Toxicology 05 – POPs; dioxins and dioxin-like PCBs
Definition persistent organic pollutants;
Persistent organic pollutants (POPs); are organic chemical substances, they are
carbon-based. They particular (bezitten) combination of physical and chemical
properties (eigenschappen) that once released into the environment;
• Remain intact for long periods of time
• Become widely distributed throughout the environment as result of natural
processes like; soil, water and air.
• Accumulate (ophopen) in fatty tissue and are found at higher concentration at
higher levels in the food chain.
• Are toxic to both human and wild life
In stockhol convention 173 Countries has agreed to;
1. Eliminate (verwijderen) production and use of POPs
2. Restrict production and use of POPs
3. Reduce the unintentional (onopzettelijke) release of POPs
Dioxins and dioxin-like (DL) compounds;
Dioxins are POPs.
Dioxin-like compounds; cover a group of halogenated
compounds;
• Dioxins; PCDDs (polychlorinated dibenzodioxins) →
connected by oxygen groups
• Furans; PCDFs (polychlorinated dibenzofurans) →
connected by oxygen groups
• Dioxin-like; PCBs (dioxin-like polychlorinated biphenyls) → connected by
carbon-carbon bond. There are different groups at the
side of the rings (substitution pattern). There are 209
different congeners possible. Not all are stable
compounds, it depends on the position of the chloride
groups.
Is it toxic? Depends on the chloride position.
- Non-orhto; rings they can still twist around carbon-carbon bond. Flat
structure, flat molecules. → detoxified
- Mono-orhto; rings can still twist around carbon-carbon bond with energy
→detoxified/toxic
- di etc.-orhto; ring cannot twist around carbon-carbon bond. NO flat structure.
→ toxic
Planar (flat) configuration makes dioxin-like compounds capable to activate the Ah
receptor
Definition persistent organic pollutants;
Persistent organic pollutants (POPs); are organic chemical substances, they are
carbon-based. They particular (bezitten) combination of physical and chemical
properties (eigenschappen) that once released into the environment;
• Remain intact for long periods of time
• Become widely distributed throughout the environment as result of natural
processes like; soil, water and air.
• Accumulate (ophopen) in fatty tissue and are found at higher concentration at
higher levels in the food chain.
• Are toxic to both human and wild life
In stockhol convention 173 Countries has agreed to;
1. Eliminate (verwijderen) production and use of POPs
2. Restrict production and use of POPs
3. Reduce the unintentional (onopzettelijke) release of POPs
Dioxins and dioxin-like (DL) compounds;
Dioxins are POPs.
Dioxin-like compounds; cover a group of halogenated
compounds;
• Dioxins; PCDDs (polychlorinated dibenzodioxins) →
connected by oxygen groups
• Furans; PCDFs (polychlorinated dibenzofurans) →
connected by oxygen groups
• Dioxin-like; PCBs (dioxin-like polychlorinated biphenyls) → connected by
carbon-carbon bond. There are different groups at the
side of the rings (substitution pattern). There are 209
different congeners possible. Not all are stable
compounds, it depends on the position of the chloride
groups.
Is it toxic? Depends on the chloride position.
- Non-orhto; rings they can still twist around carbon-carbon bond. Flat
structure, flat molecules. → detoxified
- Mono-orhto; rings can still twist around carbon-carbon bond with energy
→detoxified/toxic
- di etc.-orhto; ring cannot twist around carbon-carbon bond. NO flat structure.
→ toxic
Planar (flat) configuration makes dioxin-like compounds capable to activate the Ah
receptor
