Residues in cattle grazed on land contaminated with heptachlor

Heptachlor epoxide residues exceeding the maximum residue limit of 0.2 mg/kg have been found in fat of cattle grazed on land previously treated with heptachlor prior to planting potatoes or maize. To determine the residues accumulated in cattle exposed to contaminated land and the rate of decline on removal from the contamination, steers were grazed on a former potato paddock which had been treated the 2 previous years with heptachlor at 1.1 kg/ha. Soil residues in the paddock varied from a total of 0.42 mg/kg heptachlor and its epoxide at the beginning of the trial to 0.31 mg/kg after 16 months. Residues in the soil decreased only slightly down to a depth of 300 mm. Pasture residues were less than 0.02 mg/kg (wet basis). Heptachlor epoxide residues in the body fat of the steers increased during 19 months of exposure and reached a maximum of 0.72 mg/kg. In 4 steers removed after 14 weeks exposure, the heptachlor epoxide concentrations continued to increase from a mean of 0.24 mg/kg to a mean of 0.34 mg/kg after a further 4 weeks. Concentrations then fell progressively with a half life of 11 weeks in the body fat. There was an apparent relationship between pasture length and body fat residue, with residues increasing as pasture length decreased. The results of the experiments preclude the option of grazing cattle on pasture grown on soil treated with heptachlor for any extended period of time. It is possible that if short pastures and soft soil are avoided, and if cattle are not exposed to contaminated land for any more than 1 week in each month, then residues would remain below the maximum residue limit of 0.2mg/kg heptachlor.     

Environmental toxicology: polychlorinated biphenyls impair TNF-alpha release in vitro

Tumour necrosis factor (TNF-alpha) was induced by bacterial lipopolysaccharides (LPS)/phytohemagglutin (PHA) stimulated human whole blood in vitro. Levels of TNF-alpha were evaluated by enzyme-linked immunosorbent assay. Blood samples treated with polychlorinated biphenyls (PCB 77, PCB 126) exhibited impairment of TNF-alpha release: 50 pg/microl PCB reduced by up to 66% and 500 pg/microl PCB reduced by up to 93% the TNF-alpha release compared with the controls.     

Evaluation of the contamination degree of roe-deer with cadmium and polychlorinated biphenyls in Warmia and Mazury district

The results of investigations concerning degree the contamination degree with cadmium and polychlorinated biphenyls (PCB's) of roe-deer organs hunt in seven selected areas of Warmia and Mazury voivodship are presented. The highest mean cadmium content in the organs investigated was found in the samples from G?ebock area (liver - 0.0576 mg/kg, kidney - 3.351 mg/kg) and the lowest one was observed in the samples from Pisz area (liver - 0.181 mg/kg, kidneys - 1.653 mg/kg). Mean level of polychlorinated biphenyls residues in the roe-deer fat from Warmia and Mazury district was 0.004 mg/kg. The highest PCB's mean concentration was found in the roe-deer fat samples from Milomlyn area (0.008 mg/kg), and the lowest one in those from G?ebock area (0.002 mg/kg). Presented levels of investigated xenobiotics do not make at present (except cadmium in kidney) any toxicological threats for venison consumers in Warmia and Mazury district.     

气相色谱法测定禽蛋中有机氯农药和多氯联苯残留量

建立了同时测定禽蛋中14种有机氯农药(OCPs)和7种多氯联苯(PCBs)的气相色谱法。样品用乙腈超声提取,浓硫酸净化,气相色谱法测定,外标法定量。21种待测化合物在5～200μg/L时线性关系良好,方法定量限为0.3～0.7μg/kg,在5、20、100μg/kg三个加标水平下,鸡蛋空白样品的平均加标回收率为75.1%～103.8%,相对标准偏差为1.41%～6.64%。本法简便、快速、准确、成本低廉,适用于禽蛋中多种有机氯农药和多氯联苯的快速筛查。     

Effects of some commercial preparations of polychlorinated biphenyls in growing piglets.

Sixty-four piglets were given ad libitum commercial rations containing 250 ppm of polychlorinated biphenyls as Aroclor 1232, Aroclor 1242 and Aroclor 1254 for periods up to 12 weeks. The toxic effects of the polychlorinated biphenyls upon plasma testosterone levels, the blood coagulation system, the gross- and micropathological changes as well as the extent and differences in their distribution and accumulation were studied. Principals given Aroclor 1232, Aroclor 1242 and Aroclor 1254 for the 12 week period gained 30, 10 and 50% more in body weight respectively than did controls. In the context of the present experiment, Aroclors (especially Aroclor 1254) at 250 ppm level in the ration, appeared to act as growth promoting substances. The mode and site of action of this effect is not known. The gross and micropathological examinations of controls and principals gave no evidence of anomalies. Similarly, the data on various parameters of blood coagulation did not reveal any disturbances. However, testosterone levels in plasma were elevated in male piglets given Aroclors. Analyses of polychlorinated biphenyls showed that the highest concentrations were present in adipose tissues of all treated animals. A cumulative tendency was also evident. The levels were relatively high in brain, in some instances higher than in liver of the same group. Levels in hepatic and muscular tissue were, in many instances, of the same magnitude.     

Tissue deposition of polychlorinated biphenyls in cats fed Atlantic Ocean bluefish.

Bluefish (Pomatomus saltatrix), a very popular marine sport fish caught in Atlantic coastal waters, contain significant levels of polychlorinated biphenyls (PCBs). Since fish can be an appreciable portion of human and feline diets, a feeding study was conducted with cats fed exclusively bluefish for 86 days with determination of tissue concentrations of PCBs. The concentrations of PCBs in brain, liver, and fat were significantly higher (p = 0.01) in the fish-fed cats than in the control group using the Wilcoxon rank sum test. The highest PCB levels were in fat, the median concentrations being 48 and 0.61 ppm (dry weight) in the fish-fed and control cats, respectively. The significance of the results is discussed.     

Chlorinated pesticide residues and polychlorinated biphenyls in fish from various locations in Czechoslovakia

Samples of 14 fishes (175 samples on the whole) were examined in 1984 to 1986 for residues of chlorinated pesticides and polychlorinated biphenyls. Residues of the given substances were present in all the samples. The contents of chlorinated pesticide residues in fish are influenced mainly by the food spectrum; significant influence was also exerted by the contamination of the environment where the fish lived, by the age of the fish, and by the amount of their body fat in which the lipophile chlorinated carbohydrates are stored. No tolerance limits have been proposed in Czechoslovakia for the residues of chlorinated carbohydrates in fish bodies, except for the sum of DDT = 2.00 mg per kg of fat. When the data on the fish samples were compared with the highest admissible content of chlorinated pesticides per unit mass of fish muscle tissue tolerated in the FRG and the content of PCB tolerated in the USA, the fish from the Vltava river downstream of Prague fail to comply with these FRG and US regulations; all fish from all other places comply with them. Owing to large differences in the contents of fat in muscle between different fishes, it is more conclusive from the point of view of food hygiene to express the results as data per 1 kg of muscular tissue; these data represent real contents in fish as foodstuff.     

Residual chlorinated pesticides and polychlorinated biphenyls in the eggs and adipose tissue of wild birds

In 1983 and 1984, in the State Veterinary Institute at Jihlava, 129 samples of eggs of wild birds of 14 species were analyzed coming from different regions of the Czech Socialist Republic for the presence of residues of chlorinated pesticides and polychlorinated biphenyls (PCB). Apart from this, nine samples of hawk fat and 27 samples of buzzard fat were examined. The method of gas chromatography with a detector of electron capture was used for the analysis. The analyzed samples were found to contain residues of PCB, DDT (and mainly its metabolite DDE), HCB, alpha-HCH, gamma-HCH. No residues of other chlorinated carbohydrates were detected. The residue levels of these substances in the eggs and fatty tissues of different species of wild birds vary within a very wide range. A significant influence is exerted on these levels by the differences in food spectrum, the age of the birds, lack of food causing mobilization of food reserves, and mainly the environment where the birds live. The highest levels of residues were found in the eggs and fatty tissues of predatory birds with a narrow spectrum of food, i.e. those feeding on other birds (sparrow-hawk 33.00 mg.kg-1 in the dry matter of eggs, hawk 239.98 mg.kg-1 in fat) or those associated with water (great crested grebe 11.97 mg.kg-1, sea-gull 11.24 mg.kg-1 in the dry matter of eggs). Much lower levels of the residues of the chemicals were recorded in the species feeding mainly on small rodents (kestrel 0.681 mg.kg-1, buzzard 2.456 mg.kg-1 in the dry matter of eggs and 11.398 mg.kg-1 in fat). Some of the samples under study contained dead embryos. These embryos had particularly high residue levels, often higher than the levels regarded in literature as toxic.     

Influence of polychlorinated biphenyls on LH-stimulated secretion of progestereone and oxytocin from bovine luteal cells

Polychlorinated biphenyls (PCBs) due to their lipophilic properties can be easily accumulated in animal and human body and elicit diverse effects causing impairment of reproductive processes. Since these compounds were not be able to affect directly the luteal steroidogenesis, the aim of the present study was to verify hypothesis that PCBs can impair the effect of LH on the secretory function of luteal cells. Bovine luteal cells from different stages of the oestrous cycle (days 1-5, 6-10, 11-15 and 16-18) were exposed for 72h to various congeners of PCBs (PCB 126, PCB 77 and PCB 153) at the doses of 1, 10 or 100 ng/ml, in the presence or absence of LH (100 ng/ml), to determine the possible effect of these compounds on progesterone (P4) and ovarian oxytocin (OT) secretion. Only PCB 77 on days 1-5 and 16-18 increased P4 secretion. All PCBs decreased LH-simulated secretion of P4 from luteal cells obtained from all days of luteal phase. Dioxin-like congener (PCB 126) inhibited (P<0.05) the most evidently LH effect on P4 secretion. All congeners, except the lower doses of PCB 126, increased (P<0.05) OT secretion. They can also increase LH-stimulated secretion of OT, but the effect was dependent on the congener used and on the phase of oestrous cycle. On days 1-5 and 10-15, PCB 126 diminished LH-stimulated effect on OT secretion from luteal cells. PCB 77 (mimickig both dioxin and estradiol effect) in the higher doses, amplified effect of LH-stimulated OT secretion, while on all other days it diminished LH influence. PCB 153, which has estrogen-like properties, amplified LH effect on OT secretion during all studied days of the cycle. We conclude that PCBs (supposedly via estrogen and arylhydrocarbon - AhR receptor) may directly affect LH-stimulated function of CL. This does not appear to be a direct adverse effect on luteal steroidogenesis, but rather indirect on OT secretion from or within CL.     

Residues of chlorinated pesticides and polychlorinated biphenyls in pork and ham in past years and today

The contents of the residues of chlorinated pesticides and polychlorinated biphenyls (PCB) were investigated in 682 samples of ham and 926 samples of pork that were collected in the export meat plants. The investigation, based on the gas chromatography method with an EC detector, was performed in 1986. The tolerance of the residues of chlorinated pesticides was exceeded in 0.4% of the hams and 0.3% of the pork samples in that year. The PCB limit, proposed for pork (1.0 mg per kg of fat) was exceeded in 0.7% of the hams and 0.8% of pork samples; it can be seen from these data that the residue contents were considerably reduced in comparison with the year 1983 when this limit was exceeded in 7.0% of the hams and 6.2% of the pork samples. This decrease is due to the fact that the production of PCB was stopped, their use has been restricted, and the persons working with preparations containing PCB have been better informed about the chemical persistence, problems of residues and the like. The meat of wild boars is more contaminated than is the meat of the domestic pigs reared in large herds; this applies, first of all, to the residues of the DDT series (12.7% of the meat samples of the wild boars exceeded the limit of 2.0 mg per kg of fat) and also to the residues of HCB, lindane, and PCB. As for the PCB residues, the maximum tolerated residue content was never exceeded. A decrease in the contents of chlorinated pesticide and PCB residues resulting from the limited use of these chemicals is faster in the meat of the domestic pigs than in that of the wild boars.     

基质固相分散萃取-气相色谱法检测水产品中7种多氯联苯残留

建立了水产品中7种多氯联苯残留的气相色谱检测方法。采用HP-5石英毛细管柱（30 m×0.32 mm×0.25μm）以及气相色谱仪（带电子捕获检测器）在程序升温的条件下分离水产品中7种多氯联苯残留。方法线性范围为1～180 ng/mL,相关系数均大于0.999,定量限为0.5μg/kg,检测限为0.3μg/kg。该方法采用正己烷/二氯甲烷（9∶1）提取,佛罗里硅土分散固相萃取、净化,结果准确可靠,重复性好,回收率为84.7%～112%,相对标准偏差为0.79%～8.88%,可满足实验室对水产品中7种多氯联苯快速分析的需要。     

Liver aryl 4-monooxygenase activity in the progeny of hens receiving dietary polychlorinated biphenyls

1. The effects of relatively small concentrations of polychlorinated biphenyls (PCB) in the diet of hens on the hepatic microsomal aryl 4-monooxygenase [EC 1.14.14.1] activity in their progeny were investigated. 2. PCB caused enhanced activity of aryl 4-monooxygenase in the progeny.