic biota are the most sensitive to organochlorine pesticides (OCPs) in Lake Chaohu and can therefore serve as indicators of the lake's health and assist in the assessment of OCPs risks to human health. OCP levels in eight species of aquatic biota were measured using GC–MS, and the relationships between the biota and OCP levels in the water and suspended solids were studied. DDTs pose potential human health risks and were the predominant OCP components found in the aquatic biota. DDT had the highest mean bioaccumulation factor (BAF) and biota suspended solids accumulation factor (BSSAF) of all of the studied OCP components. The food web magnification factors (FWMF) for p, p′-DDT were greater than 1, implying that biomagnification occurred. This finding indicates that DDTs still pose a serious threat to the ecosystem and human health in Lake Chaohu, even though the agricultural application of DDT powder has been officially banned since 1983. There were significant positive relationships between OCPs levels in Culter erythropterus and those in both water and suspended solids, as well as between OCPs levels in Protosalanx hyalocranius and those in suspended solids. This finding suggests that C. erythropterus and P. hyalocranius are the most sensitive aquatic biota to OCPs and may serve as the most effective bioindicators for monitoring OCP contamination in the water and suspended solids of Lake Chaohu. Megalobrama amblycephala, which contained the highest wet weight mean OCP concentration, is the most sensitive OCP indicator and can be used to assess the human carcinogenic risk of OCPs in Lake Chaohu.     

Evaluating the necessity of additional aquatic plant testing by comparing the sensitivities of different species

At present, at least three and up to five plant species are required to assess the potential risks of herbicides to non-target aquatic plants. Several regulatory authorities are considering whether there should be further requirements based on concerns about the possible selectivity of herbicides (e.g., specific modes of action against dicotyledonous plants). The relative sensitivity of a range of aquatic plants is assessed in our work in order to evaluate the implications of differences in species sensitivity for aquatic risk assessment of herbicides. We therefore present results from ecotoxicological tests performed at Syngenta Crop Protection AG on various aquatic plants and compare them to available studies and results in literature. The criterion used for sensitivity ranking is the EC50 (median effect concentration) value, which allows a better comparison of values from different testing methods and conditions. The overall results obtained in the present work show that the aquatic risk assessment procedure for herbicides based on Lemna sp. and algae is sufficiently protective while identifying potential toxicity to non-target plants. Only few exceptions concerning herbicides with selective modes of action (e.g., auxin simulators) may require additional species testing for proper risk assessment.     

Human Health Risk Assessment of Non-Regulated Xenobiotics in Recycled Water: A Review

Water suppliers face increased pressure to explain the relative health risks from non-regulated xenobiotics that may be present in recycled water, including pharmaceuticals and personal care products (PPCPs) and endocrine disrupting compounds. This report reviews their occurrence, fate, and recent human health risk assessments for potable and non-potable water reuse. The most effective advanced treatment for PPCPs is reverse osmosis (RO) followed by advanced oxidation. During soil aquifer treatment, the majority of PPCPs are attenuated relatively quickly (within 100 days), yet some are persistent and can migrate to the underlying groundwater at low concentrations. Recently, several investigations have assessed the potential human health risks associated with xenobiotics in recycled water, focusing on exposure from drinking water (e.g., planned and unplanned indirect potable reuse) and non-potable reuse (e.g., exposure via recreational, occupational, and irrigation-related activities at sites utilizing recycled water). Risk assessments conducted over the last 10 years have found no adverse human health effects or significant risks. Though advanced treatment of wastewater that is discharged or recycled may not be required to protect public health, it may be necessary to prevent potential effects on exposed biota and to address, to some degree, the public's perception of water reuse.     

Issues in Ecological Risk Assessment of Inorganic Metals and Metalloids

Ecological risk assessment (ERA) is a process that evaluates the potential for adverse ecological effects occurring as a result of exposure to contaminants or other stressors. ERA begins with hazard identification/problem formulation, progresses to effects and exposure assessment, and finishes with risk characterization (an estimate of the incidence and severity of any adverse effects likely to occur). Risk management initially sets the boundaries of the ERA and then uses its results for decision-making. Key information required for an ERA includes: the emissions, pathways and rates of movement of contaminants in the environment; and, information on the relationship between contaminant concentrations and the incidence and (or) severity of adverse effects. Because of specific properties and characteristics of metals in general and of certain metals in particular, a generalized ERA process applicable to organic substances is inappropriate for metals. First, metals are naturally occurring and can arise, sometimes in very high concentrations, from non-anthropogenic sources; organisms can and do adapt to a wide range of metal concentrations. Second, certain metals (e.g., copper, zinc) are essential for biotic health, which means there is an effect threshold for both deficiency and excess, and that standard body burden indices such as bioaccumulation factors (BCFs) can be misleading. Third, metals can occur in the environment in a variety of forms that are more or less available to biota but adverse biological effects can only occur if metals are or may become bioavailable. Fourth, whereas the bioavailability and hence the possibility of toxicity of persistent organic substances are mainly dependent on their intrinsic properties (i.e., lipophilicity), those of metals are generally controlled by external environmental conditions. Examples include pH and ligands, which affect the metal speciation and coexisting cations (e.g., H⁺, Ca²⁺) which compete with the metal ions. ERAs involving metals must include the above four major considerations; other considerations vary depending on whether the ERA is for a site, a region, or is global in scope.     

Perfluorinated Compounds in Aquatic Products from Bohai Bay,Tianjin, China

To understand concentrations of perfluorinated compounds (PFCs) in aquatic products, and risks to human health, concentrations of 12 PFCs were measured in edible tissues of aquatic products collected from Tianjin, China, a typical industrial area on the western Bohai Sea. Perfluorooctane sulfonate (PFOS) was the predominant PFC. Concentrations of PFOS in aquatic products from Tianjin Binhai New Area (TBNA) ranged from <0.10 to 241 ng/g wet weight, with the greatest concentration observed in the edible portions of mullet (Mugil so-iuy Basilewsky). Concentrations of PFOS in mullet from the TBNA were greater than those in other species of lower trophic levels, which suggests biomagnification. Concentrations of PFOS in aquatic products from markets were greater than those of locally farmed or wild marine products. Relatively great concentrations of PFOS were not only observed in products from the rapidly growing industrial areas such as Tangu District (TG) and Hangu District (HG), but also in less industrialized areas like the Dagang District (DG). The results of the hazard assessment indicated that consumption of seawater-farmed fish and market fish posed a greater hazard than wild marine fish or freshwater-farmed fish, but the risk to human health was not great.     

Which Effect Measure Should Be Used for Impact Assessment in a New Population Context?

One characteristic feature in impact assessment based on epidemiologic studies is the transfer of an exposure-response association into a new population context. The consequences of basing this estimation procedure either on relative effect measures (e.g., relative risks) or on measures on the difference scale (e.g., excess rate) were exemplary illustrated with two air pollution studies which quantified the association between lung cancer and PM₁₀ in cohorts with varying lung cancer incidence due to different smoking habits. This example showed that the type of measure chosen may markedly influence the result of an impact assessment, if the frequency of the disease of interest varies across different populations due to other risk factors than the one considered. Thus, it was concluded that whenever studies from different population contexts are pooled, careful considerations about the appropriate type of measure are required. In environmental health risk assessment with usually small risks and unspecific (i.e., multicausal) health endpoints, an excess rate-based approach may provide a more reliable and stable estimate than a relative risk based approach in many circumstances. Methodological details of an excess rate-based approach are presented in the paper.     

Environmental Risks at Finnish Shooting Ranges—A Case Study

We studied three Finnish shooting ranges in order to define the extent of the risks associated with elevated environmental concentrations of metals and PAHs. A scoring system revealed that lead, arsenic, and antimony were the most critical contaminants. On Site 3, the concentration of lead in groundwater exceeded the drinking water standard indicating evident health risks. For the remaining two sites we calculated Acceptable Daily Doses (ADD) based on the Reasonable Maximum Exposure (RME) approach and compared them with safe exposure levels. We also used a pharmacokinetic model to determine blood lead levels (PbBs). Risks to biota were assessed using ecological benchmarks and exposure and accumulation models. Prediction of leaching was based on laboratory tests and a distribution model. The health risk assessment for lead resulted in the maximum hazard quotient (HQ) of 1.2 whereas the HQs of As and Sb remained less than 1. Some exposure scenarios produced PbB estimates exceeding 10 μ g dl^?1 but based on the uncertainty analysis we expect the health risks to remain insignificant. However, leaching of contaminants presents a risk to groundwater quality. At site 1 the ecotoxicity-based HQs demonstrate high risks to soil biota, small mammals, terrestrial plants and aquatic organisms.     

Effects of Chronic Waterborne and Dietary Metal Exposures on Gill Metal-Binding: Implications for the Biotic Ligand Model

The biotic ligand modeling (BLM) approach has gained recent widespread interest among the scientific and regulatory communities because of its potential for developing ambient water quality criteria (AWQC), which are site-specific, and in performing aquatic risk assessment for metals. Currently, BLMs are used for predicting acute toxicity (96?h LC50 for fish) in any defined water chemistry. The conceptual framework of the BLM has a strong physiological basis because it considers that toxicity of metals occurs due to the binding of free metal ions at the physiologically active sites of action (biotic ligand, e.g., fish gill) on the aquatic organism, which can be characterized by conditional binding constants (log K) and densities (B_max). At present, these models assume that only water chemistry variables such as competing cations (e.g., Na⁺, Ca²⁺, Mg²⁺, and H⁺), inorganic ligands (e.g., hydroxides, chlorides, carbonates), and organic ligands (dissolved organic matter) can influence the bioavailability of free metal ions and thereby the acute toxicity of metals. Current BLMs do not consider the effects of chronic history of the fish in modifying gill-metal binding characteristics and acute toxicity. Here, for Cu, Cd, and Zn, we review a number of recent studies on the rainbow trout that describe significant modifying effects of chronic acclimation to waterborne factors (hardness and chronic metal exposure) and dietary composition (metal and essential ion content) on gill metalbinding characteristics (on both log K and B_max) and on acute toxicity. We conclude that the properties of gill-metal interaction and toxicological sensitivity appear to be dynamic rather than fixed, with important implications for further development of both acute and chronic BLMs. Now that the initial framework of the BLM has been established, future research needs a more integrative approach with additional emphasis on the dynamic properties of the biotic ligand to make it a successful tool for ecological risk assessment of metals in the natural environment.     

N-Nitrosodimethylamine (NDMA) in Food and Beverages: A Comparison in Context to Drinking Water

Human exposure to N-nitrosodimethylamine (NDMA) from foods and beverages was modeled and upper-bound cancer risks were predicted for the United States and Canada. Approximately 0.5 (0–10.8) cancer incidents per million population from lifetime exposure to NDMA in drinking water were estimated. Lifetime exposure to NDMA from the major exogenous sources may result in 49.6 (range: 17.7–171.7) cancer incidents per million population, while meat products contribute the most (15.9/million) followed by milk products (10.9/million). Drinking water may contribute approximately 1% to the exogenous cancer risk and holds the 10th position among 10 exogenous sources. The sum of the cancer risks from the major exogenous sources (e.g., 49.6/million) is higher than the permissible limits (1–10/million) of several regulatory agencies. Thus, NDMA in exogenous sources can pose a significant source for cancer risk. Cancer risk from the exogenous sources was estimated to be much lower than that of the NDMA in the endogenous source (<1%).     

Assessment of Human Health and Ecological Risks Posed by the Uses of Steel-Industry Slags in the Environment

Steel-industry slag, a co-product of iron and steel production, is produced and sold for use in a wide range of applications. A comprehensive study of the potential human health risks associated with the environmental applications (e.g., fill, roadbase, landscaping) of iron- and steel-making slag was performed using characterization data for 73 samples of slag collected from blast furnaces, basic oxygen furnaces, and electric arc furnaces. Characterization data were compared to regulatory health-based “screening” benchmarks to determine constituents of interest. Antimony, beryllium, cadmium, trivalent and hexavalent chromium, manganese, thallium, and vanadium were measured above screening levels and were assessed in an application-specific exposure assessment using standard U.S. Environmental Protection Agency risk assessment methods. A stochastic analysis was conducted to evaluate the variability and uncertainty in the inhalation exposure and risk estimates, and the oral bioaccessibility of certain metals in the slag was quantified. The risk assessment found no significant hazards to human health as a result of the environmental applications of steel-industry slag. However, site-specific ecological risk assessment may be required for slag applications in and around small water bodies with limited dilution volume, because high pH and aluminum were found to leach at levels that may be harmful to aquatic life     

Bottom Communities of Nyivo Lagoon (Northeastern Sakhalin)

Clasterization of benthic stations by biomass of common species using an index of coenotic similarities allowed us to distinguish three communities of macrophytobenthos (Zostera marina + Z. japonica, Zostera japonica, and Potamogeton pectinatus) and eight macrozoobenthos communities (Macoma balthica, Limnodrilus hoffmeisteri + Anisogammarus tiuschovi, Spio filicornis + Archaeomysis grebnitzkii, Kamaka kuthae, Glyptotendipes paripes, Neomysis awatschensis + Dolielinotus moskvitini, Neomysis mirabilis, and Anisogammarus tiuschovi + Littorina sitkana + Crangon septemspinosa). The bulk of the bottom surface is occupied by a community of Zostera marina + Macoma balthica with the mean biomass of the dominating species reaching 0.3–1386.6 and 573.9 g/m², respectively. Specific geomorphologic and hydrologic features, as well as the presence of many estuarine areas in Nyivo Lagoon, provide conditions for numerous different fresh-and brackish water communities and variations of them. However, bottom communities cannot be clearly separated into mostly freshwater and mostly brackish communities, which is the case for Pil'tun Lagoon, a well studied lagoon in eastern Sakhalin. Several decades of timber rafting in the Tym' River has had a significant effect on bottom biota and the communities of Nyivo Lagoon. Considering the well-known negative effects of phenol and its derivatives on benthic biota and communities derived during timber decomposition, the sources of pollution of the natural environment in the lagoons of eastern Sakhalin must be evaluated and differentiated.     

A Weight of Evidence Approach to the Aquatic Hazard Assessment of Bisphenoi A

Bisphenol A (BPA; 4,4-isopropylidene diphenol) is a chemical intermediate used primarily in the production of epoxy resins and polycarbonate products. BPA has been identified in surface waters and, hence, has been the subject of considerable research into its potential effects on aquatic organisms. Available literature on the aquatic toxicity of BPA was reviewed for quality against European Union TGD and Organization of Economic Cooperation and Development GLP principles. From this review, studies of suitable quality covering numerous ecologically relevant endpoints were identified to evaluate the survival, growth, and reproductive success of aquatic organisms exposed to BPA. Those studies yielded approximately 70 no observed effect concentrations (ranging from 16 to 3640 μg/L) and lowest observed effect concentrations (160 to 11,000 μg/L) that were considered in this weight of evidence assessment. Across all data, adverse effects on survival, growth, and reproduction occurred only at concentrations of 160 μg/L and above. Secondary biochemical (e.g., vitellogenin induction) and morphological (e.g., gonad histology) data provide insight into mechanisms of action, but do not correlate with apical endpoints related to survival, growth, and reproduction. Comparing the weight of the evidence of the aquatic toxicity data that showed chronic effects at 160 μg/L and higher with typical surface water concentrations in the range of 0.001 to 0.10 μg/ L, BPA is unlikely to cause adverse effects on aquatic populations or ecosystems.     

Release of treated effluent into streams: A global review of ecological impacts with a consideration of its potential use for environmental flows

1. Worldwide, the addition of treated wastewater (i.e. effluent) to streams is becoming more common as urban populations grow and developing countries increase their use of wastewater treatment plants. Release of treated effluent can impair water quality and ecological communities, but also could help restore flow and maintain aquatic habitat in water-stressed regions. To assess this range of potential outcomes, we conducted a global review of studies from effluent-fed streams to examine the impacts of effluent on water quality and aquatic and riparian biota.
2. We identified 147 quantitative studies of effluent-fed streams, most of which were from the U.S.A. and Europe. Over 85% of the studies identified water quality as a primary study focus, including basic physical and chemical parameters, as well as trace organic contaminants. Nearly 60% of the studies had at least some focus on aquatic or riparian biota, primarily fish, aquatic invertebrates, and basal resources (e.g. algae).
3. Effluent inputs generally impaired water quality near discharge points, mainly through increased water temperature, nutrients, and concentrations of trace organic contaminants, but also via decreased dissolved oxygen levels. The majority of ecological studies found that basal resources, aquatic invertebrates, and fish were negatively affected in a variety of ways (e.g. biodiversity losses, replacement of sensitive with tolerant species). However, several studies showed the importance of effluent in providing environmental flows to streams that had been dewatered by anthropogenic water withdrawals, especially in semi-arid and arid regions.
4. Knowledge gaps identified include the abiotic impacts of effluent, such as changes in channel morphology and hydrology (e.g. how nutrient-rich and warmer effluent affects infiltration rates or interactions with groundwater), the effects of effluent on plants and vertebrates (e.g. amphibians, birds), and the impact of effluent-induced perennialisation on naturally intermittent or ephemeral streams.
5. Although effluent-fed streams often exhibit signs of ecological impairment, there is great potential for these systems to serve as refuges of aquatic biodiversity and corridors of ecological connectivity when wastewater treatment standards are high, especially in semi-arid and arid regions where natural streams have been dewatered.

     

Ecological Risk Assessment of a Metal-Contaminated Area in the Tropics. Tier II: Detailed Assessment

This study presents data on the detailed evaluation (tier 2) of a site-specific ecological risk assessment (ssERA) in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil). Combining information from three lines of evidence (LoE), chemical (ChemLoE), ecotoxicological (EcotoxLoE) and ecological (EcoLoE), in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habitat and for the retention functions in each sampling point. Habitat function included the ChemLoE calculated from total metal concentrations. The EcotoxLoE was based on reproduction tests with terrestrial invertebrates (Folsomia candida, Enchytraeus crypticus, Eisenia andrei), shoot length and plant biomass (Avena sativa, Brassica rapa). For the EcoLoE, ecological parameters (microbial parameters, soil invertebrate community, litter breakdown) were used to derive risk values. Retention function included the ChemLoE, calculated from extractable metal concentrations, and the EcotoxLoE based on eluate tests with aquatic organisms (Daphnia magna reproduction and Pseudokirchneriella subcapitata growth). Results related to the habitat function indicated that the metal residues are sufficient to cause risk to biota, while the low metal levels in extracts and the general lack of toxicity in aquatic tests indicated a high soil retention capacity in most sampling points. Integrated risk of tier 2 showed the same trend of tier 1, suggesting the need to proceed with remediation actions. The high risk levels were related to direct toxicity to organisms and indirect effects, such as failure in the establishment of vegetation and the consequent loss of habitat quality for microorganisms and soil fauna. This study shed some light on the selection of tools for the tier 2 of an ssERA in tropical metal-contaminated sites, focusing on ecological receptors at risk and using available chemical methods, ecological surveys and ecotoxicity tests.     

Evaluation of “Classic” and Emerging Contaminants Resulting from the Application of Biosolids to Agricultural Lands: A Review

The presence of detectable amounts of contaminants in treated sewage sludge (concentrations μg/kg – mg/kg) has led to concerns that land applications of biosolids may result in an accumulation of contaminants in the soil and their subsequent translocation through the food chain. Despite advances in wastewater management (e.g., anaerobic, thermophilic, and mesophilic digestion), many compounds and their metabolites remain intact following treatment. This review looks at the main risk factors relating to the occurrence of “classic” (persistent organic pollutants [POPs]) and emerging pollutants (pharmaceuticals and personal care products) in biosolids. Relevant EU legislation and risk assessment strategies for the control of emerging contaminants are also considered. Organic pollutants regulated under the Stockholm Convention on POPs along with PPCPs were identified as contaminants of concern based on the risk factors: persistence, bioaccumulation, and toxicity (PBT). PPCPs were recognized as being of particular concern as their high transformation/removal rates are compensated by their continuous introduction into the environment. This study highlights the growing concern in relation to emerging contaminants in biosolids and highlights risk assessment strategies that can be used to characterize potential human/environmental risks.     

水生动物进口风险评估综述

随着全球水产养殖业的发展,水产动物活体或水产品贸易日益频繁,不可避免地给进口国带来病原风险,造成疾病引入和传播,甚至生物入侵,严重危害水产养殖业的发展。水生动物进口风险评估(IRA),是指从别国或地区进口水生动物活体包括其受精卵、稚鱼、幼鱼、苗种、成体以及商品等的风险分析。风险分析是指对风险事件进行科学、透明、系统分析的一个过程,它由危害识别、风险评估、风险交流和风险管理4个部分构成。目前,常用的风险评估方法有定性风险评估、半定量风险评估和定量风险评估3种。定性风险评估具有灵活性强、适用范围广、易掌握的特点,能够综合各种资料、数据和信息,尤其适合初次风险评估,但容易受评估人员主观因素的影响。定量风险评估可避免主观因素的影响,评估结果准确、可靠,但需要收集大量数据,工作量巨大,评估成本也很高。通常,定性评估结果若能够提供很好的防范措施,则不必进行定量评估。将外来水生病原阻止在引进之初远比引入后根除更加容易。因此,开展水生动物进口风险评估对于阻止水生动物疾病传播和水生态环境破坏具有重要意义,同时也可为各国进行水产贸易提供参考。     

Distribution Characteristics and Risk Assessments of PAHs in Fish from Lake Taihu,China

The concentrations of PAHs in four species of fish (Common carp, Crucian carp, Bighead carp, and Topmouth culter) from Lake Taihu were tested, and the human health risks of PAHs by fish consumption were evaluated. Results showed that concentrations of PAHs in fish from Lake Taihu were 52.5–247.6 ng/g wet weight (ww), and the BaP equivalent concentrations of total PAHs (B[a]P_eq) were 0.2–0.6 ng/g ww, which were less than the screening value of 2.6 ng/g wet for human consumption. The concentration sequences of PAHs in fish from Lake Taihu from high to low were Bighead carp > Crucian carp > Common carp > Topmouth culter. The human health risk level of PAHs by fish consumption was 5.8 ± 2.5 × 10^?6, which was less than the maximum acceptable risk level of 1 × 10^?5 for human health set by the U.S. Environmental Protection Agency. The tissue residue guideline (TRG) of PAHs for protecting aquatic wildlife was 1.3 mg/kg diet ww, which was higher than the concentrations of PAHs in fish from Lake Taihu. The results indicated that fish consumption from Lake Taihu would not cause health risk or harmful effects on wildlife that consume aquatic biota.     

不同生境下空心莲子草响应模拟昆虫采食的生长和化学防御策略

外来植物往往可以入侵多种生境并受到多种昆虫的采食,而不同生境条件将可能会影响这些入侵植物对昆虫采食的防御策略。以入侵我国的克隆植物——空心莲子草为研究对象,分别选择生长在水生生境、水陆两栖生境和陆生生境中的无性个体(分株),通过50%去叶处理模拟昆虫采食,分析不同生境下空心莲子草对模拟昆虫采食处理的生长及化学防御响应的差异。模拟昆虫采食处理显著抑制了陆生生境、水陆两栖生境以及水生生境下空心莲子草的根、茎、叶和总生物量,但对3种生境下空心莲子草的生物量分配(根冠比、根生物量分配、茎生物量分配和叶生物量分配)均无显著影响。陆生生境下空心莲子草根、茎和总生物量显著高于水陆两栖生境和水生生境,根冠比显著低于水陆两栖生境和水生生境。模拟昆虫采食处理显著降低了空心莲子草的木质素含量,而对单宁和总酚含量影响不显著。生境对木质素含量无显著影响,但陆生生境下空心莲子草单宁含量显著高于水陆两栖生境和水生生境,且总酚含量显著高于水陆两栖生境,表明陆生生境中空心莲子草具有更强的防御能力。空心莲子草木质素含量与总生物量无显著相关性,但在模拟采食情况下,其总酚含量与总生物量呈显著负相关,而无论模拟昆虫采食处理存在与否,空心莲子草单宁含量与总生物量均呈显著正相关。因此,空心莲子草存在昆虫介导的生长和化学防御之间的权衡,在昆虫采食的情况下可通过减少生长来增加对化学防御物质的投入,但生境对空心莲子草这种生长-防御权衡的影响十分有限。