A pilot study on iodine in soils of Greater Kabul and Nangarhar provinces of Afghanistan.

A robust and rapid methodology for the determination of iodine by inductively coupled plasma mass spectrometry in environmental samples is presented. Data were initially obtained for the validation of the analytical measurements, using 17 commercially available soil reference materials. The methodology was then tested on soil and water samples collected in Afghanistan where iodine deficiency and its effects are reportedly prevalent. Sample collections were conducted in Greater Kabul; the iodine in agricultural soils was determined to be in the range of 1.6-4.2 mg/kg and that in water drawn for drinking and irrigation was found to range from 9.9 to 22.7 microg/L. Samples were also collected in a second region, Nangarhar province, which is located to the east of Kabul, where goitres in the local population had been reported. The iodine content in soils and water at this location was 0.5-1.9 mg/kg and 5.4-9.4 microg/L, respectively. The organic content of soils in Kabul was found to be in the range of 1.9-4.2%; in Nangarhar, organic content ranged from 1.7 to 4.5%. All of the Afghan soils were slightly alkaline at pH 7.6-8.2.