Refine search
Results 1-9 of 9
Metals in sediments and fish from Sea Lots and Point Lisas Harbors, Trinidad and Tobago
2012
Mohammed, Azad | May, Thomas | Echols, Kathy | Walther, Mike | Manoo, Anton | Maraj, Dexter | Agard, John | Orazio, Carl
Concentrations of heavy metals were determined in nearshore marine sediments and fish tissue from Sea Lots area on the west coast, at Caroni Lagoon National Park, and in the Point Lisas harbor, Trinidad. The most dominant metals found in sediments were Al, Fe and Zn with mean concentrations highest at Sea Lots (Al-39420μg/g; Fe-45640μg/g; Zn-245μg/g), when compared to sediments from Point Lisas (Al-11936μg/g; Fe-30171μg/g; Zn-69μg/g) and Caroni (Al-0400μg/g; Fe-19000μg/g; Zn-32μg/g), High concentration of Cu, Al, Fe and Zn were also detected in fish tissue from Point Lisas and Caroni. Metal concentrations in fish tissue showed significant correlation with sediment metals concentration, which suggests that tissue levels are influenced by sediment concentration. Of the metals, only Zn, Hg and Cu had a bioaccumulation factor (BAF) greater than one, which suggests a high bioaccumulation potential for these metals.
Show more [+] Less [-]Occurrence and partitioning of endocrine-disrupting compounds in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece
2012
Arditsoglou, Anastasia | Voutsa, Dimitra
An integrated study was conducted to determine the presence of phenolic and steroid endocrine-disrupting compounds (EDCs), in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece. Seawater, suspended particulate matter, sediments and biota were examined for nonylphenol, octylphenol, their mono- and diethoxylate oligomers, bisphenol A, estrone, 17α-estradiol, 17β-estradiol, estriol, mestranol and 17 α -ethynylestradiol. Phenolic compounds were detected in all of the compartments, with nonylphenol and its ethoxylates being the dominant pollutants. The occurrence of nonylphenol in sediments presents a significant risk to the biota. Mussels exhibited relatively low concentrations and low bioconcentration factors for NP and OP. The effect of terrestrial sources of the EDCs on the marine environment is discussed. The influence of suspended particulate matter and organic carbon in the partition of the EDCs between the dissolved and the particulate phase was investigated.
Show more [+] Less [-]Uptake Kinetics of As, Hg, Sb, and Se in the Aquatic Moss Fontinalis antipyretica Hedw
2012
Díaz, Santiago | Villares, Rubén | Carballeira, Alejo
Laboratory experiments were carried out to study the uptake kinetics of selected metals and metalloids in the aquatic moss Fontinalis antipyretica. For this purpose, moss specimens from a clean site were exposed to concentrations of As, Hg, Sb, and Se ranging from 0.1 to 10,000 μg l−1, for incubation times of between 1 and 22 days, and the tissue concentrations of the metals in the moss specimens were then measured. Uptake kinetics followed different patterns in relation to exposure time, although the most common was Michaelis–Menten kinetics. On the contrary, the contamination factors followed very similar patterns in relation to the exposure concentrations in all cases, with a good fit to logarithmic equations. The bioconcentration factors tended to decrease as exposure concentration increased. The bioconcentration factors for Hg were extremely high, even at the lowest concentration in water and for the shortest incubation time, which implies that F. antipyretica has a high capacity to magnify Hg levels in water, which is an important characteristic in a good biomonitor. According to the time to reach equilibrium, the minimum exposure time recommended for use in active biomonitoring by means of transplants is very variable, although high levels of the elements, except Sb, were found in the moss tissues within a few days. We do not recommend the use of this moss species to biomonitor low concentrations of Sb in water. The differences in maximum contamination factors and lowest bioconcentration factors suggest that As and Se were the most toxic of the elements under study.
Show more [+] Less [-]Influence of a Marine Diatom on the Embryonic Toxicity of 17α-Ethynylestradiol to the Abalone Haliotis diversicolor supertexta
2012
Liu, Ying | Tam, Nora Feng Yee | Guan, Yuntao | Gao, Baoyu
The embryos of a marine abalone, Haliotis diversicolor supertexta, were exposed to a typical environmental estrogen, 17α-ethynylestradiol (EE2), for 96 h, to examine the acute toxicity of EE2 to the embryogenesis of the abalone. A marine diatom, Navicula incerta, was used in the test media as settlement substrate and food for the abalone larvae. During the embryo culture, more than 30 % of EE2 could be removed from the test media by the diatom, mainly via biodegradation, leading to a decrease of water-borne exposure dose. Further, the exposure concentrations of EE2 around the living microenvironment of the abalone larvae could be magnified 350–468 times after the larvae settled on the diatom, as indicated by the bioconcentration factors of EE2 in the diatom. Increased bioaccumulation of EE2 in the diatom caused greater inhibition on the metamorphosis of the abalone larvae by enhancing the uptake of EE2 in the larvae via dietary exposure, while declined water-borne exposure dose did not affect the embryonic toxicity of EE2 and its uptake in the abalone larvae. The 96-h median effective concentration of EE2 to the metamorphosis of the abalone larvae was 10.01 μg L⁻¹, when the exposure doses in both the test media and the diatom were controlled stable. The 96-h hazard concentration for 5 % of the species was 1.20 μg L⁻¹, which was still higher than but close to the reported upper contamination level of EE2 and could be employed as the safety threshold for the metamorphosis of the abalone embryos.
Show more [+] Less [-]Potential of Aquatic Macrophytes as Bioindicators of Heavy Metal Pollution in Urban Stormwater Runoff
2012
Ladislas, Séverine | El-Mufleh, Amelène | Gérente, Claire | Chazarenc, Florent | Andrès, Yves | Béchet, Béatrice
The concentrations of heavy metals in water, sediments, soil, roots, and shoots of five aquatic macrophytes species (Oenanthe sp., Juncus sp., Typha sp., Callitriche sp.1, and Callitriche sp.2) collected from a detention pond receiving stormwater runoff coming from a highway were measured to ascertain whether plants organs are characterized by differential accumulations and to evaluate the potential of the plant species as bioindicators of heavy metal pollution in urban stormwater runoff. Heavy metals considered for water and sediment analysis were Cd, Cr, Cu, Ni, Pb, Zn, and As. Heavy metals considered for plant and soil analysis were Cd, Ni, and Zn. The metal concentrations in water, sediments, plants, and corresponding soil showed that the studied site is contaminated by heavy metals, probably due to the road traffic. Results also showed that plant roots had higher metal content than aboveground tissues. The floating plants displayed higher metal accumulation than the three other rooted plants. Heavy metal concentrations measured in the organs of the rooted plants increased when metal concentrations measured in the soil increased. The highest metal bioconcentration factors (BCF) were obtained for cadmium and nickel accumulation by Typha sp. (BCF = 1.3 and 0.8, respectively) and zinc accumulation by Juncus sp. (BCF = 4.8). Our results underline the potential use of such plant species for heavy metal biomonitoring in water, sediments, and soil.
Show more [+] Less [-]Salt marsh macrophyte Phragmites australis strategies assessment for its dominance in mercury-contaminated coastal lagoon (Ria de Aveiro, Portugal)
2012
Anjum, Naser A. | Aḥmad, Iqbāl | Válega, Mónica | Pacheco, Mario | Figueira, Etelvina | Duarte, Armando C. | Pereira, Eduarda
INTRODUCTION AND AIMS: The dominance of a plant species in highly metal-contaminated areas reflects its tolerance or adaptability potential to these scenarios. Hence, plants with high adaptability and/or tolerance to exceptionally high metal-contaminated scenarios may help protect environmental degradation. The present study aimed to assess the strategies adopted by common reed, Phragmites australis for its dominance in highly mercury-contaminated Ria de Aveiro coastal lagoon (Portugal). MATERIALS AND METHODS: Both plant samples and the sediments vegetated by monospecific stand of Phragmites australis were collected in five replicates from mercury-free (reference) and contaminated sites during low tide between March 2006 and January 2007. The sediments’ physico-chemical traits, plant dry mass, uptake, partitioning, and transfer of mercury were evaluated during growing season (spring, summer, autumn, and winter) of P. australis. Redox potential and pH of the sediment around roots were measured in situ using a WTW-pH 330i meter. Dried sediments were incinerated for 4 h at 500°C for the estimation of organic matter whereas plant samples were oven-dried at 60°C till constant weight for plant dry mass determination. Mercury concentrations in sediments and plant parts were determined by atomic absorption spectrometry with thermal decomposition, using an advanced mercury analyzer (LECO 254) and maintaining the accuracy and precision of the analytical methodologies. In addition, mercury bioaccumulation and translocation factors were also determined to differentiate the accumulation of mercury and its subsequent translocation to plant parts in P. australis. RESULTS AND CONCLUSIONS: P. australis root exhibited the highest mercury accumulation followed by rhizome and leaves during the reproductive phase (autumn). During the same phase, P. australis exhibited ≈5 times less mercury-translocation factor (0.03 in leaf) when compared with the highest mercury bioaccumulation factor for root (0.14). Moreover, seasonal variations differentially impacted the studied parameters. P. australis’ extraordinary ability to (a) pool the maximum mercury in its roots and rhizomes, (b) protect its leaf against mercury toxicity by adopting the mercury exclusion, and (c) adjust the rhizosphere-sediment environment during the seasonal changes significantly helps to withstand the highly mercury-contaminated Ria de Aveiro lagoon. The current study implies that P. australis has enough potential to be used for mercury stabilization and restoration of sediments/soils rich in mercury as well.
Show more [+] Less [-]Bioaccumulation and trophic transfer of mercury in a food web from a large, shallow, hypereutrophic lake (Lake Taihu) in China
2012
Wang, Shaofeng | Li, Biao | Zhang, Mingmei | Xing, Denghua | Jia, Yonfeng | Wei, Chaoyang
PURPOSE: Due to the fast development of industry and the overuse of agrichemicals in past decades, Lake Taihu, an important source of aquatic products for Eastern China, has simultaneously suffered mercury (Hg) contamination and eutrophication. The objectives of this study are to understand Hg transfer in the food web in this eutrophic, shallow lake and to evaluate the exposure risk of Hg through fish consumption. METHODS: Biota samples including macrophytes, sestons, benthic animals, and fish were collected from Lake Taihu in the fall of 2009. The total mercury (THg), methyl mercury (MeHg), δ¹³C and δ¹⁵N in the samples were measured. RESULTS AND DISCUSSION: The signature for δ¹⁵N increased with the trophic levels. Along with a diet composed of fish, the significant relationship between the δ¹³C and δ¹⁵N indicated that a pelagic foraging habitat is the dominant pathway for energy transfer in Lake Taihu. The concentrations of THg and MeHg in the organisms varied dramatically by ∼3 orders of magnitude from primary producers (macrophytes and sestons) to piscivorous fish. The highest concentrations of both THg (100 ng g⁻¹) and MeHg (66 ng g⁻¹), however, were lower than the guideline of 200 ng g⁻¹ of MeHg for vulnerable populations that is recommended by the World Health Organization (WHO). The daily intake of THg and MeHg of 92 and 56 ng day⁻¹ kg⁻¹ body weight, respectively, was generally lower than the tolerable intake of 230 ng day⁻¹ kg⁻¹ body weight for children recommended by the Joint FAO/WHO Expert Committee on Food Additives. Significant relationships between the δ¹⁵N and the logarithm of THg and MeHg showed an obvious biomagnification of Hg along the food web. The logarithmic bioaccumulation factor of MeHg in the fish (up to 5.7) from Lake Taihu, however, was relatively low compared to that of other aquatic ecosystems. CONCLUSION: Health risk of exposure to Hg by consumption of fish for local residents is relatively low in the Lake Taihu area. Dilution of Hg levels in the phytoplankton induced by eutrophication is a possible factor inhibiting accumulation of MeHg in fish in eutrophic Lake Taihu.
Show more [+] Less [-]Bioconcentration of two pharmaceuticals (benzodiazepines) and two personal care products (UV filters) in marine mussels (Mytilus galloprovincialis) under controlled laboratory conditions
2012
Gomez, Elena | Bachelot, Morgane | Boillot, Clotilde | Munaron, Dominique | Chiron, Serge | Casellas, Claude | Fenet, Hélène
Bioaccumulation is essential for gaining insight into the impact of exposure to organic micropollutants in aquatic fauna. Data are currently available on the bioaccumulation of persistent organic pollutants, but there is very little documentation on the bioaccumulation of pharmaceuticals and personal care products (PPCPs). The bioconcentration of selected PPCPs was studied in marine mussels (Mytilus galloprovincialis). The selected PPCPs were two organic UV filters, i.e., 2-ethylhexyl-4-trimethoxycinnamate (EHMC) and octocrylene (OC), and two benzodiazepines (BZP), i.e., diazepam (DZP) and tetrazepam (TZP). Laboratory experiments were performed in which M. galloprovincialis was exposed to these compounds either directly from water, for the less lipophilic substances (BZP) or via spiked food for lipophilic UV filters. M. galloprovincialis uptook and eliminated BZP following first-order kinetics. The biological half-life (t ₁/₂) of TZP was 1.4 days, resulting in a bioconcentration factor of 64 and 99 mL g⁻¹ dry weight (dw), respectively, for 2.3 and 14.5 μg L⁻¹ of exposure, while the biological half-life (t ₁/₂) of DZP was 0.4 days, resulting in a bioconcentration factor of 51 mL g⁻¹ dw for 13.2 μg L⁻¹ of exposure. The uptake of UV filter was rapid in mussels, followed by elimination within 24 h. EHMC increased from 15 to 138 ng g⁻¹ dw in 1 h and decreased to 25 ng g⁻¹ after 24 h for 11.9 μg L⁻¹ exposure. OC reached 839 ng g⁻¹ dw after 1 h and decreased to 33 ng g⁻¹ after 24 h for 11.6 μg L⁻¹ exposure. However, EHMC and OC were slightly accumulated in 48 h, i.e., 38 and 60 ng g⁻¹ dw, respectively.
Show more [+] Less [-]Multivariate analysis of mineral constituents of edible Parasol Mushroom (Macrolepiota procera) and soils beneath fruiting bodies collected from Northern Poland
2012
Gucia, Magdalena | Jarzyńska, Grażyna | Rafał, Elżbieta | Roszak, Magdalena | Kojta, Anna K. | Osiej, Irena | Falandysz, Jerzy
Caps and stipes of 141 fruiting bodies of Parasol Mushroom (Macrolepiota procera) and surface layer of soils collected from 11 spatially distant and background (pristine) areas in Northern Poland were analyzed for Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr, and Zn by inductively coupled plasma optical emission spectroscopy and cold vapor atomic absorption spectroscopy. In terms of bioconcentration and bioexclusion concept, K, Ag, Cu, Rb, and P were highly bioconcentrated in caps, and their bioconcentration factor values varied for the 11 sites between 120 and 500—67–420, 70–220, 10–170, and 45–100, respectively. Cd, Zn, Mg, and Na showed bioconcentration factors (BCFs) between 3.3 and 36, 3.7–15, 0.92–6.3, and 1.4–44 while Al, Ba, Ca, Co, Cr, Mn, Ni, Pb, and Sr were excluded (BCF < 1). The Parasol Mushroom is a species harvested in the wild, and its caps are of unique taste and can contain a spectrum of essential and hazardous mineral compounds accumulated at elevated concentrations, even if collected at the background (pristine) areas. These elevated mineral concentrations of the caps are due to the efficient bioconcentration potential of the species (K, Ag, Cu, Rb, P, Cd, Zn, Mg, and Na) and abundance in the soil substrates (Al, Ca, Fe, Mn). The estimated intake rates of Cd, Hg, and Pb contained in Parasol Mushroom’s caps show a cause for concern associated with these metals resulting from the consumption of between 300- and 500-g caps daily, on a frequent basis in the mushrooming season.
Show more [+] Less [-]