Health Physics Division, NIAB, Jhang Road, Faisalabad, Pakistan
Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad, Pakistan
Wheat is a staple food in Pakistan. Production of wheat is increased with extensive use of phosphate based fertilizers in agricultural fields. Activity mass concentration of primordial radionuclides due to use of phosphate fertilizers in soil enhances the external gamma dose and due to the consumption of wheat food grown on these soils also increases the internal dose. Different types of soil, including saline and normal soil in the districts of Lahore and Faisalabad in Punjab were selected for this study. The technique of gamma ray spectroscopy was used for the determination of s levels of radioactivity 226Ra, 232Th, 40K, and the nuclear fallout 137Cs in soil, wheat and wheat made products. Radioactivity in flour, chapatti, bread, nan and rusk was determined. Maximum activity was found in the chapatti sample of highly fertilized soil. Calculations were made for the determination of external absorbed dose in air from soil and internal absorbed dose in human body due to the consumption of wheat and wheat products. The average value of wheat consumption of 140 kg was used in the estimation of ingestion dose. The value of the ingestion dose due to highly fertilized soil was 206.1 μSv/Yr, while the total ingestion dose due to unfertilized farm’s food was 146.3 μSv/Yr. Risk assessment to man due to ingestion of wheat was also calculated. The cancer risk assessment due to ingestion of wheat food grown on highly fertilized soils comes as additional sufferings of 14 persons in cancer per million.