The background concentrations of ambient air pollutants were used as evaluation stan-dards. 采用大气污染物浓度的背景值为评价标准。
In the Campania region, baseline and background values are often coincident, where the samples represent catchment basins away from urban or industrial areas. 在坎帕尼亚地区,样品代表的是远离市区或者工业区的汇水盆地,所以基线值和背景值经常是吻合的。