Organoarsenical species contents in cooked seafood

The organoarsenical species arsenobetaine (AB), arsenocholine (AC), tetramethylarsonium ion (TMA+), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA) were determined in 64 cooked seafood products (fish, bivalves, squid, crustaceans) included in a Total Diet Study carried out in the Basque Country (Spain). For cooking, various treatments were employed (grilling, roasting, baking, stewing, boiling, steaming, microwaving). The results obtained show that in cooked seafood AB is the major species, followed by DMA and TMA+. AC and MMA are minor species. The results in cooked seafood were compared with the arsenic species contents obtained for the same product raw. After cooking there was an increase in DMA for sardines and bivalves and an increase or appearance of TMA+ for meagrim, anchovy, Atlantic horse mackerel, and sardine. The data provided add to the very scant information available about organoarsenical species contents in cooked seafood.

Assessment of intake from the diet

Exposure assessment is one of the key parts of the risk assessment process. Only intake of toxicologically significant amounts can lead to adverse health effects even for a relatively toxic substance. In the case of chemicals in foods this is based on three major aspects: (i) how to determine quantitatively the presence of a chemical in individual foods and diets, including its fate during the processes within the food production chain; (ii) how to determine the consumption patterns of the individual foods containing the relevant chemicals; (iii) how to integrate both the likelihood of consumers eating large amounts of the given foods and of the relevant chemical being present in these foods at high levels. The techniques used for the evaluation of these three aspects have been critically reviewed in this paper to determine those areas where the current approaches provide a solid basis for assessments and those areas where improvements are needed or desirable. For those latter areas, options for improvements are being suggested, including, for example, the development of a pan-European food composition database, activities to understand better effects of processing on individual food chemicals, harmonisation of food consumption survey methods with the option of a regular pan-European survey, evaluation of probabilistic models and the development of models to assess exposure to food allergens. In all three areas, the limitations of the approaches currently used lead to uncertainties which can either cause an over- or underestimation of real intakes and thus risks. Given these imprecisions, risk assessors tend to build in additional uncertainty factors to avoid health-relevant underestimates. This is partly done by using screening methods designed to look for "worst case" situations. Such worse case assumptions lead to intake estimates that are higher than reality. These screening methods are used to screen all those chemicals with a safe intake distribution. For chemicals with a potential risk, more information is needed to allow more refined screening or even the most accurate estimation. More information and more refined methods however, require more resources. The ultimate aims are: (1) to obtain appropriate estimations for the presence and quantity of a given chemical in a food and in the diet in general; (2) to assess the consumption patterns for the foods containing these substances, including especially those parts of the population with high consumption and thus potentially high intakes; and (3) to develop and apply tools to predict reliably the likelihood of high end consumption with the presence of high levels of the relevant substances. It has thus been demonstrated that a tiered approach at all three steps can be helpful to optimise the use of the available resources: if relatively crude tools - designed to provide a "worst case" estimate - do not suggest a toxicologically significant exposure (or a relevant deficit of a particular nutrient) it may not be necessary to use more sophisticated tools. These will be needed if initially high intakes are indicated for at least parts of the population. Existing pragmatic approaches are a first crude step to model food chemical intake. It is recommended to extend, refine and validate this approach in the near future. This has to result in a cost-effective exposure assessment system to be used for existing and potential categories of chemicals. This system of knowledge (with information on sensitivities, accuracy, etc.) will guide future data collection.

Arsenic in cooked seafood products: study on the effect of cooking on total and inorganic arsenic contents

Total and inorganic arsenic contents were analyzed in cooked seafood products consumed in Spain during the period July 1997-June 1998: hake, meagrim, small hake, anchovy, Atlantic horse mackerel, sardine, bivalves, crustaceans, squid, and salted cod. Various cooking treatments were used (grilling, roasting, baking, stewing, boiling, steaming, and microwaving). The results obtained were compared statistically with those found previously in the same products raw, and they showed that after cooking there was a significant increase in the concentration of total arsenic for salted cod and bivalves, and in the concentration of inorganic arsenic for bivalves and squid. The mean content of inorganic arsenic was significantly higher in bivalves than in any other type of seafood. For the Spanish population, the mean intake of total arsenic estimated on the basis of the results obtained in this study is 245 microg/day. The intake of inorganic arsenic (2.3 microg/day) represents 1.7% of the World Health Organization provisional tolerable weekly intake (PTWI), leaving an ample safety margin for this population, which has a very high consumption of seafood.

Total and inorganic arsenic in fresh and processed fish products

Total arsenic and inorganic arsenic contents were determined in 153 samples of seafood products consumed in the Basque Country (Spain): fish (white fish and blue fish), mollusks, crustaceans, and preserved fish. White fish presented higher levels of total arsenic and lower levels of inorganic arsenic than the blue fish, indicating possible differences in the metabolization of inorganic arsenic. For total arsenic, 66% of the samples exceeded the maximum permitted level by the strictest international legislation in seafood products [1 microg g(-)(1), wet weight (ww)]. The levels of inorganic arsenic were considerably lower than the maximum authorized in New Zealand (2 microg g(-)(1), ww), the only country with legislation for inorganic arsenic in fish and fish products. It is recommended that legislation based on levels of inorganic arsenic should be established.

Food surveillance in the Basque Country (Spain). II. Estimation of the dietary intake of organochlorine pesticides, heavy metals, arsenic, aflatoxin M1, iron and zinc through the Total Diet Study, 1990/91

Total diet samples purchased at monthly intervals between March 1990 and December 1991 were analysed for different contaminants and nutrients. Each total diet sample included 91 food items which were combined after preparation and/or cooking into 16 groups of similar foods. The 'market basket' was based on a food survey which referred to the adult population (25-60 years) carried out in the Basque Country between 1988 and 1990. The dietary intakes (micrograms/day) of lead (43), cadmium (11), mercury (18), arsenic (291), hexachlorobenzene (HCB) (0.2), alpha-hexachlorocyclohexane (alpha-HCH) ( < 0.1), beta-hexachlorocyclohexane (beta-HCH) (0.1), gamma-hexachlorocyclohexane (gamma-HCH) (2.9), dichlorodiphenyltrichloroethane (DDT) (0.3), dichlorodiphenyldichloroethene (DDE) (0.9), dichlorodiphenyldichloroethane (DDD)(0.2), dieldrin (0.5), heptachlor epoxide ( < 0.1), alpha-endosulphan (0.1) and beta-endosulphan (0.1) were all well below the respective Acceptable Daily Intakes or Provisional Tolerable Weekly Intakes. However, arsenic intake was much higher than that estimated in other countries and gamma-HCH was detected in anomalously high levels in the bread group. Dietary intakes of delta-hexachlorocyclohexane (delta-HCH), aldrin, endrin, heptachlor and methoxychlor were not calculated because no residues were detected in any of the samples. Aflatoxin M1 intake was not estimated owing to the low levels detected. Finally, zinc intakes (11.6 mg/day) were below the recommended dietary allowances for Spain and the same was true for iron (11.3 mg/day), but only for females.

Food surveillance in the Basque country (Spain) I. The design of a total diet study

A total diet study has been initiated in the Basque country (Spain), the purpose of which is to provide estimates of the average intake of both food contaminants and certain nutrients. The types and quantities of foods that make up the average Basque 'Total Diet' are based on the results of surveys carried out between 1988 and 1990. These surveys have identified the major items in the national diet (91 categories of foods) which are combined for the total diet study, for analysis, into 16 groups of similar foods. Each group is being analysed for selected contaminants of concern which initially are: heavy metals (mercury, lead, cadmium and arsenic), organochlorine pesticides (HCB, HCH (alpha, beta, gamma, delta), DDT (DDE, TDE), dieldrin, aldrin, endrin, heptachlor, heptachlor epoxide, endosulfan and methoxychlor) and selected trace element nutrients (zinc, selenium and iron). In the milk and dairy products groups an assessment of aflatoxin M1 contamination is also being carried out.