Geographical variations of cadmium and arsenic concentrations and arsenic speciation in Chinese rice

• Published in: Environmental pollution (1987) Vol. 238; pp. 482 - 490
• Main Authors: Chen, Hongping, Tang, Zhu, Wang, Peng, Zhao, Fang-Jie
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2018
• Subjects: acceptable daily intake; Arsenic; Arsenic - analysis; Arsenic speciation; body weight; cacodylic acid; Cadmium; Cadmium - analysis; China; detection limit; Dietary intake; Environmental Monitoring; Environmental Pollutants - analysis; Environmental Pollution - statistics & numerical data; exposure pathways; Food and Agriculture Organization; Food Contamination - analysis; Food Contamination - statistics & numerical data; food safety; Geography; Humans; industrialization; markets; Oryza - chemistry; Rice; risk; soil pollution; toxic substances; World Health Organization; China; Arsenic speciation; Cadmium; Dietary intake; Arsenic; Rice
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2018.03.048

Rapid industrialization in China in recent decades has resulted in soil contamination in some areas, raising the concern about food safety. Consumption of rice represents a major exposure route for the toxic elements cadmium (Cd) and arsenic (As). We collected 160 polished rice from local markets in 20 provinces in China and determined total Cd and As concentrations and As speciation. Total Cd concentration ranged from below the detection limit to 0.77 mg kg−1, with 10% of the samples exceeding the Chinese limit (0.2 mg kg−1). Rice Cd concentration showed a distinct geographical pattern, increasing from low levels in the north to high levels in the south of China. Median daily Cd intake from rice varied from 0.01 μg kg−1 body weight in the north to 0.61 μg kg−1 body weight in the south of China, representing between 1% and 73% of the tolerable daily intake (TDI) recommended by FAO/WHO. The highest median Cd intake from rice was in Hunan province with 2 times TDI. Total As concentration ranged from 0.011 to 0.186 mg kg−1, with inorganic As (iAs) and dimethylarsinic acid (DMAs) on average accounting for 69% and 31%, respectively. All samples were below the Chinese limit for iAs in rice (0.2 mg kg−1). There was no clear geographical pattern in rice total As concentration, but rice produced in northeastern China contained higher percentages of DMAs and lower percentages of iAs. This study highlights a high risk of Cd exposure from rice consumption for the population of southern China and suggested strategies for reducing Cd accumulation in rice crop. [Display omitted] •160 polished rice samples were collected from local markets in 20 provinces in China.•Rice Cd concentration showed an increasing trend from north to south of China.•Dietary Cd intake from rice was high in the population in southern China.•Rice total As showed no clear geographical pattern, but rice methylated As% was higher in northeast China. High Cd concentrations are found in rice samples from southern China, posing a high risk of Cd exposure from rice consumption for population in the region.