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It has previously been shown that across different arsenic (As) soil environments, a decrease in grain selenium (Se), zinc (Zn), and nickel (Ni) concentrations is associated with an increase in grain As. In this study we aim to determine if there is a genetic element for this observation or if it is driven by the soil As environment. To determine the genetic and environmental effect on grain element composition, multielement analysis using ICP-MS was performed on rice grain from a range of rice cultivars grown in 4 different field sites (2 in Bangladesh and 2 in West Bengal). At all four sites a negative correlation was observed between grain As and grain Ni, while at three of the four sites a negative correlation was observed between grain As and grain Se and grain copper (Cu). For manganese, Ni, Cu, and Se there was also a significant genetic interaction with grain arsenic indicating some cultivars are more strongly affected by arsenic than others. [ABSTRACT FROM AUTHOR]

The concentration of arsenic (As) in rice grains has been identified as a risk to human health. The high proportion of inorganic species of As (As,) is of particular concern as it is a nonthreshold, class 1 human carcinogen. To be able to breed rice with low grain As, an understanding of genetic variation and the effect of different environments on genetic variation is needed. In this study, 13 cultivars grown at two field sites each in Bangladesh, India, and China are evaluated for grain As. There was a significant site, genotype, and site by genotype interaction for total grain As. Correlations were observed only between sites in Bangladesh and India, not between countries or within the Chinese sites. For seven cultivars the As was speciated which revealed significant effects of site, genotype, and site by genotype interaction for percentage Asi. Breeding low grain An cultivars that will have consistently low grain As and low Asi, over multiple environments using traditional breeding approaches maybe difficult. although CT9993-5-10-1-M, Lemont, Azucena, and Te-qing in general had low grain As across the field sites. [ABSTRACT FROM AUTHOR]

An extensive data set of total arsenic analysis for 901 polished (white) grain samples, originating from 10 countries from 4 continents, was compiled. The samples represented the baseline (i.e., not specifically collected from arsenic contaminated areas), and all were for market sale in major conurbations. Median total arsenic contents of rice varied 7-fold, with Egypt (0.04 mg/kg) and India (0.07 mg/kg) having the lowest arsenic content while the U.S. (0.25 mg/kg) and France (0.28 mg/kg) had the highest content Global distribution of total arsenic in rice was modeled by weighting each country's arsenic distribution by that country's contribution to global production. A subset of 63 samples from Bangladesh, China, India, Italy, and the U.S. was analyzed for arsenic species. The relationship between inorganic arsenic content versus total arsenic content significantly differed among countries, with Bangladesh and India having the steepest slope in linear regression, and the U.S. having the shallowest slope. Using country-specific rice consumption data, daily intake of inorganic arsenic was estimated and the associated internal cancer risk was calculated using the U.S. [ABSTRACT FROM AUTHOR]