Epidemiological Assessment of Per Capita Absorption of Heavy Metals in Four Native Species of Rice, Yasuj, Iran- 2016 Download PDF

Aim: Rice with scientific name of oryza sativa is one of the most important cereals and food items in the world that is the world's second most important cereal after wheat . It has been estimated that in 2010, about 603 million tons of rice were produced around the world, that most of which (about 583 million tons) was cultivated in Asia .Most studies have mentioned the most common cases of rice contamination with heavy metals to of infection with elements arsenic, copper, cadmium, mercury and lead. Although several studies have been conducted and reported in other areas of the country on native species of each region, but no report has been found about the native species of Kohgiluye and Boyer-Ahmed province, therefore researchers have designed an independent study on the measurement of heavy metals pollutants in local varieties of consumed rice in order to fill existing information vacuum. Material and Method: In order to run tests, samples of rice were prepared from two species as 5g, and then they were burned in a temperature of 450°C for 4 to 5 hours and after adding 0.5cc concentrated nitric acid, the samples were dried. After this time, Then a solution of 7: 1000 nitric acid was prepared. Samples were entered into atomic absorption for measurement of heavy metals. VARIAN atomic absorption spectrophotometer was used with AA240FS model which had been made in America with flame system accuracy of ppm.In order to estimate the average weekly absorption of studied consumed rice, element daily intake (EDI) using the following equation and the results were used to calculate weekly and monthly per capita consumption. Weekly absorption of the heavy metals including cadmium, lead and arsenic was calculated by multiplying the amount of these metals in daily and weekly rice consumption amount. The calculated mean values were compared PTWI(Provisional Tolerable weekly intake : PTWI) and EDI index was evaluated.PTWI is the reference value which has been determined by the Jib committee of experts of the UN FAO and and the WHO on food additives (JECFA). Results: The concentration of cadmium, lead and chromium lower than the national and international standards but this did not conform to results and the reason may be how to plant and water pollution and soil of rice fields are the other factors. The average concentration of 290 micrograms for cadmium accumulated during a week was 290µg/kg for Champa, 156.4 µg/kg for cadmium species, 102.8 for Shamim, and for cadmium it was 80.4 µg/kg for rice species of Gerdeh. The average cumulative concentration of lead per week was obtained 33.2 µg/kg for Champa, 27.74 µg/kg for Shamim, for lead 13.02 µg/kg for Fajr, and 25.83 µg/kg for Gerdeh species. This is due to the cumulative effects of heavy metals and adverse effects on the human population. As well as a significant threat to food security in particular. Discussion: The comparison of the level of exposure to the estimated densities of heavy metals in metals in different species PTWI levels indicates that the level of exposure for all of the metals mentioned is lower than the standard level. Though it indicates an appropriate situation about the cases investigated ,it is necessary to do a constant and exact examination of such foods. It shows the necessity of making a proper program to recognize the possible sources of contamination and to make the contaminations less dense in the local kinds of rice.