[Accumulation of hydroxylated PCB metabolites in blood]

In order to investigate some potential accumulate properties of hydroxylated PCB metabolites, blood and tissues such as livers, kidneys, lungs and adipose tissue from rats exposed to a commercial PCB (Aroclor 1254) were analyzed for hydroxylated PCBs (OH-PCBs). A large number of OH-PCBs were detected in the liver 1 day after exposure among which almost 13 have been identified in the blood. OH-PCBs were retained selectively in the blood probably due to binding between the OH-PCBs and a protein in serum. One major OH-PCB determined in rat blood was 4-OH-2', 3, 3', 4', 5-pentaCB formed from 2, 3, 3', 4, 4'-pentaCB after NIH shift. Blood of a grey seal from the Baltic also contained at least 8 OH-PCB congeners with 2 major compounds determined as 4-OH-2', 3, 3', 4', 5-pentaCB and 4-OH-2, 3, 3', 4', 5, 5'-hexaCB. Thus, 4-OH-2', 3, 3', 4', 5-pentaCB is the most retainable OH-PCB congener in blood from rats and seal. Human serum have also been found to contain a few number of OH-PCBs at concentration of 0.6 ng/g serum which corresponds to one fourth of PCB level.

Studies of transformer repair workers exposed to PCBs: I. Study design, PCB concentrations, questionnaire, and clinical examination results

A cross-sectional study compared 55 transformer repairmen, 38 currently, and 17 previously exposed to polychlorinated biphenyls (PCBs) with 56 non-exposed subjects. PCBs exposures occurred from air and contaminated surfaces, predominantly from Aroclor 1260 with some exposure to Aroclor 1242. Each worker underwent: a questionnaire; standardized medical examination; delayed hypersensitivity testing; and determination of serum and adipose tissue lipid total PCB concentrations. Adipose and serum [PCBs] were significantly higher in the currently exposed, but previously exposed workers did not differ significantly from comparison subjects. No subjects had a classical syndrome of PCB poisoning. A number of neurobehavioral and irritant symptoms were significantly more prevalent in the exposed group, but were probably not related to PCBs. Comedones were more frequent in the exposed group, but no evidence of classical chloracne was noted. Cutaneous delayed hypersensitivity responses to mumps and to trichophyton antigens did not differ between the groups. The association of PCBs with job functions were explored.

Mucinous gastric hyperplasia in a colony of rhesus monkeys (Macaca mulatta) induced by polychlorinated biphenyl (Aroclor 1254)

Since 1971, 45 of 259 male rhesus monkeys housed in a primate building have died of a chronic and progressive disease characterized by diarrhea, dehydration, weakness, gingivitis, emaciation, and alopecia. The principal necropsy finding in these monkeys, and in eight others killed for experimental purposes, was hypertrophic and hyperplastic mucinous gastropathy involving both the mucosa and submucosa. The toxic agent involved was identified as the polychlorinated biphenyl (PCB), Aroclor 1254. The suspected source of the toxic agent was a concrete sealer used during building construction.

[Experimental studies for the hygienic standardization of Lasso in water]

Experimental hygienic-toxical study was carried out on amide herbicide lasso, aiming at its hygienic standardization in water. The studies were carried out in three aspects for the determination of its effect upon the organoleptic qualities of water, on the sanitary regime of water-reservoirs and toxic effect on organism. Threshold and subthershold concentrations of the deleterious effect on colour, small and taste of water were determined as well as on B0N5, on sanitary-indication microflora and on cold blooded organisms. The toxicological parameters for acute, subacute and chronic oral toxicity on albino rats were established. On the base of the experimental studies, differentiated hygienic norms (MAC) of lasso were elaborated in the three categories water-reservoirs - I mg/1 for I category and 5 mg/1 for II and II category.

Experimental polychlorinated biphenyl toxicosis in germfree pigs

The effects of polychlorinated biphenyls were studied in eight germfree pigs. Beginning at fourteen days of age, two pigs each were fed daily 12.5, 25, 50 and 100 mg/kg body weight of polychlorinated biphenyls as Aroclor 1254. Three germfree pigs were negative controls. Clinically the treated pigs had inappetance, a hemorrhagic diarrhea, erythema of the nose and the anus, retarded growth, distended abdomen and at the higher dose levels, incoordination and coma followed by death. Deaths occurred in 11 to 35 days after exposure. At necropsy, the piglets exhibited grossly enlarged mottled liver, erosions of the gastric mucosa, hemorrhages through the mesentery and the intestinal wall, a fibrinous pericarditis, a hypoplastic thymus and congested swollen thyroid glands. The histopathological lesions included hepatic centrolobular necrosis, interstitial myocarditis, endocarditis, myopathy of the muscles, gastric erosions and colitis. All of the organs examined for polychlorinated biphenyls had elevated residue levels which were particularly high in the fat, liver, psoas muscle, brain and kidney and were higher than has been reported in conventional pigs fed approximately equal concentrations of polychlorinated biphenyls. The severity of clinical signs, pathological changes and tissue concentrations were directly related to the dose administered and were more pronounced in the germfree pigs than has been described in conventional pigs.

Ingested polychlorinated biphenyl Aroclor 1242 and growth, calcium and zinic absorption, and intestinal ultrastructure in chicks

Decreased growth, edema, labored breathing, internal hemorrhaging, and high mortality were seen in chicks fed 48 or 197 p.p.m. Aroclor 1242 for 7 weeks. Calcium absorption was increased when birds were fed 197 p.p.m. PCB while zinic absorption was increased in birds fed both levels of PCB. Duodenal mucosal cell respiration rates were unaffected by either PCB treatment. Upon ultrastructural examination, mitochondrial alterations, lipid accumulations in the lamina propriae, edema, and swollen endoplasmic reticula were found in duodenal mucosal cells. Necrotic areas were found in the kidney proximal tubule region of PCB fed birds.