Total mercury,cadmium and lead levels in main export fish of Sri Lanka

Total mercury (Hg), cadmium (Cd) and lead (Pb) levels were determined in the muscle of four commercialised exported fish species Thunnus albacares (yellowfin tuna), Xiphias gladius (swordfish), Makaira indica (black marlin) and Lutjanus sp (red snapper) collected from the Indian Ocean, Sri Lanka, during July 2009–March 2010 and measured by atomic absorption spectrophotometry. Results show that swordfish (n = 176) contained the highest total Hg (0.90 ± 0.51 mg/kg) and Cd (0.09 ± 0.13 mg/kg) levels, whereas yellowfin tuna (n = 140) contained the highest Pb levels (0.11 ± 0.16 mg/kg). The lowest total Hg (0.16 ± 0.11 mg/kg), Cd (0.01 ± 0.01 mg/kg) and Pb (0.04 ± 0.04 mg/kg) levels were found in red snapper (n = 28). Black marlin (n = 24) contained moderate levels of total Hg (0.49 ± 0.37), Cd (0.02 ± 0.02) and Pb (0.05 ± 0.05). Even though there are some concerns during certain months of the year, this study demonstrates the safety of main export fish varieties in terms of total Hg, Cd and Pb.     

Survey of total mercury and methylmercury levels in edible fish from the Adriatic Sea

Total mercury and methylmercury concentrations were measured in the muscle tissue of different fish species from the Adriatic Sea to ascertain whether the concentrations exceeded the maximum level fixed by the European Commission. Large species-dependent variability was observed. The highest total mercury mean concentrations were in benthic (0.20-0.76 μg g^-1 wet wt) and demersal fish (0.22-0.73 μg g^-1 wet wt), while pelagic species showed the lowest levels (0.09-0.23 μg g^-1 wet wt). In 15% of frost fish, in 42% of skate and in 30% of angler fish samples total mercury concentrations exceeded the maximum level fixed by the European Commission (Hg = 1 μg g^-1 wet wt); for the species for which the maximum level was set to 0.5 μg g^-1 wet wt, concentrations exceeding the prescribed legal limit were observed in 6.4% of bokkem, in 6.6% of pandora, in 20% of megrin, in 12.5% of four-spotted megrim, in 16% of striped mullet, in 5.0% of forkbeard and in 5.3% of picarel samples. In all the different species, mercury was present almost completely in the methylated form, with mean percentages between 70 and 100%. Weekly intake was estimated and compared with the provisional tolerable weekly intake recommended by the FAO/WHO Expert Committee on Food Additives. A high exposure was associated with the consumption of only skates, frost fish and angler fish, thought the consumption of the other species, such as, megrim, four spotted megrim, red fish striped mullet and forkbeard, resulted in a weekly intake slightly below the established provisional tolerable weekly intake.     

The influence of industrial-scale canning on cadmium and lead levels in sardines and anchovies from commercial fishing centres of the Mediterranean Sea

The current study encompassed a survey on the levels of toxic trace elements in two highly consumed fish species in commercial fishing centres of western, central and eastern Mediterranean Sea. A Zeeman GTA-AAS graphite furnace atomic absorption spectrometry system was used throughout the study. Toxicological evaluation of the samples revealed a low Cd content in the raw samples, ranging between 0.003 and 0.027?mg?kg^?1. Pb presented significantly higher values, from 0.037 to 0.297?mg?kg^?1, occasionally reaching the limit of 0.3?mg?kg^?1. Heavy metal levels were particularly higher in bones, thus raising queries about the safe consumption of fish intended to be eaten as a whole, a very common practice for small fish and canned products. The influence of industrial-scale canning showed that canning enhanced heavy metal levels by 35%–80%. The effect of canning depended on metal type and reduction of moisture loss after the steam-roasting step of the canning procedure.     

Lead,cadmium and mercury levels in the 2010 Korean diet

This study analysed the level of contamination of harmful heavy metals in 3820 food samples available in Korea in 2010. A total of 119 types of samples were collected, including corns, vegetables, fruits, fishes, mollusks, shellfish, crustaceans, seaweed, bean products, meats and eggs from seven major cities. These samples were analysed using ICP-MS after pre-treatment with a microwave-digestion system. Results of lead, cadmium and mercury analyses were compared with the standard specifications of Korea Food Standards Codex. As a result, high levels of Pb, Cd and Hg were detected in “cockle,” “dried-squid” and “shark-meat.” Acceptable intake for consumers was checked using provisional tolerable weekly intake values. Such results will be utilised as data on the exposure of human body through foods. In addition, satisfactory results were obtained through purchase and analysis of National Institute of Science and Technology–certified reference materials to obtain reliability on analysis results.     

Estimate of mercury and methyl mercury intake associated with fish consumption from Sagua la Grande River,Cuba

This paper provides an estimate of the weekly intake of total mercury (THg) and methyl mercury (MeHg) from consumption of fish from the Sagua la Grande River, Villa Clara, Cuba, by determining the THg levels in different fish species. The levels varied between 0.143 and 0.484 μg g^?1 on a fresh weight basis. None of the analysed fish was found to have levels above the national and international regulatory levels, although THg levels over 0.2 μg g^?1, the threshold concentration established by the World Health Organization (WHO) for the consumption by vulnerable population groups, were found in 75% of samples. The MeHg level was found to be 84% of the THg content. A Food Frequency Survey was given to 127 townspeople to estimate river fish consumption. The weekly intake of MeHg was found to be greater than the value established by the provisional tolerable weekly intake (PTWI) in 50% of children, in 80% of pregnant women, and in 75% of women in childbearing age. These weekly intakes can represent an important risk to the population's health, especially for vulnerable groups.     

Exposure to cadmium, lead and mercury in the adult population from Eastern Poland, 1990-2002

The aim was to estimate the adult exposure to cadmium, lead and mercury from daily household diets in Eastern Poland (Lublin city and province). A duplicate diet approach was used to top collect diet samples in 1990, 1993, 1998 and 2002. Cadmium and lead contents were measured by flame atomic absorption and the mercury content was measured by cold vapour atomic absorption spectrometry. The intake of the three elements was calculated using FOOD computer software. The exposure to cadmium taken with daily diets was from 16.4 - 34.5 μg/person/day (27-58% PTWI). The lead exposure was 66.5 - 106 μg/person/day (31-49% PTWI), which posed a smaller risk, and the exposure risk to mercury of 4.08-6.65 μg/person/day (10-16% PTWI) was even lower.     

Cadmium and total mercury in some cephalopods from the South Adriatic Sea (Italy)

In the framework of a wide monitoring programme on the presence of heavy metals in marine organisms caught in the South Adriatic Sea, cadmium and total mercury concentrations were determined in flesh and hepatopancreas of 512 specimens of two species of cephalopods. The aim of the study was to establish the quality of the marine food with respect to the health of consumers and to investigate cadmium and mercury distribution in organisms representing different habitats. For both elements, higher levels were found in spider octopus (Octopus salutii) than in broadtail squid (Illex coindeti). Between the two different tissues analysed, higher concentrations were observed in hepatopancreas than flesh. According to the rules in force, no flesh sample showed cadmium and total mercury concentrations exceeding the peak permitted values of 2mg/kgwetwt and 0.5mg/kgwetwt respectively.     

Total mercury and methylmercury content in edible fish from the Mediterranean Sea

The objective of this study was to determine the current levels of total mercury and methylmercury in the muscle tissues of different fish species caught in the Mediterranean Sea to ascertain whether these concentrations exceed the maximum level stipulated by the European Commission Decision. Total mercury concentrations in the muscles of skates ranged from 0.18 to 1.85 mg/kg (wet weight) (average, 1.00 mg/kg) while levels of 0.11 to 1.92 mg/kg (wet weight) (average, 0.70 mg/kg) and 0.21 to 1.74 mg/kg (wet weight) (average, 0.70 mg/kg) were recorded for blue whiting and red mullet, respectively. For 66.7% of long nose skate samples, 61.4% of thornback ray samples, 42.8% of winter skate samples, and 38% of starry ray samples, the total mercury concentrations exceeded the prescribed legal limit (1.0 mg/kg [wet weight]). Concentrations exceeding the maximum total mercury level stipulated by the European Commission Decision (0.5 mg/kg [wet weight]) were observed in 63.6 and 40% of blue whiting and striped mullet samples, respectively. Mercury was present in the different species almost completely in the methylated form at 55 to 100%. Weekly intakes were estimated and compared with the provisional tolerable weekly intake recommended by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives.     

新疆昌吉地区食用菌中汞和镉含量的分析检测

目的了解昌吉地区食用菌中重金属汞和镉含量的情况,保障食用菌安全性。方法在昌吉地区的超市、农贸市场等地随机采集7种不同的食用菌,依据国标(GB5009.17食品中汞的检测第一法;GB5009.15食品中镉的检测第一法)测定其中汞和镉的含量,同时采用单因子污染指数法和综合因子污染指数法对食用菌的污染程度进行评价。结果 210种样品中汞超标率0.95%,镉超标率2.38%,且同种食用菌对不同重金属的富集能力有差异,黑平菇、鸡腿菇、平菇、金针菇、圆菇和杏鲍菇的富集趋势均为镉总汞;而香菇的富集趋势则为总汞镉。分级结果为金针菇、黑平菇、鸡腿菇、平菇、杏鲍菇为一级产品;圆菇为二级产品;香菇为三级产品。不同采样点中汞污染最高的是源自农贸市场的食用菌,平均值为0.054 mg/kg;镉污染最高的是市场,平均值为0.059 mg/kg。结论昌吉大部分地区重金属污染较为严重,可能是食用菌生长环境中重金属含量较高所致,因此需要从栽培源头加大控制防范力度。     

Assessment of mercury and cadmium via seafood consumption in Italy: estimated dietary intake (EWI) and target hazard quotient (THQ)

Mercury (Hg) and cadmium (Cd) were quantified in fish, cephalopods and crustaceans from Italian supermarkets. Sample compliance with European dietary standards as well as human health risks according to provisional tolerable weekly intake (PTWI) and the methodology of target hazard quotient (THQ) were evaluated. Both element levels were under European legal limits, except for some fish having Hg and Cd contents exceeding or equal to critical values. Estimated weekly intakes (Hg: fish = 0.07–1.44 µg kg^?1 bw week^–1; cephalopods = 0.05–0.15 µg kg^?1 bw week^–1; crustaceans = 0.04–0.08 µg kg^?1 bw week^–1; and Cd: fish = 0.04–0.32 µg kg^?1 bw week^–1; cephalopods = 0.07–0.27 µg kg^?1 bw week^–1; crustaceans = 0.05–0.11 µg kg^?1 bw week^–1) as well as THQ < 1 were within safe limits. Although there seems to be no important risks associated with seafood consumption, Hg exposure was in some cases close to safety margins and thus levels of this metal should be under frequent surveillance.     

Total mercury levels in muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) from the Mediterranean Sea (Italy).

This study was carried out to determine the current levels of total mercury in the muscle tissue of swordfish (Xiphias gladius) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean Sea with the purpose of ascertaining whether the concentrations exceeded the maximum level fixed by the European Commission Decision. In addition, specimens of each species were divided into different ranges of weight to investigate the influence of size on mercury accumulation in order to provide data upon which commercial fishing strategies and marketing of swordfish and bluefin tuna may be based. Higher mean levels of total mercury were found in bluefin tuna (1.02 microg g(-1) wet wt) than in swordfish (0.49 microg g(-1) wet wt). In 4.3% of swordfish and in 44.3% of bluefin tuna analyzed, total mercury concentrations exceeded the maximum level fixed by the European Commission Decision (Hg = 1 microg g(-1) wet wt). Besides, for bluefin tuna the total mercury level variability observed, due to size, suggests that there should be greater regulatory control by the authorities.     

Total mercury levels in commercial fish species from Italian fishery and aquaculture

ABSTRACT

Total mercury levels were measured in 42 commercial fish species caught off the Central Adriatic and Tyrrhenian coasts of Italy and in 6 aquaculture species. The study on wild fish covered species differing in living habitat and trophic level. The study on farmed fish covered marine and freshwater species from intensive and extensive aquaculture and their feed. Mercury levels were analysed by thermal decomposition–amalgamation–atomic absorption spectrophotometry. Total mercury concentrations in the muscle of wild fish showed a high variability among species (0.025–2.20 mg kg^?1 wet weight). The lowest levels were detected in low trophic-level demersal and pelagic–neritic fish and in young individuals of high trophic-level species. Levels exceeding the European Commission limits were found in large-size specimens of high trophic-level pelagic and demersal species. Fish from intensive farming showed low levels of total mercury (0.008–0.251 mg kg^?1). Fish from extensive rearing showed variable contamination levels, depending on the area of provenience. An estimation of the human intake of mercury associated to the consumption of the studied fish and its comparison with the tolerable weekly intake is provided.     

Norwegian monitoring programme on the inorganic and organic contaminants in fish caught in the Barents Sea, Norwegian Sea and North Sea, 1994-2001

The results from part of a monitoring programme of contaminant levels in fish and other seafood products initiated by the Directorate of Fisheries in Norway in 1994 are presented. Concentrations of 22 elements (four are presented here: As, Cd, Hg and Pb) and HCB, HCH, PCB 28, 52, 101, 105, 118, 138, 153, 156, 180, pp-DDD, p-DDE, p-DDT, sum DDT and ¹³⁷Cs were determined in 17 species of fish caught in three sampling locations: the Barents Sea, the Norwegian Sea and the North Sea. The fish species analysed in the survey were limited to species of commercial importance for Norway with catching volumes of at least 10 000 metric tons year^-1. The survey started in 1994 and is expected to continue beyond 2010. The analyses were carried out on 25 individual fish from each species and each sampling location, and the locations were representative of commercial fishing grounds for the species in question. The concentrations of contaminants found were considerably lower than the maximum levels permissible in fish set by CODEX and the European Union for contaminants in seafood products.     

山东省南四湖水产品中铅、镉、砷、汞污染状况的调查与分析

目的调查南四湖水产品中铅、镉、砷、汞的污染,分析南四湖的污染状况。方法对南四湖7种主要经济鱼类及鸭、螺、藕、菱角等湖产品共2 5 0份进行铅、镉、砷、汞含量的检测;其中鱼、鸭以池养鱼、家鸭作为对照。结果铅、镉、汞含量均高于对照组,最高超出国家标准1 3.2倍;而砷只在鲫鱼、鳊鱼、鲂鱼中的含量高于对照组。结论通过对南四湖湖水及湖产品污染4种元素的检测分析表明,湖区受周围工业污染严重,应进一步加强综合治理。     

Cadmium content in fresh and canned squid (Loligo opalescens) from the Pacific coastal waters of California (USA)

Cadmium (Cd) levels were determined in 70 samples of mantle tissue and 70 whole individual squid (Loligo opalescens; commercially known as California squid). Samples were collected from the coastal zones of California (USA) during the period 2007/2008. To further investigate consumer exposure to processed fishery products, cadmium concentration was also determined in 200 canned samples of squid. Cd concentrations in raw mantle were low, between 0.01 and 0.29 mg kg^?1 and below the tolerance limit of current regulations (1 mg kg^?1). Respective concentrations in whole individuals were significantly higher, ranging from 0.51 to 1.18 mg kg^?1, attributed to the presence of the visceral portion in whole squid samples. Cd concentrations varied in relation to age and sex of squid, indicating that several physiological factors may influence accumulation. Furthermore, canning of squid substantially enhanced Cd levels. Cd concentration ranged 0.17–0.67 mg kg^?1 in canned mantle tissue and 0.86–2.07 mg kg^?1 in canned whole squid samples, due to both concentration after canning and movement of the metal between different tissues. Several biological compounds, including metallothioneins, nucleic acids and enzymes, may affect Cd concentrations in commercial fishery products.     

Essential elements and contaminants in tissues of commercial pelagic fish from the Eastern Mediterranean Sea

BACKGROUND: It is important to determine the concentrations of essential and non‐essential metals in fish for human health. The essential elements and contaminants (Pb and Cd) were determined seasonally in the muscle and liver of some pelagic fish species round herring (Etrumeus teres), chub mackerel (Scomber japonicus), golden grey mullet (Liza aurata) and Mediterranean horse mackerel (Trachurus mediterraneus) from the Iskenderun Bay, Eastern Mediterranean Sea. RESULTS: The Na, K, Ca and Mg were the most abundant elements in muscle and liver tissues. The Na, K, Ca and Mg concentrations in fish tissues were between 51.7 and 3426 mg kg^?1. Muscle accumulated the lowest levels of elements. Trace element and contaminant levels in muscle were highest in spring and summer. The Cu, Zn and Cr concentrations were highest in summer. The Ni, Mn and Fe concentrations were highest in spring. The maximum Pb concentrations in the muscle and liver of fish species was 0.39 and 0.80 mg kg^?1 in autumn. The maximum Cd concentration in the muscle of fish was 0.27 mg kg^?1 in spring and the maximum Cd concentration in the liver was 0.78 mg kg^?1 in summer. CONCLUSION: The Cr, Pb, Cd, Cu and Zn levels in muscle were found to be lower than permissible limits reported by various authorities. Estimated weekly and daily intake for Pb and Cd by consumption of fish muscle were far below the PTWI and PTDI values established by FAO/WHO. Copyright © 2009 Society of Chemical Industry     

Effects of washing pre-treatment on mercury concentration in fish tissue

The objective of this study was to examine the effect of washing pre-treatment on mercury concentration in fish fillet. Response surface methodology was used to investigate the influence of three variables, pH (1–6.5), NaCl (0–1% w/v) and exposure time (5–30 min) by using a three-factor central composite design. The aim was to obtain the best possible combination of these variables in order to reduce mercury in fish fillet. The experimental data were adequately fitted into a second-order polynomial model with multiple regression coefficients (R ²) of 0.961. The results indicated that the reduction of mercury in fish flesh significantly depends on the pH of the solution used. The overall optimal condition resulting in the maximum mercury reduction in fish fillet was obtained at a combined level pH of 2.79, NaCl of 0.5% and exposure time of 13.5 min. The optimized protocol produced a solution that can reduce mercury from raw fish fillet up to 81%.     

Dietary exposure of Hong Kong secondary school students to total mercury and methylmercury from fish intake

Fish is the main source of dietary exposure to methylmercury (MeHg), which is a public health concern owing to its potential neurotoxicity. To evaluate the public health risk, this study estimated the total mercury (tHg) and MeHg exposure from fish intake in Hong Kong secondary school students. Median tHg and MeHg concentrations of 280 samples purchased from different commercial outlets (covering 89 species of whole fish and three types of canned tuna), together with the local food consumption data of secondary school students obtained by semi-quantitative food frequency questionnaire in 2000, were used to estimate dietary exposure from fish intake for the average and high consumer (95th percentile exposure). For tHg, the median concentration was 63 µg kg^–1 (range 3–1370 µg kg^–1) and estimated exposures ranged 0.5–0.6 µg kg^–1 body weight (bw) week^–1 for an average consumer and 1.6–1.9 µg kg^–1 bw week^–1 for a high consumer. For MeHg, median concentration was 48 µg kg^–1 (range 3–1010 µg kg^–1) and estimated dietary exposures were 0.4–0.5 µg kg^–1 bw week^–1 for an average consumer and 1.2–1.4 µg kg^–1 bw week^–1 for a high consumer. These values are below the respective provisional tolerable weekly intake (PTWI) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA). The health risk is greater for high consumers since MeHg exposures may approach or exceed the PTWI when other dietary sources are taken into account.     

2012—2016年内蒙古地区主要食品中铅镉总汞污染调查分析

目的 了解内蒙古地区食品中铅、镉、总汞的污染水平,为及时发现食品安全隐患和进行风险预警提供基础数据。方法 按照2012—2016年内蒙古自治区食品中化学污染物监测计划,结合内蒙古地区地产食品种类及分布特点,采集内蒙古地区12个盟市的本地产食品样品,采用国家食品安全标准方法对样品中铅、镉、总汞进行检测,按照食品污染物限量标准进行评价。结果 共采集8类食品,其中监测铅含量的有效样品为4 212份,检出率为32.72%(1 378/4 212),超标率为0.76%(32/4 212),超标的食品类别主要为食用菌(以鲜食用菌计),超标率为7.37%(14/190);监测镉含量的有效样品为4 173份,检出率为54.18%(2 261/4 173),超标率为0.58%(24/4 173),超标的食品类别主要为食用菌(以鲜食用菌计)、水产动物及其制品及肉与肉制品,超标率分别为3.68%(7/190)、2.06%(9/437)及1.15%(6/524);监测总汞含量的有效样品为4 217份,检出率为32.68%(1 378/4 217),超标率为0.50%(21/4 217),超标食品主要为食用菌(以鲜食用菌计)及蔬菜,超标率分别为3.68%(7/190)与1.01%(11/1 088)。结论 内蒙古地区生产的食用菌(以鲜食用菌计) 、水产动物及其制品、肉与肉制品、蔬菜中存在重金属污染情况,应引起高度重视。     

Impact of Physical and Chemical Pretreatments on Texture of Octopus (Eledone moschata)

ABSTRACT: Octopus ( Eledone moschata ) muscle is tougher than muscle from other aquatic organisms and requires pretreatment for tenderization. Response surface methodology was applied to evaluate and model the effect of NaCl, vinegar (acetic acid), mechanical tumbling, and thermal processing on the texture (toughness) of octopus muscle (four-factor, three-level Box-Behnken design). The force required for a 2-mm probe to fully penetrate a 20-mm-long, 10-mm-wide, and 5-mm-thick mantle muscle segment was measured with aTA-XT2i texture analyzer. Prolonged tumbling and heating of octopus muscle resulted in decreased toughness. Addition of NaCl during tumbling did not affect toughness consistently. When acetic acid was introduced, very significant reduction in toughness of octopus muscle was observed. The statistical model was further used for optimization of levels of experimental parameters to achieve the desired texture.