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2,3,7,8-Tetrachlorodibenzofuran (TCDF) is a polychlorinated dibenzofuran with a chemical formula of C 12 H 4 Cl 4 O. TCDF is part of the chlorinated benzofuran (CDF) family that contains between 1 and 8 chlorine atoms attached to the parent dibenzofuran ring system. The CDF family includes 135 compounds, of which only a few have been studied.
Dibenzofuran is a heterocyclic organic compound with the chemical structure shown at right. It is an aromatic compound that has two benzene rings fused to a central furan ring. All the numbered carbon atoms have a hydrogen atom bonded to each of them.
TCDD also affects the balance of several hormones. In some species, but not in all, severe liver toxicity is seen. [8] [36] Taking into account the low doses of dioxins in the present human population, only two types of toxic effects have been considered to cause a relevant risk to humans: developmental effects and cancer. [3] [8]
Polychlorinated dibenzofurans with chlorines at least in positions 2,3,7 and 8 are much more toxic than the parent compound dibenzofuran, with properties and chemical structures similar to polychlorinated dibenzodioxins. These groups together are often inaccurately called dioxins.
Today, concentrations of dioxins are found in all humans, with higher levels commonly found in persons living in more industrialized countries. The most toxic dioxin, 2,3,7,8-tetrachlorodibenzodioxin (TCDD), became well known as a contaminant of Agent Orange, a herbicide used in the Malayan Emergency and the Vietnam War. [11]
The toxicity of the individual congeners may vary by orders of magnitude. With the TEFs, the toxicity of a mixture of dioxins and dioxin-like compounds can be expressed in a single number – the toxic equivalency (TEQ). It is a single figure resulting from the product of the concentration and individual TEF values of each congener. [1]
Chronic solvent-induced encephalopathy (CSE) is a condition induced by long-term exposure to organic solvents, often—but not always—in the workplace, that lead to a wide variety of persisting sensorimotor polyneuropathies and neurobehavioral deficits even after solvent exposure has been removed.
The array of symptoms typically seen in carbamate poisoning include both muscarinic and nicotinic symptoms. [1] Muscarinic receptor effects include: Bradycardia, or reduced heart rate; Bronchospasm, or tightening of the bronchioles of the lungs; Miosis, or constriction of the pupils; Vomiting and abdominal pain; Diarrhea; Excessive sweating and ...