تأثیر امواج میکروویو تابشی از تلفن‌های همراه بر آزادشدن جیوه از ترمیم‌ آمالگام‌های دندانی

Background and Aim: Mercury or Hydrargyrum (Hg) is the most non-radioactive toxic element known. Dental amalgam is made up of 50% mercury.. Electromagnetic fields may increase the emission of mercury from dental amalgam fillings. It was thus aimed to study the effects of electromagnetic fields of mobile use on the level of mercury released from dental amalgam restorations. Materials and Methods: In this case control clinical trial, study urinary mercury concentrations of 14 healthy University students were measured both before amalgam restoration (zero level), and on days 1, 2, 3 and 4 after restoration. All the subjects had the same diet. Dental treatment was given for all 14 students regarding 2 molars on one side (i.e the side of cellphone exposure), one class I and one class II restorations with identical volume and surface area of the amalgam fillings). All the students had not used mobile phones before the study and did not have any previous amalgam restorations. The test group consisting of seven female students were exposed to microwave radiation emitted from a Nokia 3310 mobile phone (SAR=0.96 W kg-1) that was in talk mode for 15 minutes on days 1-4 after restoration. Seven other female students who had the same condition matched the first group except exposure to microwave radiation were taken as the controls. Urine samples were collected 1 hour after each mobile use (real exposure) and one hour without mobile use (false exposure). After freezing, the samples were sent to the Toxicology Laboratory of Imam Reza Hospital (Mashhad, Iran) and mercury levels in samples were measured by cold vapor atomic absorption spectrometry. The obtained data was analysed by means of a statistical software (SPSS version 13.0) and statistical tests of ANOVA and Student-t at the significant level of P≤0.05. Results: Our study demonstrated an elevation of mercury level released from dental amalgam fillings after exposure to microwave radiation emitted form mobile phones. Mean (±SE) concentration levels of mercury in urine samples in the case group were 2.43±0.25, 2.71±0.27, 3.79±0.25, 4.8± 0.27 and 4.5±0.32 g/L one day before the amalgam restoration and on days 1, 2, 3 and 4, respectively. But mean Hg concentration levels in controls were 2.07±0.22, 2.34±0.30, 2.51±0.25, 2.66± 0.24 and 2.76±0.32 g/L on the respective days. Conclusion: Results obtained from this study show a significant increase of the mercury release in urine after mobile phone use. This finding confirms early reports that showed an increased release of mercury from dental amalgam restorations in undersea welding.