A comparative assessment of arsenic distribution in rice produced in Pakistan and other geographical regions

Variability in total arsenic in rice for human consumption was evaluated using 250 commercial rice samples obtained from cereal markets and retail stores in the primary rice growing area of Punjab, Pakistan. Twelve of the 250 rice samples were found to exceed the recently set advisory limit of 0.2 mg/kg of arsenic in rice, with a maximum detected concentration of 0.356 mg/kg. This study demonstrates the need to quantify the relationship between arsenic in water, soil and paddy crop. It is thus hypothesized that the origin of arsenic in rice grains is from arsenic contaminated ground water used for paddy field irrigation. The data set produced from 250 rice samples is compared with the literature values to derive a global arsenic distribution of arsenic in rice. The order of ranking with respect to distribution and intensity of arsenic in rice grain is revealed as China>Bangladesh>USA>EU>Spain>Taiwan>Thaiand>India>Sweden>Pakistan.