土壤背景值研究工作,自七十年代以来,美国、苏联、英国、加拿大、日本等国,在这方面作了比较深入的研究。在我国,1977年由中国科学院土壤背景值协作组对北京、南京地区土壤背景值研究以来,已有不少城市和地区进行了这方面的工作。但是,对于背景值统计和背景图绘制的样本容量的确定,还没有一个被大家公认的原则;对于 Soil background value research work, since the seventies, the United States, the Soviet Union, Britain, Canada, Japan and other countries, made a more in-depth study in this regard. In our country, many cities and regions have done some work in this area since 1977 by the Soil Background Value Collaboration Group of Chinese Academy of Sciences on the soil background values ​​in Beijing and Nanjing. However, there is no universally accepted principle for the determination of the sample size of background statistics and background drawing; for