Occupational exposure to hexachlorocyclohexane

Summary In a lindane (-hexachlorocyclohexane =-benzenehexachloride)-producing factory 57 workers were studied with regard to their blood levels of the three hexachlorocyclohexane isomers:-, -, and-HCH. The TLV-TWA (MAK value 1979) for-HCH of 0.5 mg/m³ was not exceeded at any of the workplaces where HCH is synthesized and purified to lindane. Additionally, in some of the workers samples of s.c. adipose tissue were taken for determination of HCH-isomer content. An external group of 20 clerks was examined in the same way for control purposes.In contrast to the control persons, none of whom had HCH-concentrations in serum above the respective detection limits, the values determined in serum of the exposed workers were in the following ranges:-HCH: 10–273 g/l,-HCH: 17–760 g/l, and-HCH: 5-188 g/l. Of special interest is the observation of a significant increase of-HCH-concentration in serum with the time of employment in lindane production, indicating a pronounced accumulation of this substance in the human organism. Concentrations of this isomer in s.c. adipose tissues were about 300-fold higher than in serum. A significant correlation between both parameters could be established.The results of this study show that adherence to the TLV-TWA of-HCH is not sufficient for control of HCH-exposure. Furthermore, biological monitoring of exposed workers is necessary taking into account the three more important isomers-, -, and-HCH.     

Congener-specific data on polychlorinated biphenyls in tissues of common porpoise from Puck Bay,Baltic Sea

Individual congeners of polychlorinated biphenyls (PCBs), including the highly toxic non-ortho coplanar 3,3,4,4-tetrachlorobiphenyl (IUPAC No. 77), 3,3,4,4,5-pentachlorobiphenyl (IUPAC No. 126), and 3,3,4,4,5,5-hexachlorobiphenyl (IUPAC No. 169), and their mono- and di-ortho analogs, have been identified and quantified in the blubber, liver, and muscles of three female common porpoise Phocoena phocoena collected from the Puck Bay (inner Gulf of Gdask, Poland) in 1989–1990, to elucidate actual concentrations and toxic potential. The total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent for 13 coplanar PCBs in blubber was 1,500±470 pg/g wet wt. 2,3,4,4,5-Pentachlorobiphenyl (IUPAC No. 118) was the most contributing individual and occupied between 57 and 67% in total toxic equivalent of coplanar PCBs in blubber, while 2,2,4,4,5,5-hexachlorobiphenyl (IUPAC No. 153), 2,3,3,4,4-pentachlorobiphenyl (IUPAC No. 105) and 2,2,3,4,4,5-hexachlorobiphenyl (IUPAC No. 138) comprised between 9.5–14, 7.6–11.5, and 7.2–11.0%, respectively (totally 82–95%), and 2,3,3,4,4,5-hexachlorobiphenyl (IUPAC No. 156) was absent. A potentially most toxic non-ortho PCB members such as 3,3,4,4,5-pentachlorobiphenyl, 3,3,4,4,5,5-hexachlorobiphenyl and 3,3,4,4-tetrachlorobiphenyl were only minor contributors, altogether occupying between 1.0 and 14.5% in total TEQ of coplanar PCBs. Concentrations of total PCBs in lipids of the blubber ranged from 26 to 47 g/g and were comparable or lower than reported earlier for common porpoises from the Baltic Sea, North Sea, and North Atlantic by other authors.     

Short-term exposure of zooplankton to the synthetic pyrethroid,fenvalerate, and its effects on rates of filtration and assimilation of the alga,Chlamydomonas reinhardii

In acute tests of toxicity, two cladocerans,Daphnia galeata mendotae andCeriodaphnia lacustris, and the calanoid,Diaptomus oregonensis, were more sensitive to fenvalerate thanDaphnia magna, the organism used in standard laboratory bioassays. The 48-hr EC₅₀s for each species/stage in order of increasing sensitivity were adultD. magna — 2.52 g/L;D. magna (48-hr old) — 0.83 g/L; adultD. galeata mendotae — 0.29 g/L; adultC. lacustris — 0.21 g/L;D. galeata mendotae (48-hr old) — 0.16 g/L; adultDiaptomus oregonensis — –0.12 g/L. No toxicity was observed when these organisms were exposed to a range of concentrations of the emulsifiable concentrate without fenvalerate (the EC blank).Rates of filtration of the¹⁴C-labelled alga,Chlamydomonas reinhardii byD. galeata mendotae, C. lacustris andD. oregonensis were decreased significantly at sublethal concentrations of fenvalerate after only 24-hr exposure.Ceriodaphnia lacustris showed the greatest sensitivity with rates of filtration significantly decreased at 0.01 g fenvalerate/ L. Concentrations of fenvalerate 0.05 g/L resulted in decreased rates of filtration byD. galeata mendotae. A concentration of 0.10 g fenvalerate/ L caused rates of filtration to increase inD. oregonensis. whereas 0.05 and 0.5 g/L resulted in a decrease in these rates.Rates of assimilation of algae byD. galeata mendotae, C. lacustris andD. oregonensis exposed to similar concentrations of fenvalerate were decreased at concentrations 0.05 g fenvalerate/L. Changes in rates of assimilation were not as sensitive a parameter of toxicity as changes in rates of filtration. The EC blank had no significant effects on rates of filtration or assimilation for all three species.     

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.     

Toxicity of mercury,copper, nickel,lead, and cobalt to embryos and larvae of zebrafish,Brachydanio rerio

The toxicity of mercury (HgCl₂), copper (CuCl₂: 5 H₂O), nickel (NiSO₄: 6 H₂O), lead (Pb(CH₃COO)₂: 3 H₂O) and cobalt (CoCl₂: 6 H₂O) was studied under standardized conditions in embryos and larvae of the zebrafish,Brachydanio rerio. Exposures were started at the blastula stage (2–4 h after spawning) and the effects on hatching and survival were monitored daily for 16 days. Copper and nickel were more specific inhibitors of hatching than cobalt, lead, and mercury. Nominal no effect concentrations determined from the dose-response relationships (ZEPs, Zero Equivalent Points) for effect on hatching time were 0.05 g Cu/L, 10 g Hg/L, 20 g Pb/L, 40 g Ni/L and 3,840 g Co/L, and those for effect on survival time were 0.25 g Cu/L, 1.2 g Hg/L, 30 g Pb/L, 80 g Ni/L, and 60 g Co/L. The no effect concentrations for Ni, Hg and Pb are consistent with previously reported MATC values for sensitive species of fish. The no effect concentrations for copper are 1–2 orders of magnitude lower than previously reported values. The major reason for the latter discrepancy was considered to be the absence of organics that can complex copper ions in the reconstituted water that we used, which had a hardness of 100 mg/L (as CaCO₃) and a pH of 7.5–7.7. Unexposed controls were started with embryos from different parental zebrafishes and the parental-caused variability in early embryo mortality, median hatching time and median survival time were estimated.     

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.     

Chronic toxicity of the bromoxynil formulation Buctril® to Daphnia magna exposed continuously and intermittently

Two chronic toxicity tests were conducted in which Daphnia magna were either continuously or intermittently exposed to bromoxynil octanoate (BO; as Buctril^®) for 28 d. In the intermittent exposure test, daphnids were exposed to daily pulses of BO with 24-h mean concentrations equal to those in the continuous exposure test, and the peak concentrations were three times the 24-h mean values. After 28 d of continuous exposure to BO, survival of daphnids was reduced at 80 g/L, whereas mean number of young per adult, intrinsic rate of natural increase, and mean weight of adults were all reduced at 40 g/L. Intermittent exposures to daily pulses of BO for 28 d caused reduced survival of daphnids at 24-h mean concentrations 40 g/L and reduced mean number of young per adult, intrinsic rate of natural increase, and mean weight of adults at 24-h mean concentrations 20 g/L. The estimated geometric mean-maximum acceptable toxicant concentrations of BO based on 24-h mean nominal values were 28 g/L for continuous exposures and 14 g/L for intermittent exposures. These results demonstrated that continuous-exposure studies may not be adequate in assessing herbicide toxicity to aquatic biota when concentrations fluctuate temporally.     

Metabolism and storage ofp,p′ dicofol in American kestrels (Falco sparverius) with comparisons to Ring Neck Doves (Streptopelia risoria)

Residues ofp,p dicofol,p,p dichlorobenzophenone (p,p DCBP),p,p dichlorobenzhydrol (p,p DCBH), 1,1-bis (4-chlorophenyl)-2,2-dichloroethanol (p,p DCD) and 1,1-bis (4-chlorophenyl)-2,2 dichloroethylene (p,p DDE) are reported in liver, fat, brain and oviducts of American kestrels exposed top,p dicofol. Breeding female kestrels were exposed to oral gavage dosages of 3.0 and 0.3 mg dicofol/kg body weight per day, equivalent to 1 or 10 mg dicofol/kg diet, for 39 days. Kestrels exhibited an eggshell thinning response similar to that produced by DDE, under these exposures. The major hepatic metabolite of dicofol in kestrels was DCD, but most organochlorine stored in tissues was in the form of dicofol. DDE was not a major metabolite of dicofol in kestrels. Compared with doves, kestrels had a significantly reduced metabolic capacity to transform dicofol to DCBP and DCBH, and had a steeper dose-response curve for dicofol-induced eggshell thinning.     

Extended-spectrum β-lactamases fromKlebsiella pneumoniae strains isolated at an Italian hospital

Eighteen strains ofKlebsiella pneumoniae recently isolated from hospitalized patients were resistant or moderately resistant to oxyimino-cephalosporins (ceftazidime and/or cefotaxime), aztreonam, cefoxitin and all but one were susceptible to imipenem. Analysis of enzymes produced by these clinical isolates revealed a wide pattern of extended-spectrum -lactamases. All isolates produced one or more -lactamases that were characterized preliminarily by their isoelectric point. Strains isolated early were from patients in the Intensive Care Unit and produced an ES-lactamase with an apparent pI of 7.6, whereas the later isolates were from surgical and medical wards of the same hospital and produced ES-lactamases with apparent pI of 8.2 and 8.4, repectively. This suggests the emergence of SHV-5 and MIR-1 -lactamases in our hospital. Agarose gel electrophoresis of plasmid DNA revealed the presence of a similar plasmid of approximate size 60 Kb in all isolates.     

Effects of dieldrin in food on growth and bioaccumulation in mallard ducklings

The effects of dieldrin in food organisms and commercial feed on growth and bioaccumulation were determined in mallard ducklings (Anas platyrhynchos). Dieldrin-fed crickets, mealworms and annelid worms, and dieldrin-spiked commercial feed, were fed to mallard ducklings for 8 days. Mean measured food concentrations (animals plus feed) of <0.2, 2.6, 26.2, and 49.3 g/g dieldrin did not affect growth after 14 days. Tissue dieldrin concentrations (g/g wet wt) increased rapidly: up to 80.7 (lipid), 30.1 (skin), 4.1 (liver), 1.8 (muscle), and 1.6 (brain) g/g. Dieldrin concentrations in tissues were up to 3.7 times greater than in the test diets.     

Belgian collaborative study of the in-vitro susceptibility of the Bacteroides fragilis group

The antimicrobial susceptibility of clinical isolates of the Bacteroides fragilis group obtained from nine large Belgian university and community hospitals was studied. Of the -lactam antibiotics tested, none were active against 100% of the isolates. Piperacillin was active against 93% of the strains at a breakpoint of 64 lag/ml. The percentage of isolates inhibited at 16 g/ml (and 32 g/ml) for the 7-alpha-methoxy antibiotics was: cefoxitin 84 [94]; latamoxef 87 [93]; and cefotetan 64 [79]. B. fragilis tended to be more susceptible to all -lactams than the other members of the group.Among the non -lactam antibiotics, the resistance rate for minocycline, doxycycline, clindamycin and erythromycin (at a breakpoint of 4 g/ml) were l%, 4%, 14% and 34%, respectively. Like the -lactams, clindamycin was less active against non B. fragilis species of the group.Chloramphenicol, metronidazole and tinidazole were still active against 100% of the isolates at their breakpoint values (8 lag/ml).     

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).     

Health behaviours and socio-economic status in Ontario, Canada

Data from the 1990 Ontario Health Survey were used to investigate the association of socio-economic status with the likelihood of meeting current recommendations for four health behaviours (smoking, fat intake, alcohol consumption, and physical activity level) in adults living in Ontario (Canada). Health behaviours were categorised as unhealthy if they did not meet current recommendations in Ontario (smoking, fat intake < 30% of dietary energy, alcohol intake < 14 units per week, low level of leisure-time physical activity). Two summary variables based on the number ofÔ unhealthyÕ behaviours were also examined: the crude number of unhealthy behaviours reported and the likelihood of reporting 3 or 4 unhealthy behaviours. Four measures of socio-economic status were used: educational achievement, household income status, source of household income, and occupational prestige. Multiple logistic and linear regression analyses were performed to explore the association of each unhealthy behaviour and of the summary variables with socio-economic status indicators (taken independently or simultaneously), controlling for demographic characteristics. Except for the positive relationship between income status and high alcohol intake, measures of unhealthy behaviours were inversely associated with the socio-economic indices, suggesting that individuals in lower socio-economic groups are at an increased risk for health problems.     

Isomer-specific analysis and toxic evaluation of polychlorinated biphenyls in striped dolphins affected by an epizootic in the western Mediterranean sea

Isomer-specific concentrations of polychlorinated biphenyls (PCBs) including planar, mono- and di-ortho congeners and concentrations of DDT were determined in striped dolphins affected by a morbillivirus epizootic in the western Mediterranean in 1990. Extremely high concentrations of PCBs ranging from 94 to 670 g/g (wet wt) were detected in the blubber. Similarly, DDT concentrations were high, between 22 and 230 g/g (wet wt). The concentrations of three non-ortho coplanar PCBs were 43 (3,3,4,4-T₄CB), 6.8 (3,3,4,4,5-P₅CB), and 7.8 (3,3,4,4,5,5-H₆CB) ng/g (wet wt), respectively, the highest residue levels reported to date. The estimated 2,3,7,8-TCDD toxic equivalents of non-, mono- and di-ortho PCB congeners in striped dolphins were several times higher than those observed for other marine mammals and humans. Mono-ortho congeners contributed greater 2,3,7,8-TCDD toxic equivalents than non-ortho members. The higher ratio of 3,3,4,4,5,5-H₆CB/3,3,4,4,5-P₅CB (IUPAC 169/126) suggested a strong induction of mixed function oxidase enzymes and highlighted the possibility of using this ratio as an index for risk assessment of PCB contamination in marine mammals. Elevated concentrations of PCBs may have played a role in the immune depression in striped dolphins, ultimately leading to the development of morbillivirus disease.     

Effects of an Elementary School Intervention on Students' “Connectedness” to School and Social Adjustment During Middle School

This research examined the effects at follow-up during middle school of a comprehensive elementary-school intervention program, the Child Development Project, designed to reduce risk and promote resilience among youth. Parental consent to participate in the middle school study was obtained for 1,246 students from six program and six matched comparison elementary schools. Three of the program elementary schools were in the high implementation group, and three were in the low implementation group during the elementary school study. Findings indicated that, studywide, 40% of the outcome variables examined during middle school showed differences favoring program students, and there were no statistically reliable differences favoring comparison students. Among the high implementation group, 65% of the outcome variables showed differences favoring program students. Overall, program students were more engaged in and committed to school, were more prosocial and engaged in fewer problem behaviors than comparison students during middle school. Program students who experienced high implementation during elementary school also had higher academic performance, and associated with peers who were more prosocial and less antisocial than their matched comparison students during middle school. Implications of these findings for prevention programming are discussed.     

Fluoride accumulation and bone strength in wild black-crowned night-herons

Fluoride was measured in femurs of black-crowned night-herons (Nycticorax nycticorax) living adjacent to a phosphate processing complex near Pocatello, Idaho. Fluoride (ash wt.) in femurs ranged from 540 g/g to 11,000 g/g and increased (P=0.0001) with age, but with no difference (P=0.80) between sexes. Adult males (4 years) contained 5,409 g/g compared to 6,042 g/g for adult females. The tibiotarsus (=tibiae in text) increased in diameter with age (P=0.015) in this study; fluoride was nearly related (P=0.065) to the increase. As the diameter increased with age, wall thickness decreased (P=0.011) suggesting excessive internal bone resorption, but fluoride concentrations were not implicated in the relationship (p= 0.64). The apparent increase in diameter and decrease in wall thickness may have partially neutralized each other's effects on strength. Although significantly higher concentrations of fluoride were present in adults than in Third Year herons, no significant change in bone strength (maximum load or modulus of rupture) was detected between the two age classes, but three of the four comparisons showed adults with less strength (i.e., a hint of diminished strength with age). The tibiae of Hatch Year birds were significantly weaker than documented in older age classes, but incomplete growth was thought responsible. The strong relationship between age and fluroide concentrations reduced our ability to separate a fluoride effect from an age effect. Other authors believed fluoride was responsible for an increase in bone diameter and the fluoride residues encountered in adults were within the range indicative of poisoning in cattle. In addition, the adult night-herons had about 1.6 times higher fluoride concentrations than owls which showed reduced reproductive success under laboratory conditions.     

Aquatic hazard assessment of the organophosphate insecticide fonofos

This study determined the acute and chronic toxicity of the organophosphate insecticide fonofos to standard freshwater aquatic organisms under laboratory conditions. Fonofos was acutely toxic to bluegill (Lepomis macrochirus), Daphnia (D. magna), and midge (Chironomous riparius) at 5.3, 2.7, and 39 g/L, respectively. Three fonofos formulations (technical, 94.8% A.I.; 20G, field granular 20% A.I.; and 4E, field liquid 4#/gal A.I.) exhibited similar acute toxicities to bluegill. Exposure to fonofos delayed reproduction and decreased the intrinsic rate of increase of Daphnia during 21-d chronic exposure at the lowest tested concentration (0.08 g/L). The no observable effect concentration (NOEC) for Daphnia survival was 0.42 g/L; 0% survival occurred at the lowest observable effect concentration (LOEC) of 1.45 g/L. The NOEC for midge emergence was 3.42 g/L; only 34% emergence occurred at the LOEC of 8.24 g/L. Chronic 30-d exposure of juvenile bluegills decreased growth and survival at 5.65 g/L (LOEC), but no effects occurred at 2.33 g/L (NOEC). The relative hazard of fonofos to aquatic life is similar to other carbamate and organophosphate corn insecticides.     

Transmission of antibodies to Chlamydia Psittaci and Coxiella Burnetii through eggs and “crop milk” in pigeons

Young semi-domesticated pigeons captured or hatched from eggs gathered in Bratislava during 1989–1991 were examined for complement fixing antibodies to Chlamydia psittaci and agglutinating antibodies to Coxiella burnetii. Antibodies to Ch. psittaci were present in 76% of birds younger than 24 h, in 47.7% between 1 and 10 days of age and in 12% of nestlings over 10 days old. Antibodies to Ch. psittaci were also detected in crop milk of 4.1% of 1 to 10 day old birds and in 4.5% of specimens older than 10 days. Antibodies to C. burnetii were not found in juvenile birds under 24 h old, but antibodies against this agent were present in 16.4% birds between 1 and 10 days old and in 18% over 10 days old. Antibodies to C. burnetii were also detected in crop milk collected from crops of 2% of the young birds between 1 and 10 days.     

Contaminant residues in fish and sediments from lakes in the Atchafalaya River Basin (Louisiana)

Conversion of bottomland hardwood forests agricultural land has reduced habitat and water quality in many lakes in the floodplain of the lower Mississippi River. The objectives of this study were to ascertain current contaminant residue concentrations in fish and sediment from lakes in the Atchafalaya River Basin and to determine the influence of overflow and agricultural land use on contaminant levels. Fish and sediment samples were collected from eight lakes that differed in overflow (no overflow, headwater overflow, backwater overflow) and land-use characteristics (presence or absence of agricultural land). Residue analysis of 24 sediment and 82 fish samples collected from the study lakes showed that contaminant residues were uniformly low. Total DDT concentrations, consisting mainly of DDE, were found in 98% of the fish samples and generally were the highest residues though they rarely exceeded 0.50 g/g. Dieldrin, -BHC and -BHC, in concentrations rarely exceeding 0.05 g/g, were detected in about 50% of the fish samples. Total organochlorine pesticide and PCB residues were less than 2.00 g/g in all fish from all lakes, except for a 3.46 g/g total in spotted gar (Lepisosteus oculatus) from one lake. Sediments were free from pesticide residues except for occasional traces (0.01 g/g) of -BHC. Metal residue concentrations in fish and sediment samples were typical of uncontaminated areas. Lake systems in the Atchafalaya River Basin appeared to be relatively uncontaminated by agricultural pesticides, but metal and organic residues in fish were similar from lakes with the same land-use and overflow characteristics.     

Toxicity of the herbicides 2,4-D,DEF, propanil and trifluralin to the Dungeness crab,Cancer magister

Lethal and sublethal responses to the herbicides 2,4-D, DEF®, propanil, and trifluralin of various life history stages of the Dungeness crab,Cancer magister, were examined to estimate maximum acceptable toxicant concentrations (MATC) of each compound for this species. Zoeae were found, in long term tests, to be the most sensitive stage. Based on the experiments with this stage, MATCs were concluded to be >0.95, <6.9g for DEF, 26, <220g/L for trifluralin, 80, < 1,700g/L for propanil, and < 1,000g/L for the free acid form of 2,4-D.Technical Paper No. 4819, Oregon Agricultural Experiment Station