Histopathological examination was carried out on male rats after single subcutaneous administration of 1, 2-dibromo-3-chloropropane (DBCP). DBCP produced injury in the kidney, testis, intestine, lympho-hematopoietic tissues, epididymis and liver. The renal injury consisted of proximal tubular necrosis in the outer medulla and degeneration of glomerular podocytes. Seminiferous epithelial desquamation and tubular atrophy were seen in testis. In lympho-hematopoietic tissues, there was depletion of lymphocytes as well as myeloid cells. Intestinal epithelial necrosis and rare mitosis occurred in the crypt of Lieberkiihn. Hepatic and epididymal injuries were relatively mild. The lesions developed dose-dependently, the minimal effective doses appearing to be 30 mg/kg for kidney, 100 mg/kg for testis, intestine and lympho-hematopoietic tissues and 300 mg/kg for epididymis and liver. These results indicated that DBCP might be a radiomimetic toxicant.
The effects of cadmium in pups born to rats exposed, during the gestation period, to low levels of Cd (4.2 and 8.4μg Cd2+/ml drinking water) on the brain biogenic amines and tissue metal distribution were studied. A significant increase in 5-HT level in whole brain was observed at day 1 of age, while after 90 days of withdrawal of treatment, increases in striatal DA and cortical 5-HT were evident. Zn level registered an increase in brain but a decrease in liver. Cu level was reduced in all the three regions studied, viz., brain, liver and kidney, at day 1 of age while after 90 days of withdrawal of treatment the effect persisted in liver. Cd levels showed significant increase only at day 1 of age. Our current findings reveal that exposure to even low levels of Cd during the early develop-mental stages might result in long lasting biochemical alterations in the young ones and some of the changes may persist even upto the adult stage.
An analytical method for water-soluble trivalent and hexavalent chro-mium [Cr(III) and Cr(VI)] was developed using fast protein liquid chromatography equipped with an anion exchange column (FPLC system). The system allowed rapid separation of Cr(III) as an EDTA chelate and Cr(VI) from water extracts of chromium fume particles. The elution times of these chromium species were several minutes or less. Both species in the eluates were determined by UV (275-230 nm) absorption and Cr(VI) also by VIS (370 nm) absorption. The detection limit of Cr(III) was 7 ng and that of Cr(VI) was 2 ng. The average chromium recoveries examined by atomic absorption spectrophotometry (AAS) ranged from 97% to 107% for both species. The FPLC system was also applied to the investigation of chromium forms in a culture medium (Eagle's minimum essential medium with L-glutamine and fetal calf serum) treated with Cr(III) or/and Cr(VI). The eluates were analyzed for both chromium species by AAS and for Cr(VI) only by the VIS method. Cr(III) was recovered in three fractions involving newly formed complexes with some of the medium components. One of them was shown to be Cr(III)-albumin complex. Cr(VI) was recovered in a single peak separated from these Cr(III) complexes. No reduction of Cr(VI) to the trivalent state was observed. These results indicate that the FPLC method is applicable to the determination of water-soluble trivalent and hexavalent chromium species in both nonbiological and biological samples.
Upon performing colorimetric determination of chromium with diphenyl-carbazide (DPC), the following were found. The color development proceeded not only in dilute sulphuric acid solution, but also in solutions of HNO3, HCl, HClO4 and CH3COOH or in mixed solutions of these acids. Wide concentration ranges (about 0.01-0.5N) of these single acids allowed perfect development of the Cr6+ coloration with DPC. Mixed solutions of 0.1-1% of these acids also resulted in perfect color development. HC1O4 proved to be the most excellent oxidant of Cr3+ to Cr6+ for the reaction with DPC compared with Mn02 and Pb02. The mixed acid (HC104+H2SO4) was more suitable than single HC1O4 for this oxidation.
Chromium in fumes generated in work environments including sites of welding work appears in various and complex states. Determination of chromium speciation in samples is useful for estimating the toxicity of such fumes. In the present study, determination of chromium speciation in chromium fumes prepared using a plasma metal sprayer, which are regarded as a model of actual fumes, was carried out. Fumes were treated with heated sodium carbonate solution, ammonium chloride-ammonia buffer solution at pH 9.5, Tris-HCl buffer solution at pH 7.5, hydrochloric acid, heated dilute sulfuric acid, distilled water, and a boiling mixture of sulfuric acid and perchloric acid in various series of the tests. The amounts of chromium (III) and chromium (VI) dissolved in each solution were determined, and the dissolution rates in those solutions were examined. The fumes were concluded to contain dichromium trioxide with a corundum structure (25%), chromium (III) oxide (45%) and chromium (VI) oxide (27%) mixed at random in a nonstoichiometric state, and chromium trioxide (3%). The procedure presented could be applied to the determination of chromium speciation in various types of fumes with a few modifications. In addition, the sodium carbonate leaching method has been demon-strated to be available for the determination of chromium (VI) in such samples.