Cadmium Pollution in the Soil-rice Ecosystem of Bangladesh: A review

The people of Bangladesh are in deliberate health risk threat due to the entrance of excessive amounts of Cd as a result of the unsafe content of the metal in both agricultural soil and rice grain. This review is designed to update the available information regarding the presence of Cd in Bangladesh’s soil-rice ecosystem. There is inadequate research so far about Cd in the agricultural system of Bangladesh. None of the studies found suitable to represent the presence of Cd in the soil-rice ecosystem in Bangladesh. This is because most of the investigations involve a particular region of the country with a limited number of samples. A review of the available literature shows that agricultural soils of Bangladesh contain Cd within the range of 0.83–5.23 mg/kg which is higher than the limit value (1 mg/kg). Triple superphosphate (TSP) fertilizer is the major source of Cd in paddy soils. On the other hand, studies identified higher Cd content in the rice grain above the safe limit (0.2 mg/kg). Consumption of rice is the major route to transfer Cd from soil to Bangladeshi citizens. Therefore, the practice of effective measures to minimize Cd content in rice grain is required to reduce the dietary intake of Cd. The maximum allowable concentration (MAC) for Cd in rice may be set to 0.10 mg/kg for Bangladesh for reliable health risk assessment. There should be an national reference MAC value set by Government of Bangladesh (GoB) which also need to be updated in every five to ten years.