THe effect of 2,4-dichlorophenoxyacetic acid on growth and nitrogen-fixation of blue-green algaAnabaenopsis Raciborskii

Sodium salt of 2,4-dichlorophenoxyacetic acid (80% active ingredient), commonly applied for the control of aquatic weeds, was used to observe its effect on the growth and nitrogen fixation of a heterocystous bloom forming blue-green algaAnabaenopsis raciborskii. A concentration of 10g per ml of 2,4-D showed stimulation of growth and nitrogen fixation and these were almost unaffected in presence of its 100g per ml in the medium. The alga could tolerate up to 800g per ml in liquid culture media with and without nitrate nitrogen and up to 90g per ml on to agar plates. Nitrogen fixation was inhibited in presence of its higher concentrations.     

Residue dynamics and biological effects of polychlorinated biphenyls in aquatic organisms

Toxicity, residue dynamics, and biological effects of polychlorinated biphenyls (Aroclor^® series) were investigated in several freshwater invertebrates and fishes. Acute static toxicities (LC50) of PCB's ranged from 3.2 to 2,400g/L for invertebrates and from 1.2 to 61 mg/L for fish. The LC50's for invertebrates exposed in flow-through diluter systems for 5 to 10 days were 0.6 to 80g/L and those for fish exposed for 30 days were 3.0 to 433g/L. Invertebrates accumulated Aroclor 1254 residues up to 6,300 times greater than those to which they were exposed. Biological accumulation of Aroclors 1248 and 1254 by channel catfish (Ictalurus punctatus) was 56,370 to 61,190 times the levels in water after 77 days. Dietary exposures of coho salmon (Oncorhynchus kisutch) to Aroclor 1254 at rates of 1.45 to 14,500g/kg body weight per day had no effect on growth; no observable toxicosis was produced until 260 days; all fish in the group treated with the highest concentration died after 260 to 265 days. Thyroid activity, as measured by 72-hr thyroidal¹²⁵I uptake, increased significantly. Thyroid activity in channel catfish fed Aroclors 1232, 1248, 1254, or 1260 at concentrations of 2.4 and 24g/g was altered only by Aroclor 1254.     

Effects of 3,4-dichloroaniline on fish populations. Comparison between r- and K-strategists: A complete life cycle test with the guppy (Poecilia reticulata)

In order to compare data derived from life cycle tests with zebrafish (Brachydanio rerio Ham.- Buch.), an r-strategist, with data of fish exhibiting a differing strategy of reproduction, a complete life cycle test with the guppy (Poecilia reticulata Peters) was performed with the chemical 3,4-dichloroaniline. The generation of guppies exposed during the whole life span (F_I) reacted with more sensitivity than the generation exposed only as adults (F_o): Growth of adult females and reproduction was reduced significantly at 200 g/L in F_o, and even at 2 and 20 g/L in F_I. The survival rates of the early life stages were not influenced at the tested concentrations. There is hardly any difference in acute toxicity of adult guppies and zebrafish. With regard to chronic toxicity at lower concentrations, however, both species react differently: Guppy reproduction is the most sensitive parameter (zebrafish reproduction is not influenced at 200 g/L), but zebrafish larvae react most drastically (no survival of larvae at 200 g/L in F_I, reduced survival of larvae at 20 g/L in F_II, Nagel 1988). Consequently, zebrafish cannot be a valid model for assessment of the effects of chemicals on populations with differing reproductive strategies.     

Environmental impact of mosquito pesticides: Toxicity and anticholinesterase activity of chlorpyrifos to fish in a salt marsh habitat

Chlorpyrifos was tested for its influence on thein vitro andin vivo brain acetylcholinesterase (AChE) activity ofFundulus heteroclitus under laboratory as well as field conditions. The concentration required for a 50% reduction in the mvitro enzyme activity (I₅₀) was 7.2 × 10^–2 mM for the parent compound and 4.1 × 10^–6 mM for its oxygen analog. A 96-hr exposure of live fish to 1.0g/L chlorpyrifos resulted in a maximum AChE inhibition of 24%. At a concentration of 2.1g/L or higher, a 100% enzyme inhibition was observed after a 24-hr exposure period, followed by varying degrees of recovery during the next 24 hr. A second peak of AChE inhibition, proportional to the concentration of the insecticide, was observed 72 hr after the initial exposure and this was followed by a second phase of recovery during the next 24 hr. In spite of an initial 100% AChE inhibition at test concentrations of 2.1g/L and above, the fish mortality was less at lower concentration of the insecticide than at the higher levels. The 96-hr TL₅₀ and TL₅ (tolerance limit for 50% and 5% fish survival) of chlorpyrifos forF. heteroclitus were 4.7g/L and 12.2g/L, respectively. The LT₅₀ (lethal time in which 50% of the fish died) at a concentration of 5.6g/L was 49.5 hr.Fish exposed to 4 successive field applications of chlorpyrifos granules showed AChE inhibition ranging from 56 to 100% and the insecticide effect was cumulative in nature. By 24 hr after the second application, 18.6% of the treatment fish had died; live fish collected at this time showed a 96% depression of AChE activity. AChE inhibition was still evident (62%) in fish 69 days after the final application of chlorpyrifos.Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers-The State University of New Jersey, New Brunswick, New Jersey 08903, USA. Supported by a grant from N. J. State Mosquito Commission.     

Effects of herbicides on streamAufwuchs productivity and nutrient uptake

The effects of atrazine and a combination of alachlor, atrazine, metolachlor, and metribuzin on the productivity and nutrient uptake rates of native streamAufwuchs communities were investigated in two separate artificial stream experiments. After an 8-day colonization period, the first experiment employed constant doses of atrazine at 0 g/L (control), 24 g/L and 134 g/L. The second experiment employed a pulsed dose having maximum concentrations of 35 g/L alachlor, 109 g/L atrazine, 90 g/L metolachlor, and 21 g/L metribuzin. Each 20-day experiment was run at both 10C and 25C. Constant exposure to 24 g/L atrazine yielded a significant reduction in both ash-free dry weight (AFDW) and chlorophylla at 25C but not at 10C. Constant exposure to 134 g/L atrazine yielded significantly less AFDW and chlorophylla at both temperatures. The pulsed exposure to four herbicides yielded significantly less AFDW at both temperatures, while chlorophylla was significantly less only at 10C. During continual exposure to 134 g/L atrazine, both NO₂ + NO₃ and silica uptake rates appeared to be reduced at both temperatures, although the differences were generally not statistically significant. At 10C uptake rates of soluble reactive phosphorus and NO₂ + NO₃ were depressed temporarily by exposure to the pulse of four herbicides, recovering to control rates within a few days, while no effect on uptake rates was discerned at 25C. The temperature difference between experimental runs had a greater effect on nutrient uptake rates than did the herbicide treatments during a run. The results indicate thatAufwuchs growth and nutrient uptake rates may be reduced temporarily by herbicide exposures in agricultural streams. However, greater effects on these processes may be exerted by other factors accompanying storm events, such as reduced temperatures.     

Biological response of male and female volunteers to inorganic lead

Summary Lead (20 and 30 g/kg body weight/day) was administered as lead acetate during 3 weeks to human volunteers of both sexes. The following parameters were measured: lead in blood (PbB), erythrocyte -aminolaevulinic acid dehydratase activity (ALAD), protoporphyrin IX in the erythrocytes (PPE), -aminolaevulinic acid excretion in urin (ALAU) and haemoglobin (Hb).The response and sequence of these parameters were as follows: at first PbB increased and ALAD decreased at the same time within 3 days. In females PPE started to increase after about 2 weeks up to 2 times preexposure values; in males ingesting 20 g/kg/day there was no change. Males ingesting 30 g/kg/day showed a smaller increase of PPE which appeared after 3 weeks. ALAU only increased temporarily in the first week in males ingesting 30 g/kg/day.Part of this study was made possible by a grant from the Directorate Health Protection of the European Economic Community.Research assistent.     

Effect of lead on postnatal development of the bank vole (Clethrionomys glareolus)

Female bank voles (Clethnonomys glareolus Schreber, 1780) were given lead-contaminated food (2.5, 60, 380, and 730 g g^–1 of lead) after giving birth to litters. The concentrations of lead in bodies of young voles were determined after 5th, 10th, 15th, and 20th days of life. The concentrations of lead in the offspring increased with elevation of lead level in the diet of mothers. Lead accumulation became remarkable after 15th day, particularly in the bodies of the young born to mothers given 380 and 730 g g^–1 of dietary lead. The adverse effect of lead on the growth of young voles (declining weight increments) was observed in groups receiving highly contaminated food. The mortality among the young was also monitored. It occurred in whole litters as well as individuals and attained the highest values in groups given 730 g g^–1 of dietary lead.     

Eine Fehlerquelle und ihre Kompensation bei der δ-AminolÄvulinsÄurebestimmung im Harn nach Grabecki

Zusammenfassung Grabecki et al. bestimmten die -AminolÄvulinsÄure (ALS) im Urin photometrisch ohne Reinigung oder Isolierung. Diese bei der überwachung von Bleiarbeitern oft benutzte Methode wurde auf ihre ZuverlÄssigkeit untersucht.Die der ALS entsprechende Extinktion wird durch Störstoffe — insbesondere Harnstoff — in AbhÄngigkeit von deren Konzentration vermindert. Nach der Zugabe von 20 g ALS/ml zu 16 Spontanurinproben zeigte die Messung des Extinktionszuwachses eine lineare und negative Korrelation mit der Dichte (r=–0,76) und der Kreatininkonzentration (r=–0,74). Die Standardabweichung der Einzelwerte betrug 4,8 g ALS (= 24%) und in einer anderen Gruppe von 39 Proben 3,1 g ALS (= 15,5%). Diese Standardabweichung ist wesentlich ein Parameter der Störstoffe und nicht des analytischen Verfahrens.Harnstoff ergibt mit Ehrlichs Reagens eine GelbfÄrbung, die als relatives Ma\ der Störstoffe im Urin photometriert wurde. Die Ergebnisse korrelieren mit der Hemmung der ALS-Werte ausgezeichnet (r=–0,92). Dieser Befund eröffnet einen einfachen und schnellen Weg zur Korrektur der Ergebnisse nach der Grabecki-Methode.

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A source of error and its compensation in the determination of -aminolevulinic acid in urine after Grabecki

Summary Grabecki et al. determined -aminolevulinic acid (ALA) in urine photometrically withouth purification or isolation. This method, frequently used in supervision screening employees working with lead, was tested for reliability.The extinction corresponding to ALA is decreased in relation to the concentration of interfering substances, especially urea. After the addition of 20 g ALA/ml to 16 spot urine samples the measurement of the increase in extinction showed a linear and negative correlation with the specific gravity (r=–0.76) and the creatinin concentration (r=–0.74). The standard deviation of the single values was 4.8 g ALA (= 24%) and in another series of 39 samples 3.1 g ALA (= 15.5%). Essentially this standard deviation is a parameter of the interfering substances and not of the analytical procedure.When Ehrlich's reagent is mixed with urea a yellow coloration results; this was determined photometrically as a relative measure of the interfering substances in urine. The results showed excellent correlation with the inhibition of the ALA-values (r=–0.92). This observation facilitates simple and rapid correction of the results obtained by Grabecki's method.

     

Farm worker exposure to terbufos [phosphorodithioic acid,S-(tert-butylthio) methylO,O-diethyl ester] during planting operations of corn

Eleven farmers were monitored for dermal and respiratory exposure to terbufos [phosphorodithioic acid, S-(tert-butylthio) methyl O,O-diethyl ester] during a typical working day while planting corn and applying COUNTER^® 15-G systemic insecticide-nematicide. The average estimated dermal exposure was 72 g/hr while the estimated respiratory exposure was 11 g/hr. The results of urinary alkyl phosphate analyses were all negative showing no detectable absorption of terbufos. Plasma and red blood cell cholinesterase values of exposed farmers showed no significant difference in activity when compared to either preexposure or control values indicating no adverse physiological effects from the exposure. Based on these results, the use of COUNTER 15-G does not present a significant hazard, in terms of acute toxicity, to farmers using this product for the control of corn insects.     

The acute and chronic toxicity of cadmium to different life history stages of the freshwater crustaceanAsellus aquaticus (L)

Different life-history stages of the freshwater isopod crustaceanAsellus aquaticus were exposed to a range of cadmium concentrations using a semi-static toxicity testing procedure. Median lethal concentrations (96-hr LC50) ranged from 80 g Cd/L for juveniles to >2,000 g Cd/L for embryos. Pre-treatment of eggs with cadmium did not increase their tolerance to the metal as juveniles. The responses of each stage are discussed in relation to the use of macroinvertebrate toxicity test data in predicting the hazardous effects of pollutants.     

Toxicity of natural pyrethrins and five pyrethroids to fish

The toxicity of natural pyrethrins and five pyrethroids was determined with coho salmon (Oncorhynchus kisutch), steelhead trout (Salmo gairdneri), fathead minnow (Pimephales promelas), channel catfish (Ictalurus punctatus), bluegill (Lepomis macrochirus), and yellow perch (Perca flavescens). The 96-hour LC₅₀'s in static tests at 12C ranged from 24.6 to 114g/1 of natural pyrethrins and from 0.110 to 1,140g/1 of pyrethroids. Two pyrethroids, RU-11679 and SBP-1382^(R), were over 10 times more toxic than pyrethrum extract in the flow-through tests. Coldwater species of fish were more sensitive than warmwater species to all the compounds. Temperature (12–22C) influences the toxicity of natural pyrethrin and the pyrethroids. The natural pyrethrin was more toxic to fish in pH 6.5 than in pH 9.5 water, but the toxicity of pyrethroids was not influenced in that pH range. The two most toxic pyrethroids, RU-11679 and SBP-1382, were deactivated more rapidly in water solutions than natural pyrethrins, S-bioallethrin, dimethrin, andd-trans allethrin.     

I. Evaluation of the toxic risk of DDT in the rat: During accumulation

An investigation was undertaken on the accumulation of DDT and its metabolites in the rat. Rats received 14.5 mg DDT/kg b.w. every day for 52 days. Growth, food intake, body composition, and the activities of various enzymes were little affected. However, the level of total lipids fell 30% and the weight of the liver rose 20% due to cellular hypertrophy induced by the DDT. The quantity of DDT and its metabolites found in the carcass was 24 mg/rat i.e. three times that found in rats dead after a single dose of 200 mg/kg. Liver and brain contained 130 g/rat and 10 g/rat, respectively i.e. five times lower than those found in the rats which died from an acute dose of DDT. In the carcass,p,p DDT accumulates more thanp,p DDE orp,p DDD; the latter is preponderant in the liver.     

Effects of Kepone® on the sheepshead minnow in an entire life-cycle toxicity test

A life-cycle toxicity test with the estuarine sheepshead minnow (Cyprinodon variegatus) and the insecticide Kepone^® (chlordecone) in seawater showed that the maximum acceptable toxicant concentration (MATC) lies between 0.074 and 0.12 g Kepone/L, based on reduced standard length of progeny at 0.12g/L and higher concentrations. The application factor range (MATC/96-hr LC50) for sheepshead minnows exposed continuously to Kepone is from 0.001 to 0.002. Other adverse effects of Kepone exposure were: External signs of poisoning in fish exposed to concentrations 0.074g/L, fatty degeneration of the liver and histological evidence of vertebral damage in some fish exposed to 0.78g/L, reduced growth of parental fish at 0.39 and 0.78g/L, reduced fecundity and fertility of eggs at 0.78g/L, and reduced survival of embryos produced by fish exposed to 0.78g/L. Average bioconcentration factors (concentration in tissue ÷ average measured concentration in water) ranged from 2,600 for 21-day-old juveniles to 7,600 for adult males. ^®Registered trademark, Allied Chemical Corp., 40 Rector St., New York, NY 10006. Mention of trade names or commercial products does not constitute endorsement by the Environmental Protection AgencyGulf Breeze Contribution No. 425     

The accumulation and loss of dieldrin and endrin in the Eastern oyster

Oysters demonstrated an ability to significantly concentrate dieldrin and endrin. Concentration ratios obtained after 168-hr exposures to endrin were 1670 at 0.1g/L and 2780 at 50g/L. Dieldrin was concentrated to higher levels. Exposure to¹⁴C-Iabelled dieldrin at 0.5g/L produced whole body concentrations 2880 times the ambient level at 168 hr, while exposure to nineg/L of dieldrin resulted in aconcentration ratio of 2070 following the same period of exposure. Both endrin and dieldrin showed distinct linear regions in semi-logarithmic plots of uptake against time. Initial uptake was rapid and was followed by somewhat slower but still rapid uptake over the next 6 to 48 hr. Uptake within each of the stages followed an exponential form.     

Effect of sublethal pentachlorophenol on early oogenesis in maturing female rainbow trout (Salmo gairdneri)

Female rainbow trout (Salmo gairdneri) were exposed to sublethal levels of purified pentachlorophenol (99 + % PCP) and the effects upon ovarian development were assessed. A significant increase in atresia among Stage 2 oocytes (Balbiani stage), was recorded in females exposed for 18 days to 22 and 49 g/L during July 1984. The number of viable Stage 2 oocytes, relative to controls, were reduced to 52% and 19% at 22 and 49 g/L, respectively, significantly reducing the number of viable oocytes available to complete oogenesis. A similar response under identical conditions was not observed in December 1983. This is the first report demonstrating a significant effect on oogenesis following sublethal PCP exposure during early summer.     

Effects of nabam on developingXenopus laevis embryos: Minimum concentration,biological stability,and degradative products

This study was carried out to determine 1) the minimum concentration at which the fungicide ethylenebisdithiocarbamate disodium salt (nabam) would induce malformations in developingXenopus laevis embryos, 2) whether nabam in solution retained toxicological and teratogenic effects over long periods of time, 3) to compare the toxic and teratogenic effects of nabam's degradative products ethylene thiourea and ethylene diamine, 4) to compare toxic and teratogenic effects of the related substances methyl isothiocyanate and sodium thiocyanate, and 5) to compare the effects of combinations of these substances.Xenopus laevis embryos at yolk plug stage (Nieukoop and Faber stages 10–12) were exposed to various concentrations of fresh and one- to seven-week old nabam solutions, ethylene thiourea, ethylene diamine, methyl isothiocyanate, sodium thiocyanate, and combinations of some of these substances. Fresh nabam solutions induced malformations of the notochord in a majority of embryos at concentrations as low as 40 g/L. Embryos treated with 40 g/L nabam stored 1–7 weeks developed normally. Embryos treated with 100 g/L nabam stored 1–7 weeks developed severe malformations of the notochord, delayed pigmentation of the eye, and increased mortality. In addition, embryos exposed to 100 g/L nabam stored 4–7 weeks also experienced delayed development of the gut and a general decrease in size. Embryos exposed to fresh 100 g/L nabam solutions developed only malformations of the notochord. Concentrations of methyl isothiocyanate of less than 1.0 g/L were sublethal. Methyl isothiocyanate (1.0–1,000 g/L) was extremely toxic with 100% mortality recorded by day 7 in all groups. Sodium thiocyanate, ethylene thiourea, and ethylene diamine (100–10,000 g/L) were neither toxic nor teratogenic. Combinations of ethylene thiourea and methyl isothiocyanate at or beyond 5,000 g/L, or 1.0 g/L respectively were acutely lethal. At concentrations of 100–1,000 /L ethylene thiourea and 0.01–0.1 g/L methyl isothiocyanate, the tadpoles that hatched had swollen and kinked notochords, similar to animals exposed to fresh 40 g/L nabam. Thus, the aquatic environment when contaminated with very low levels of the fungicide nabam is hazardous to the development of amphibian embryos.     

Effect of carbofuran on selected macroinvertebrates in a prairie parkland pond: An enclosure approach

A series of enclosures were placed in an alkaline, prairie parkland pond in Alberta, Canada. Seven enclosures served as controls, 7 were treated with a mid-July application of the carbamate insecticide, carbofuran at 5 g/L, and another 7 received a 25-g/L application, a range of concentrations that could occur in a shallow pond (1 m deep) following accidental contamination while aerially-spraying adjacent fields for grasshopper control at the recommended rate of 140 g/ha. Macroinvertebrate numbers and biomass were monitored for 7 days prior to and 55 days after treatment. Results are presented for 8 taxa including the amphipod,Hyalella azteca, Chironominae larvae, Tanypodinae larvae, the snails,Physa andHelisoma, the leech,Helobdella stagnalis, damselfly nymphs, and nymphs of the mayfly,Caenis which together accounted for 97% of all the invertebrates collected during the study. At 5 g/L, carbofuran had no detectable adverse effects. At 25 g/L,H. azteca abundance and biomass declined to 10% and 6%, respectively, of their pre-treatment levels. Chironominae biomass declined to 17% of its pre-treatment level, owing mainly to the sensitivity ofChironomus. Secondary effects were not overt, althoughHelisoma abundance and biomass remained high throughout the post-treatment period in the 25 g/L enclosures in contrast to the controls where it declined during this period.     

Uptake and loss of inorganic mercury in the Eastern oyster (Crassostrea virginica)

Eastern oysters (Crassostrea virginica) were found to accumulate significant levels of mercury on exposure to relatively low concentrations of mercuric chloride. Accumulation occurred in two distinct phases which may be described as a two compartment system in which accumulation is logarithmic in the first phase and linear in the second. Mercury, during the initial phase, showed a minimum outward concentration flux of 0.025 hr^–1 indicating reversibility of accumulation prior to the change in phase. However, mercury was not excreted at the end of the second phase following exposure to 10, 40, 80, and 100g/1 for 256 hr.     

Urinaryβ 2-microglobulin and renal functions in elderly people in an area with no known cadmium pollution (Japan)

Urinary ₂-microglobulin (MG) was determined in 99 elderly people above 50 years of age from an area with no known cadmium pollution. With advancing age, the urinary MG increased as well as the urinary protein, urinary retinol-binding protein (RBP), and plasma urea nitrogen. Nevertheless, age effects were not observed in renal functions such as creatinine clearance or tubular reabsorption of phosphorus. Analysis of the relationship between urinary MG and parameters of the renal functions suggested 2-step increases in urinary MG: a slight increase between 160 and 1600g/L and a remarkable increase above 1600g/L. The latter strong increase in urinary MG was closely related with depressed tubular reabsorption of MG, but was independent of tubular reabsorption of phosphorus. The screening level of urinary MG for renal tubular dysfunction is suggested at 1600g/L.     

Pesticide residues in human colostrum: Seasonal variations,Yugoslavia

Levels of HCH, HCH, HCH,o,pDDE,p,pDDE andp,pDDT were measured in 59 samples of colostrum collected in the autumn 1982 and the spring 1983 from healthy nursing mothers on the third day after delivery. Pesticide residues were identified and quantitated on a gas chromatograph. Concentrations of HCH were significantly higher in the autumn (mean, 1.71g/L) than in the spring (0.67g/L), while concentrations of HCH were significantly lower in the autumn (0.49g/L) than in the spring (1.50g/L). The differences between the two seasons were not statistically significant for HCH (0.95 g/L vs 0.88g/L),o,pDDE (0.73g/L vs 1.34g/L),p,pDDE (68.63g/L vs 53.72g/L) andp,pDDT (20.00 (g/L vs 14.29 (g/L).Calculated average daily HCH (Lindane) intake of 0.04g/kg body wt (b.w.) and total DDT intake of 4.16 (/kg b.w. in a 3.5 kg newborn, ingesting 60 ml/kg b.w. of colostrum on the third day of life was below the upper limit of FAO/WHO Acceptable Daily Intake (ADI) (0.01 mg/kg b.w. for Lindane and 0.005 mg/kg b.w. for DDT) in the spring. In the autumn, Lindane intake of 1.10k/kg b.w. was below the FAO/WHO ADI and total DDT intake of 5.36 g/kg b.w. was slightly above the FAO/WHO ADI.