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.     

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。     

Residues of polychlorinated biphenyls (PCB) and organochlorine insecticides in liver tissue from terrestrial Danish predatory birds

Several observations of the occurrence of PCB in marine organisms have been published since Jensen (1966) proved the presence of these compounds as pollutants in the environment. In the last years the occurrence in terrestrial animals, especially birds have been reported a.o. by Prestt & Moore (1970).     

Influence of harvest processes on pork loin and ham quality

The purpose of this study was to determine the specific effects of extending the interval between dwell time and the duration of scalding on pork quality attributes. Sixty-four Duroc x Yorkshire pigs were randomly assigned to a 2 x 2 factorial treatment arrangement. Treatments included extending the dwell duration from 5 to 10 min and extending the scald duration from 5 to 8 min. All carcasses entered the cooler 50 min after exsanguination. At exsanguination, blood was collected for three 1-min intervals and then for a final 2-min period. Temperature and pH of the LM and semimembranosus muscle (SM) were measured at 45 min, and at 2, 4, 6, and 24 h postmortem (PM). Hunter L*, a*, and b* values were determined on the LM, SM, and biceps femoris (BF). Purge loss was measured on the SM, BF, and the sirloin end of the loin. Drip loss was measured in duplicate from LM chops after 1 and 5 d of storage. Warner-Bratzler shear force (WBS) measurements were determined on LM chops aged 1, 3, 5, and 7 d PM. Over 99% of the collected blood was obtained during the first 3 min after sticking. Carcasses scalded for 8 min had greater (P < 0.05) semi-membranosus 2 h temperature (28.8 degrees C) than carcasses scalded 5 min (27.3 degrees C). An 8-min scald process resulted in longissimus dorsi chops with lower hue angle and greater WBS values than the 5-min scald process. Increasing dwell time from 5 to 10 min resulted in biceps femoris chops with greater hue angle and loin chops with greater WBS values at 3 d PM. Harvest processes did not significantly affect subjective quality scores, Hunter L* values, purge or drip loss. Lengthening the duration of dwell and scalding may result in a more rapid PM pH decline. Reducing the duration of scalding may lead to increased time for manual removal of hair. Because of differences in facilities, it is recommended that individual facilities monitor dwell and scald durations to determine how to best minimize time of entry into the cooler.     

Management of land and livestock contaminated with polychlorinated biphenyls

Investigations were conducted on several small neighbouring beef cattle and sheep farms that were found to be contaminated with polychlorinated biphenyls (PCBs). The residues detected contained about 62% w/w chlorine and soil concentrations ranged from 0.35 to 1.9 mg/kg. Beef cattle and sheep grazing the contaminated land had PCB concentrations in their fat of 0.3 to 1.7 mg/kg and 0.19 to 0.45 mg/kg, respectively. The concentration of PCBs in the caudal fat of cattle was 0.3 to 2 times the concentration of PCBs in the land they were grazing and was positively related to stocking rates. PCBs were present in milk fat from cattle at about the same concentration as in caudal fat, and lactation appeared to contribute to decontamination. Wool grease from sheep contained about 1 to 2 times the concentration of PCBs in subcutaneous fat. Calves of contaminated cows also became contaminated. The half-life for decontamination of PCBs in a group of 8 young female beef cattle was calculated at 13 months. PCBs were detected in pasture samples at concentrations ranging from less than 0.01 mg/kg to 0.12 mg/kg. However, PCBs were not detected in any sample of hay cut from these paddocks. In 4 sheep fed a sole ration of this hay, traces of PCBs were detected in their fat following 89 days of feeding. Grazing livestock for meat production on land contaminated with PCBs is not recommended because livestock readily acquire residues, and PCBs persist in soil and livestock for long periods. Grazing sheep for wool production on land contaminated with PCBs may be an option.     

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.     

Determination of chlorinated pesticides in food and in human adipose tissue]

Residues of chlorinated pesticides in feed for laying hens, in eggs, poultry organs, potatoes, flour, and human fat tissues were determined by means of gas chromatography using electron recording detector. Further the amount of chlorinated hydrocarbon residues in potatoes from various parts of the South Moravian Region was stated. HCH amounts in human fat tissues recorded in Czechoslovakia were higher than in some West European countries, DDT content being, however, on the same level.     

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.     

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.     

Sulfonamide residues in pork: past, present, and future

The Food Safety and Inspection Service (FSIS) of the U. S. Department of Agriculture (USDA) has been involved for a number of years with the problem of sulfonamide residues in pork. In the 1970s, concern was raised regarding the use of sulfonamides when food safety criteria used for premarketing approval of new animal drugs and the safety data base for sulfonamides were found to be inadequate. Regulatory analytical methods for monitoring sulfonamides were developed and put to use by FSIS. With educational efforts by government and industry, by 1980 it was thought that the problem was being solved. In the 1980s, however, the sulfonamide violation rate began to increase; the USDA strengthened its educational programs, developed a rapid test for sulfonamides and pursued regulatory initiatives. By 1987 sulfonamide violations in liver tissue (i.e., greater than .1 ppm) had declined to 3.8%; however, new toxicological information associating sulfamethazine with the development of follicular cell adenomas of the thyroid gland in rats and mice led the FSIS to begin an enhanced sulfamethazine control program in the spring of 1988. The FSIS believes that production quality assurance is the key to prevention. The Agency's initiatives toward this end are designed both to encourage industry accountability and to provide disincentives for violators. The current approaches to the sulfonamide problem hold the clear promise of a satisfactory solution.