Effects of different dietary levels of cadmium,lead, copper,and zinc on the vitality of the forest pest insect Lymantria dispar L. (Lymantriidae,Lepid)

Lymantria dispar (gypsy moth) larvae were reared on both a natural diet of oak leaves and an artificial medium contaminated independently with four different metal nitrates. Larvae were contaminated up to pupation either from 1st or 4th instars at four concentrations differing by a factor of 5. The lowest concentration levels were 2 g/g Cd, 4 g/g Pb, 10 g/g Cu, and 100 g/g Zn based on nutrient medium dry weight. Developmental rate, growth, mortality and reproductive success were determined. No-Observed-Effect-Concentrations (NOECs) calculated were dependent on the metal, the parameter investigated and the stage at which exposure commenced. In general, larvae exposed from the 4th instar were less susceptible to metal toxification than those exposed from hatching. Considering all parameters investigated, dietary NOECs were determined to be 2 g/g Cd, 4 g/g Pb, 10 g/g Cu, and 100 g/g Zn.     

Bromacil and diuron herbicides: Toxicity,uptake, and elimination in freshwater fish

Fathead minnows, 30 days old, were exposed to technical grade bromacil and diuron in flow-through tests to determine acute toxicity. LC₅₀ values for bromacil were 185, 183, 182 and 167 mg/L at 24, 48, 96, and 168 hr, respectively; and for diuron, 23.3, 19.9, 14.2, and 7.7 mg/L at 24, 48, 96, and 192 hr, respectively. Eggs, newly hatched fry, and juvenile fish were continuously exposed to lower concentrations of the herbicides for 64 days. Growth was significantly reduced (p 0.01) at the lowest bromacil exposure of 1.0 mg/L. Therefore, it was not possible to determine a no effect concentration. The no effect concentration for diuron was 33.4 g/L, while the lowest concentration which resulted in adverse effects was 78.0 g/L. Adverse effects at 78.0 g/L were an increased incidence of abnormal or dead fry immediately after hatch (p 0.01) and decreased survival throughout the exposure period (p 0.05). Neither herbicide accumulated significantly in fish tissue, as bioconcentration factors were <3.2 and 2.0 for bromacil and diuron, respectively. Rainbow trout (Salmo gairdneri) injected with radiolabeled bromacil or diuron eliminated over 90% of the radioactivity within 24 hr. Parent compound and metabolites were detected in the aquarium water in both cases. Metabolites of diuron recovered from the water included 3,4-dichloroaniline and several demethylated products.     

Effects of sublethal concentrations of triphenyltinacetate on rainbow trout (Oncorhynchus mykiss)

To evaluate the toxic effects of sublethal concentrations of the fungicide triphenyltinacetate (TPTAc), a prolonged toxicity study was made on rainbow trout (Oncorhynchus mykiss). Fish were exposed to TPTAc concentrations ranging from 1 to 6 g TPTAc/L for 28 and 18 days, respectively, using a flow-through exposure system. Hematological findings included an increase of the total number of erythrocytes and an elevated incidence of erythrocyte degradation stages at 4 g TPTAc/L and higher. The hemoglobin content and the packed-cell volume increased as well at 4 and 1 g TPTAc/L. Whereas the total number of leucocytes increased in fish exposed to 1 g TPTAc/L, the number of leucocytes tended to decrease at higher concentrations. The percentage of lymphocytes within the differential blood cell count decreased. The histopathological examination of TPTAc-exposed fish showed a dose-related lymphocytic depletion of the spleen, accompanied by a proliferation of reticuloendothelial cells and an increased erythrophagia even at the lowest TPTAc concentration. In severe cases, cell necrosis was evident. In liver tissue, a depletion of the glycogen deposits within the hepatocytes could be detected in fish exposed to 4 and 6 g TPTAc/L. The analysis of the phenyltin compounds within various organs of fish by HRGC-FPD revealed remarkable concentrations of triphenyltin of up to 16.1 g/g with the following order of residue levels: liver > kidney > spleen > gills > muscle. Di- and monophenyltin were found only in traces of 1–109 ng/g in these organs. The present study indicates that TPTAc negatively affects rainbow trout in a concentration range that might be present in aquatic environments.     

Biological and environmental monitoring of occupational exposure of pharmaceutical plant workers to methotrexate

Summary The exposure of 11 pharmaceutical plant workers to methotrexate (MTX) was studied. Personal air samples were taken during the different manufacturing processes: drug compounding, vial filling, and tablet preparation. The uptake of MTX was established by the determination of MTX in urine. MTX was analyzed using the fluorescence polarization immunoassay (FPIA), a method that is frequently used for monitoring serum levels in patients treated with MTX. The FPIA method was modified in such a way that MTX could be measured quickly and efficiently in air and urine samples. MTX was detected in air samples of all workers except for those involved in the vial filling process (range: 0.8–182 g/m³; median: 10 g/m³). The highest concentrations were observed for workers weighing MTX (118 and 182 g/m³). MTX was detected in urine samples of all workers. The mean cumulative MTX excretion over 72–96 h was 13.4 g MTX-equivalents (range: 6.1–24 g MTX-equiva g MTX-equivalents (range: 6.1–24 g MTX-equivalents). lents). A significantly lower background level of 10.2 g A significantly lower background level of 10.2 g MTX-equivalents was measured in urine of 30 control persons (range: 4.9–21 g MTX-equivalents).     

Effect of aflatoxin B and rubratoxin B on bacteriophage and rabbit cornea cells

Summary Rabbit cornea cells exhibited a sensitivity to 1 g aflatoxin b₁ and 5 g rubratoxin B per ml of growth medium. No changes were observed in the bacteriophages tested in the presence of 25 g aflatoxin b₁ or 100 g rubratoxin B per ml of medium by the plaque-forming unit method or single-step growth curves.     

Toxicity of seleno-L-methionine, seleno-DL-methionine, high selenium wheat, and selenized yeast to mallard ducklings

The toxicity of four chemical forms of selenium (seleno-L-methionine, seleno-DL-methionine, selenized yeast, and high selenium wheat) was compared in day-old mallard ducklings (Anas platyrhynchos). In the first experiment, in which the basal diet was 75% wheat, survival after 2 weeks was lower for ducklings fed 30 g/g selenium as seleno-L-methionine (36%) than for ducklings fed 30 g/g selenium as seleno-DL-methionine (100%) or 30 g/g selenium from high selenium yeast (88%). The concentration of selenium at 2 weeks in the livers of survivors was similar for ducklings fed 15 g/g selenium as seleno-DL-methionine (12 g/g, wet weight), seleno-L-methionine (11 g/g), and high selenium wheat (11 g/g), but was lower when the selenium came from selenized yeast (6.2 g/g). When fed 30 g/g selenium from the various sources, the selenium concentrations in liver were 20 g/g for seleno-DL-methionine, 19 g/g for seleno-L-methionine, and 9.9 g/g for selenized yeast. In a second experiment, in which the basal diet was a commercial duck feed, survival after 2 weeks was 100% in ducklings fed 30 g/g selenium as seleno-DL-methionine, seleno-L-methionine, or selenized yeast. Selenium concentrations in liver were similar for ducklings fed the 30-g/g selenium diets as the DL or L forms of selenomethionine (27 and 25 g/g), but lower for ducklings fed selenized yeast (13 g/g). The greater toxicity of the L form of selenomethionine was probably related to the palatability or nutritional nature of the wheat-based diet used in experiment 1, but the exact reason for the difference between the DL and L forms is unknown. Biologically incorporated selenium, derived from high selenium wheat, was no more toxic than selenium derived from the two purified forms of selenomethionine, and the selenium in selenized yeast was not as toxic as that in the two forms of selenomethionine.     

Chronic toxicity and bioaccumulation of 2,5,2′,5′- and 3,4,3′,4′-tetrachlorobiphenyl and Aroclor® 1242 in the amphipodHyalella azteca

The addition of 100 (g/L of Aroclor^® 1242 (A1242) or 2,5,2,5-tetrachlorobiphenyl (TeCB) during 10 week chronic toxicity tests withHyalella azteca resulted in complete mortality. There were no effects on survival, growth, or reproduction after addition of 30 g/L. Toxic effects were observed at tissue levels of between 30 and 180 g/g on a wet weight basis, and tissue levels appear to be a better indicator of toxicity than levels in water. No toxic effects were observed after additions of up to 2,700 g/L of the coplanar congener 3,4,3,4-TeCB.H. azteca has the ability to avoid accumulating in excess of 140 g/g 3,4,3,4-TeCB. The amount taken up was proportional to the amount added in water up to 100 g/L, but was constant at higher additions, possibly accounting for its relatively low toxicity. The low toxicity of the coplanar congener, as compared to the non-coplanar 2,5,2,5-TeCB, is in direct contrast to the high toxicity of coplanar PCB congeners to mammals and may be associated with slower rates of aromatic hydrocarbon metabolism in amphipods. Polychlorinated biphenyl levels measured in amphipods from Lake Ontario are approximately 100-fold below levels associated with toxicity inH. azteca, but are above levels which, through biomagnification up the food chain, lead to salmonid residues in excess of 2 g/g, a tolerance limit for human consumption.     

Peroxidase-catalyzed oxidation of chlorophenols to polychlorinated dibenzo-p-dioxins and dibenzofurans

Chlorophenols are transformedin vitro to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/ Fs) by peroxidase-catalyzed oxidations. This is demonstrated with bovine lactoperoxidase as well as horseradish peroxidase, and with 3,4,5- and 2,4,5-trichlorophenol (TrCP). The yield of total PCDD/Fs with lactoperoxidase was 11 g per g 345-TrCP and 10 g per g 245-TrCP, of which 2,3,7,8-substituted PCDD/Fs constituted 8.5 and 2.2 g/g, respectively, corresponding to 0.85 and 1.2 g/g of Nordic TCDD-equivalents.     

Uptake of dietary PCB by pregnant big brown bats (Eptesicus fuscus) and their fetuses

Summary Effect of commercial grade pesticide furadan (3% a.i. as carbofuran) was studied on the survival, growth and nitrogen fixation of blue-green algaNostoc muscorum. The lower concentration of furadan i.e. 25 g/ml enhanced survival, growth and nitrogen fixation in the alga whereas these were gradually inhibited in higher concentrations (50–1000 /ml) and the presence of more than 1200 g/ml was algicidal. The preliminary observations revealed that pesticide is biodegraded by the alga.     

Internal lead and cadmium exposure in 6-year-old children from western and eastern Germany

Lead and cadmium levels in blood and deciduous teeth (shed incisors only) of 6-year-old German children were determined in 1991 in a large epidemiological study carried out in rural and urban areas of western Germany (Duisburg, Essen, Gelsenkirchen, Dortmund, Borken) and eastern Germany (Leipzig, Halle, Magdeburg, Osterburg, Gardelegen, Salzwedel). In total, blood lead and cadmium levels of 2311 German children and tooth lead and cadmium levels of 790 German children were analyzed. Blood lead levels were generally low in all study areas with geometric means between 39.3 g/1 and 50.8 g/l in the western German and between 42.3 g/1 and 68.1 g/l in the eastern German study areas. The mean blood lead level of Turkish children (n = 213) living in the western German study areas was 50.1 g/l and thus 5.6 g/1 higher than the overall geometric mean of the western German children. The higher exposure may be explained by a higher oral uptake from food and different living conditions. These children were excluded from multiple regression analysis because they were all living in the western study areas. The mean tooth lead levels ranged between 1.50 and 1.74 g/g in the western and between 1.51 g/g and 2.72 g/g in the eastern study areas. Thus, they show a distribution pattern similar to blood. Blood and tooth lead levels were higher in urban than in rural areas and higher in the eastern German than in the western German study areas. With regard to the blood and tooth cadmium concentrations, no significant differences between the study areas could be found. The mean cadmium levels in blood ranged between 0.12 g/1 and 0.14 g/l and the mean tooth cadmium concentrations between 20.8 ng/g and 27.8 ng/g. Blood and tooth lead and cadmium levels of the eastern and western German children were thus mainly at a relatively low level in all rural and urban study areas. The study demonstrates and confirms that blood and tooth lead levels are influenced by several demographic, social, and environmental variables. The results indicate that there has been a further significant decrease of lead and cadmium exposure in western German children since our last epidemiological study carried out in the same study areas in 1985/1986.     

Susceptibility of clinical isolates of campylobacter pylori to 24 antimicrobial and anti-ulcer agents

Forty-nine isolates of Campylobacter pylori were tested for their susceptibility to twenty antibiotics and four anti-ulcer agents by an agar dilution technique. Penicillin and amoxycillin were the most active drugs (MIC₉₀, 0.06 /ml); erythromycin, cefazolin, minocycline, ciprofloxacin, ofloxacin and gentamicin were sligthtly less active (MIC₉₀, 1 g/ml). Moderate activity was found for doxycyclin, rifampin, nitrofurantoin, norfloxacin, pefloxacin, enoxacin, paromomycin, metronidazole and tinidazole. All strains were resistant to trimethoprim (MIC > 512 g/ml). Nalidixic acid (MIC₉₀, > 256 g/ml) and colistin (MIC₉₀, > 64 gg/m1) had little to no activity. Of four anti-ulcer drugs, only bismuth subcitrate showed activity (MIC₉₀, 64 g./ml).Strains resistant to all 4-quinolones were found in patients who had previously received ofloxacin as part of a clinical trial aimed at eradication of C. pylori. These isolates remained susceptible to amoxycillin, tetracyclines and to other classes of antibiotics.Corresponding author.     

DDT Residues in samples of human milk,and in mothers' and cord blood serum,in a continental town in Croatia (Yugoslavia)*

Summary Concentrations of p,p'-DDE, p,p-DDD, and p,p-DDT were determined in 34 samples of human milk obtained 3–5 days after delivery and in 37 samples obtained at later times of lactation (up to 55 weeks). All samples contained p,p-DDE, but only several contained p,p-DDD and p,p-DDT. The concentrations of p,p-DDE were 31 g/l in the beginning of lactation and 53 g/l at later time intervals. The concentration ranges in both groups overlap almost completely and the difference in the mean values is not significant.Serum samples from 35 mothers and cord blood were also analyzed. All samples contained p,p-DDE, the concentrations being 18 g/l and 6.8 g/l in the mothers' and cord blood serum, respectively. Serum samples of 24 nonpregnant women contained the same amount of p,p-DDE (20 pg/1) as mothers' sera.All samples were collected in a continental town of Croatia (Yugoslavia) between 1977 and 1979. The concentrations of DDT residues were determined by gas chromatography, and two methods for extraction from milk were used and compared.This work was supported in part by the Environmental Protection Agency (USA) and the World Health Organization (Geneva)     

Comparative toxicity of arsenic compounds and their accumulation in invertebrates and fish

The toxicity of arsenic III, arsenic V, sodium dimethyl arsenate, and disodium methyl arsenate to stoneflies, snails, amphipods, and trout, and the bioaccumulation of these compounds were studied during a 28-day flow-through test.Daphnia magna were exposed for 21 days in static tests to determine life-cycle effects. All animals were exposed to concentrations of approximately 100 and 1000g/L (as arsenic) of each of the compounds. Arsenic III, the most toxic compound, caused a significant reduction in the survival of amphipods at 1000g As/L after seven days. None of the compounds significantly affected the survival of other test species after 28 days or reduced young production inDaphnia after 14 days of exposure. The concentration of accumulated arsenic in stoneflies, snails,and Daphnia was as much as 131, 99, and 219 times greater than the water concentration, whereas amphipods and rainbow trout contained arsenic residues similar to the controls. Residues in stoneflies, snails, andDaphnia exposed to 1000g As/L were higher than those in animals exposed to 100g As/L, but appeared to reach a steady state after 14 days. Total arsenic accumulation was greatest in organisms exposed to inorganic arsenic, particularly at 100g/L.     

Occupational exposure to fosetyl-Al fungicide during spraying of ornamentals in greenhouses

Eight workers were monitored by the dermal patch/hand rinse technique for exposure to the fungicide aluminum tris-o-ethyl phosphonate [fosetyl-Al or ALIETTE^®] during treatment of ornamentals in a greenhouse, using commercial back-pack sprayers. The mean total dermal exposure for mixers was 512 g a.i./hr and for applicators 389 g a.i./hr. Mixers had higher exposure to the face and neck (213 g/hr) than did applicators (115 g/hr). Workpants provided 4 to 6 times greater protection than workshirts. The highest exposure for both activities was to the forearms. Hand exposure represented only 6% of total exposure, while regions protected by clothing contributed 47% of total exposure for mixers and 60% for applicators. Respiratory exposure contributed 7–9% of total exposure. The high variability in dermal patch results suggests a lack of precision in the sampling methodology, and indicates a need for larger sample sizes.     

Comparative toxicity of selenite and selenate to the amphipodHyalella azteca

Selenium contamination of aquatic ecosystems is rapidly becoming a concern throughout the United States, leading to a lowering of the freshwater selenium criteria by the U.S. Environmental Protection Agency from 35 g/L to 5 g/L measured as total selenium. However, considerable information indicates important differences in bioaccumulation and toxicity between the various selenium forms. We conducted a series of experiments to determine the comparative toxicity of selenite and selenate to the amphipodHyallela azteca. In 48 h, 96 h, and 240 h (10 d) LC50 tests, selenite was 2 to 4 times more toxic than selenate, the difference decreasing as exposure time increased. This difference in toxicity was even more pronounced in the 24 d reproductive bioassay, where selenite caused a significant decrease in number of young per female at 200 g/L while selenate had no effect up through 700 g/L (the highest concentration tested).     

Bioaccumulation and toxicity of selenium in Chironomus decorus larvae fed a diet of seleniferous Selenastrum capricornutum

The bioaccumulation and toxicity of selenium in a simple aquatic food chain was investigated by feeding a diet of seleniferous algae (Selenastrum capricornutum) to fourth instar midge (Chironomus decorus) larvae. Treatment diets consisted of S. capricornutum cultured in three concentrations of selenite (0, 10, and 40 g Se/L) and four concentrations of selenate (0, 4, 10, and 40 g Se/L). The seleniferous algae was freeze-dried and utilized as a diet for the midge larvae. The data show that, under laboratory conditions, a 96 h dietary exposure of 2.11 g Se/g dry weight significantly reduced larval growth at tissue concentrations 2.55 g Se/g dry weight. The results demonstrate that some invertebrates are very sensitive to dietary selenium exposure. When compared to similar studies with Daphnia magna, the data suggest that invertebrate primary consumers differ in the metabolism of dietary selenium.     

Internal exposure to organic substances in a municipal waste incinerator

Summary Fifty-three persons occupied in a municipal waste incinerator were examined with respect to their internal exposure to organic substances which may be produced during pyrolysis of organic matter. For this purpose the levels of benzene in blood, polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in plasma, and mono- (MCPs), di- (DCPs), tri- (TCPs), tetra-(TECPs) and pentachlorophenol (PCP) and hydroxypyrene in urine were determined. For control purposes, 431 men and women were examined. Significantly higher values for the workers were found for the excretion of hydroxypyrene [median (m): 0.24vs 0.11 g/l; non-smokers], 2,4/2,5-DCP (m: 10.5 vs 3.9 g/l) and 2,4,5-TCP (m: 1.2 vs 0.8 g/l) and for the HCB level in plasma (m: 4.4 vs 2.8 g/l). For the concentrations of 4-MCP and 2,3,4,6/2,3,5,6-TECP, the controls had significantly higher concentrations in urine than did the workers in the incineration plant (m: 4-MCP 1.7 vs 1.2; 2,3,4,6/2,3,5,6-TECP: 1.2 vs 0.3 g/l). No significant differences between workers and controls were detected with respect to benzene in blood (m: 0.20 vs 0.28 g/l; non-smokers), 2,4,6-TCP and PCPs in urine (m: 0.85 vs 0.60 and 2.2 vs 2.2 g/l) or the levels of PCB congeners in plasma (m: 138, 153, 180: 5.6 vs 4.1 g/l). The elevated levels of hydroxypyrene, 2,4/2,5-DCP, 2,4,5-TCP and HCB in biological material may be related to the incineration of the waste. These elevations, however, are very small and are of interest more from the environmental than from the occupational point of view.     

Sublethal Effects of Trace Metals (Cd,Cr, Cu,Hg) on Embryogenesis and Larval Settlement of the Ascidian <Emphasis Type="Italic">Ciona intestinalis</Emphasis>

Toxicity of Cadmium (Cd), Chromium (Cr), Copper (Cu), and Mercury (Hg) on the early developmental stages of Ciona intestinalis was investigated. Developmental defects of larvae after exposure of gametes throughout their development to the larval stage were assessed. Gamete exposure to increasing metal concentrations resulted in a significant decrease of the percentage of normally hatched larvae, showing median effective concentrations (EC₅₀) of 721 g/L (6.42 M) for Cd, 12772 g/L (226 M) for Cr, 36.6 g/L (0.576 M) for Cu, and 44.7 g/L (0.223 M) for Hg. Larval attachment was significantly affected when gametes were exposed to the metals throughout development. The EC₅₀ reducing larval attachment by 50% were 752 g/L (6.7 M) for Cd, 15026 g/L (289 M) for Cr, 67.8 g/L (1.607 M) for Cu, and 78.1 g/L (0.389 M) for Hg. Therefore, on a molar basis Hg is three times more toxic than Cu, 20–30 times more than Cd, and 700–1000 times more toxic than Cr, for both responses.     

A pilot study of lead and cadmium exposure in young children in Stockholm,Sweden: Methodological considerations using capillary blood microsampling

A capillary blood microsampling technique was tested among urban young children in Stockholm. Blood lead (BPb) and hemoglobin (Hb) concentrations were determined in capillary blood obtained by fingerstick from 41 children, 13–20 months old, and the accompanying parent. The quality control included control for lead (Pb) and cadmium (Cd) contamination of material and equipment used for blood sampling, washing procedures for the hands and fingers to be punctured, comparisons of Pb and Cd concentrations in blood obtained by fingerstick and by brachial vein puncture from the same individuals, analysis of external quality control samples for Pb and Cd in blood together with the collected samples, and evaluation of the analytical performance using linear regression analysis.The results showed that blood sampling material may contaminate the blood samples with amounts of Pb and Cd that would seriously influence the monitoring results in the low concentration range (<100 g Pb/L and <1 g Cd/L). However, it is possible to obtain reliable BPb concentrations (>10 g Pb/L), but not BCd concentrations (<1 g Cd/L), with the capillary blood microsampling technique tested provided that a strict quality control is applied. The sampling procedure tested was well accepted by the children and their parents. The children's median BPb concentration (27 g/L; range 9–73 g/L) was similar to the median BPb concentration of their parents (27 g/L; range 7–74 g/L). However, the correlation between child and parent BPb concentrations was poor (R²=0.20), which may indicate different sources to Pb exposure in children and parents.     

Some hygienic observations from the glass industry

Summary Metallic compounds and other agents used in the manufacturing of glass are probably responsible for the cancer risks observed for glassworkers, especially glassblowers. Few hygienic observations have been reported from the art glass industry. Three glassworks were therefore studied with regard to air concentrations of lead, arsenic, nickel and manganese. The hygienic conditions of the blow-pipes were investigated at these glassworks and another two with regard to inside deposits of slag containing lead, arsenic, manganese and nickel as possible transporters that cause oral exposure. Atomic absorption spectrophotometry was used for the analyses. Apart from lead, the metal concentrations in the air were around the detection limit. Glassworks producing heavy crystal glass usually had higher concentrations of lead in the air than the semi-crystal glassworks. Seven out of 12 samples from heavy crystal glassworks exceeded the Swedish threshold limit of 50 g/m³, while only four out of 28 samples from the semi-crystal glassworks exceeded this limit. Regarding metals in the slag from inside the blow-pipes, the concentrations (geometrical means) of lead and nickel were higher in the heavy crystal glassworks (6.9 g lead/mg slag, and 5.0 g nickel/mg slag versus 0.7 g lead/mg slag and 0.6 g nickel/mg slag in semi-crystal glassworks, respectively). The concentration of arsenic was similarly low in the pipes from all the glassworks ( 0.30 g/mg slag) and the concentration of manganese was only slightly higher in heavy crystal glassworks (5.4 g/mg slag versus 3.6 g/mg slag in semi-crystal glassworks).