Threshold Effect Level Research Articles

Suspended particulate matter transport of polycyclic aromatic hydrocarbons in the lower Columbia River and its estuary

AbstractAnalysis of suspended particulate material (SPM) collected from the Columbia River and its estuary in 2007–2008 revealed the ubiquitous presence of polycyclic aromatic hydrocarbons (PAHs) from several distinct sources. The two dominant ones were: (1) a suite of non‐alkylated, three to five‐ringed compounds derived from high temperature combustion and (2) perylene, a compound of diagenetic origin. A particle‐selective, hydrodynamic trapping process explains how both PAH types become concentrated on both a particle weight and organic carbon basis in the estuarine turbidity maximum (ETM) by as much as 10 times relative to the riverborne particle source. The ETM is a transient sedimentary feature at the land‐to‐sea interface of river‐dominated estuarine systems which, in the case of our study region, is located remotely from the likely site of initial PAH input. Particle normalized concentrations for PAH of notable environmental concern, such as fluoranthene, chrysene, and benzo[a]pyrene, exceeded the EPA‐defined threshold effects level in all cases and were typically at, or above, the probable effects level. Comparison with results from studies for other waterways around the world indicates PAH concentrations in ETM‐trapped particles from the Columbia River estuary are higher than those documented for SPM in waters of many far more industrialized and populated regions. Our refined understanding of PAH behavior in the Columbia River and its estuary should prove valuable for reliably modeling the transport and dispersal mechanism that is characteristic of other hydrophobic, particle associated persistent organic pollutants prevalent in this system, and for other river‐dominated estuarine systems.

The State of Marine Pollution in the Waters adjacent to Shipyards in Korea -3. Evaluation of the Pollution of Heavy Metals in Offshore Surface Sediments around Major Shipyards in Summer 2010

In order to evaluate the pollution of heavy metals in offshore surface sediments around shipyards in Korea, surface sediment samples were collected at eleven stations around four major shipyards located in the southeastern coast of Korea in summer 2010 and nine kinds of heavy metals such as copper(Cu), zinc(Zn), cadmium(Cd), lead(Pb), chrome(Cr), arsenic(As), mercury(Hg), iron(Fe) and aluminum(Al) in sediments were analyzed. The concentrations of Cu at all sampling stations were in the range of 47.10~414.96 ㎎/㎏ and exceeded TEL(Threshold Effects Level) 20.6㎎-Cu/㎏ of Korean marine environmental standards for offshore sediments and ERL(Effect Range-Low) 34.0㎎-Cu/㎏. The concentrations of Cu at seven stations around four shipyards were 65.18~414.96㎎/㎏ and exceeded PEL(Probable Effects Level) 64.4㎎-Cu/㎏ of Korean marine environmental standards for offshore sediments. The concentration of Cu at one station around B-shipyard was 414.96 ㎎/㎏ and exceeded ERM(Effect Range-Median) 270.0㎎-Cu/㎏. The concentrations of Zn at all stations were in the range of 135.09~388.79㎎/㎏ which exceeded ERL 150.0㎎-Zn/㎏. The concentrations of Zn at seven stations around four shipyards were 157.57~388.79㎎/㎏ and exceeded PEL 157.0㎎-Zn/㎏. The concentration of Zn at one station around B-shipyard was 388.79㎎/㎏ and was approaching ERM 410.0㎎-Zn/㎏. The concentrations of Cd at all stations were in the range of 0.11~0.54㎎/㎏ and were below TEL 0.75㎎-Cd/㎏ and ERL 1.2㎎-Cd/㎏. The concentrations of Pb at all stations were in the range of 18.04~105.62㎎/㎏ . The concentrations of Pb at two stations around B-shipyard were 73.87~105.62㎎/㎏ which exceeded TEL 44.0㎎-Pb/㎏ and ERL 46.7㎎-Pb/㎏, and were below PEL 119.0㎎-Pb/㎏ and ERM 218.0㎎-Pb/㎏. The concentrations of Cr at all stations were in the range of 51.26~85.39㎎/㎏ . The concentration of Cr at one station around B-shipyard was 85.39㎎/㎏ and exceeded ERL 81.0㎎-Cr/㎏. The concentrations of As at all stations were in the range of 8.70~22.15㎎/㎏ which exceeded ERL 8.2㎎-As/㎏ and were below ERM 70.0㎎-As/㎏. The concentrations of As at eight stations around A-shipyard, B-shipyard and D-shipyard were 14.93~22.15㎎/㎏ which exceeded TEL 14.5㎎-As/㎏ and were below PEL 75.5㎎-As/㎏. The concentrations of Hg at all stations were in the range of 0.02~0.35㎎/㎏. The concentrations of Hg at three stations around A-shipyard were 0.11~0.13㎎/㎏ which were almost equal to TEL 0.11㎎-Hg/㎏. Those at two stations around B-shipyard were 0.27~0.35㎎/㎏ which exceeded TEL 0.11㎎-Hg/㎏ and ERL 0.15㎎-Hg/㎏, and were below PEL 0.62㎎-Hg/㎏ and ERM 0.71㎎-Hg/㎏ . The concentrations of Fe and Al at all stations were in the range of 2.90~3.66 % and 3.12~6.80 %, respectively. These results imply that heavy metals such as copper, zinc, lead, arsenic and mercury were likely to be transferred to marine environment from shipyards, especially from B-shipyard.

Distribution and enrichment of trace metals in marine sediments from the Eastern Equatorial Atlantic, off the Coast of Ghana in the Gulf of Guinea

We present results of a preliminary geochemical assessment of Cd, Pb, V, As, Ni, Cu, Zn, Mg, Al, K, Ca, and Fe in marine sediments from the Eastern Equatorial Atlantic, off the Coast of Ghana. Samples were taken along 4 regions G1, G2, G3 and G4 at approximately 25m, 100m, and 250m, 500m and 1000m depths. Elemental compositions were assessed through the estimation of Al-normalized enrichment factors and geochemical accumulation indices, and the concentrations determined to produce any potential toxic effects to biota. Significant enrichment of the bottom sediments with Cd, Ni and As were observed at some locations with sediments showing signs of heavy pollution with As at region G4. Apart from Ni, V and As which were beyond threshold effects levels at most regions, all other metals were below probable effect levels. Both natural and anthropogenic processes controlled trace metal accumulation and distribution in the Ghanaian coastal environment.

Research Article: DDT, Dioxins, and PCBs in Sediments in a Historically Polluted Estuary along the Gulf of Mexico

This study assessed current profiles of organochlorine pollutants in sediment of Escambia Bay and River in northwest Florida, United States (US), which experienced catastrophic environmental collapse in the 1970s as a result of unregulated industrial and domestic sewage releases. Fifty-seven composite sediment samples were collected with a ponar grab sampler. Organochlorines were extracted with United States Environmental Protection Agency (USEPA) Method 3550 and concentrations were determined with USEPA Method 1668A for polychlorinated biphenyls (PCBs), USEPA Method1613B for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and USEPA Method 8081A for 4,4′-dichlorodiphenyltrichloroethane (DDT), 4,4′-Dichlorodiphenyldichloroethane (DDD), and 4,4′-Dichlorodiphenyldichloroethylene (DDE). For PCBs, 12 (21%) out of the 57 samples exceed the Florida threshold effects level (TEL) of 21.6 μg/kg and no sample exceeds the Florida probable effects level (PEL) of 189 μg/kg. The 17 PCDD/F congeners that a...

<b>Diffuse sources of pollution and their influence on the nature of the sediments in Água Preta Lake

Sediments in aquatic systems are indicators of contamination levels. Therefore, they play an important role in the assessment of the nature and intensity of human impact on aquatic environments. The objective of this work was to assess the levels of pollution by determining the concentrations of various metals and phosphorus forms in the sediments of Água Preta Lake, which supplies water to the Metropolitan Region of Belém, in north-eastern Brazil. Our data indicate non-uniform sedimentation with a large granulometric fraction of silt. The predominant form of phosphorus was inorganic phosphorus, to the detriment of the organic form. Observed mean concentrations of nickel, copper, lead, and zinc were lower than the PEL (Probable Effect Level). However, the highest observed concentrations of nickel and lead exceeded the prescribed TEL (Threshold Effect Level), which suggests pollution from an anthropogenic source.

Anthropogenic flank attack on polar bears: interacting consequences of climate warming and pollutant exposure

Polar bears (Ursus maritimus) are subjected to several anthropogenic threats, climate warming and exposure to pollutants being two of these. For polar bears, one of the main effects of climate warming is limited access to prey, due to loss of their sea ice habitat. This will result in prolonged fasting periods and emaciation and condition related negative effects on survival and reproduction success. Prolonged fasting will result in increases of the tissue concentrations of persistent organic pollutants (POPs) in polar bears, and thus increase the probability for POP levels to exceed threshold levels for effects on health, and thus on reproductive success and survival. There are clear potentials for interactions between impacts of climate warming and impacts of pollutant exposure on polar bears. It is likely that that fasting-induced increases of POPs will add to mortality rates and decrease reproductive success beyond effects caused by loss of habitat alone. However, there is a lack of studies that have addressed this. Thus, there is a need to focus on population effects of POP exposure in polar bears, and to consider such effects in relation to the effects of climate induced habitat loss.

Spatial distribution and pollution assessment of trace metals in surface sediments of Ziqlab Reservoir, Jordan.

Surface sediment samples were collected from Ziqlab dam in northwestern Jordan to investigate the spatial distribution of selected trace metals and assess their pollution levels. The results showed that the concentrations of Pb, Cd, and Zn exceeded the environmental background values. Cd, Ni, and Cr contents were higher than the threshold effect level (TEL) in 63, 83, and 60 % of the reservoir sediments, respectively; whereas Pb, Zn, and Cu were less than the TEL limit. The concentrations of trace metals in reservoir sediment varied spatially, but their variations showed similar trends. Elevated levels of metals observed in the western part (adjacent to the dam wall) were coincided with higher contents of clay-silt fraction and total organic matters. Multivariate analysis indicated that Pb, Co, and Mn may be related to the lithologic component and/or the application of agrochemicals in the upstream agricultural farms. However, Cd and Zn concentrations were probably elevated due to inputs from agricultural sources, including fertilizers. Evaluation of contamination levels by the Sediment Quality Guidelines of the US-EPA, revealed that sediments were non-polluted to moderately polluted with Pb, Cu, Zn, and Cr, but non-polluted to moderately to heavily polluted with Ni and non-polluted with Mn. The geoaccumulation index showed that Ziqlab sediments were unpolluted with Pb, Cu, Zn, Ni, Cr, Co, and Mn, but unpolluted to moderately polluted with Cd. The high enrichment values for Cd and Pb (>2) indicate their anthropogenic sources, whereas the remaining elements were of natural origins consistent with their low enrichment levels.

Assessing of Metals and Metalloids in Surface Sediments along the Gulf of Aqaba Coast, Northwestern Saudi Arabia

Batayneh, A.T.; Ghrefat, H.; Zumlot, T.; Elawadi, E.; Mogren, S.; Zaman, H.; Al-Taani, A.A.; Nazzal, Y., and Elwahaidi, M., 2015. Assessing of metals and metalloids in surface sediments along the Gulf of Aqaba coast, northwestern Saudi Arabia.The Gulf of Aqaba in northwestern Saudi Arabia is among the world's most important areas in terms of marine diversity and economic potential. Its coastal area witnessed significant anthropogenic changes as a result of rapid economic development and urbanization during recent decades. To document the impacts of these changes on the local environment, the distribution of heavy metal and metalloid pollutants (Fe, Al, As, Cu, B, Zn, Ba, Cr, Pb, Mn, Hg, V, Co, Mo, Se, Sb, Cd, and Be) and their variations in the surface sediments were investigated. Based on average concentrations, the dominance is as follows: Fe > Al > As > Cu > B > Zn > Ba > Cr > Pb > Mn > Hg > V > Co > Mo > Se > Sb > Cd > Be. The results showed a strongly positive linear correlation among Ba, Cr, Pb, and V. The studied sediments' quality was assessed using the geoaccumulation index (Igeo), an enrichment factor (EF), and two other sediment testing criteria (China State Bureau of Quality and Technical Supervision, or CSBTS, and Canadian guidelines). Hg is the only element with a moderate-to-strong concentration in terms of the Igeo, exceeding the primary, secondary, and tertiary CSBTS criteria and the threshold and probable effect levels of the Canadian guidelines. As causes moderate pollution, because its presence in the sediments exceeds the threshold effect level of the Canadian guidelines. The EF results showed Hg as a strong pollutant metal in the surface sediments of the study area, followed by As and Cu metals.

Bioconcentration and bioaccumulation of metal in freshwater Neotropical fish Geophagus brasiliensis

From the concentration in water and sediments, bioconcentration and bioaccumulation of copper (Cu), manganese (Mn), zinc (Zn), iron (Fe), cobalt (Co), cadmium (Cd), chrome (Cr), silver (Ag), lead (Pb), nickel (Ni), aluminum (Al), and arsenic (As) were determined in the gills, liver, and muscles of Geophagus brasiliensis in the Alagados Reservoir, Ponta Grossa, Paraná, Brazil. Metals were quantified through AAS, and a study was carried out on the existing relations between metal and body weight, size, and genre of this species. The level of metal in the water of the reservoir was lower than the maximum set forth in the legislation, except for that of Cd and Fe. In sediments, Cu, Cd, Cr, and Ni presented concentrations above the threshold effect level (TEL). Pb and Cr were above the limits for the G. brasiliensis. The tendency of metals present in the muscles of G. brasiliensis was Al > Cu > Zn > Fe > Co > Mn > Cr > Ag > Ni > Pb > Cd > As. In the gills, it was Al > Fe > Zn > Mn > Co > Ag > Cr > Ni > Cu > As > Pb > Cd, and the liver presented Al > Cu > Zn > Co > Fe > Mn > Pb > Ag > Ni > Cr > As > Cd. The bioconcentration and bioaccumulation of metal in the tissues follow the global tendency liver > gills > muscle. The statistical analysis did not point to significant differences in the metal concentration and body weight, size, and gender of the species in the three tissues under analysis.

Heavy metal concentrations in natural and human-impacted sediments of Segara Anakan Lagoon, Indonesia.

The concentrations of eight elements (Cr, Cu, Fe, Mn, Ni, Ti, V, and Zn) in surface sediments from Segara Anakan Nature Reserve (SARN), Indonesia, were determined using inductively coupled plasma-atomic emission spectroscopy following microwave-assisted acid digestion. In general, the heavy metal concentrations of the sediments were found to decrease in the sequence Fe > Ti > Mn > Zn > V > Cu > Cr > Ni. Sediment pollution assessment was carried out using a pollution status index contamination factor, pollution load index, geoaccumulation index, and enrichment factor as well as by comparing the measured values with two sediment quality guidelines, i.e., threshold effect level and probable effect level. The evaluation showed that in the refinery site stations, Cr, Ni, and Zn concentrations found in the SANR sediments may cause the adverse effect to occur over a wider range of organisms and can contribute to a more serious harmful effect.

The metazoan parasite communities of the shoal flounder (Syacium gunteri) as bioindicators of chemical contamination in the southern Gulf of Mexico.

BackgroundBecause agriculture and offshore oil extraction are significant economic activities in the southern Gulf of Mexico, high concentrations of nutrients and hydrocarbons are expected. As parasite communities are sensitive to environmental impacts, these contaminants should have an effect on metrics such as species richness, relative abundance and similarity. Consequently, these community metrics can be used as indicators of aquatic environmental health. Our objectives were to describe the parasite communities of the shoal flounder Syacium gunteri and to determine potential thresholds above which environmental contaminants become major controlling factors of parasite community metrics.MethodsThe study area included 33 sampling sites in the southern Gulf of Mexico, where benthic sediments, water and shoal flounder individuals were collected. Data on ecto- and endo-parasites from flounder and nutrients, contaminants and physicochemical variables from the water and sediments were obtained. The statistical associations of the parasite community metrics at the component and infracommunity levels and the environmental data were analysed using redundancy analysis (RDA).ResultsOverall, 203 shoal flounder were examined for parasites, recovering 13 metazoan parasite species, and 48 physicochemical (e.g. temperature, nutrients) and contaminant (e.g. hydrocarbons, heavy metals) variables were obtained. The larval stages of the cestode Oncomegas wageneri and the nematodes Pseudoterranova decipiens and Hysterothylacium sp. were numerically dominant at the component and infracommunity levels. The parasite community metrics had significant negative statistical associations with both nitrate and total PAHs. With the exception of these two chemicals, which exceeded the threshold effect levels (TELs), no other environmental variable exceeded the range considered safe for marine organisms.ConclusionsThe community metrics chosen generally had robust statistically significant associations with both physicochemical and contaminant variables, which supports the ecological relevance of these parameters as indicators of aquatic environmental health. Within the study area, the shoal flounder and their parasites live in a polluted environment with relatively high levels of hydrocarbons and nitrate. Regarding nitrate, we emphasise that if uncontrolled sewage discharge continues in the southern Gulf of Mexico, hypoxic conditions similar to those caused by the Mississippi river can be expected in the near future.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-014-0541-3) contains supplementary material, which is available to authorized users.

Assessing the ecological quality status of a temperate urban estuary by means of benthic biotic indices

Benthic indices are commonly used tools for assessing the environmental quality, because they represent a simple source of scientific information. However, their performance could vary depending on the application area and perturbation types, thus they should be tested before used in other remote geographic regions. This study aims to test the use of some of the most widely common benthic biotic indices for assessing the environmental quality of Montevideo’s coastal zone at a seasonal scale against many physicochemical variables. From all the evaluated indices, AMBI appears to be the most suitable one to assess the environmental quality. The study also allowed us to infer the most relevant physicochemical variables: protein, lipid and heavy metal sediment concentration. Additionally, site-specific threshold effect levels for heavy metals and biopolymers were established, which appear to be useful to determine tolerable levels of such stressors in future assessments or monitoring programs for the study area.

Using Sets of Geochemical Analyses and Toxicity Tests to Assess the Effects of Sewage Disposal in Santos Bay, Brazil

The submarine sewage outfall of Santos (SSOS) is a significant source of contaminants to the marine ecosystems of Santos Bay. The present study aimed at assessing the influence of SSOS on the sediment quality of Santos Bay. To achieve that sediments were collected at 5 sampling sites located around the SSOS diffusers, then sets of chemical analyses and toxicity tests were conducted. The results indicated that, at the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding Threshold Effect Level values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals. Chronic toxicity occurred in all samples, whereas acute toxicities were more evident in the sediments from station 4 (West). Toxicities correlated to Hg, ammonia, detergents, total N, total S and % mud. Results evidenced that sediments around SSOS are affected by effluent discharges, and that the combined use of sets toxicity tests together with chemical analyses may provide a better overview of the sediment quality.

Distribution, mobility, and pollution assessment of Cd, Cu, Ni, Pb, Zn, and Fe in intertidal surface sediments of Sg. Puloh mangrove estuary, Malaysia.

Sungai Puloh mangrove estuary supports a large diversity of macrobenthic organisms and provides social benefits to the local community. Recently, it became a major recipient of heavy metals originating from industries in the hinterland as a result of industrialization and urbanization. This study was conducted to evaluate mobility and pollution status of heavy metals (Cd, Cu, Ni, Pb, Zn, and Fe) in intertidal surface sediments of this area. Surface sediment samples were collected based on four different anthropogenic sources. Metals concentrations were analyzed using an atomic absorption spectrophotometer (AAS). Results revealed that the mean concentrations were Zn (1023.68 ± 762.93 μg/g), Pb (78.8 ± 49.61 μg/g), Cu (46.89 ± 43.79 μg/g), Ni (35.54 ± 10.75 μg/g), Cd (0.94 ± 0.29 μg/g), and Fe (7.14 ± 0.94%). Most of the mean values of analyzed metals were below both the interim sediment quality guidelines (ISQG-low and ISQG-high), except for Pb concentration (above ISQG-low) and Zn concentration (above ISQG-high), thus suggesting that Pb and Zn may pose some environmental concern. Cadmium, Pb, and Zn concentrations were above the threshold effect level (TEL), indicating seldom adverse effect of these metals on macrobenthic organisms. Pollution load index (PLI) indicated deterioration and other indices revealed the intertidal surface sediment is moderately polluted with Cd, Pb, and Zn. Therefore, this mangrove area requires urgent attention to mitigate further contamination. Finally, this study will contribute to data sources for Malaysia in establishing her own ISQG since it is a baseline study with detailed contamination assessment indices for surface sediment of intertidal mangrove area.

Concentration of trace elements in feathers of waterfowl, Korea.

Cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), manganese (Mn), zinc (Zn), and iron (Fe) were analyzed in the breast feather of white-fronted geese (Anser albifrons, n = 15), mallards (Anas platyrhynchos, n = 4), and spot-billed ducks (Anas poecilorhyncha, n = 13) found dead in Gimpo, Korea. All of the mallards and eight of the 13 spot-billed ducks had embedded shot. Concentrations of Pb, Cr, Cu, Mn, Zn, and Fe were significantly different among waterfowl species. Mallards with embedded shot had relatively higher Pb, Cr, Mn, and Fe concentrations than the other species. Cd and Cr in feathers of waterfowl species were within the range reported for other birds, and no specimen exceeded the tentative threshold effect levels of Cd (2μg/g dry weight (dw)) and Cr (2.8μg/g dw) for birds. However, Pb in feathers of all four mallards and two spot-billed ducks exceeded the threshold for deleterious effects (>4μg/g dw). Essential elements such as Cu, Mn, Zn, and Fe in the feather of waterfowl species were not at toxic levels and within the background or normal range for the homeostatic mechanisms.

Assessment of pollution and ecological risk of heavy metals in the surface sediments of Ulsan Bay, Korea

Heavy metal concentrations in the surface sediments of specially managed Ulsan Bay were investigated to determine metal distribution, pollution status and its ecological risk using pollution indices (enrichment factor and geo-accumulation index), potential ecological risk index and sediment quality guidelines (SQGs). The order of mean concentration (mg/kg) of metals was Zn (361.9) > Cu (95.6) > Pb (90.7) > Cr (64.7) > Ni (32.2) > Co (16.6) > As (15.8) > Cd (0.40) > Hg (0.16) in sediments of Ulsan Bay. Spatial distribution of metals in sediments showed a significantly higher concentration near industrial complexes, indicating that metal pollution is caused by anthropogenic sources. The results of enrichment factor (EF) and geo-accumulation index (Igeo) showed that sediments were significantly accumulated with Cu, Zn, As, Cd, Pb and Hg, indicating moderate to very severe enrichment (pollution) by these metals. Based on the potential ecological risk index, Hg and Cd posed a very high and a considerable potential ecological risk. Cu and As posed a moderate potential ecological risk, while, other metals (Cr, Co, Ni, Zn and Pb) rarely posed any potential ecological risk to the coastal environments. The sediments in Ulsan Bay showed a very high level of ecological risk, dominated by Hg and Cd. Metal concentrations in sediments were 80% for Cu, 96.7% for Zn, 50% for As, 70% for Pb and 50% for Hg above the threshold effects level (TEL), respectively.

Metal bioavailability potential of São Francisco river sediments in Três Marias (Minas Gerais - Brazil)

Sediment contamination by metals is very common and frequently researched worldwide with the objective of assessing the environmental impact of these contaminants. The bulk metal concentration in sediments is not enough for assessing toxicity and therefore, needs additional research and assays. To estimate the potentially bioavailable fraction of the metals in the sediment, the acid-volatile sulfides / simultaneously extracted metals (AVS/SEM) method was used. Seven samples in duplicate were collected from the São Francisco River and its tributary, near a zinc metallurgical plant in the city of Três Marias (MG). The AVS/SEM results suggest that, although the bulk metal concentrations are above TEL (Threshold Effects Level: A chemical concentration above which some adverse effect to biota is expected), samples from the São Francisco River presented relatively low potential for bioavailability (uncertain toxicity). These results should be taken into consideration before deciding about contaminated sediment management.

Relationships Between Persistent Organic Pollutants and Circulating Immunoglobulin-Y in Black-Legged Kittiwakes and Atlantic Puffins

Have Although persistent organic pollutants (POPs) may affect the immune system, few field studies actually examined this effect. There are indications that POP exert effects on the immune system; however, in the Arctic ecosystem data are scarce. The aim of this study was to examine immune functions in two medium trophic-positioned seabirds, the black-legged kittiwakes (Rissa tridactyla) and Atlantic puffins (Fratercula arctica). Overall POP concentrations were higher in kittiwakes than puffins and males had significantly higher concentrations than females. Mean concentrations of total polychlorinated biphenyls (ΣPCB9) were 4700 ± 200 and 9600 ± 1400 ng/g lipid weight and 2800 ± 180 and 3900 ± 200 ng/g lipid weight in female and male kittiwake and puffin blood, respectively. Levels of immunoglobulin-Y (IgY) in blood of kittiwakes were not markedly affected by concentrations of POP. Similarly, the primary IgY response to tetanus toxoid was not affected by POP concentrations in a subsample of immunized kittiwakes. In puffins, there were significant correlations between the IgY-response and some of the POPs, but with low explanatory values. These results suggest that POPs concentrations were lower than, or just at the threshold level for effects of the proposed IgY biomarker. It is also conceivable that the IgY levels are not a suitable endpoint for evaluating perturbation of the immune system in free-living seabirds.

Metal contamination of surface sediments of the Sfax–Chebba coastal line, Tunisia

Concentrations of several heavy metals (Pb, Cr, Cd, Cu, Zn and Fe) in surface sediment were determined to investigate the distributions and the metallic pollution status in Sfax–Chebba coastal area (southeast of Tunisia). Sediment samples were collected from 20 locations, representing three different site groups (i.e., site I: urban zone, site II: pre-urban zone and site III: rural zone). Heavy metal contents were analyzed by Atomic Absorption Spectrometry. The obtained results showed that generally, heavy metal concentrations in the coastal sediments near Sfax city (urban zone) were higher than those at other stations because of the anthropogenic activities. These concentrations exceeded the threshold effect levels. This was confirmed by the chemometric approaches (enrichment factors, geoaccumulation index and principal component analysis) which showed a significant impact of multiple anthropogenic sources. Moderate to extremely severe enrichment of sediments in terms of Pb, Cr, Cd, Cu and Zn were shown to exist in site I. Severe enrichment by Cd was also observed in other sites. Based on the geoaccumulation index, Pb, Cr, Cd, Cu and Zn can be considered as unpollutants to extreme pollutants.

Quantitative dose–response analysis of ethyl methanesulfonate genotoxicity in adult gpt‐delta transgenic mice

The assumption that mutagens have linear dose-responses recently has been challenged. In particular, ethyl methanesulfonate (EMS), a DNA-reactive mutagen and carcinogen, exhibited sublinear or thresholded dose-responses for LacZ mutation in transgenic Muta™Mouse and for micronucleus (MN) frequency in CD1 mice (Gocke E and Müller L [2009]: Mutat Res 678:101-107). In order to explore variables in establishing genotoxicity dose-responses, we characterized the genotoxicity of EMS using gene mutation assays anticipated to have lower spontaneous mutant frequencies (MFs) than Muta™Mouse. Male gpt-delta transgenic mice were treated daily for 28 days with 5 to 100 mg/kg EMS, and measurements were made on: (i) gpt MFs in liver, lung, bone marrow, kidney, small intestine, and spleen; and (ii) Pig-a MFs in peripheral blood reticulocytes (RETs) and total red blood cells. MN induction also was measured in peripheral blood RETs. These data were used to calculate Points of Departure (PoDs) for the dose responses, i.e., no-observed-genotoxic-effect-levels (NOGELs), lower confidence limits of threshold effect levels (Td-LCIs), and lower confidence limits of 10% benchmark response rates (BMDL10 s). Similar PoDs were calculated from the published EMS dose-responses for LacZ mutation and CD1 MN induction. Vehicle control gpt and Pig-a MFs were 13-40-fold lower than published vehicle control LacZ MFs. In general, the EMS genotoxicity dose-responses in gpt-delta mice had lower PoDs than those calculated from the Muta™Mouse and CD1 mouse data. Our results indicate that the magnitude and possibly the shape of mutagenicity dose responses differ between in vivo models, with lower PoDs generally detected by gene mutation assays with lower backgrounds.