تعيين ميزان سرب در اجزاج متشكله نان منطقه 5 شيراز در سال 1379

lead detection in bread ingredients of the fifth district of Shiraz city in 2000

Introduction: Lead is one of the most toxic heavy metals in acute and chronic human toxicity. Due to immense side effects of long- term exposure of people to contamination, lead contamination is one of the serious problems in different communities especially in developing countries. In our pervious study, we evaluated the amount of lead in the bread used in six districts of Shiraz city. The results revealed high lead contamination in the bread used in the fifth district. In this study we are going to find the source of contamination in the view of bread ingredients. Methods: Samples of salt, flour and water were collected from 83 backeries in the fifth district of Shiraz city. The salt samples were dissolved in distilled water and the flour samples were dissolved in nitric and perchloric acid. Distilled water was used as blank for salt and water samples whereas nitric and perchloric acid solution was used as blank for flour samples. Lead content of all the samples was detected by atomic absorption with natrium lamp at 283.3 nm. Results: Lead level in salt and water applied by all 83 bakeries was below the standard level (0.05ppm). But this level in flour samples of 9 bakeries was higher than standard level. Discussion: These findings showed that in order to find out the correct reason, there is a need to monitor the internal and external conditions of the bakeries.