我国城市不同功能区地表灰尘重金属分布及来源

Heavy Metals and Their Sources in Outdoor Settled Dusts in Different Function Areas of Cities

为揭示城市不同功能区地表灰尘重金属的分布规律及污染来源,在文献调研的基础上,通过对多个省会城市主要功能区地表灰尘重金属数据的分析和比对,阐述了我国城市不同功能区地表灰尘中Cd、Cu、Pb和Zn的分布及累积差异,并探讨了不同功能区地表灰尘重金属的可能来源及影响因素.结果表明,工业区地表灰尘重金属含量最高,交通区地表灰尘重金属含量最低,商业区和居民文教区地表灰尘重金属含量处于中等水平.4种功能区之间地表灰尘重金属水平分异较大的元素是Zn和Pb,Cu和Cd在不同功能区地表灰尘中的含量差异较小.相对于城市土壤,工业区地表灰尘重金属累积最重,其它3个功能区地表灰尘重金属累积差异不明显,但相对而言,交通区地表灰尘重金属累积最轻.不同功能区地表灰尘累积程度差异最小的元素是Cd.

To study the distribution of heavy metals in outdoor settled dusts in different functional areas,based on the literature published,we described the difference in heavy metal accumulation in functional areas and their sources by comparing and analyzing the data of heavy metal concentrations in some capital cities.The results showed that industrial area had the highest heavy metal concentration,followed in descending order by residential area and commercial area,and finally,traffic area.The levels of Zn and Pb in the four functional areas showed higher spatial variability,while there was little difference in Cu and Cd levels.Compared to the heavy metal concentration in urban soils,industrial area appeared heavily accumulated and traffic area appeared lighter accumulated with heavy metals,while there was little difference among other three functional areas expect industrial area.The accumulation of Cd in the four functional areas showed the lowest spatial variability.