ارزيابي ريسك اكولوژيك آلاينده هاي سرب و كادميوم در گرد و‌غبار حياط مدارس مناطق منتخب شهر تهران

Evaluating the Ecological Risk of Lead and Cadmium Contaminants in the Courtyard Dust of Schools in Selected Regions of Tehran

زﻣﯿﻨﻪ و ﻫﺪف: ﭘﺪﯾﺪه آﻟﻮدﮔﯽ ﻫﻮا در ﻣﻨﺎﻃﻖ ﺷﻬﺮي و ﺻﻨﻌﺘﯽ از ﻣﻬﻢ ﺗﺮﯾﻦ ﻣﺸﮑﻼت زﯾﺴﺖ ﻣﺤﯿﻄﯽ اﺳﺖ ﮐﻪ ﺳﻼﻣﺖ اﻧﺴﺎن ﻫﺎ را ﺗﻬﺪﯾﺪ ﻣﯽ ﻧﻤﺎﯾﺪ. در ﻣﯿﺎن اﯾﻦ آﻻﯾﻨﺪه ﻫﺎ، ﻓﻠﺰات ﺳﻨﮕﯿﻦ ﻣﻮﺟﻮد در ﮔﺮد و ﻏﺒﺎر ﻫﻮا ﻗﺎدرﻧﺪ ﻣﺴﺘﻘﯿﻤﺎً از ﻃﺮﯾﻖ ﺑﻠﻊ و ﺗﻨﻔﺲ وارد ﺑﺪن اﻧﺴﺎن ﺷﻮﻧﺪ و ﯾﺎ از ﻃﺮﯾﻖ رﯾﺰش ﻫﺎي ﺟﻮي ﺑﻪ ﺳﻄﺢ زﻣﯿﻦ ﺑﺮﺳﻨﺪ و ﭘﺲ از آﻟﻮدﮔﯽ ﻣﻨﺎﺑﻊ آب و ﺧﺎك و ورود ﺑﻪ ﺳﺎﺧﺘﺎر ﮔﯿﺎﻫﺎن از ﻃﺮﯾﻖ آب و ﻏﺬا وارد ﺑﺪن ﺷﻮﻧﺪ. اﯾﻦ ﭘﮋوﻫﺶ ﺑﺎ ﻫﺪف ﺗﻌﯿﯿﻦ ﻣﯿﺰان ﻏﻠﻈﺖ آﻻﯾﻨﺪه ﻫﺎي ﺳﺮب و ﮐﺎدﻣﯿﻮم در ﮔﺮد و ﻏﺒﺎر ﺣﯿﺎط ﻣﺪارس ﻣﻨﺎﻃﻖ ﻣﻨﺘﺨﺐ ﺷﻬﺮ ﺗﻬﺮان ﺻﻮرت ﮔﺮﻓﺖ. روش ﺑﺮرﺳﯽ: در ﻣﺠﻤﻮع 24 ﻧﻤﻮﻧﻪ ﮔﺮد و ﻏﺒﺎر رﯾﺰﺷﯽ از ﺣﯿﺎط 8 ﻣﺪرﺳﻪ ﻣﻨﺘﺨﺐ واﻗﻊ در ﻣﻨﺎﻃﻖ22،21،12،11،9،5،1 ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﭘﺮاﮐﻨﺪﮔﯽ اﯾﻦ ﻣﻨﺎﻃﻖ در ﺳﻄﺢ ﺷﻬﺮ ﺗﻬﺮان در آﺑﺎن ﻣﺎه ﺳﺎل1395 ﺟﻤﻊ آوري ﮔﺮدﯾﺪ. ﺳﭙﺲ ﻣﻘﺎدﯾﺮ ﻓﻠﺰات ﺳﻨﮕﯿﻦ ﺳﺮب و ﮐﺎدﻣﯿﻮم ﺗﻮﺳﻂ دﺳﺘﮕﺎه ﺟﺬب اﺗﻤﯽ ﺷﻌﻠﻪ اﻧﺪازه ﮔﯿﺮي ﺷﺪ ﯾﺎﻓﺘﻪ ﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺑﯿﻦ ﻣﯿﺰان ﻏﻠﻈﺖ ﻓﻠﺰات در اﯾﺴﺘﮕﺎه ﻫﺎي ﻣﺨﺘﻠﻒ اﺧﺘﻼف ﻣﻌﻨﯽ داري وﺟﻮد دارد . ﻫﻢ ﭼﻨﯿﻦ ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺗﻤﺎﻣﯽ اﯾﺴﺘﮕﺎه ﻫﺎي ﻣﻮرد ﺑﺮرﺳﯽ از ﻟﺤﺎظ ﺷﺎﺧﺺ ﻣﯿﺰان ﺧﻄﺮ اﮐﻮﻟﻮژﯾﮏ ﺑﺮاي ﻣﻮﺟﻮدات زﻧﺪه در ﺳﻄﺢ ﺧﯿﻠﯽ ﺑﺎﻻ ﻫﺴﺘﻨﺪ ﺑﺤﺚ و ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ﺑﻪ ﻃﻮر ﮐﻠﯽ ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﺪ در ﻣﻨﺎﻃﻘﯽ ﺑﺎ ﺑﺎر ﺗﺮاﻓﯿﮑﯽ ﺑﺎﻻ و ﺗﺮدد زﯾﺎد ﺧﻮدرو در ﺷﻬﺮ ﺗﻬﺮان ، ﻣﯿﺰان آﻻﯾﻨﺪﮔﯽ و ﺧﻄﺮ اﮐﻮﻟﻮژﯾﮏ ﺑﺎﻻﺗﺮي ﻧﺴﺒﺖ ﺑﻪ ﺳﺎﯾﺮ ﻣﻨﺎﻃﻖ وﺟﻮد دارد.

Abstract Background and Objective: The phenomenon of air pollution in urban and industrial areas is one of the most important environmental problems that threaten human health. Among these pollutants, heavy metals contained in air dust can enter the human body directly through ingestion and breathing, or through ground falls to the surface of the earth, and after contamination of water resources and entering the structure of plants through Water and food enter the body. This study aimed to determine the concentration of lead and cadmium contaminants in the dust of the yard of selected schools in Tehran. Method: A total of 24 dust loss samples were collected from the courtyard of eight selected schools, due to the dispersion of these areas in Tehran during the fall. Then, the values of heavy metals of lead and cadmium were measured by a flame atomic absorption. Findings: The results showed that there is a significant difference between the concentrations of metals in different stations; also, the results showed that all stations studied were very high in terms of ecological risk index for living organisms. Discossion and Conclusion: In general, the results show that in areas with high traffic load and high traffic in Tehran, the highest pollution and high ecological risk were not available in other regions.