Compare the amount of lead and cadmium accumulation of Tehran pine leaves in warm and cold season in Tehran metropolitan (Azadi district)

This study aimed to evaluate the absorption rate of lead and cadmium in form of pine trees in Tehran. For this purpose, the contaminated sites (Azadi, Tarasht, Airports, Mimamat) and control sites (Cheetgar) were sampled during both summer and winter (July and January) from their leaves, and the concentration of lead and cadmium were measured in Tehran pine trees with using graphite furnace GBC savant AA model. Samples were performed in randomized statistical sampling with complete block design during three replications and data were analyzed by using variance and Duncan at 95% with using SPSS software. The results showed that the maximum amount of lead absorption was 1136.60 nanograms per gram in heating season and the least amount of lead absorbtion was in heating season, which related to Cheetgar station (control) and also, 155.13 nanograms per gram related to Tarasht station. The maximum amount of lead absorption was related to cold season in Tarasht station (603 ng per gram) and the least amount of lead absorbtion was related to heating season with 101.7ng per g in Cheetgar station (control). Also, the maximum amount of cadmium absorption was related to warm season with 59.10 nanograms per gram in Tarasht station, the minimum amount of cadmium absorption was related to Cheetgar station control (26/24 ng per g) and also, the maximum amount of cadmium absorption was related to cold season (70.20 nanograms per gram) and the minimum amount of cadmium absorption was related to Cheetgar station (control) (5.4 ng per g). Pollution rate reaches its maximum in winter in Tehran and deciduous trees are bare. Therefore, goal of this study investigate the association and attract in winter, which has more pollution than summer with inversion phenomenon. Consequently, Pine species can be used as a bioindicator for heavy metals like lead and cadmium.