Mercury content in Chilean fish and estimated intake levels.

The intake of fish products is a major public health concern due to possible methyl mercury exposure, which is especially toxic to the human nervous system. This pilot study (n = 46) was designed to determine mercury concentrations in fish products for national consumption (Chilean jack mackerel, hake, Chilean mussel, tuna) and for export (salmon, Patagonian toothfish, swordfish, southern hake), and to estimate the exposure of the general population. The fish products were collected from markets in Talcahuano, Puerto Montt and Santiago. Samples were analyzed at the National Environmental Center by cold vapor atomic absorption spectrophotometry. Mercury levels in swordfish and one canned tuna sample exceeded levels prescribed by national and international standards. The remaining two export products (Patagonian toothfish, also known as Chilean sea bass, and salmon) complied with international limits, which are more demanding than Chilean regulations. Theoretical estimates of mercury intake varied from 0.08 to 3.8 microg kg(-1) bw day(-1) for high fish consumers, exceeding the provisional tolerable intake for tuna, Chilean seabass, Chilean jack mackerel and swordfish. This group appears to be at the greatest risk from mercury contamination among the Chilean population.     

Mercury levels in wheat and other cereals, oilseed and biological samples

Analyses of 80 samples of wheat showed a mean mercury content of 8 ng/g, with a range of 4 to 18 ng/g (ng = 10^?9 g). Wheat flour contained the same amount of mercury as wheat. Other cereals and oilseeds contained 4 to 29 ng/g of mercury. Levels of mercury varied for other organic materials analysed. The analytical method used is relatively rapid and simple when certain precautions are followed. The method consists of an oxygen-bomb combustion of samples, reduction of the mercury in the bomb washings to elemental mercury and then analysis of the mercury by cold vapour atomic absorption spectrophotometry. The limit of detection of the method is approximately 1 to 2 ng of mercury/g of sample. The reliability of the method was verified by quantitative recoveries of added organic and inorganic mercury compounds from wheat and barley and by carrying out collaborative tests.     

Mercury and methylmercury levels in the main traded fish species in Hong Kong

This survey was undertaken to determine the levels of aflatoxins in melon seeds. Among 65 samples analyzed by liquid chromatography (LC), the results showed that aflatoxin B₁ (AFB₁) was the major toxins in melon seeds, detected in 58 samples (89.2% of the total) at an average concentration of 8.5?ng?g^?1. The level of AFB₁ in 12 samples exceeded the maximum tolerated level for AFB₁ in Iranian (5?ng?g^?1) regulations; in other words, 18.5% of samples were unfit for human consumption.     

News: Researchers find unexpectedly high levels of contaminants in remote sea birds

Science.     

Mercury levels in hair from people eating large quantities of Swedish freshwater fish

Mercury concentrations in hair were related to fish-eating habits in a group of 50 people reported to have a high consumption of freshwater fish. Mercury levels in hair ranged from 0.3 to 10.8 mg/kg with a mean +/- SD of 3.2 +/- 2.3 mg/kg. The average mercury level in hair from men was significantly higher than that in hair from women (3.8 +/- 2.6 mg/kg versus 2.4 +/- 1.8 mg/kg. Seven individuals (14%) had levels above 6 mg/kg. In people with equal fish consumption, significantly higher mercury levels were found in the hair of those eating fish from lakes M?laren and V?ttern than in those eating fish from Lake Hj?lmaren. It has been reported that fish from the latter lake contains approximately 0.2 mg/kg mercury, whereas fish from the other two lakes contains approximately 0.4 mg/kg. The mean mercury level in hair was higher in the group eating freshwater fish more than three times a week (greater than or equal to 500 g fish flesh/week) than in the group eating less, although the difference was of borderline significance. Within couples (n = 16) eating equal numbers of fish meals per week, the men had significantly higher levels (mean 3.7 mg/kg) than the women (mean 2.5 mg/kg). The results from the present study show that people with a high consumption of Swedish freshwater fish have elevated levels of mercury in their hair, when compared with previously reported levels in the hair of Swedish pregnant women.     

Mercury,lead, arsenic,and cadmium in Norwegian seafood products and consumer exposure

ABSTRACT

Seafood can be a source of contaminants, which may raise health concerns. The aim of this study was to analyse the levels of inorganic contaminants in commercially available seafood products and assess consumer exposure. Commercially available samples were collected from 2015–2018 and analysed as composite samples for mercury, lead, arsenic, and cadmium, using accredited methods. Levels of cadmium, lead, and arsenic were low and human exposure of these metals would be minimal from consumption of the analysed seafood products. Mercury levels were well below the EU maximum limit for mercury in fish. However, children, who are high consumers, might be at risk of exceeding the tolerable weekly intake for methyl mercury, when eating products with the highest mercury levels. The collected data can be used for future risk-benefit assessments as intake of processed seafood products represent a large proportion of the populations' seafood intake in Europe.     

Secondhand smoke exposure and C-reactive protein levels in youth.

Using data from the National Health and Nutrition Examination Survey (NHANES, 1999-2002), we examined the association of secondhand tobacco exposure, estimated by serum cotinine, with serum C-reactive protein (CRP) concentrations in nonsmoking participants, aged 6-18 years. The association between serum cotinine and serum CRP was analyzed using multiple linear regression, with adjustment for other study variables. All analyses used weighted data and adjustments for design effects. Multiple regression analysis indicated that a change in serum cotinine of 0.5 ng/ml was associated with a 0.96 mg/dl change in CRP (95% CI=0.93-1.00), even after adjustment for age, white blood cell count, and body mass index percentile. We found a significant association between secondhand smoke exposure, assessed by serum cotinine, and elevated serum CRP among nonsmoking youth. Secondhand smoke exposure may pose an important long-term cardiovascular risk for children and adolescents.     

Polychlorinated biphenyls in seafood: contamination levels and human dietary exposure

Different species of fish and crustaceans from the Adriatic Sea, were analysed for polychlorinated biphenyls (PCBs) to estimate the update of daily intake of these contaminants from food. The estimates of the daily TEQs intake b.w. resulted below the range of 1–4 pg TEQs/kg b.w./day set by the World Health Organisation for almost all the species examined except for conger and mackerel. This result supports the assumption of a substantial reduction in intake of these compounds from seafood.     

Changes in baseline levels of nucleotides during ice storage of fish and crustaceans from the Portuguese coast

Adenine nucleotides and related compounds were measured in North Atlantic hake, monkfish, rockfish, Norway lobster, and red shrimp from the South of Portugal immediately after catch and after a 72-hours ice storage period. To preserve the samples until analysis, a freezing technique with liquid nitrogen was developed and data compared with those from immediate extraction. The use of plastic vials in liquid nitrogen freezing gave similar data as when immediate post mortem extraction was done. Inosine monophosphate (IMP) was the main nucleotide present in the fish species, whereas adenosine monophosphate (AMP) was the major component of crustaceans. During ice storage of fish, adenine nucleotides were almost completely converted to IMP. Rockfish showed a significant catabolism of IMP with conversion to hypoxanthine (Hx). Red shrimp and, especially, Norway lobster presented an important transformation of AMP into IMP. In general, Hx was either not detected (crustaceans) or was present in very low amounts, the highest levels being detected in rockfish after ice storage. This species presented also after 72 h the highest K value (58%), whereas in the other cases the values ranged between 7% and 11%. Trigonelline (Trigo), a UV-absorbing betaine, was also present in both crustacean species together with adenosine triphosphate (ATP) and related compounds.     

Interventions targeting child undernutrition in developing countries may be undermined by dietary exposure to aflatoxin

Child undernutrition, a form of malnutrition, is a major public health burden in developing countries. Supplementation interventions targeting the major micronutrient deficiencies have only reduced the burden of child undernutrition to a certain extent, indicating that there are other underlying determinants that need to be addressed. Aflatoxin exposure, which is also highly prevalent in developing countries, may be considered an aggravating factor for child undernutrition. Increasing evidence suggests that aflatoxin exposure can occur in any stage of life, including in utero through a trans-placental pathway and in early childhood (through contaminated weaning food and family food). Early life exposure to aflatoxin is associated with adverse effects on low birth weight, stunting, immune suppression, and the liver function damage. The mechanisms underlying impaired growth and aflatoxin exposure are still unclear but intestinal function damage, reduced immune function, and alteration in the insulin-like growth factor axis caused by the liver damage are the suggested hypotheses. Given the fact that both aflatoxin and child undernutrition are common in sub-Saharan Africa, effective interventions aimed at reducing undernutrition cannot be satisfactorily achieved until the interactive relationship between aflatoxin and child undernutrition is clearly understood, and an aflatoxin mitigation strategy takes effect in those vulnerable mothers and children.     

Effect of intertidal exposure on Vibrio parahaemolyticus levels in Pacific Northwest oysters

Interest in Vibrio parahaemolyticus (Vp) increased in the United States following Vp-associated gastroenteritis outbreaks in 1997 and 1998 involving the West Coast and other areas. The present study evaluated multiple aspects of Vp ecology in the Pacific Northwest with three objectives: (i) to determine the effect of low-tide exposure on Vp levels in oysters, (ii) to determine the relationship between total and pathogenic Vp, and (iii) to examine sediments and aquatic fauna as reservoirs for pathogenic Vp. Samples were collected from intertidal reefs along Hood Canal, Wash., in August 2001. Fecal matter from marine mammals and aquatic birds as well as intestinal contents from bottom-dwelling fish were tested. Total and pathogenic Vp levels in all the samples were enumerated with colony hybridization procedures using DNA probes that targeted the thermolabile direct hemolysin (tlh) and thermostable direct hemolysin (tdh) genes, respectively. The mean Vp densities in oysters were four to eight times greater at maximum exposure than at the corresponding first exposure. While tdh-positive Vp counts were generally < or = 10 CFU/g at first exposure, counts as high as 160 CFU/g were found at maximum exposure. Vp concentrations in sediments were not significantly different from those in oysters at maximum exposure. Pathogenic (tdh positive) Vp was detected in 9 of 42 (21%) oyster samples at maximum exposure, in 5 of 19 (26%) sediment samples, but in 0 of 9 excreta samples. These results demonstrate that summer conditions permit the multiplication of Vp in oysters exposed by a receding tide.     

边销茶中蒽醌污染状况及其暴露风险评估

目的 了解我国边销茶中蒽醌（以9,10-蒽醌为代表）的污染状况,评估我国边销茶饮用人群的暴露水平及健康风险。方法 用气相色谱串联质谱法（GC-MS/MS）测定边销茶样品中蒽醌（以9,10-蒽醌为代表）的含量,基于2016—2017年边销茶中9,10-蒽醌食品安全风险监测数据,结合内蒙古自治区、西藏自治区、青海省居民的边销茶消费量数据,通过简单分布评估法对当地居民通过饮用边销茶蒽醌的暴露量进行估计,并与每日允许摄入量（ADI,6.8 μg/kg·BW）比较后进行风险评估。结果 141份边销茶样品中蒽醌总检出率为75.18%,平均含量为0.029 2 mg/kg,我国尚未制定茶叶中蒽醌的限量标准,以2014年欧盟法规条例（EU）No 1146/2014中规定的茶叶中蒽醌最大残留限量0.02 mg/kg作为参考,总超标率为57.45%。定型包装和散装的边销茶蒽醌超标率分别为64.63%和47.46%。简单分布评估结果显示,我国内蒙古自治区、西藏自治区和青海省饮茶者全人群每日通过边销茶摄入蒽醌的平均水平为9.37×10^-4 μg/kg·BW,占ADI的0.013 8%;边销茶高消费人群的每日暴露量（P95暴露量）为3.12×10^-3 μg/kg·BW,占ADI的0.045 9%。不同性别-年龄组中,45~59岁女性组每日平均暴露量和P95暴露量最高,分别为1.41×10^-3和6.16×10^-3 μg/kg·BW,远低于ADI值。结论 内蒙古自治区、西藏自治区和青海省居民经边销茶摄入的蒽醌对人体造成的健康风险较低,处在可接受水平。但我国边销茶中普遍存在蒽醌污染,需要进一步对茶叶中蒽醌进行溯源分析并控制污染源。另外,为积极应对欧盟等国家和地区对我国出口茶叶的蒽醌含量限定,建议相关部门研究制定茶叶中蒽醌的合理限量规定。     

我国大闸蟹中二噁英类持久性有机污染物的暴露水平研究

目的研究我国大闸蟹中二噁英类持久性有机污染物(persistent organic pollutants,POPs)的暴露水平,评估大闸蟹中二噁英类POPs的主要污染来源。方法样品经正己烷和二氯甲烷(1:1,V:V)提取,浓硫酸沉淀脂类杂质后,过复合硅胶柱和碱性氧化铝柱净化分离目标物。采用同位素稀释高分辨气相色谱-高分辨质谱法(isotope dilution high resolution gas chromatograph-high resolution mass spectrometer,isotope dilution HRGC-HRMS)分析大闸蟹及其食物源中二噁英和多氯联苯的含量。结果蟹肉中二噁英类POPs的总毒性当量(toxic equivalent,TEQ)为0.0092～1.65 pg TEQ/g,平均浓度为0.27 pg TEQ/g。蟹黄(蟹膏)中二噁英类POPs的TEQ浓度水平为1.3～15 pg TEQ/g,平均浓度是蟹肉中平均TEQ值的21倍。估算一亩蟹塘中的物料平衡,发现饲料中二噁英类POPs的TEQ值是大闸蟹的0.85倍,玉米、水草和水仅贡献蟹塘中TEQ输入的4.7%,不考虑生物过程,沉积物中TEQ输入是饲料输入的77倍。结论蟹塘中二噁英类POPs的TEQ输入量高于其输出量,其中沉积物是大闸蟹中二噁英类POPs的主要贡献者,定期清理和更换养殖蟹塘中的沉积物可有效减少大闸蟹对二噁英类POPs的暴露。     

Variation in human sweet taste receptor may result in different levels of sweet intensity variability between sweet stimuli

Understanding the physiological activation and genetic variation of the sweet taste receptor (T1R) can improve formula optimisation for products intended for a population of genetically diverse people. Computer modelling and cell culture techniques have thoroughly described the structure and binding sites of the T1R. The structure contains two subunits (T1R2 and T1R3) with multiple domains where sweet molecules can interact. The interaction takes place between individual molecules and amino acid residues of the T1R. The residues with which individual molecules interact differ between sweeteners. Person‐to‐person differences in the residue sequence of the T1R can arise from variation in the genes that encode the T1R, potentially effecting the function of the receptor. As a result of the specificity of the binding interactions, a specific genetic variation may affect sensitivity to some sweeteners, while sensitivity to other sweeteners remains normal. Therefore, it can be hypothesised that the level of person‐to‐person sweetness sensitivity variation may differ for each sweetener depending on the binding site of the molecule and site of T1R variation. The T1R structure, binding sites and genetic variation will be reviewed, as well as potential parameters to predict the degree of sensitivity variation and formulation strategies to minimise the effects of sensitivity variation.     

Ethylacetate extracts of the muscles of Anguilla japonica suppress glucose levels in db/db mice via activation of AMP-activated protein kinase

Hypoglycemic effects of ethylacetate extracts of Anguilla japonica (EMA) muscles in db/db mice were investigated. To understand the mechanism responsible for the hypoglycemic effects of EMA, the effects of EMA on AMP-activated protein kinase (AMPK) activation in L6 myotubes and in vivo using type II diabetic db/db mice were analyzed. In L6 myotubes, the phosphorylation degrees of AMPK and acetyl-CoA carboxylase (ACC) were markedly increased and glucose uptake was significantly (p<0.001) increased by EMA, compared with untretaed L6 myotubes. However, in L6 myotubes, these effects were abolished by compound C, an AMPK inhibitor. Moreover, EMA significantly reduced non-fasting blood glucose and serum insulin levels, and strongly induced AMPK phosphorylation in skeletal muscle tissues of db/db mice. EMA regulates glucose levels in L6 myotubes and in diabetic mice by activation of AMPK. Beneficial effects for diabetes treatment are indicated.     

The variability of urinary cotinine levels in young children: implications for measuring ETS exposure.

This study examined the within-subject variability of urinary cotinine levels in young children (aged = 0.6-7.2 years) of smoking parents to determine the number of urine samples needed to provide accurate estimates of exposure to environmental tobacco smoke (ETS) for different time intervals. Secondary analyses were conducted of five independent studies (N = 376), in which multiple urinary cotinine measures had been collected over time periods up to 13 months. Over measurement periods of 4-15 days, the within-subject cotinine levels varied 3-5 times more than would be expected based on measurement error alone. Over 7-13 months, the within-subject variability was 10-20 times higher than would be expected based on the measurement error. Findings indicated that cotinine measures from single urine samples provided highly accurate estimates of only recent exposure (i.e., 2-3 days; rho = 0.99). To achieve similarly precise estimates of the mean cotinine level of an individual child over 4-15 days, up to nine urine samples may be necessary. Up to 12 urine samples may be required to achieve similarly precise estimates of ETS exposure over a 4- to 13-month period. Epidemiologic and clinical research on ETS exposure in children can benefit from multiple urine samples (a) to accurately measure average exposure at the level of the individual child, (b) to describe temporal patterns, (c) to detect incidences of peak exposure that would remain underrecognized if monitoring is limited to a single time point, and (d) to establish stable baseline levels and endpoints based on urine samples collected over clinically relevant time periods.     

广东省鳜鱼和杂交鳢中孔雀石绿和硝基呋喃残留调查及暴露评估

目的了解广东省主要养殖地的鳜鱼和杂交鳢中孔雀石绿及其代谢物和硝基呋喃类代谢物的残留情况。方法利用高效液相色谱-串联质谱法对鱼肉中的孔雀石绿及其代谢物和硝基呋喃类代谢物残留量进行测定。结果2013年孔雀石绿的总检出率为11.7%,硝基呋喃类代谢物的总检出率为20%。2014年孔雀石绿的总检出率为25%,硝基呋喃类代谢物的总检出率为12.5%。近两年总孔雀石绿残留量在0.58~19.1μg/kg之间,总硝基呋喃类代谢物残留量在0.66~36.6μg/kg之间。暴露评估显示:人体每天可能的孔雀石绿的平均暴露量0.24μg,即每人每日膳食暴露量为0.004μg/kg BW,最高暴露量1.10μg,即每人每日膳食暴露量为0.02μg/kg BW;人体可能的每天呋喃西林代谢物的平均暴露量为0.34μg,即每人每日膳食暴露量为0.005μg/kg BW,最高暴露量为0.87μg,即每人每日膳食暴露量为0.01μg/kg BW;人体可能的每天呋喃唑酮代谢物的平均暴露量0.56μg,即每人每日膳食暴露量为0.009μg/kg BW,最高暴露量2.10μg,即每人每日膳食暴露量为0.03μg/kg BW。结论近两年鳜鱼和杂交鳢中孔雀石绿和硝基呋喃类检出率相对较低,膳食暴露评估显示孔雀石绿在此范围内对人体健康损害危险性极小。     

Human exposure assessment: a case study of 8 PAH contaminated soils using in vitro digestors and the juvenile swine model

In vitro digestors can be used to provide bioaccessibility values to help assess the risk from incidental human ingestion of contaminated soils. It has been suggested that these digestors may need to include a lipid sink to mimic human uptake processes. We compare the correspondence between in vivo polycyclic aromatic hydrocarbon (PAH) uptake for eight different PAH contaminated soils with PAH release in in vitro digestors in the presence and absence of a lipid sink. Lipid sinks were essential to the success of the in vitro digestors in predicting juvenile swine PAH uptake. In the presence of the lipid sink, results of the In Vitro Digestion model (IVD) closely corresponded with a slope of 0.85 (r(2) = 0.45, P < 0.07) to the in vivo results. The Relative Bioaccessibility Leaching Procedure (RBALP) results did not correspond to the in vivo study but did tightly reflect total soil PAH concentration. We conclude that the basis of this difference between digestors is that the RBALP used an aggressive extraction technique that maximized PAH release from soil. Systemic uptake in juvenile swine was not linked to soil PAH concentration but rather to the thermodynamic properties of the soil.     

Dietary exposure assessment of putrescine and cadaverine and derivation of tolerable levels in selected foods consumed in Austria

Biogenic amines (histamine, tyramine, putrescine, cadaverine, agmatine, spermidine and spermine) are nitrogenous compounds. They occur naturally in living organisms and are involved in many biological processes. Nonetheless, high amounts in food may be hazardous to human health. The diamines putrescine and cadaverine in food can potentiate the effects of simultaneously ingested histamine. In protein-rich foods, high concentrations of these diamines are indicative for hygienic deficiencies in the food chain. Even though being formed endogenously and being essential for some physiological metabolic pathways, both diamines are known as precursors for carcinogenic nitrosamines. Putrescine also plays a certain role in tumour growth. Nevertheless, no tolerable levels in foods have been established so far. The present study suggests tolerable levels in cheese, fermented sausages, fish, sauerkraut and seasonings that are based on toxicological threshold levels, occurrence of diamines in foods and food consumption in Austria. Average daily intake of putrescine via fermented food was calculated to be 6.8 (female adults) and 8.8 (male adults) mg per person. Respective numbers for cadaverine were 9.8 and 11.6 mg per person and day. For putrescine, proposed maximum tolerable levels for sauerkraut, fish, cheese, fermented sausages and seasonings are 140, 170, 180, 360 and 510 mg/kg, respectively. Likewise, for cadaverine, in sauerkraut, fish, cheese, fermented sausages and seasonings, maximum tolerable levels are 430, 510, 540, 1,080 and 1,540 mg/kg, respectively. These limits can be met by current manufacturing practices, as ascertained from the results of our own studies and from literature. Admittedly, only few data are published on toxicological threshold levels of these diamines, which mean that these tolerable levels are associated with some uncertainty.     

中国部分地区猪肉中指示性多氯联苯污染水平和膳食暴露风险评估

目的 调查中国猪肉中指示性多氯联苯(PCBs)的污染水平以及我国居民膳食暴露情况和风险。方法选取2020年中国13个省(自治区、直辖市)为监测点采集猪肉样品,采用同位素稀释-气相色谱-高分辨磁质谱联用法测定203份猪肉中7种指示性PCBs(PCB28、PCB52、PCB101、PCB118、PCB138、PCB153、PCB180)的含量,并分析其指纹特征。依据各省(自治区、直辖市)猪肉的消费量数据,评估居民通过猪肉暴露指示性PCBs的健康风险。结果 猪肉中7种指示性PCBs(∑₇PCBs)的平均浓度范围为0.053(广西)～0.826 ng/g脂肪(浙江),P95浓度范围为0.091(广西)～2.702 ng/g脂肪(浙江)。PCB28和PCB52为主要的指纹特征。中国居民通过食用猪肉每日摄入∑₇PCBs的平均水平和P95水平分别为(0.062±0.076)ng/kg·BW和(0.158±0.207)ng/kg·BW,暴露风险指数(ERI)均小于1。结论 中国猪肉中∑₇PCBs的污染水平较低,居民通过猪肉膳食暴露指示性...