Metallothionein as an indicator of water quality: assessment of the bioavailability of cadmium, copper, mercury and zinc in aquatic animals at the cellular level

The study of metallothioneins (MTs) has greatly improved our understanding of body burdens, metal storage and detoxification in aquatic organisms subjected to contamination by the toxic heavy metals, Cd, Cu, Hg and Zn. These studies have shown that in certain organisms MT status can be used to assess impact of these metals at the cellular level and, whilst validation is currently limited to a few examples, this stress response may be linked to higher levels of organisation, thus indicating its potential for environmental quality assessment. Molluscs, such as Mytilus spp., and several commonly occurring teleost species, are the most promising of the indicator species tested. Natural variability of MT levels caused by the organism's size, condition, age, position in the sexual cycle, temperature and various stressors, can lead to difficulties in interpretation of field data as a definitive response-indicator of metal contamination unless a critical appraisal of these variables is available. From laboratory and field studies these data are almost complete for teleost fish. Whilst for molluscs much of this information is lacking, when suitable controls are utilised and MT measurements are combined with observations of metal partitioning, current studies indicate that they are nevertheless a powerful tool in the interpretation of impact, and may prove useful in water quality assessment.

Concentrations en métaux toxiques chez Crassostrea gasar (huître de mangrove) en zone urbaine lagunaire d'Abidjan (Côte d'Ivoire)

This paper presents results related to a study of toxic heavy metals concentrations (Cd, Cu, Hg and Zn) in Crassostrea gasar (mangrove oyster). A comparative study is made between samples collected in urban region (Abidjan) and those from rural areas (Assinie-Mafia and Assouindé). Toxic metals concentrations in oyster samples collected in urban zone are higher than those in rural samples, as a result of chemical pollution due to urban and industrial wastes. Correlations between pollutants-weight of organisms and pollutants are good.

Assessment of contaminant body burdens and histopathology of fish and shellfish species frequently used for subsistence food by Alaskan Native communities

Subsistence food items can be a health concern in rural Alaska because community members often rely on fish and wildlife resources not routinely monitored for persistent bioaccumulative contaminants and pathogens. Subsistence activities are a large part of the traditional culture, as well as a means of providing protein in the diets for Tribal members. In response to the growing concerns among Native communities, contaminant body burden and histopathological condition of chum and sockeye salmon (Oncorhynchus keta and Oncorhynchus nerka) and the shellfish cockles and softshell clams (Clinocardium nuttallii and Mya arenaria) were assessed. In the Spring of 2010, the fish and shellfish were collected from traditional subsistence harvest areas in the vicinity of Nanwalek, Port Graham, and Seldovia, AK, and were analyzed for trace metals and residues of organic contaminants routinely monitored by the NOAA National Status & Trends Program (NS&T). Additionally, the fish and shellfish were histologically characterized for the presence, prevalence and severity of tissue pathology, disease, and parasite infection. The fish and shellfish sampled showed low tissue contamination, and pathologic effects of the parasites and diseases were absent or minimal. Taken together, the results showed that the fish and shellfish were healthy and pose no safety concern for consumption. This study provides reliable chemistry and histopathology information for local resource managers and Alaska Native people regarding subsistence fish and shellfish use and management needs.

Assessing the impacts of the Deepwater Horizon oil spill: the National Status and Trends Program response; a summary report of coastal contamination

NOAA’s National Status and Trends Program (NS&T) collected oyster tissue and sediments for quantification of polycyclic aromatic hydrocarbons (PAHs) and petroleum associated metals before and after the landfall of oil from the Deepwater Horizon incident of 2010. These new pre- and post- landfall measurements were put into a historical context by comparing them to data collected in the region over three decades during Mussel Watch monitoring. Overall, the levels of PAHs in both sediment and oysters both pre- and post-landfall were within the range of historically observed values for the Gulf of Mexico. Some specific sites did have elevated PAH levels. While those locations generally correspond to areas in which oil reached coastal areas, it cannot be conclusively stated that the contamination is due to oiling from the Deepwater Horizon incident at these sites due to the survey nature of these sampling efforts. Instead, our data indicate locations along the coast where intensive investigation of hydrocarbon contamination should be undertaken. Post-spill concentrations of oil-related trace metals (V, Hg, Ni) were generally within historically observed ranges for a given site, however, nickel and vanadium were elevated at some sites including areas in Mississippi Sound and Galveston, Terrebonne, Mobile, Pensacola, and Apalachicola Bays. No oyster tissue metal body burden exceeded any of the United States Food and Drug Administration’s (FDA) shellfish permissible action levels for human consumption.

Support for integrated ecosystem assessments of NOAA’s National Estuarine Research Reserve System (NERRS): assessment of ecological condition and stressor impacts in subtidal waters of the Sapelo Island National Estuarine Research Reserve

A study was conducted in June 2009 to assess the current status of ecological condition and potential human-health risks throughout subtidal estuarine waters of the Sapelo Island National Estuarine Research Reserve (SINERR) along the coast of Georgia. Samples were collected for multiple indicators of ecosystem condition, including water quality (dissolved oxygen, salinity, temperature, pH, nutrients and chlorophyll, suspended solids, fecal coliform bacteria and coliphages), sediment quality (granulometry, organic matter content, chemical contaminant concentrations), biological condition (diversity and abundance of benthic fauna, fish tissue contaminant levels and pathologies), and human dimensions (fish-tissue contaminant levels relative to human-health consumption limits, various aesthetic properties). Use of a probabilistic sampling design facilitated the calculation of statistics to estimate the spatial extent of the Reserve classified according to various categories (i.e., Good, Fair, Poor) of ecological condition relative to established thresholds of these indicators, where available. Overall, the majority of subtidal habitat in the SINERR appeared to be healthy, with over half (56.7 %) of the Reserve area having water quality, sediment quality, and benthic biological condition indicators rated in the healthy to intermediate range of corresponding guideline thresholds. None of the stations sampled had one or more indicators in all three categories rated as poor/degraded. While these results are encouraging, it should be noted that one or more indicators were rated as poor/degraded in at least one of the three categories over 40% of the Reserve study area, represented by 12 of the 30 stations sampled. Although measures of fish tissue chemical contamination were not included in any of the above estimates, a number of trace metals, pesticides, polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) were found at low yet detectable levels in some fish at stations where fish were caught. Levels of mercury and total PCBs in some fish specimens fell within EPA guideline values considered safe, given a consumption rate of no more than four fish meals per month. Moreover, PCB congener profiles in sediments and fish in the SINERR exhibit a relative abundance of higher-chlorinated homologs which are uniquely characteristic of Aroclor 1268. It has been well-documented that sediments and fish in the creeks and marshes near the LCP Chemicals Superfund site, near Brunswick, Georgia, also display this congener pattern associated with Aroclor 1268, a highly chlorinated mixture of PCBs used extensively at a chlor-alkali plant that was in operation at the LCP site from 1955-1994. This report provides results suggesting that the protected habitats lying within the boundaries of the SINERR may be experiencing the effects of a legacy of chemical contamination at a site over 40km away. These effects, as well as other potential stressors associated with increased development of nearby coastal areas, underscore the importance of establishing baseline ecological conditions that can be used to track potential changes in the future and to guide management and stewardship of the otherwise relatively unspoiled ecosystems of the SINERR.

Distribution of Cu, Zn, Pb and Cd in some recent molluscan shells from Lake Mariut sediment

Shells and shell fragments were the principal constituents of the core sediment taken from LakeMariut. Their trace metals were studied to assess their contribution to environmental adjustment. The results indicated that the shells of Biomphalaria alexandrina, Mercierella enigmatica and Melanoida tuberculate contain higher amounts of Cu and Zn than the widely distributed shells of Lucina sp. and Cerastoderma edule. The Pb contents found in different types of shells were higher than the other metals. The Cd contents found in different shell types were the most important fraction in comparison to the total Cd in the sediments of the lake. The relationship between the concentrations of trace metals and mineralogical analysis revealed that lead tended to be more concentrated in aragonite than in calcite.

Concentration of toxic metals in benthic organisms off Bombay coast

Concentration of toxic metals namely Zn, Cu, Fe, Cd and Pb in the marine benthos off Bombay Coast, Maharashtra (India) was estimated. Maximum concentration of Zn, Fe and Pb was from the organisms of Thana Creek. Higher concentration of Cu was encountered in benthic organisms off Versova. Cd was detected in some organisms and was maximum in the organisms collected from Mahim.

Toxicity of heavy metals to brine shrimp Artemia

Bioassay were carried out on 48h cultured nauplii of brine shrimp Artemia by exposing them to seven trace elements viz. copper (Cu), zinc (Zn), cadmium (Cd), nickel (Ni), lead (Pb), iron (Fe) and manganese (Mn). Synergistic effects of all these elements and additive effects of Cu and Zn, Cd and Pb, and Ni and Fe were also investigated. Comparatively, the degree of toxicity for compound bioassays was higher than individual simple tests. The values were averaged and the expected median lethal concentration [LC sub(50)] of tested heavy metals was obtained by probit analysis on the basis of cumulative numbers of dead organisms after 24 and 48h. The order of toxicity of the metals to Artemia was Pb>Cd>Cu>Ni>Zn>Fe>Mn. Potency ratios of the seven metals were also calculated. The 24 and 48h variations obtained in LC sub(50) values were significantly different and relative implications of these are discussed.

Fabrication and optimizing of metal nano silicate as toxic metal absorbent from sea water

Pure Water, is a crucial demand of creature life. Following industrial development, extra amount of toxic metals such as chromium enters the environmental cycle through the sewage, which is considered as a serious threat for organisms. One of the modern methods of filtration and removal of contaminants in water, is applying Nano-technology. According to specific property of silicate materials, in this article we try to survey increased power in composites and various absorption in several morphologies and also synthesis of Nano-metal silicates with different morphologies as absorbent of metal toxic ions. At first, we synthesize nano zink silicate with three morphologies considering context and the purpose of this survey. 1) Nano synthesis of zink silicate hollow cavity by hydrothermal method in mixed solvent system of ethanol/glycol polyethylene. 2) Zink nano wires silicate in a water-based system by controlling the amount of sodium silicate. 3) Synthesis of nano zink silicate membrane. After synthesizing, we measured the cadmium ion absorbance by synthesized nano zink silicates. Controlling PH, is the applied absorption method. Next step, we synthesized nano zink-magnesium silicate composite in two various morphologies of nanowires and membrane by different precent of zink and magnesium, in order to optimize synthesized nano metal silicate. We used zink nitrate and magnesium nitrate and also measured cadmium absorption by synthesized nano metal silicates in the same way of PH control absorption. In the 3rd step, in order to determine the impact of the type of metal in nano metal silicate, we synthesized nano magnesium silicate and compared its absorption with nano zink silicate. Furthermore, we calculated the optimal concentration in one of synthesizes. Optimal concentration is the process which has the maximum absorption. While applying two methods of absorption in the test, finally we compared the effect of absorption method on the absorption level. Below you find further steps of synthesis: 1) Using IR, RAMAN, XRD spectroscopy to check the accuracy of synthesis. 2) Checking the dispersion of nano particles in ethanol solution by light microscope. 3) Measuring and observing particles with scanning electron microscope (SEM). 4) Using atomic absorption device for measuring the cadmium concentration in water-based solutions. The nano metal silicates were synthesized successfully. All of synthesized nano absorbents have the cadmium ion absorbency. The cadmium absorption via nano absorbents depend on various factors such as kind of metal in nano silicate and percent of metal in nano metal silicate composite. Meanwhile the absorption and PH control of medium containing the absorbent and solution would affect the cadmium absorption.

Toxic pollutants, health indices and population dynamics of Harbor Seals in San Francisco Bay, 1989-1992

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Contaminant trends in US National Estuarine Research Reserves

Inputs of toxic chemicals provide one of the major types of anthropogenic stress threatening our Nation's coastal and estuarine waters. To assess this threat, the National Oceanic and Atmospheric Administration's (NOAA’s) National Status and Trends (NS&T) Program Mussel Watch Project monitors the concentrations of more than 70 toxic chemicals in sediments and on the whole soft-parts of mussels and oysters at over 300 sites around the U.S. Twenty of the 25 designated areas that comprise NOAA's National Estuarine Research Reserve System (NERRS) have one or more Mussel Watch monitoring sites. Trace elements and organic contaminants were quantified including As, Ag, Cd, Cu, Hg, Ni, Pb, Zn, ΣPCBs, ΣPAHs, DDT and its metabolites, and butyltins. The Mussel Watch sites located in or near the 20 Reserves provide for both status and trends. Generally the Reserves have trace element and organic contaminant concentrations that are at or below the median concentration determined for all NS&T Mussel Watch monitoring data. Trends were derived using the Spearman-rank correlation coefficient. It was possible to determine if trends exist for sites at which six or more years of data are available. Generally no trends were found for trace elements but when trends were found they were usually decreasing. The same general conclusion holds for organic contaminants but more decreasing trends were found than for trace elements. The greatest number of decreasing trends were found for tributyltin and its metabolites. (PDF contains 203 pages)

Trace element concentrations in muscle tissue of the benthopelagic grenadier (Coryphaenoides armatus) from the Iberian deep-sea

11 specimens of Coryphaenoides armatus were collected at former dumping sites for radioactive material in the Iberian deep sea at a depth of 4700 m and their muscle tissue was analysed for four trace elements (copper, zinc, cadmium and lead) by differential pulse anodic stripping voltammetry (DPSAV). Concentrations of zinc were typical for fish muscle in general; copper content was somewhat higher than generally found in fish. The cadmium and lead contents were at a level found in fish from the open sea but the lead content of 2 specimens taken in area East-B was found to be higher.

Metals and pesticide levels found in fish taken from Vancouver Lake: memorandum to Steve O'Brien, dated May 19, 1977

The Vancouver Lake Pilot Dredge Study revealed concentrations of certain chemicals which could be of concern: the metals copper, zinc and mercury and the pesticides lindane and aldrin were found in significant amounts. (PDF contains 1 page)

Toxic effect of Raphia vinifera on fish leech (Piscicola geometra)

This study examines acute toxicity of Raphia vinifera on fish leech, Piscicola geometra. The leeches with a mean total length of (TL) 4.2+1.0cm were exposed to various concentrations of both crude powdered and ethanolic extracts of the botanical. Median lethal concentration (LC50) was determined with static-renewal tests using logarithmic and arithmetic graphic methods. The LC50 (for 96 hours of crude powdered (aqueous) extracts of the botanical on Piscicola geometra was 1.10 ppm arithmetically and 1.14ppm logarithmically. The 95% confidence limits was 0.10ppm arithmetically and 0.12ppm logarithmically. The LC50 of ethanolic extract of the poison at 96-h was 0.5ppm arithmetically and 0.48ppm logarithmically. The 95% confidence limits were less than 0.10ppm. The use of extracts of R. vinifera in the control of leeches in fish ponds is discussed

Evaluation of the body burdens of heavy metals in five commercially important fishes from different locations in Kainji Lake

The level and distribution of some heavy metals viz Cadmium, Lead, Copper Zinc, and Cobalt in five commercially important fishes, water and sediments at three different locations in Kainj Lake were determined using standard methods. The results show that the ranges of heavy metals mu g/g in fishes in Dam site Laotian are: Cd (0.05~c0.01-20~c01), (Pb(ND-1.12 plus or minus )1), Cu (0.81~c25-2.93~c06), Zn (20.89 arrow right .15-36.78~c2.97), Co(0.08~c01-0.27~c02); in cover Dam, the ranges are Cd (0.04~c02-0.16~c0.2), Pb (nd-02~c01), Cu(0.75~c05-2.61~c13), Zn(15.70~c1.55-32.23~c2.70), Co(0.04~c02-0.25~c0.01) and in Yuna they are Cd (0.05~c01-0.14~c02), Pb (nd-0.32~c01), Cu (0.23~c07-2.70~c05), Zn(15.50 plus or minus `.35-25.62~c2.47), Co(0.07~c02-23~c0.01). The metals concentration (mg/l) in the water sample from Dam site, cover dam and Yuna respectively are Cd(0.007~c001,. 004~c001 and 0.005~001), Pb(013~c001, ND and ND), Cu(.055~c008.030~c007, 05 plus or minus .010), Zn(0.13~c01, 0.060 plus or minus .0055) and Co (.026 plus or minus .022 plus or minus .004, .024 plus or minus .004), while the metals concentration ( mu g/g) in sediments sample from Dam site, cover dam and Yuna are respectively Cd(.05 plus or minus .01, .02 plus or minus .01), Pb(16.00~c1.00, ND and 9.33~c1.01), Cu(24.00~c1.34, 4.26 plus or minus .91 and 11.08~c1.32), Zn(42.00~c1.00, 35~c10 and 38.00 plus or minus .45), Co(15.00~c1.17, 8.69~c1.21 and 10.91~c44). The concentrations of the tested heavy metals are within the acceptable standards of WHO (1987a)