Derivation and validation of thresholds of cadmium, chromium, lead, mercury and arsenic for safe rice production in paddy soil.

Cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg) and arsenic (As) are potent toxicants to human health via dietary intake. It is imperative to establish accurate soil thresholds based on soil-plant transfer models and food safety standards for safe agricultural production. This study takes rice genotypes and soil properties into account to derive soil thresholds for five heavy metal(loid)s using the bioconcentration factors (BCF) and species sensitivity distribution (SSD) based on the food safety standard. The BCF generated from two paddy soils was calculated to investigate the sensitivity of heavy metal accumulation in nine rice cultivars in a greenhouse pot experiment. Then, empirical soil-plant transfer models were developed from a middle-sensitivity rice cultivar (Denong 2000, one selected from nine rice) grown in nineteen paddy soils with various soil properties under a proper exogenously metal(loid)s concentration gradient. After normalization, hazardous concentrations from the fifth percentile (HC5) were calculated from the SSD curves, and the derived soil thresholds were obtained from HC5 prediction models that based on the combination of pH and organic carbon (OC) or cation exchange capacity (CEC). The soil Cd threshold derived based on pH and organic carbon (pH < 7.5, OC ≥ 20 g kg-1) was 1.3-fold of those only considering pH, whereas the Pb threshold (pH > 6, CEC ≥ 20 cmolc kg-1) was 3.1 times lower than the current threshold. The derived thresholds for five elements were validated to be reliable through literature data and field experiments. The results suggested that deriving soil heavy metal(loid)s threshold using SSD method and local food safety standards is feasible and also applicable to other crops as well as other regions with potential health risks of toxic elements contamination in agricultural production.

Avaliação da concentração de mercúrio em rações caninas comercializadas em Niterói, Rio de Janeiro / Evaluation of the mercury concentration in canine feeds sold in Niterói, Rio de Janeiro

Dentre os metais pesados de maior preocupação para saúde humana e animal, tem-se o mercúrio, cuja forma orgânica é a mais agressiva aos sistemas. A fonte mais comum de adquirir tal metal é através do consumo de pescado e seus derivados, sendo que para os pets (animais de companhia) a ingestão é via rações formuladas com tal matriz alimentar. Logo, foram feitas análises através do DMA 80 de tal elemento em distintas rações comerciais no município de Niterói para avaliar a qualidade do produto ofertado. Os resultados para as rações úmidas de peixe apresentaram 80% em desacordo com a legislação vigente para alimentos humanos, sendo necessário mais estudos e uma legislação específica para mercúrio para alimentação animal.

Concentração de mercúrio total em atum enlatado comercializado no município do Rio de Janeiro: risco potencial à saúde? / Concentration of total mercury in canned tuna marketed in the city of Rio de Janeiro

Este estudo determinou o teor total de mercúrio (HgT) em 69 atuns em conserva de 13 marcas comercializadas no sudoeste do Brasil. Todos os valores são reportados em µg.g-1 de peso úmido. O potencial de risco para a saúde foi estimado com base na concentração de mercúrio e consumo médio (175 g / semana) de peixes no Brasil em comparação com ISPT de 1,6 µg.kg-1 (FAO / WHO, 2010). Uma grande variação na concentração de mercúrio em diferentes espécies foi observada. A concentração média de mercúrio foi de 0,256 ± 0,215 µg.g-1 com maior valor de 1,060 µg.g-1 em uma única lata. Em geral, a concentração média foi inferior à legislação de 1,0 µg.g-1 para espécies predadoras (BRASIL, 2014). A ingestão semanal estimada (EIS) variou de 0,2 a 1,7 µg.kg-1. Para as marcas analisadas de consumo de peixe no Brasil, não há ocorrência de risco à saúde humana. No entanto, uma marca foi superior a ISPT de 1,6 µg.kg-1, não mostrando segurança para o grupo de risco específico. Serão necessários mais estudos, incluindo dados específicos sobre o consumo de atum em conserva em populações específicas, bem como o tipo de peixe, tamanho e local de pesca.

Temporal variability of blood lead, mercury, and cadmium levels in elderly panel study (2008-2014).

BACKGROUND: Biological measurements have been employed as useful biomarkers for exposure. Because of its property of reflecting toxicokinetic differences, however, within-subject variability leads to biased results in epidemiologic studies. METHOD: We examined the variability of lead (Pb), mercury (Hg), and cadmium (Cd) levels in blood samples from 1429 participants among 1677 elderly individuals aged over 60 years who lived in an urban area from August 2008 to April 2015. RESULTS: The geometric means of blood Pb, Hg, Cd were 1.92µg/dL, 2.48µg/L, and 1.33µg/L, and the intra-class correlations (ICCs) were 0.81, 0.71, and 0.83, respectively. The mean values of Pb and Hg levels in this study were lower than the results from single spot samples in other national biomonitoring surveys in Korea, with the exception of Cd was higher than those in other studies. Moreover, the predicted exceedances over the guidance levels for Pb, Hg, and Cd were 1.9%, 4.2%, and 0.3%, respectively. CONCLUSION: Korean elderly were exposed to high levels of Pb, Hg and Cd. Especially, those who had high levels of Cd were continuously exposed to Cd during study period with the 6 collection intervals. Therefore, factors affecting environmental Cd exposure should be further studied in the future.

The heavy metals cadmium, lead and mercury in raw materials of animal origin: evaluation of data from practice.

Raw materials from animal origin are widely used in homoeopathy. Due to the lack of dedicated limits, the quality requirements for herbal drugs of the European Pharmacopoeia (Ph. Eur.) and/or the German Homoeopathic Pharmacopoeia (Homöopathisches Arzneibuch, HAB), including limits for heavy metals such as cadmium, lead and mercury, have been applied. A recent database evaluation shows that for some raw materials of animal origin the Ph. Eur. limits for herbal drugs cannot be met in practice. For this reason proposals for new limits for cadmium, lead and mercury are made based on recent experiences from the companies' daily practice. These specific limits are suggested to be included in the individual monographs of the Ph. Eur. or at least the German HAB, respectively, for Ambra grisea, Euspongia officinalis, Formica rufa and Sepia officinalis.

A baseline study of levels of mercury, arsenic, cadmium and lead in Northeast Arctic cod (Gadus morhua) from different parts of the Barents Sea.

This study is one of several baseline studies that will provide basic and reliable information about the content of undesirable substances in important species of fish caught in Norwegian waters. Concentrations of metals in the muscle and liver of more than 800 Northeast Arctic cod caught at 32 sites in the Barents Sea are reported. The highest concentration of both mercury in the muscle and cadmium in the liver was found in cod caught in the western part of the Barents Sea, while the highest concentration of total arsenic was found in cod from the eastern part. The arsenic concentrations varied greatly among individual fish, ranging from 0.3 to 170 mg kg(-1) wet weight in the muscle. Such high levels of total arsenic have never previously been reported in any fish, and the primary factor for these high concentrations is likely to be the shrimp in the cod diet.

[Hygienic evaluation of air and soil pollution with mercury in the area of location of a coke plant]. / Gigienicheskaia otsenka zagriazneniia atmosfernogo vozdukha i pochvy rtut'iu v raione razmeshcheniia koksokhimicheskogo proizvodstva.

It has been established that processes of coal carbonization are accompanied by intensive mercury discharge into the air and soil. The maximum levels of ambient air contamination by mercury are determined 0.5 km away from the source--0.0016 mg/m3, 3 km away from the source--lower than 0.00024 mg/m3. Technogenic area of mercury is almost twice the territory of the plant, and it is stretched along the prevalent direction of the winds. Mercury concentrations at different distances away from the plant were 2.76 mg/kg (0.5 km), 1.97 mg/kg and 0.26 mg/kg. Simultaneous isolation of mercury from coals in the process of coal carbonization is recommended.

[Evaluation of cadmium, mercury and lead intake with daily food rations]. / Ocena pobrania kadmu, rteci i olowiu z calodziennymi odtworzonymi racjami pokarmowymi.

Using the data of the Central Statistical Bureau concerning the consumption of about 90 basic food products daily food rations were reproduced as taken by medium-income worker families. The diets were reproduced in Lublin, Olsztyn, Poznan, Warsaw and Wroclaw determining in them cadmium, mercury and lead by atomic absorption spectrophometry. It was found that weekly intake of cadmium with food rations was in the range from 133 to 189 mcg, that of lead was 504 to 952 mcg, and mercury from 61.6 to 154.0 mcg. The obtained results were not exceeding 50% PTWI for any of these metals but they were rather higher than those in previous years, which indicates increasing contamination of food products with toxic elements. In areas with higher industrialization level the dietary intake of metals was as a rule higher than in areas with lower accumulation of industry.