Dietary Exposure to Inorganic Arsenic in the Norwegian Population

ABSTRACT

Request from the Norwegian Food Safety Authority The Norwegian Food Safety Authority (NFSA) requested a statement from the Norwegian Scientific Committee for Food Safety (VKM) on the dietary exposure to inorganic arsenic in the Norwegian population. VKM was asked to comment on the following; 1.) Why the European Food Safety Authority (EFSA) assessment from 2009 found that the Norwegian population had higher dietary exposure to total arsenic than other European populations, 2.) Whether the Norwegian population or special groups of the population have food consumption patterns which could lead to a different dietary exposure to inorganic arsenic than what is reported for the European population, and 3.) Whether the consumption rice and rice products, such as rice cakes, and in Hijiki seaweed could pose additional health risks for children and adults. How VKM has addressed the request VKM has appointed a working group consisting of members of the Panel on Contaminants and from the VKM secretariat to answer the request. The Panel on Contaminants has reviewed and revised the draft prepared by the working group and finally approved the assessment on dietary exposure to inorganic arsenic in the Norwegian population. What arsenic is and its toxicity to humans Arsenic is a metalloid occurring in many different chemical forms in the environment. In the terrestrial environment, arsenic is mainly found as inorganic arsenic, i.e. arsenite and arsenate. In the aquatic environment, more than a 100 arsenic species have been identified. The organic form arsenobetaine is the major form in fish and other seafood. Humans are mainly exposed to arsenic through food and drinking water. Food is the major source for most people, but for people living in regions with naturally elevated concentrations of arsenic in groundwater, drinking water is the major source. The toxicity of arsenic species depends on the chemical form, with inorganic arsenic (arsenite and arsenate) being more toxic than organic arsenic compounds. Inorganic arsenic is carcinogenic, but not genotoxic, and is classified as a human carcinogen. Dietary total arsenic exposure in Europe and Norway The dietary exposure to total arsenic for the Norwegian population was estimated by EFSA (2009). The Norwegian exposure levels were the highest among the European populations. A high exposure to total arsenic for Norwegian adults was also estimated in the Norwegian Fish and Game study (Birgisdottir et al., 2013). Fish and seafood is the main contributor to the dietary exposure to total arsenic, and a high consumption of fish and seafood leads to a high dietary exposure to total arsenic. Dietary inorganic arsenic exposure in Europe and Norway There was little variation in the estimated dietary exposures to inorganic arsenic for the European populations (EFSA, 2014). The dietary exposure to inorganic arsenic has earlier been estimated for the Norwegian adult population based on a study including participants with high consumption of fish and other seafood and game meat, and participants representing the general population (Birgisdottir et al., 2013). The estimates for inorganic arsenic exposure were within the ranges reported by EFSA (2014), suggesting that Norwegian adults do not have specific eating patterns leading to a different dietary exposure to inorganic arsenic than other European adult populations. In the European populations, the main contributors to dietary exposure of inorganic arsenic were the food groups “grain-based processed products (non rice-based)”, “rice”, “milk and dairy products” and “drinking water” (EFSA, 2014). There is no information regarding specific dietary patterns of Norwegian sub-populations possibly leading to a higher exposure to inorganic arsenic. Fish and other seafood generally contain high levels of total arsenic, but the level of inorganic arsenic is very low. Exposure to inorganic arsenic through consumption of rice and rice products, and Hijiki seaweed The dietary exposures to inorganic arsenic in the European populations are within the range of the BMDL01 values and therefore possible health risks cannot be excluded (EFSA, 2009; EFSA, 2014). The estimated dietary exposure to inorganic arsenic in the Norwegian adult population (Birgisdottir et al., 2013) is also within the range of the BMDL01 values. Rice was identified as one of the main contributors to the dietary exposure to inorganic arsenic in Europe (EFSA, 2014). Rice and rice products contain higher levels of inorganic arsenic than other food groups and individuals with a high consumption of rice and rice products may have a higher exposure to inorganic arsenic than the rest of the population, resulting in an added health risk. For infants and toddlers, rice and rice products are not an important source of inorganic arsenic (EFSA, 2014). According to EFSA (2014) the main contributor to exposure to inorganic arsenic in infants and toddlers was “milk and dairy products”, then “drinking water”, “grain-based processed products (non rice-based)” and “Foods for infants and young children”. However, the dietary exposure to inorganic arsenic in toddlers and children is higher than in adults because of their higher food consumption relative to body weight (EFSA, 2014). Rice cakes are a product, which may contain particularly high levels of inorganic arsenic, and consumption of rice cakes by children will increase their exposure to inorganic arsenic (Livsmeddelsverket 2015, DTU Food 2013). Thus, Norwegian infants and toddlers with a high consumption of rice and rice products, such as rice cakes, may have a higher exposure to inorganic arsenic than other infants and toddlers, resulting in an added health risk. The edible seaweed Hijiki generally contains high levels of inorganic arsenic, whereas other seaweeds contain low levels of inorganic arsenic. Any consumption of Hikiji seaweed will lead to an additional exposure of inorganic arsenic, resulting in an added health risk.