Influence of pesticides contamination on the emission of PCDD/PCDF to the land from open burning of corn straws

Open burning of crop residues has been identified as an important emission source of PCDD/PCDF to the environment. This paper presents the first known data on the emission of PCDD/PCDF to the land considering the influence of pesticides applied in crops planting. Emission factor for PCDD/PCDF to the land from open burning of corn straw with pesticides contamination ranged from 0.07 to 0.57 ng WHO2005-TEQ/kg straw burned with a mean value of 0.24 ng WHO2005-TEQ/kg straw burned and median value of 0.20 ng WHO2005-TEQ/kg straw burned, respectively. The concentration was 35 to 270 times higher than that without additional pesticide contaminated. Initial observation was that emission factor for PCDD/PCDF from open burning of crop residues was overestimated in the former UNEP Dioxin Toolkit. Pesticides contamination should be considered in some hotpots where special and over dosed pesticides has been sprayed especially in developing countries.

► Pesticides applied on the corn straws would influence the emission of PCDD/PCDF in the open burning process of the straws.
► Contaminated straw released 35 to 270 times higher PCDD/PCDF than that without.
► Pesticides contamination should be included in hotpots about PCDD/PCDF emission.