the study of toxic metals contamination (pb, cd, as, al) on medicinal plants cultivated near arak industrial manufactures

background: medicinal plants use is growing in iran and controlling their quality in terms of contamination with toxic metals is critical. city of arak, due to its large industrial plants, is one of the most polluted cities of iran these pollutants can be transferred to the farms. methods: in this study, concentrations of metals such as aluminum, arsenic, lead and cadmium are measured by atomic absorption spectrometry in five medicinal plants (thymus vulgaris, melissa officinalis, achillea millefolium, rosmarinus officinalis, salvia officinalis) cultivated around the city of arak. results: according to the test results, the aluminum concentration levels were between 319.06 and 561.08 μg.g- and the amount of arsenic in the samples ranged from 0.246 to 0.293 μg.g- minimum and maximum lead levels were 0.254 and 3.022 μg.g-, respectively. with regard to cadmium, the lowest and highest values obtained were 0.031 μg.g- and 0.144 μg.g-, respectively.conclusion: high level of aluminum concentrations can be associated with aluminum factory located 25km far from the cultivation area.