Association of dietary intake and urinary excretion of inorganic arsenic in the Japanese subjects

Combination of isotope dilution with liquid chromatography-inductively coupled plasma mass spectrometry for the simultaneous monitoring and evaluation of cadmium and inorganic arsenic in polished rice

A new monitoring and evaluation technique for cadmium (Cd) and inorganic arsenic (i-As) in rice was developed, where the isotope dilution (ID) method was applied in combination with high performance liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS), following heat-assisted extraction. Cadmium and i-As in a rice sample were extracted using the HNO3-H2O2 extractant, and an appropriate amount of enriched 111Cd was spiked into it. Cadmium and As species were measured simultaneously by LC-ICP-MS. The cadmium concentration was calculated from the isotope dilution analysis, and i-As was determined by the comparison (1 point calibration) method using additional 111Cd as an internal standard. The proposed method provides accurate and precise determination of Cd based on the isotope dilution analysis. Moreover, it can be applied to a rapid screening test to find contaminated rice samples, by means of monitoring the intensity ratios of natural 111Cd and i-As to the additional 111Cd. The developed technique was applied to analyzing multiple rice reference materials, and the measurement results of Cd and i-As agreed with the certified values within the uncertainty range. It is noted that the grain size of rice samples does not affect the extraction data, when the rice sample is crushed into powder less than 850 μm. The proposed method was very useful for the monitoring and evaluation of Cd and i-As in rice as a precise analytical method as well as a screening method.

Burden of Coronary Heart Disease and Cancer from Dietary Exposure to Inorganic Arsenic in Adults in China, 2016

Background and Objectives:

Inorganic arsenic (iAs) can cause a wide range of health problems, including coronary heart disease (CHD) and lung, bladder, and skin cancer. Although dietary iAs intake is the primary source of iAs, the burden of CHD and cancers from dietary iAs exposure in Chinese adults has not been well known.

Methods:

To estimate the iAs exposure level in Chinese adults’ diet, we systematically collected food-specific iAs concentrations in China from Chinese and English literature databases during 2000-2020. Food consumption was extracted from two nationwide food and nutrition surveys in China. The population attributable fraction was calculated based on the dose-response relationship between iAs and CHD risk. Combining the 2016 Chinese tumor registry data, we calculated the annual incidence of cancer from dietary iAs exposure to measure the disability-adjusted life year (DALY) in 2016.

Findings:

The total amount of daily foodborne iAs intake was 0.55 μg/kg bw/day among Chinese adults. The DALY of foodborne iAs-associated CHD was 3,017,510, which accounted for 10.18% of total CHD DALY in Chinese adults in 2016. Moreover, the carcinogenic DALY for lung cancer, bladder cancer, and skin cancer of Chinese residents in 2016 related to dietary iAs was 314.24, 9.89, and 167.32 thousand, accounting for 2.05%, 1.70%, and 35.5% of the total cancer burden, respectively.

Conclusions:

Our findings suggested that dietary iAs exposure causes a substantial disease burden in Chinese adults. More efforts for foodborne iAs control are critical to reducing the disease burden of CHD and cancer in China and other countries with similar dietary patterns.

Dietary intake and urinary excretion of methylated arsenicals of Japanese adults consuming marine foods and rice

Dietary intake and urinary excretion of monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine (AsB) were measured in 150 adult Japanese subjects. Duplicate diet (DD) samples and first void of urine on the next morning of DD sampling day were collected and analysed for arsenic species with liquid chromatography-ICP mass spectrometry. Median (min-max) intakes of MMA, DMA and AsB were <2.3 (<2.3-<2.3), 4.57 (<2.3-24.3), and 13.6 (<2.4-231) μg As/day, respectively, and median urinary concentrations were 1.90 (<0.37-26.), 21.9 (<0.27-141) and 19.6 (<0.37-1063) ng As/mg creatinine, respectively. Interrelationships between intake levels and urinary concentrations were mostly significant with positive coefficients indicating mutual association due to co-exposure, metabolism and/or dietary habit. Urinary concentrations and intake levels of AsB were also positively correlated confirming the applicability of urine analysis as biomarker of exposure. The present descriptive results provide with essential piece of information in assessing health risk of methylated arsenicals for population who consume marine products and rice.

A Simplified Questionnaire for the Assessment of Inorganic Arsenic Intake in a Japanese Population

A simplified questionnaire was developed to assess inorganic arsenic (iAs) intake level in a Japanese population. The two page questionnaire included photographs of single serving sizes of rice and cooked hijiki (Hizikia fusiforme: brown algae), and asked subjects about the number of servings of rice and cooked hijiki, two predominant dietary sources of iAs in Japan, they consume in a day. Daily intake of iAs was estimated for 72 Japanese subjects using the questionnaire together with data of iAs content in rice and hijiki seaweed, and the estimated intakes were compared with actual iAs intakes of the subjects as measured for a duplicate diet using liquid chromatography–inductively coupled plasma mass spectrometry. A highly significant correlation was found between the estimated and measured intakes (r = 0.65, p < 0.001); however, the slope of regression indicated a systematic error in the intake estimation. Possible sources of error are discussed herein. It was concluded that this approach is promising if minor improvements are made to the questionnaire.