Dioxins and dioxin-like compounds

Abstract

Dioxins are a group of unwanted contaminants almost exclusively produced from anthropogenic sources. These compounds are generally persistent in the environment, resistant towards metabolism, hydrophobic and lipophilic, and hence bioaccumulating in the fatty tissues of animals and humans. Traditionally, waste incineration and iron ore sintering were the largest sources of dioxins. Biomass burning, especially uncontrolled burning, is becoming increasingly more significant as a source, as regulatory interventions as well as technological advances lead to marked emission reductions in the industrial customary contributions. After an introduction overviewing chemical structures and properties, toxicity and health effects, and emission sources of dioxins and dioxin-like compounds, this chapter introduces some formation pathways of dioxins from biomass related thermal processes and discusses various influencing factors for formation and emission of dioxins. Different methods used for sampling and analysis of dioxins from different sources are then reviewed. Generally, determination of dioxins highly relies on high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/ HRMS). Several alternatives to the HRGC/HRMS-based methods are also introduced. Numerous techniques were developed and applied for remediation, reduction and prevention of dioxins emissions and these are surveyed and compared.