DDTs was the primary compound in soil samples,accounting for 98.9% of the pesticides POPs. The source of DDTs was garden soils in city parks.

• 其中滴滴涕占总有机氯农药类POPs物质的98.；9%25；是北京地区土壤中残留有机氯农药类POPs物质的主要成分；城市公园、园林土壤是城市滴滴涕的主要污染源