Chlorine, liver content

Administration of a PCB mixture (mean chlorine content 54%) twice a week for 6 weeks via a stomach tube to rats at relatively low dose levels led to histopathologic changes in the liver, increases in cholesterol and triglyceride levels, and serum enzyme increases. At the 2mg/kg dose, centrilobular hepatic necrosis and elevated cholesterol levels were observed. Increases in bilirubin and triglyceride levels occurred only at 50mg/kg and increases in SCOT (AST) and SGPT (ALT) only at doses above 50mg/kg. ... 

The highest concentrations of studied chlorophenols (2,4-, 2,4,6- and 2,3,4,6-) have been found in kidney, liver and spleen and the lowest concentrations in muscle and brain, either after parenteral administration of these chlorophenols themselves or as metabolites of other organochlorine compounds. Over 80% of the dose is excreted in urine and 5-20% in faeces. Metabolism varies somewhat depending on chlorine content the low-chlorine substances tend to be excreted as glucuronide and sulfate conjugates with higher chlorine substitution, excretion of the unchanged substance tends to increase. Formation of chlorinated 1,4-quinones is a minor pathway except for 2,3,5,6-tetrachlorophenol (WHO, 1989). 

In their acute toxic effects on the skin and liver PCBs resemble the chlorinated naphthalenes. Acute yellow atrophy is produced in the liver and enhanced in the presence of CHClj (synergism). Toxicity increases with increase in chlorine content of the PCB, and with oxide formation. Skin lesions (chloracne) consist of small pimples and dark pigmentation of exposed areas. Later comedones and pustules develop. With systemic intoxication, progressive symptoms are nausea, vomiting, weight loss, jaundice, edema, abdominal pain, and, where liver damage is severe, it is followed by coma and death (Sax, 3d ed., p. 551). 

The higher the chlorine content of the diphenyl compound, the more toxic it is liable to be. Oxides of chlorinated diphenyls are more toxic than the unoxidized materials. In persons who have suffered systemic intoxication, the usual signs and symptoms are nausea, vomiting, loss of weight, jaundice, edema, and abdominal pain. If the liver damage has been severe the patient may pass into a coma and die. 

Liver portions (tip and mid-ventral blubber samples) of seals from the pack-ice of Queen Maud Land were analyzed for their contents in trace elements (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn) and chlorinated hydrocarbon residues (DDE, DDT, dieldrin, PCBs, TDE) (72). Samples were stored at -20°C pending analysis. The metals were quantified by AAS after digestion, as appropriate. The organic compounds were first extracted with hexane, cleaned-up and then assayed by gas-liquid chromatography with EC detection. Concentrations in the high pg g level... 

It was discovered in the 1970s that chlorination of raw water high in organic content and/or infused with seawater results not only in the disinfection of water, but also in the formation of disinfection by-products (DBPs). These include trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles (HANs) J55-56 These chemicals are individually toxic at high concentrations and can cause cancer, liver disease, kidney disease, birth defects, and reproductive failuresJ57 59 ... 

Biotransformation of certain chlorinated hydrocarbon insecticides results in their conversion to metabolites which are less polar than the parent chemical. Heptachlor and aldrin are converted to the more lipophilic compounds heptachlor epoxide and dieldrin, respectively, whereas DDT is converted to DDE. The primary residue of DDT, which persists to the present day in animals and humans after exposure over a decade ago, is DDE. Following biotransformation, these compounds distribute to tissues which are higher in neutral lipid content than are the major organs of metabolism and excretion, the liver and kidney. These lipid-rich tissues are relatively, deficient in the so-called mixed-function oxidase (MFO) enzyme systems necessary for biotransformation of the halogenated hydrocarbons to more polar and thus more easily excreted compounds. As a result, these lipophilic chemicals remain unchanged in adipose tissue with only limited amounts returning to the circulation for possible metabolism and excretion. Paradoxically, aldrin and heptachlor metabolism results in an increased rather than reduced body load. This is opposite of the pattern seen for most other pesticide classes. 

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