Үнэ авах Levels sources and spatial distribution of heavy metals The study area is located in the middle of Tangshan city the northern part of Jidong plain North China (118°02′46″ °30′28″E 39°29′21″–39°45′20″N) covers urban center and parts of Kaiping Guye and Fengnan districts with a total area of approximately 500 ...