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The evaluation of toxicokinetics of green liquor applies constituent/ion based approach. Therefore, toxicokinetics of these different ions is discussed separately in the chapters dealing with toxicokinetics. Sodium and potassium hydroxides, sulfides, oxidised sulfur constituents and carbonates, in the GL are dissociated in the body fluids. The true speciation of these ions in the human body is determined mainly by the nature of the ion, pH and ionic composition of the physiological fluids.

Sodium and potassium hydroxides and carbonates in GL are rapidly dissolved in the body. Resulted sodium and potassium ions are normal and essential constituents of the blood and other body fluids and their concentration in the blood is controlled by renal excretion . Carbonate and hydroxide ions in GL could potentially affect the acid-base balance of the body. However, they are usually neutralized by gastric acid and the pH regulation mechanisms of the blood.Therefore they are not expected to be systemically available in the body under normal handling conditions. However, due to their corrosive properties in high concentrations the alkalis might cause burns to the skin and therefore facilitate the exposure of GL to the body.

 

Soluble sulfide salts dissociate into sulfide ions that are oxidated to sulfates (major metabolic excretory pathway) or methylated (minor detoxification pathway) and excreted by the kidney. Similarly, tiosulfate in GL is excreted by the kidney. Sulfide ions also can react with the hydrogen ions in water to form the hydrosulfide ion (HS¯) or hydrogen sulfide (H2S). The relative concentrations of these species are a function of the pH of the water; hydrogen sulfide concentrations increase with decreasing pH. After ingestion there can be formation of H2S in the stomach due to acidity.The formed H2S can be absorbed through the gastrointestinal tract, bound by plasma albumin and distributed to different organs causing toxic effects. Direct toxic effects to lung tissues are also possible if volatile H2S is formed and inhaled. It is doubtful whether skin absorbs enough sulfides to cause systemic poisoning. Hydrogen sulfide is excreted primarily as sulfate (free sulfate or thiosulfate) in the urine. It is also excreted unchanged in exhaled air and in feces and flatus.

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