Dietary Sources of Methylated Arsenic Species in Urine of the United States Population, NHANES 2003–2010

Abstract

BackgroundArsenic is an ubiquitous element linked to carcinogenicity, neurotoxicity, as well as adverse respiratory, gastrointestinal, hepatic, and dermal health effects.ObjectiveIdentify dietary sources of speciated arsenic: monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA).MethodsAge-stratified, sample-weighted regression of NHANES (National Health and Nutrition Examination Survey) 2003–2010 data (∼8,300 participants ≥6 years old) characterized the association between urinary arsenic species and the additional mass consumed of USDA-standardized food groups (24-hour dietary recall data), controlling for potential confounders.ResultsFor all arsenic species, the rank-order of age strata for median urinary molar concentration was children 6–11 years > adults 20–84 years > adolescents 12–19 years, and for all age strata, the rank-order was DMA > MMA. Median urinary molar concentrations of methylated arsenic species ranged from 0.56 to 3.52 µmol/mol creatinine. Statistically significant increases in urinary arsenic species were associated with increased consumption of: fish (DMA); fruits (DMA, MMA); grain products (DMA, MMA); legumes, nuts, seeds (DMA); meat, poultry (DMA); rice (DMA, MMA); rice cakes/crackers (DMA, MMA); and sugars, sweets, beverages (MMA). And, for adults, rice beverage/milk (DMA, MMA). In addition, based on US (United States) median and 90th percentile consumption rates of each food group, exposure from the following food groups was highlighted: fish; fruits; grain products; legumes, nuts, seeds; meat, poultry; and sugars, sweets, beverages.ConclusionsIn a nationally representative sample of the US civilian, noninstitutionalized population, fish (adults), rice (children), and rice cakes/crackers (adolescents) had the largest associations with urinary DMA. For MMA, rice beverage/milk (adults) and rice cakes/crackers (children, adolescents) had the largest associations.

Arsenic Metabolites and Methylation Capacity Among Individuals Living in a Rural Area with Endemic Arseniasis in Inner Mongolia, China

“…Arsenic species differ in their toxicity, and iAs is more toxic than organic arsenic. Therefore, arsenic methylation has been considered a detoxification mechanism because of the relatively low toxicity of MMA and DMA [20][21][22][23]. However, recent investigations suggest that MMA III and DMA III are more toxic than iAs arsenite [24,25].…”

MDI Biological Laboratory Arsenic Summit: Approaches to Limiting Human Exposure to Arsenic

“…Application of pesticides containing arsenic by cotton, tobacco, grape and apple growers in the South Central U.S. in the 1950s has resulted in accumulation of low levels of arsenic in treated soils [49, 52, 59, 62, 63]. Food plants, such as rice, that take in and accumulate arsenic, both naturally occurring and anthropogenic, from the soil pose potential health risks to humans who eat them on a regular basis [7–9, 41–45, 48, 50, 51, 64]. A recent study suggests that arsenic exposure in food is a significant source of overall exposure.…”

“…In addition, some rice-based products including toddler formulas and energy bars, especially those made with organic brown rice syrup, have been identified as major contributors to arsenic exposure [43–45, 48, 49, 60]. Furthermore, some fish, shellfish, meat, poultry, dairy products and cereals are also dietary sources of arsenic [50, 63]. Seafood contains organic forms of arsenic, such as arsenobetaine, which is thought to be less toxic than the inorganic forms that are found in water: however the toxicity of arsenolipids and arsenosugars in seafood are not well described [51, 54, 55].…”

Poultry Consumption and Arsenic Exposure in the U.S. Population

“…In populations with low arsenic levels in drinking water, exposure to inorganic arsenic (iAs) occurs mainly through diet, particularly through the consumption of rice and other grains, as well as some juices and wine [Davis et al 2012;deCastro et al 2014; U.S. Food and Drug Administration (FDA) 2014a; Navas- Acien et al 2011]. iAs is a toxic and carcinogenic metalloid that occurs naturally in water, air, and soil and enters the food supply through geological releases, contaminated water, and anthropogenic sources such as pesticide residue, nonferrous metal smelting, and waste incineration [Agency for Toxic Substances and Disease Registry (ATSDR) 2007].…”

“…Previous studies in NHANES have evaluated poultry consumption as a potential confounder of dietary arsenic exposure (Davis et al 2012) or in analyses without accounting for other dietary sources of arsenic such as seafood (deCastro et al 2014). Our objective was to evaluate whether consumption of poultry in the past 24 hr was associated with increased arsenic exposure as measured in urine by total arsenic and DMA during a time period when arsenic-based poultry drugs were approved for use in the United States.…”