Environmental dynamics of phosphate esters. II. Uptake and bioaccumulation of 2-ethylhexyl diphenyl phosphate and diphenyl phosphate by fish

Uptake, clearance and disposition of ¹⁴C-labelled 2-ethylhexyl diphenyl phosphate (EHDP) and ¹⁴C-diphenyl phosphate (DPP) by rainbow trout (Salmo gairdneri) were investigated using short-term static exposures. Bioconcentration factors of 1314 and 0.3 were calculated for EHDP and DPP, respectively. Highest levels of radioactivity were found in liver and intestine following exposure to 60 μg/L EHDP. A portion (up to 40%) of the radioactivity in each tissue was in the form of DPP while a similar portion was extractable with methanol but could not be identified.     

Dynamics of isopropylphenyl diphenyl phosphate in fathead minnows

The fate of a triaryl phosphate (ring-UL-¹⁴C-2-isopropylphenyl diphenyl phosphate) was examined in fathead minnows. Diphenyl phosphate was identified as a major metabolite in whole body fish samples. A significant portion of the radioactive residues appeared to be associated with biogenic compounds, indicating “in vivo” reactions of biochemicals with ¹⁴C-metabolites or ¹⁴C-ring cleavage of 2-isopropylphenyl diphenyl phosphate and subsquent incorporation into biochemical pathways.     

Fathead minnow (Pimephales promelas) embryo to adult exposure to decamethylcyclopentasiloxane (D5)

The cyclic siloxane decamethylcyclopentasiloxane (D5) is a high production volume chemical which has recently been assessed under the Canadian Chemicals Management Plan (CMP). Cyclic volatile methyl siloxanes (cVMS) are one of the challenge substances in the CMP batches. To provide toxicity and growth information on a species of relevance to the Canadian environment, we assessed D5 in a fathead minnow (Pimephales promelas) embryo to young adult assay. The test was 65 d in length, and exposed fathead minnow eggs to juveniles until near maturity (60 d post-hatch). The D5 concentrations in flow-through fish exposure aquaria were about one-third of nominal D5 concentrations. Fathead minnows were exposed to 0.25, 0.82, 1.7, 3.6, and 8.7 μg L⁻¹ D5. During the exposure of fathead minnows to D5 there were few effects seen. Egg hatching and larval fish survival and growth were normal. Juvenile fish survival and growth were good in all environmentally-relevant concentrations of D5, and were similar to control fish. The two highest D5 concentrations (8.7 μg L⁻¹ and 3.6 μg L⁻¹, mean measured D5) increased the condition factors of fathead minnows compared to water control and DMSO control fish. Although there were few effects of D5 in our fathead minnow study, the compound was taken up and stored in fish bodies over the 65-d exposure. The bioconcentration factor for D5 in fathead minnows was 4450, for the lowest environmentally-relevant D5 exposure water concentrations, and 4920 for all D5 exposure concentrations tested.     

Environmental photochemistry of PCDDs. Part I. Kinetics and quantum yields of the photodegration of 1,2,3,4,7-penta- and 1,2,3,4,7,8-hexachlorodibenzo-p-dixin in aqueous acetontrile

For the determination of the quantum yields of 1,2,3,4,7-pentachlorodibenzo-$\text{p}$-dioxin ($\text{1}$) and 1,2,3,4,7,8-hexachlorodibenzo-$\text{p}$-dioxin ($\text{2}$), ten Pyrex glass photochemical cells were constructed and their correction factors determined. Quantum yields at 313 nm for $\text{1}$ and $\text{2}$ in aqueous acetonitrile (4:6 v/v) were (9.781 ± 2.376) 10^?5 and (1.096 ± 0.020) × 10^?4, respectively. These quantum yields and the measured absorption spectra were used to estimate the environmental phototransformation first-order rate constants and photochemical half-lives of $\text{1}$ and $\text{2}$ in water under conditions of variable sunlight intensity during various seasons from solar intensity data available in the literature. In summer, typical half-lives for the phototransformation of $\text{1}$ and $\text{2}$, respectively, near the surface of water bodies at 40° north latitude would be 364 ± 88 and 151 ± 3 h; whilst such values in winter would be 1257 ± 309 and 518 ± 10 h.     

The effect of cadmium ion on the growth,photosynthesis, and nitrogenase activity of Anabaenainaequalis

The growth of $\text{Anabaena}$$\text{inaequalis}$ was significantly inhibited by Cd²⁺ concentrations greater than 0.02 ppm (μg/ml) and completely inhibited at 0.06 ppm (Day 12). Cadmium had no significant effect upon the lag phase of growth or the culture doubling time, but caused the retardation phase to arrive sooner. One ppm Cd²⁺ significantly inhibited the rates of both photosynthesis and acetylene reduction, by $\text{A}$. $\text{inaequalis}$, with complete inhibition at 4 and 20 ppm respectively. Cell sensitivity increased directly with exposure time. Cadmium caused some cell lysis of $\text{A}$. $\text{inaequalis}$ and induced an increase in filament length, heterocyst frequency, and a loss of cellular contents from filament apical cells. The cellular abnormalities observed and the fact that toxicity increased with longer exposure times, suggested that metal toxicity resulted from effects of Cd²⁺ taken up by cells rather than Cd²⁺ at the cell surface.     

Interaction of higher marine fungi with the herbicide atrazine. III. Adsorption of atrazine to the marine fungus Dendryphiellasalina

The adsorption of the herbicide ¹⁴C-atrazine to the marine fungus $\text{Dendryphiella}$$\text{salina}$ was studied using sodium azide as an inhibitor of active uptake. Adsorption of atrazine (94 ppb) was found to reach equilibrium within six hours. Adsorption as a function of concentration (9.4 to 468 ppb) conformed to the empirically derived Freundlich equation giving a K value of 6.2. Atrazine on the fungal cell surface was easily desorbed by successive artificial seawater washes indicating a relatively loose binding. The ability of the marine fungus $\text{D.}$$\text{salina}$ to remove ¹⁴C-atrazine from an artificial seawater medium suggests an environmental role in the transport and redistribution of atrazine in estuaries.     

Hydrocarbons in Sand Crabs (Emeritaanaloga) from Southern California (U.S.A.)

$\text{Emerita}$$\text{analoga}$ (Crustacea:Hippidae) from three southern California (U.S.A.) beaches contained 0.9 to 24.1 μg/g dry wt saturated hydrocarbons, and 3.6 to 21.4 μg/g dry wt unsaturated hydrocarbons. Major constituents were (in wt. % total): n-alkanes (13.1%), heneicosapentaene plus heneicosahexaene (1.0%), squalene (5.1%), and unidentified polyenes (7.8%). Crabs from beaches exposed to small boat traffic and natural oil seepage were slightly and severely tainted, respectively, with petroleum hydrocarbons. Animals from San Nicolas Island (85 km offshore) contained only biogenic compounds.     

The fate of dichlorvos in soil

Experiments were conducted to determine the factors responsible for the loss (adsorption, chemical hydrolysis, microbial degradation, etc.) of dichlorvos (2,2-dichlorovingl $\text{0}$,$\text{0}$-dimethyl phosphate) in soil perfusion systems of Houston Black clay. The rate of disappearance from the perfusate (hence the rate of dichlorvos degradation in soil) was related directly to the presence of $\text{Bacillus}$$\text{cereus}$ in the perfusion system, the pH of the system, and the extent of dichlorvos adsorption. Gas liquid chromatographic analyses of the perfusates showed that dichlorvos disappearance was rapid when $\text{B}$. $\text{cereus}$ was added to a previously sterilized soil perfusion system (50% in 3.9 days). Under sterile conditions, 50% of the added dichlorvos was recovered after 10 days. When $\text{B}$. $\text{cereus}$ was added to a mineral salts medium containing dichlorvos as sole ccrbon source, 49% of the initial dichlorvos concentration was degraded in 4 days. The organism was not capable of utilizing dichlorvos as a sole phosphorus source. Chemical hydrolysis of dichlorvos in aqueous, buffered, soil-free systems showed that hydrolysis did not occur in very acid systems (<pH 3.3), but increased with increasing pH values (26% in 4 days at pH 6.9), and was rapid at pH 9.3 (> 99% in 2 days). The extent of dichlorvos adsorption was determined by comparing the initial loss of dichlorvos in a sterile, soil-free extract solution with the initial loss in a sterile soil perfusion system. The rapid initial disappearance of dichlorvos in the presence of sterilized soil was attributed to soil adsorption of the pesticide. After 10 days both systems contained equal concentrations (50%) of dichlorvos. Non-biological mechanisms accounted for 70% of the total degradation of dichlorvos, while bacterial degradation accounted for 30% in the soil perfusion systems.     

Effect of cadmium and zinc on intestinal absorption of xylose and tryptophan in the fresh water teleost fish, Heteropneustesfossilis

The effect of cadmium and of zinc on the rate of uptake of a pentose sugar xylose and an aminoacid tryptophan by the intestine of a teleost fish, $\text{Heteropneustes}$$\text{fossilis}$ was studied under two experimental conditions. In the first, four concentrations of cadmium or zinc (1.0 mM, 0.1 mM, 0.01 mM and 0.001 mM) mixed with the nutrient solution were filled in the intestinal sacs, and the rate of absorption was recorded after 1 h at 23°C. In the second experiment fish were exposed by bath to a sublethal concentration of cadmium (0.26 mg/1) or zinc (4 mg/1) for 15 and 30 days and the rate of absorption of the two nutrients was measured. The activity of intestinal Na⁺, K⁺ activated adenosine triphosphatase was also assayed. The two heavy metals at all the four concentrations decreased the rate of intestinal transport of nutrients. Increase in the concentration of each of the heavy metals decreased the uptake of nutrients, but the decreases were not linear. The rate of intestinal absorption of the two nutrients was also reduced by exposure of fish to the heavy metals $\text{in}$$\text{vivo}$. The activity of Na⁺, K⁺ ATPase decreased $\text{in}$$\text{vitro}$ with all four concentrations of cadmium and zinc and was diminished in fish exposed for 15 and 30 days. Of the two heavy metals, cadmium was more effective in reducing the rate of transport of xylose and tryptophan.     

Modular containers for microcosm and process model studies on the fate and effects of aquatic contaminants

Container modules are described for the laboratory simulation of selected processes and ecosystems that are representative of lentic environments. Emphasis is placed on design features permitting mass balance accountability of contaminant residues and procedural cautions required for the proper use of the described systems in environmental simulations. Experiments on the efficiency of container modules for microbial mineralization studies were conducted using ¹⁴CNaHCO₃, and acidification resulted in a ¹⁴CCO₂ recovery of $\text{97.3 ± 4.7\% (}\text{x}\text{?}\text{± SD}\text{)}$. The trapping efficiency of pesticides volatilized from water and glass surfaces was investigated using the same module and the mean recoveries of ¹⁴C-fonofos and ¹⁴C-trifluralin were 114.2 ± 3.2% and 95.2 ± 3.5%, respectively. The mass balance capabilities of the system was also demonstrated for extended microcosm exposures to ¹⁴C-trifluralin.     

Phthalates and the aquatic environment: Part II The bioconcentration and depuration of di-2-ethylhexyl phthalate (DEHP) and di-isodecyl phthalate (DIDP) in mussels (Mytilus edulis)

Mussels ($\text{Mytilus edulis}$) were exposed to di-2-ethylhexyl phthalate (DEHP) and to di-isodecyl phthalate (DIDP) over a period of 28 days. The bioconcentration factor (BCF) as measured by ¹⁴C analysis, reached estimated plateau levels corresponding to mean BCF values of approximately 2500 and 3500 for the DEHP and DIDP respectively. The mussels were then held in clean seawater for a further 14 days and ¹⁴C analysis showed a depuration half-life of approximately 3.5 days for both phthalates. During the whole 42 days of the experiment general observations on the health of the animals showed no evidence of any adverse effects.     

Dietary exposure of rainbow trout to 8:2 and 10:2 fluorotelomer alcohols and perfluorooctanesulfonamide: Uptake, transformation and elimination

The bioaccumulation of perfluorooctanesulfonamide (PFOSA) and two fluorotelomer alcohols (8:2 FTOH, 10:2 FTOH) by rainbow trout (Oncorhynchus mykiss) through dietary exposure, including depuration rates and metabolism was investigated. Concentrations in the spiked feed ranged from 10.9 μg g⁻¹ wet weight (wet wt) for PFOSA and 6.7 μg g⁻¹ wet wt for 8:2 FTOH to 5.0 μg g⁻¹ wet wt for 10:2 FTOH. Trout was fed at 1.5% body weight per day for 30 d and depuration was followed for up to 30 d following previously published dietary exposure protocols. Perfluorooctanesulfonate (PFOS) was the major perfluoroalkylsulfonate (PFSA) detected in fish following dietary exposure to PFOSA. Half-lives of PFOS and PFOSA were 16.9 ± 2.5 and 6.0 ± 0.4 d, respectively. A biomagnification factor (BMF) of 0.023 was calculated for PFOSA which indicates that dietary exposure to PFOSA does not result in biomagnification in the rainbow trout. PFOS had a BMF of 0.08. The fluorotelomer saturated acids (8:2 FTCA, 10:2 FTCA) and fluorotelomer unsaturated acids (8:2 FTUCA, 10:2 FTUCA) were the major products detected in rainbow trout following dietary exposure to 8:2 FTOH and 10:2 FTOH, respectively. Half-lives were 3.7 ± 0.4, 2.1 ± 0.5, 3.3, and 1.3 d for 10:2 FTCA, 10:2 FTUCA, 8:2 FTCA, and 8:2 FTUCA, respectively. Small amounts of perfluorooctanoate (PFOA) and perfluorodecanoate (PFDA) were also detected in the FTOH exposed fish.     

Accumulation of bis(tributyltin) oxide by the mud crab, Rhithropanopeusharrisii

Accumulation of ¹⁴C labelled bis(tributyltin) oxide (TBTO) by the mud crab, $\text{Rhithropanopeus}$$\text{harrisii}$, was determined through short-term exposure to labelled water and food. The potential for trophic accumulation during chronic low level exposure is emphasized.     

Phthalates and the aquatic environment: Part I The effect of di-2-ethylhexyl phthalate (DEHP) and di-isodecyl phthalate (DIDP) on the reproduction of Daphnia magna and observations on their bioconcentration

$\text{Daphnia magna}$ were exposed to di-2-ethylhexyl phthalate (DEHP) and to di-isodecyl phthalate (DIDP) at nominal concentrations up to 100 μg/1 over a 21 day period. The phthalates had no effect on reproduction, and the parent $\text{Daphnia}$ showed bioconcentration factors of 209 (DEHP) and 116 (DIDP) as determined by ¹⁴C analysis.     

Toxicite aigue du vanadium vis-a-vis de quelques especes benthiques et phytoplanctoniques marines

$\text{Acute toxicity of vanadium to some marine benthic and phytoplanktonic species}$The acute toxicity of vanadium as sodium metavanadate to three benthic ($\text{Carcinus}$$\text{maenas}$, $\text{Mytilus}$$\text{galloprovincialis}$, and $\text{Nereis}$$\text{diversicolor}$) and three phytoplankton species ($\text{Dunaliella}$$\text{marina}$, $\text{Prorocentrum}$$\text{micans}$ and $\text{Asterionella}$$\text{japonica}$) were studied. In general the phytoplankton were found to be more sensitive than the benthic organisms used in our experiments. Considering the results from LC₅₀ (9 days) experiments, the organisms, can be classified in the following decreasing order of sensitivity: $\text{D}$. $\text{marina}$ (0.5 ppm), $\text{A}$. $\text{japonica}$ (2 ppm), $\text{P}$. $\text{micans}$ (3 ppm), $\text{N}$. $\text{diversicolor}$ (10 ppm), $\text{C}$. $\text{maenas}$ (35 ppm), $\text{M}$. $\text{galloprovincialis}$ (65 ppm).     

Kinetics of oxidation of methylhydrazines in water. Factors controlling the formation of 1,1-dimethylnitrosamine

The kinetics of oxidation of methylhydrazine ($\text{MMH}$) and 1,1-dimethylhydrazine ($\text{UDMH}$) by dissolved oxygen in water has been measured at various acidities as a function of catalyst (cupric ion) concentration. In dilute solutions the oxidation occurs through a cupric ion catalyzed process as well as by an uncatalyzed step. The extent of formation of nitrosodimethylamine ($\text{NDMA}$) depends upon the initial $\text{UDMH}$ concentration. In dilute solutions $\text{NDMA}$ is not formed, but in more concentrated solutions, $\text{NDMA}$ formation increases with increasing $\text{UDMH}$ content, reaches a maximum at 60–80% $\text{UDMH}$ (by volume) and then decreases. The $\text{NDMA}$ yield appears to approximately parallel the viscosity of the medium, and it is speculated that the factors which control viscosity may also be responsible for governing $\text{NDMA}$ formation.     

Inhibitory Effects on Esterase Enzymes Buche and Ache in Rainbow Trout (Oncorhyncus mykiss) Produced by the Slow Release Insecticide Chitosan Diethyl Phosphate

The study on the toxicity of chitosan diethyl phosphate (ChDP), a controlled release insecticide, on the activities of butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) in rainbow trout exposed to this pesticide was carried out. It was found that ChDP reduced BuChE activity in O. mykiss by a factor of eight at 6 days, with high fluctuation to the end of the exposition time at 12 days. The in vitro analysis of brain AChE treated with ChDP and Phenamiphos showed that it was competitively inhibited by both organophosphates. The values obtained for K_m and V_max for the AChE-ChDP (K_m: 21.23 μ M; V_max: 43.10 μ mol/min/g) and AChE-Phenamiphos (K_m: 38.62 μ M; V_max: 38.91 μ mol/min/g) systems were relatively low compared to values of the AChE (control) system (K_m: 62.99 μ M; V_max: 63.29 μ mol/min/g). Results reported in this study confirmed that chitosan diethyl phosphate performs similarly to organophosphate pesticides, producing inhibition in cholinesterases in rainbow trout.     

Metabolites of diisopropylnaphthalene in carp Part 2. Invitro experiment

This study described an $\text{in}$$\text{vitro}$ experiment on biotransformation of 2,6-DIPN in carp hepatopancreas. It has already been revealed by the previous $\text{in}$$\text{vivo}$ studies to be metabolized with enzymatic oxidation in the liver and been postulated a metabolic pathway. These results were confirmed by means of incubation with 2,6-DIPN in carp hepatic microsome preparation with NADPH, and G-6-P as co-factor. It was suggested that DIPN may be mainly metabolized in the hepatic cytochrome P-450 in the microsomes system. The kinetic parameters i.e. apparent Michaelis constant (Km) and maximum velocity (Vmax), in the metabolites formation were also calculated.     

Di-n-butyl phthalate degrading endophytic bacterium Bacillus amyloliquefaciens subsp. strain JR20 isolated from garlic chive and its colonization in a leafy vegetable

The bioconcentration and elimination of racemic benalaxyl (BX) in trout liver microsomes and in juvenile rainbow trout (Oncorhynchus mykiss) were investigated to determine whether the fish can bioconcentrate and degrade this fungicide enantioselectively. Both enantiomers of BX were extracted with organic solvents and evaluated using high-performance liquid chromatography. In the microsomes, BX degradation followed first-order kinetics, and the S?(+) enantiomer of BX was eliminated twice as rapidly as the R?(?) enantiomer, resulting in residues enriched for R?(?)?BX. In vivo experiment, chiral analysis showed an obvious selective bioconcentration of BX based on statistically altered enantiomer fractions (EFs) in the fish compared with the values in the water. The R?(?)?BX was initially preferentially bioconcentrated by rainbow trout and then dissipated more slowly than its antipode. The mean half-lives for individual enantiomers were calculated as 31.6 h for R?(?)?BX and 20.3 h for the S?(+)?form. The results of the study showed that the degradation of BX enantiomers was stereoselective in rainbow trout.     

Photoreaktionen von Stickstoffdioxid mit Indan in Lösung

Photochemical reactions of nitrogendioxide and indane $\text{1}$ were investigated in homogeneous phase with wavelengths above 290 nm. Nitro- and hydroxyindanes were isolated as the principal transformation products. The resulting photoproducts $\text{2}$ - $\text{9}$ could be identified by spectroscopical methods such as ¹H-NMR, UV, IR and MS.