Siahkal area (15 km southwest of Lahijan), is located in SE of Rasht 1:100000 geological map. According to the geochemical samples, collected in the coverage of this map, concentration of some elements like Mn, Co, Ni and Pb, have been detected to be higher than normal values, creating a series of symptoms and environmental pollution. For example, they can result in some malformations in plants decreasing the root and stem diameter, shortening, or a change in the color of leaf and stem of plants and trees. Environmental pollution may give rise to diseases in human beings such as sensitivity of respiratory problems, and even cancer. According to the Siahkal 1:50000 map, in some regions such as : Paeen gavaber, Jeer gavaber, up and down Zarkooti, some elements like Mn, Co, Ni and Pb, show high concentrations than the standard values.