Field Survey of Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans (PCDD/Fs) in Sewage Biosolids Treated Ontario Agricultural Soils

Preface

The public has expressed concern that the concentrations of two organic contaminants, namely polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), will increase in agricultural soils which receive sewage biosolids, and pose significant risk to human and animal health. The intent of the field survey described herein was to address this concern. The field survey looked at the concentrations of PCDDs and PCDFs in a limited number sewage biosolids treated soils and selected sewage biosolids utilized on agricultural land, and compared the concentrations found in those media to Ontario concentration limits, and also to the findings reported in other studies.

This survey is the second of its type carried out in Ontario to monitor concentrations of parameters of concern in agricultural soils which receive sewage biosolids. The first field survey looked at soil pH, phosphorus and heavy metal levels. The report for that survey is entitled Analytical Results, Findings and Recommendations of the 1995 OMAFRA Sewage Biosolids Field Survey (OMAFRA, 1995).