بررسي غلظت عناصر آهن، سرب و كادميوم نزولات جوي مناطق پرترافيك شهر همدان

Study on Heavy Metals Content (Fe, Pb and Cd) in Atmospheric Precipitation Collected from the High Traffic Intensity Regions of City of Hamedan

زﻣﯿﻨﻪ و ﻫﺪف: ﺑﺪون ﺷﮏ ﯾﮑﯽ از ﻣﻬﻢﺗﺮﯾﻦ ﻣﺴﺎﯾﻞ ﻣﺤﯿﻂزﯾﺴﺘﯽ ﺗﻬﺪﯾﺪﮐﻨﻨﺪه ﺳﻼﻣﺖ اﻓﺮاد در ﮐﻼن ﺷﻬﺮﻫﺎي اﯾﺮان، ﻣﺸﮑﻞ آﻟﻮدﮔﯽ ﻫﻮا اﺳﺖ. ﻧﺰوﻻت ﺟﻮي ﻣﺆﺛﺮﺗﺮﯾﻦ راه زداﯾﺶ آﻻﯾﻨﺪهﻫﺎ از اﺗﻤﺴﻔﺮ اﺳﺖ و ﻓﻠﺰات ﺳﻨﮕﯿﻦ ﻣﻮﺟﻮد در آن ﻣﯽﺗﻮاﻧﺪ ﺑﻪﺧﻮﺑﯽ ﻧﻤﺎﯾﺎن ﮔﺮ وﺿﻌﯿﺖ آﻟﻮدﮔﯽ ﻣﺤﯿﻄﯽ در ﻧﻮاﺣﯽ ﻣﺨﺘﻠﻒ ﺷﻬﺮي ﺑﺎﺷﺪ. ﻟﺬا، اﯾﻦ ﭘﮋوﻫﺶ ﺑﺎ ﻫﺪف ﺑﺮرﺳﯽ ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ آﻫﻦ، ﺳﺮب و ﮐﺎدﻣﯿﻮم در ﻧﺰوﻻت ﺟﻮي ﻣﻨﺎﻃﻖ ﭘﺮﺗﺮاﻓﯿﮏ ﺷﻬﺮ ﻫﻤﺪان در ﻓﺼﻞ زﻣﺴﺘﺎن ﺳﺎل 1392 اﻧﺠﺎم ﯾﺎﻓﺖ. روش ﺑﺮرﺳﯽ: 24 ﻧﻤﻮﻧﻪ ﻧﺰوﻻت ﺟﻮي از 8 اﯾﺴﺘﮕﺎه ﭘﺮﺗﺮدد ﻣﺴﺘﻘﺮ در ﺳﻄﺢ ﺷﻬﺮ ﻫﻤﺪان ﺑﺮداﺷﺖ و ﺑﻪ ﺑﻄﺮيﻫﺎي ﭘﻠﯽاﺗﯿﻠﻨﯽ ﻣﻨﺘﻘﻞ ﺷﺪ. ﺑﻪ ﻫﺮ ﺑﻄﺮي ﭼﻨﺪ ﻗﻄﺮه اﺳﯿﺪ ﻧﯿﺘﺮﯾﮏ ﺑﻪﻣﻨﻈﻮر رﺳﺎﻧﺪن pH ﻧﻤﻮﻧﻪﻫﺎ ﺑﻪ 2 اﻓﺰوده ﺷﺪ. ﺑﻌﺪ از ﻃﯽ ﻣﺮاﺣﻞ آﻣﺎدهﺳﺎزي آزﻣﺎﯾﺸﮕﺎﻫﯽ، ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ در ﻧﻤﻮﻧﻪﻫﺎ ﺑﻪ روش ﻃﯿﻒ ﺳﻨﺠﯽ ﻧﻮري ﭘﻼﺳﻤﺎي ﺟﻔﺖ ﺷﺪه اﻟﻘﺎﯾﯽ )ICP-OES( ﺧﻮاﻧﺪه ﺷﺪ. ﭘﺮدازش آﻣﺎري دادهﻫﺎ ﺗﻮﺳﻂ ﻧﺮماﻓﺰار SPSS اﻧﺠﺎم ﯾﺎﻓﺖ. ﯾﺎﻓﺘﻪﻫﺎ: ﻣﯿﺎﻧﮕﯿﻦ ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ آﻫﻦ، ﺳﺮب و ﮐﺎدﻣﯿﻮم در ﻧﻤﻮﻧﻪﻫﺎ )ﻣﯿﮑﺮوﮔﺮم در ﻟﯿﺘﺮ( ﺑﻪﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 10/25±8/94 ،69/50±142/62 و 17/61±0/29 و در ﻣﻮرد ﻋﻨﺼﺮ ﮐﺎدﻣﯿﻮم ﺑﯿﺶﺗﺮ از رﻫﻨﻤﻮد ﺳﺎزﻣﺎن ﺑﻬﺪاﺷﺖ ﺟﻬﺎﻧﯽ ﺑﺮاي ﺗﺨﻠﯿﻪ ﺑﻪ ﻣﻨﺎﺑﻊ آب ﺳﻄﺤﯽ ﺑﻮد. ﻧﺘﯿﺠﻪﮔﯿﺮي: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﯿﺎﻧﮕﯿﻦ ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ ﺳﺮب و ﺑﻪ وﯾﮋه ﮐﺎدﻣﯿﻮم در ﻧﺰوﻻت ﺟﻮي و ﺑﻪ ﺗﺒﻊ آن در رواﻧﺎب ﺣﺎﺻﻞ ﺑﻪ واﺳﻄﻪ ﺣﺠﻢ ﺑﺎﻻي ﺗﺮاﻓﯿﮏ ﺷﻬﺮي و آﻻﯾﻨﺪهﻫﺎي ﻣﻨﺘﺸﺮﺷﺪه ﻧﺎﺷﯽ از آن ﺑﺎﻻ ﺑﻮده اﺳﺖ. از اﯾﻦ رو، ﺑﺮاي ﺟﻠﻮﮔﯿﺮي از ﺗﻬﺪﯾﺪ ﻣﻨﺎﺑﻊ ﭘﺬﯾﺮﻧﺪه آب ﺳﻄﺤﯽ و زﯾﺮزﻣﯿﻨﯽ و ﺣﻔﻆ ﺳﻼﻣﺖ ﻣﺼﺮفﮐﻨﻨﺪﮔﺎن، اﻧﺪﯾﺸﯿﺪن ﺗﻤﻬﯿﺪاﺗﯽ ﺑﺮاي ﺟﻤﻊآوري و ﺗﺼﻔﯿﻪ رواﻧﺎب ﻧﺎﺷﯽ از ﻧﺰوﻻت ﺟﻮي ﺗﻮﺻﯿﻪ ﻣﯽ ﺷﻮد.

Background and Objective: Air pollution is one of the most important environmental problems which can lead to the human health effects especially in the metropolitans. Atmospheric precipitation including rain and snow are the most effective way for removing pollutant from the atmosphere and its heavy metals can describe the variability of the environmental pollution in different urban areas. Therefore, this study was conducted to assess the metal (Fe, Pb and Cd) concentrations in the atmospheric precipitation collected from high traffic intensity areas of city of Hamedan in 2014. Method: A total of 24 snow samples were collected from 8 selected stations located in different regions of city of Hamedan with high traffic intensity. The samples were stored in polyethylene bottles and were acidified at a pH lower than 2 by adding concentrated HNO3 in order to avoid metal adsorption onto the inner bottle walls. Element (Fe, Pb and Cd) concentrations were determined using ICP-OES. All statistical analyses were done by SPSS software. Findings: The results showed that the mean concentrations (µg/L) of Fe, Pb and Cd in snow samples were 69.5 ± 143, 10.2 ± 8.94 and 17.6 ± 0.290, respectively. Also, the mean concentrations of Cd were significantly higher than maximum permissible limits established by WHO. Conclusion: The results indicate that rainfall collected from the high traffic intensity regions of city of Hamedan is polluted with Cd due to the high traffic volumes and their emitted pollutions, therefore, for maintaining of surface and groundwater resources and also public health consider the suitable strategies is recommended.