Human exposure to dietary inorganic arsenic and other arsenic species: State of knowledge, gaps and uncertainties

Abstract

Inorganic arsenic (iAs) is ubiquitous in the environment as arsenite (AsIII) and arsenate (AsV) compounds and biotransformation of these toxic chemicals leads to the extraordinary variety of organoarsenic species found in nature. Despite classification as a human carcinogen based on data from populations exposed through contaminated drinking water, only recently has a need for regulatory limits on iAs in food been recognized. The delay was due to the difficulty in risk assessment of dietary iAs, which critically relies on speciation analysis providing occurrence data for iAs in food – and not simply for total arsenic. In the present review the state of knowledge regarding arsenic speciation in food and diet is evaluated with focus on iAs and human exposure assessment through different dietary approaches including duplicate diet studies, market basket surveys, and total diet studies. The analytical requirements for obtaining reliable data for iAs in food are discussed and iAs levels in foods and beverages are summarized, along with information on other (potentially) toxic co-occurring organoarsenic compounds. Quantitative exposure assessment of iAs in food is addressed, focusing on the need of capturing variability and extent of exposure and identifying what dietary items drive very high exposure for certain population groups. Finally, gaps and uncertainties are discussed, including effect of processing and cooking, and iAs bioavailability.

Concentrations of urinary arsenic species in relation to rice and seafood consumption among children living in Spain

“…This is especially true for infants and young children whose diet is generally of lower food diversity, and characterized with a higher food consumption per body weight compared to adults, which in turn exacerbates dietary exposure (Cubadda et al, 2016; EFSA, 2009; Karagas et al, 2016). In our study children at 4 years of age had higher rice and seafood product consumption per body weight than at 7 years.…”

“…The metabolic process is incomplete such that i-As along with MMA and DMA metabolites are excreted in urine (Tseng, 2009). Health risks associated with exposure to organic arsenic compounds such as DMA and MMA are less certain than i-As, and AsB, which is excreted in the urine unchanged and regarded as non-toxic (Cubadda et al, 2016; Feldmann and Krupp, 2011; Molin et al, 2015). …”

“…Diet is the main source of i-As exposure when relatively low arsenic drinking water is available, the maximum level of which is regulated at 0.01 mg/l in the EU (Cubadda et al, 2016; EFSA, 2009; The Council of the European Union, 1998). The 0.01 mg/l is also the WHO guideline value for arsenic in drinking water and thus the legal limit in many countries around the world (WHO, 2011).…”

“…As far as seafood is concerned, AsB dominates in fish, whereas other organic arsenic compounds such as arsenosugars and arsenolipids are also found in seafood products, including i-As in bivalves, crustaceans and algae (Feldmann and Krupp, 2011; Fontcuberta et al, 2011; Krishnakumar et al, 2016; Molin et al, 2015; Navas-Acien et al, 2011; Taylor et al, 2016). Thus, if relatively low arsenic drinking water is available, rice and seafood products are principal total arsenic, including potentially toxic arsenic species, dietary sources (Cubadda et al, 2016; EFSA, 2009). However, limited information is as yet available regarding the contribution of these key food items to urinary arsenic species concentration as exposure biomarker during childhood, especially among those with increased and consistent rice and seafood product consumption, such as those living in Spain, whose consumption of rice and seafood products is enhanced by the Spanish gastronomic culture.…”

Mitigating dietary arsenic exposure: Current status in the United States and recommendations for an improved path forward

“…This paper and the four others that accompany it (Cubadda et al, 2017; Davis et al, 2017; Punshon et al, 2017; Taylor et al, 2017) are products of the Collaborative on Food with Arsenic and Associated Risk and Regulation (C-FARR), a two-year effort led by the Dartmouth Superfund Research Program and Children’s Environmental Health and Disease Prevention Research Center. The goal of C-FARR is to synthesize the current information pertaining to arsenic from soil to plate, based on key questions and knowledge gaps identified by policy stakeholders and scientists from interdisciplinary backgrounds, to inform future regulatory and policy decisions affecting dietary arsenic exposure.…”