Iranian Journal of

Backgrounds and Objectives: Mercury is a heavy metal that is widespread in the environment and has many toxic effects. At present, MeHg exposure on women remain an important issues for researching, especially those of continuous uptake in high-fish consumption.MeHg can be transferred to infant through breast milk. The objective of this study was to characterize the risk of Hg exposure in mothers in south of the Caspian Sea.
Materials and Methods: In this study mercury in hair of 70 breast-feeding women (17-36 years old) and influencing factor on it, were assessed. Mothers lives in nur, nowshahr and chamestan cities and villages of Nur and Nowshahr. In order to researching on influencing factors, mothers fill questionnaires. Hair samples (about 1 gr) were obtained from mothers. The mercury was measured by LECOAMA254AdvancedMercuryAnalyzer (USA) according toASTM, standard NO.D-6722.
Results: Total mean mercury concentration in mothers hair obtained 0.19±0.09 ( &mug gr^-1). Tukey test show that the influence of the variables place of live (p=0.02), fish and sea food consumption of mother (P=0.00) were significantly affected on hair mercury concentration of mothers. The other factors (age and number of dental amalgam filling ) had no significant effect on mercury levels in hair of mothers.
Conclusion: Total mean mercury concentration in mothers hair were lesser than normal dose recommended byWHO (2&mug g^-1) and EPA reference (5 &mug g^-1). Analysis of questionnaires showed that three kinds of fish including carp, golden mulle and kutum. Although were often used in this study, mercury concentration in fish was not determined, but in according to significate relation between fish consumption and mercury concentration in mother#s hair, pollution with mercury in the fish can be the main factor of mercury exposure in this study.

Backgrounds and Objectives:There have been always concerns regarding to consumption of aquatic products, particularly fish, due to the possibility of heavy metals bioaccumulation in aquatic creatures organs, throughout the world.Aresearch project was carried out to assess the level of concentrated total mercury in different tissues of Silver carp as the most consumed fish from Sanandaj Ghesglagh reservoir in the region.
Materials andMethods:Twenty four silver carp were captured randomly during July to December 2009. Prior measuring mercury concentrations in white muscle, red muscle and liver tissues by AdvancedMercuryAnalyzer (Model Leco, 254AMA) on the dry weight basis, biometry procedure was done.
Results: Mean accumulated mercury in white muscle, red muscle and liver tissues were 367 (S.E.± 26.43), 311 (S.E.± 32.22) and 251 (S.E.± 28.70) ng gr -1 on the dry weight basis, respectively. Pair comparisons between the level of concentrated mercury in all tissues, except white muscle tissues (F5, 18 = 1.52, P = 0.2332) showed a significant difference (P < 0.05).
Conclusion: The level of accumulated mercury in muscle and liver tissues of all samples weighted above 850 grams were higher than the established limits by WHO, FAO and EPA. Our results emphasis that the consumption of silver carp from Sanandaj Gheshlagh Reservoir might place the health of all those peoples who live in the region at risk.

Background and Objectives: The heavy metals pollution in aquatic ecosystems especially mercury, always makes concern about health of aquatic organisms. So, the purposes of this study were determination of total mercury in different tissues of the three species of the most important water birds at north of Iran and comparison with world health standards.
Materials and Methods: Generally, 51 birds were captured randomly. Then, samples of feather, liver, kidney and muscle were taken and the mercury concentrations were determined by Advanced Mercury Analyzer (Model Leco, AMA 254).
Results: The most amount of accumulated mercury was in great cormorant's liver (piscivorous species). Means of mercury concentration in liver of great cormorant, mallard, and coot were 14.80, 2.05, 0.18 in kidney 12.00, 1.90, 0.17 in feather 6.57, 1.09, 0.23 and in muscle 8.67, 0.26, 0.09 mg/kg dry weight respectively. Means Comparison showed significant difference among all tissues (P < 0.05), But there were not significant difference between sexes (P > 0.05)
Conclusion: The levels of accumulated mercury in all tissues of great cormorant were more than the established limits by WHO, FAO and EPA. The other species had less use limitation, but mercury concentration in mallards was considerable. These results can be a serious warning for consumers these birds, especially vulnerable people.

Background and Objectives: The present study was designed to determine total mercury concentrations in sediment and the soft tissues of two bivalve species, Saccostrea cucullata and Callista umbonella, in coastline of Bandar Abbas in 2011. Materials and Methods: Generally, 67 bivalves and 10 sediment samples were collected from two stations (terminal of Bandar Abbas and tourism park of Soro). We measured total mercury concentrations in each sample using Mercury Analyzer (Leco AMA 254). Results: Means of mercury concentration were 145.58 and 151.13 (ng/g dw) in soft tissues of oyster S. cucullata and 34.5 and 63.95 in the soft tissues of Clam C. umbonella in two stations, terminal of Bandar Abbas and tourism park of Soro respectively. Total mercury concentrations were 30.27 and 20.55 (ng /g dw) in the sediment samples in two stations, terminal of Bandar Abbas and tourism park of Soro respectively. A significant difference was found in mercury concentrations between soft tissue of the two species (p <0.01). Conclusion: Considering higher concentration of mercury in the soft tissues of oyster S. cucullata than clam C. umbonella, lower coefficient of variation in soft tissue of oyster relative to clam C. umbonella, and also significant correlations between mercury levels in the soft tissue of oyster and sediments, it can be concluded that the soft tissues of oyster S. cucullata can be used as biomonitoring agent for mercury in intertidal zone of Bandar Abbas. In comparison with food safety standards (FDA, EU Commission and NHMRC), mercury concentrations in oysters were well within the permissible limits for human consumption.

Background and Objectives: Due to the importance of Sanandaj Gheshlagh Reservoir (SGR) in the region and proven mercury pollution in SGR water, a research project was carried out to determine the amount of mercury concentration and bioaccumulation and its behavior through a food route in SGR food chain (i.e., water, sediments, fish, and human).This was done, because it has been reported that mercury concentration and its toxicity could increase during mercury exchange between trophic levels. Materials and methods: During April to December 2012, 24 water, sediment, and fish samples (Capoetta trutta) (4 samples per month) from SGR and 24 human hair samples from Sarab Ghamish village settlers (the major Capoetta trutta consumers in the region) were collected. Results: Total mercury mean concentration in water, sediment, Capoeta trutta, and human hair were 0.0028±0.000128, 0.110±0.0057, 0.296±0.0119, 2.059±0.1704 ppm respectively. Calculated bioconcentration factors were 4 × 10 and 1 × 10² in SGR sediment and fish, and related biomagnifications factors were 40 and 5 respectively. Conclusion: Due to the high bioaccumulation, biomagnifications factors and mercury concentration recorded in edible parts of SGR fish, local consumers should not eat more than 1182 gram of this fish weekly without accounting for other potential sources of total mercury in their food basket.

Background and Objective: Present study aimed to investigate response of metallothionein (MT) in oyster Crassostrea sp. to the experimental concentrations of Hg and Cd in order to assess the possibility of MT usage as a biomarker of Hg and Cd contamination in this mollusk. Materials and Methods: Oysters were collected from docks of Imam Khomeini Port. After seven days acclimation period in laboratory, they were exposed with Hg at concentrations of 15 and 75 µg.L^-1 and Cd at concentrations of 15 and 150 µg.L^-1 for 14 days. MT levels were measured through spectrophotometric method after extraction and precipitation. After preparation and acid digestion, the concentration of heavy metals was quantified by atomic absorption. Results: The amounts of MT in oysters exposed with Hg and Cd were significantly increased compared with control samples (P<0.05). The highest value of MT biosynthesis in oysters exposed with concentrations of Hg and Cd were 137.2±7.6 and 312.4±17.9 µg.g^-1 w.w respectively. Exposing the oysters with Cd induced biosynthesis of MT more than three times compared with control samples. Among Hg and Cd, there was only significant correlation between biosynthesis of MT and Cd bioaccumulation in oysters (P<0.01). Conclusion: MT protein in oyster Crassostrea sp. can be considered as a suitable biomarker of Cd contamination in body and environment. Hence, it could be used for assessing and monitoring ecosystems.

Background and Objective: Mercury (Hg) is considered as a global pollutant that is widely dispersed in the environment. Monitoring of total mercury (THg) concentration in the sediments without determination of organic mercury (OHg) and selenium (Se) is an unreliable approach to evaluate the precise toxicological effects of Hg. In the present study, concentrations of THg, OHg and Se in the surface sediments of the eastern and western parts of Anzali wetland were investigated. In addition, the correlation of THg and OHg with Se and total organic carbon were analyzed.

Materials and Methods: Forty surface sediment samples were collected from the eastern and western parts of the wetland. Analysis of total and organic mercury in the sediment samples were done with Advanced Mercury Analyzer and the concentration of selenium was measured using inductively coupled plasma atomic emission spectroscopy (ICP-OES).

Results: The average concentrations of THg in the East and West wetlands were 109.53 and 68.39 ng/g dw, respectively. The average concentration of THg in the sediments of the eastern part of Anzali Wetland was significantly higher than that of the western part (P<0.001). The mean concentrations of OHg in East and West wetland were about 34.91 and 28.84 ng/g dw, respectively. There was  no significant relationship. The ratio of OHg to THg showed significant differences in the two studied areas. The average concentrations of Se in East and West wetlands were 156.25 and 163.75 ng/g dw, respectively. There was a significant negative correlation between the concentration of selenium and organic mercury in sediments of  the western part of  wetland (P<0.05).

Conclusion: The THg concentration in the sediments of Anzali wetland was lower in comparison to other studied regions of the world. However, the percentage of OHg in the Eastern and Western part of wetland was high. Therefore, bioavailability and toxicity of Hg would be high in the sediments and aquatic environment. In this study, in spite of high molar ratio of Se to THg, there was relatively high content of OHg. We recommend to measure the various Se-species that are effectively bound to inorganic Hg and to determine the amount of Se and Hg in aquatic organisms.