Showing papers in "Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes in 1986"

Effects of wastewater from olive processing on seed germination and early plant growth of different vegetable species

Abstract: The effects of wastewater from olive processing on seed germination and early plant growth of different vegetable species were examined Three types of wastewater at different concentrations were tested: raw wastewater, wastewater with organic matter removed and deionized wastewater Results generally indicate an inhibitory effect on seed germination and early plant growth by all treatments containing any kind of wastewater Of the three types of effluent, raw wastewater had the greatest depressive effect, followed by deionized wastewater and finally effluent with organic matter removed Barley showed the least sensitivity to phytotoxic effects while tomato was the plant most affected The remaining vegetable species showed an intermediate sensitivity

Degradation and metabolism of Oxamyl and phenamiphos in soils

Abstract: Degradation and metabolism of the nonvolatile nematicides‐insecticides [14C]oxamyl and [14C]phenamiphos (P) were investigated using three Southeastern U.S. soils (Arredondo sand, Cecil sandy loam and Grenada silt loam). Oxamyl in moist soils (10 and 33 kPa) was rapidly mineralized to CO2, with N,N‐dimethyl‐2‐(methylthio)acetamide oxime (DMAO) being the major intermediate metabolite. Half‐lives (t½) for extractable 14C in [14C]oxamyl treated soils ranged from 8 to 50 d. Although the principal 14C component in organic solvent extracts was oxamyl, 4 to 27% of applied 14C in the extracts were found to be associated with metabolites. Consequently, t½ values for oxamyl would be smaller than t½ values for extractable 14C. Oxidation of ? to phenamiphos sulfoxide (PSO) in Arredondo soil was rapid. PSO was then slowly degraded to phenamiphos sulfone (PSO2), and at the same time PSO was also hydrolyzed to PSO phenol. Total toxic residue (TTR = ? + PSO + PSO2) in moist soil (10 and 33 kPa) disapppeared more ...

Persistence of granular and EC formulations of chlorpyrifos in a mineral and an organic soil incubated in open and closed containers

Abstract: Samples of a mineral soil (Plainfield sand) and an organic soil (muck) were treated with granular and EC formulations of chlorpyrifos and incubated at 27±1°C and 65±5% RH in open and closed containers. Duplicate samples of each soil‐formulation‐container combination were analyzed for residual chlorpyrifos during a 23 wk period. The disappearance rates observed demonstrate that the relative importance of formulation and containment on overall persistence depends on soil type. For the mineral soil, disappearance was slower from closed containers and formulation had only a slight effect while, in the organic soil the granular formulation disappeared slower than the EC and there was little difference between open and closed containers. The relative importance of degradation and volatilization in the disappearance of chlorpyrifos from soil is discussed.

Observations on the effect of soil type, treatment intensity, insecticide formulation, temperature and moisture on the adaptation and subsequent activity of biological agents associated with carbofuran degradation in soil

Abstract: A sand, a sandy loam, a clay loam, and an organic (muck) soil all developed anti‐carbofuran activity within 28 days of an initial treatment. This activity was demonstrated by the rapid disappearance of the insecticide from the soils on retreatment. In all except the muck, homogeneous initial treatments of 10 and 1 ppm caused activity to develop while treatments of 0.1 and 0.01 ppm did not. Muck soil developed activity when treated at 100 and 10 ppm. Activity did not develop in the sandy loam at 1.3 and 4.5% moisture, but did at 5 higher moisture levels tested (9 to 36%). Likewise clay loam did not become active within 28 days when held at 20% moisture but did at 30, 40 and 50%. The effect of treatment intensity, formulation and temperature on activity development was examined only for the sandy loam. Activity developed on treatment with both granular and flowable formulations. Activity did not develop within 28 days at 3°C, but did at 15 and 28°C. Activated sandy loam maintained its activity when...

Comparative studies of the fate of atrazine‐14C and pentachlorophenol‐14C in various laboratory and outdoor soil‐plant systems

Abstract: Mass balance and fate of atrazine‐ 14C and pentachlorophenol‐ 14C (PCP‐ 14C) were studied in short‐term tests in a closed aerated laboratory soil‐plant system, using two concentrations in soil and two plant species, as well as under outdoor conditions for one vegetation period. In the laboratory, for both pesticides bioaccu‐mulation factors of radiocarbon taken up by the roots into plants were low. They were higher for lower (1 ppm) than for higher soil concentrations (6 ppm for atra‐zine, 4 ppm for pentachlorophenol) and varied with the plant species. Mineralization to 14CO2 in soil was negatively related to soil concentration only for PCP‐ 14C. Conversion rates in soil including the formation of soil‐bound residues were higher for the lower concentrations of both pesticides than for the higher ones; conversion rates in plants were species‐dependent. In 14 terms of CO2 formation and of conversion rates, PCP was less persistent in soil than was atrazine. For both pesticides, laboratory data on co...

Accumulative sampling of trace pesticides and other organics in surface water using xad‐4 resin

Abstract: XAD‐4 resin accumulative sampling was tested as a means of on‐site extraction of surface waters. Recoveries for most organochlorine, organophosphorus, organonitrogen, chlorophenol, and chlorophenoxy acid pesticides and related pollutants were acceptable (>50%) when spiked at the 10 and 0.1 ppb levels. Detection limits of 1–100 ppt were attainable for most compounds in river water, although lower levels required the use of an HPLC cleanup/fractionation step prior to those GC determinations using electron‐capture detection. XAD‐4 accumulative sampling was competitive with solvent extraction of grab samples in terms of recoveries, and offered advantages in volume of water sampled, detection limits, and sample handling. The wide range of solute applicability combined with the ease of constructing and operating the accumulative sampler recommends it over grab sampling for many types of monitoring applications.

Trace metal residues in finfish from Maryland waters, 1978-1979.

Abstract: Levels of seven heavy metal residues, arsenic, cadmium, chromium, copper, lead, mercury and zinc were monitored in samples of various species of finfish harvested from the Maryland section of the Chesapeake Bay and its tributaries over a two year period (1978-79). Results of the analysis of the edible portions of these finfish are presented along with the species of finfish, date and location of harvest. A number of samples of finfish gonad and liver tissue were analyzed to study the relative level of preconcentration of heavy metals in these tissues compared to the edible (flesh) portion. Results of this study are consistent with other available data for Atlantic Coast finfish. Gonad tissue, when compared to flesh, show enrichment of copper and zinc and decreased mercury and cadmium levels. Liver tissue shows enrichment in copper, zinc and cadmium and generally lower levels of mercury compared to flesh.

Biodegradation of pesticides in soil: Rapid degradation of isofenphos in a clay loam after a previous treatment

Abstract: In May 1983, isofenphos (Amaze® 20G) was applied in a 15 cm wide band at 11.0 g AI per 100 m to clay loam soil contained in duplicate small field plots and it was incorporated into the soil by light raking to simulate application for corn rootworm, Diabrotica spp., control. Soil samples were taken from within the band at intervals over 49 wk and were analyzed for insecticide content. After soil samples were taken from the band in the spring of 1984, the soil was thoroughly mixed and the application, sampling and analyses were repeated. In 1984 isofenphos was much less persistent than in 1983. Laboratory tests with 1984 soil samples taken pretreatment and 3 and 10 wk post‐treatment all showed that isofenphos disappeared significantly faster in previously‐treated soil compared to previously‐untreated control soil, ie. 1–2% vs 55–83% remaining after 7 days, suggesting that soil microorganisms had developed a capacity for rapid isofenphos degradation.

Assessment of teratogenic potential of trichlorfon in mice and rats

Abstract: Trichlorfon was evaluated for its teratogenic potential in the CD‐1 mouse at doses of 200, 300 or 400 mg/kg/day administered by gavage on days 7–16 of gestation. In the CD‐1 mouse, TCF was teratogenic, fetotoxic and lethal at the two highest dose levels which were also maternally lethal. At the lowest dose level which was not maternally lethal, there was a significant decrease in the number of calcified centers in the forepaws and hindpaws indicating fetotoxicity and a delay in maturation. TCF was administered at doses of 50, 100 or 200 mg/kg/day to CD rats by gavage on gestational days 7–19 (study I) or 8–20 (study II). In the CD rat in both study I and II, the highest dose level was maternally lethal. In study I, TCF was teratogenic with a shift in rib profile. In study II, TCF was teratogenic with an increased incidence in malformations of the urinary system. Additionally, TCF was fetotoxic with reduced ossification of the skulls at the lowest and highest dose levels.

Aflatoxin decomposition in various soils

Abstract: The persistence of aflatoxin in the soil environment could potentially result in a number of adverse environmental consequences. To determine the persistence of aflatoxin in soil, 14C‐labeled aflatoxin B1, was added to silt loam, sandy loam, and silty clay loam soils and the subsequent release of 14CO2 was determined. After 120 days of incubation, 8.1% of the original aflatoxin added to the silt loam soil was released as CO2 • Aflatoxin decomposition in the sandy loam soil proceeded more quickly than the other two soils for the first 20 days of incubation. After this time, the decomposition rate declined and by the end of the study, 4.9% of the aflatoxin was released as CO2. Aflatoxin decomposition proceeded most slowly in the silty clay loam soil. Only 1.4% of aflatoxin added to the soil was released as CO2 after 120 days incubation. To determine whether aflatoxin was bound to the silty clay loam soil, aflatoxin B1 was added to this soil and incubated for 20 days. The soil was periodically extra...

Calculating biodegradation rates

Abstract: Mathematical modeling of biodegradation is useful in determining the rate of loss of parent compound and the rate of production of secondary metabolites. These measures are important in estimating the persistence of xenobiotics in the environment. This paper reviews methods of fitting one and two compartment models to experimental data. Models for both decrease in parent compound and increase in metabolites in batch systems are discussed. The uses of the various mathematical parameters derived from the models are summarized.

Screening pesticides for their ability to damage bacterial DNA

Abstract: Twenty-six pesticides and pesticide degradation products were screened (125 micrograms - 2000 micrograms) for their ability to induce unrepairable damage to bacterial DNA. Three repair test systems were utilized in this study, the Salmonella typhimurium (TA1538/TA1978), the E. coli K-12 (Pol A1+/Pol1-) and the E. coli WP2 (WP2, WP2uvrA, WP67, CM611 and CM571). Aldicarb (1000 micrograms), benomyl (250 micrograms), 2-aminobenzimidazole (2000 micrograms), captan (125 micrograms), fenazalor (500 micrograms), 5,6-dichloro-2-trifluoromethylbenzimidazole (NC-2983) (250 micrograms), isothymol (250 micrograms), maleic hydrazide (1000 micrograms), pentachloronitrobenzene (1000 micrograms) were DNA-damaging to one or more bacterial test systems. Isothymol and NC-2983 affected all three test systems. Chlorinated hydrocarbon insecticides, some being recognized as carcinogens, did not produce a zone of inhibition in any of the tester strains possibly due to their poor solubility and diffusion in the agar overlay. It was concluded that these tests can be performed along with bacterial reversion tests to complement each other as short-term screening tests for potential carcinogens and mutagens.

Absorption, deposition and distribution of dietary aluminium in immature rats: Effects of dietary vitamin D3 and food‐borne chelating agent

Abstract: We report the levels of aluminium, calcium and potassium in selected tissues of growing rats administered dietary or subcutaneous aluminium, and also the effect of dietary aluminium in combination with cholecalciferol, or with lactose plus a dietary chelating agent. Dietary aluminium decreased the growth rate of normal rats and increased the deposition of aluminium in the tissues. Animals given lactose with a dietary chelator showed a 17 ‐ 100% increase in brain, heart, and muscle aluminium concentration in comparison with those fed aluminium alone. Animals fed both aluminium with cholecalciferol also showed increased levels (12–39%) of aluminium, chiefly in muscle and heart in comparison with those fed aluminium alone. Aluminium deposition was correlated positively with Ca2+ and ?+ levels among each of these tissues. We conclude that in normal growing rats aluminium deposition is increased in heart and muscle in the presence of vitamin D3 and in brain, heart and muscle in the presence of lactose...

Organophosphate dichlorvos induced dose-related differential alterations in lipid levels and lipid peroxidation in various regions of the fish brain and spinal cord.

Abstract: The effect of dichlorvos (DDVP) (0–0, dimethyl 2: 2‐dichlorovinyl phosphate), on various lipid fractions and lipid peroxidation in the discrete areas of the brain and spinal cord were studied in the fresh water teleost (Heteropneustes fossilis). Fishes were exposed to three different doses (3.0, 6.0 and 9.0 ppm) of DDVP daily for 7 days. Dose‐related increase in the levels of total lipids, cholesterol and esterified fatty acids was detected in the fore brain, optic lobes, cerebellum, medulla oblongata and spinal cord. However, phospholipids were significantly decreased in the aforementioned regions of the central nervous system. The rate of lipid peroxidation was significantly increased in all the regions of the CNS.

Plant availability of bound anilazine residues in a degraded loess soil

Abstract: The relative biological availability of benzene ring-U-/sup 14/C and triazine-U-/sup 14/C anilazine for maize plants was studied in a degraded loess soil in a standardized microecosystem. The total uptake of radiocarbon in the course of the 4-week experiment was 3.1 and 4% respectively of the radioactivity applied if anilazine was uniformly mixed into the soil immediately before beginning the experiment. However, if anilazine was subjected to a degradation at 65% of the maximum water holding capacity of the soil and temperatures varying daily between 16 and 27/sup 0/C for 100 days before the plant experiment then the uptake was reduced to 0.4 or 0.7% respectively. The uptake from soil with non-extractable (bound) anilazine residues was similarly low. The mineralization rate of aged and bound anilazine residues was below 0.1% of the radioactivity applied. Up to 2/3 of the radioactivity present in the soil after the plant experiment remained in the humic fraction.

The effect of formulation and moisture level on the persistence of carbofuran in a soil containing biological systems adapted to its degradation

Abstract: In a laboratory experiment in which soils were mixed frequently in an effort to maintain homogeniety, technical carbofuran was rapidly degraded to 95% of the initial application remained after 24 hr but significant and variable loss was observed after 3 days (87–10% remaining). In contrast, there was no significant difference in the rate of disappearance of a granular formulation of carbofuran (Furadan® 15G) from previously‐treated and previously‐untreated soils when maintained at 11.3% moisture: Disappearance was relatively slow requiring 3 wk for ca. 90% decrease. When maintained at 27.0% moisture, the rate of disappearance of the granular formulation from the previously‐treated soil was significantly different from that in the previously‐untreated soil (eg. 2 vs 80% remaining at 7 days). The results demonstrate that an adapted soil micr...

A simple method to determine relative volatilities of aqueous formulations of pesticides

Abstract: A simple gravimetric method was developed to determine relative volatilities of aqueous formulations of pesticides. The technique involved evaporation of a liquid film from a plastic mesh surface. The suitability of the method for volatility determinations was tested against liquids of known boiling points, and adjuvant solutions of different concentrations. During the initial stage of evaporation, the percentage of weight remaining at time ‘t’ followed a nearly linear decrease with most formulations. At the second stage, however, a curvilinear decrease was noted, followed by an asymptotic limit at the final stage. Regression analysis of the data obtained during the first two stages of evaporation indicated that the method is sensitive enough to identify small differences in the evaporation rates of aqueous formulations of pesticides.

Teratogenicity of bifenox and nitrofen in rodents.

Abstract: The teratogenicity of the diphenyl ether herbicide bifenox [2,4-dichlorophenyl 3'-carboxymethyl-4'-nitrophenyl ether] was compared to that of nitrofen [2,4-dichlorophenyl 4'-nitrophenyl ether] in rats and in mice. Neither compound increased prenatal mortality in mice. Because nitrofen causes both malformations that are compatible with survival to weaning and a high incidence of perinatal (but not of fetal) mortality, emphasis was placed on postnatal parameters of bifenox toxicity. In rats, bifenox caused a low incidence of "bloody tears", but it did not decrease survival to term or to weaning in rats or mice, and did not reduce Harderian gland weight in mice. Because the weight of the Harderian glands is a more objective measure of their status than is the presence of an eye discharge, it is concluded that bifenox is not teratogenic at the levels administered. Nitrofen decreased litter size, pup weight, and Harderian gland weight in mice.

Phosmet residues in an orchard and adjacent recreational area.

Abstract: Two cover sprays of phosmet were applied to an orchard adjoining a camping area and a bird sanctuary with a resident goose population. Insecticide residues were monitored on orchard leaves, orchard ground cover, ground cover in the camp‐site and along the adjacent lakeshore. Despite attempts to minimize drift, significant spray residues were found outside the target area. Residues on ground cover and leaves were reduced by sprinkler irrigation subsequent to spray application.

Interactions of pesticides with fresh - water algae 1. Effect of methomyl and its possible degradation by Phormidium fragile

Abstract: The insecticide methomyl showed no significant effect on the growth of the fresh‐water alga Phormidium fragile up to a concentration of 112.5 ppm. However, at higher concentrations inhibition was observed. Biochemical analysis showed a gradual decrease in all nitrogen fractions, total carbohydrate content, chlorophyll a and carotenes contents. Furthermore, a considerable decrease in the amount of both soluble and insoluble phosphorus fractions was also observed. The organism was capable of degrading 48.6% of the applied radiolabelled insecticide of which only 0.1% of 14C‐activity was trapped as 14CO2 . Furthermore, the chloroform and aqueous fractions contained 50.4% and 35.0%, respectively of the initial radioactivity. Thin‐layer Chromatographic analysis showed the presence of three metabolites of methomyl one of which was identified as the oxime.

Degradation of isofenphos in cornfields with conservation tillage practices

Abstract: Isofenphos (Amaze®, Oftanol®, 1‐methylethyl 2‐[[ethoxy‐[(l‐methylethyl)aminol phosphinothloyl]oxy]benzoate) was applied at planting to study the effects of four different tillage treatments (no‐tillage, fall chisel plow, Paraplow®, and fall moldboard plow) on isofenphos degradation rates and routes in cornfields over two growing seasons. Soil samples were taken at intervals extending over 69 days each growing season. Tillage treatment had no significant effect on isofenphos degradation rates and products. However, the repeated application of isofenphos had a very significant effect on lsofenphos degradation. Degradation was much more rapid the second year. A laboratory experiment comparing sterile and nonsterlle soils, with and without isofenphos history, confirmed enhanced mlcrobial degradation resulting from two consecutive years of isofenphos application. In the first year, isofenphos oxon was found at greater amounts relative to the second year. Soil bioassays conducted on soils collected fro...

Toxicity of some ricefield pesticides to the crayfish P. Clarkii. under laboratory and field conditions in lake albufera (Spain).

Abstract: Static toxicities in mature crayfish (Procambarus clarkii) were determined, for eight insecticides, two herbicides and one fungicide which were frequently used in rice cultivation at Lake Albufera in Valencia (Spain). Three concentrations of each product were used: a) The concentration that was recommended by the dealer (in mg/L of active ingredient): Carbofuran 0.40, Carbaryl 0.80, Malathion 0.80, Trichlorfon 0.40, Endosulfan 0.56, Lindane 0.56, Fenitrothion 0.40, Cyfloxylate 0.02, Molinate‐Thiobencarb 1.50, Copper Sulfate 0.42. b) Half of the recommended concentration, c) Double of the recommended concentration. In all three of the concentrations tested, only Fenitrothion and Cyfloxylate caused a considerable mortality. The other ones do not actually produce any important effects on P. clarkii in our conditions. Nevertheless, insecticides are more toxic than herbicides or fungicides, as the latter show a rather low toxicity.

Chemical residues during screening, composting, and soil incorporation of cotton gin waste

Abstract: Residues of pesticides and harvest aid chemicals (defoliants) were studied in the products of ginning of cotton. Particular emphasis was on residue partitioning during the mechanical separation of cotton gin waste into its clean (primarily lint) and fines (primarily dirt and plant parts) fractions following rotating screen separation. The higher residues were associated with the fines fraction among the two chemicals (DEF and dicofol) studied in this regard. The behaviour of residues of five chemicals was studied during aerobic and semi‐anaerobic Composting of both whole gin waste and the fines fraction. Propargite, methidathion, and chlorate residues declined significantly during both composting treatments while DEF and paraquat were stable to composting, when composted gin wastes were amended to field soil, residue levels were generally very low to undetectable in the soil, indicating little potential hazard for a composting‐amendment operation. Analysis of air samples indicated that only the s...

Kinetics and mechanisms of interaction of simazine with humic acids

Abstract: The adsorption of simazine on two fractions of hu‐mic acids of different molecular size was investigated at a pH range of 2.5 to 6.2. The amounts of the herbicide adsorbed decreased with increasing pH for both of the two humic acids fractions used and no adsorption was observed at pH 5.5. The adsorption capacity of fraction I (Mv >100,000) exceeded that of fraction IV (Mv < 4,000) over the entire pH region used. No appreciable changes in the adsorbed amounts were observed after 24 hours. Continuous flow dialysis techniques were used to determine the extent of binding between simazine and dissolved humic acids. It was observed that 50% and 60% of simazine added were thus removed from the dialysis bags containing humic acids fractions I and IV,respectively. Higher amounts of simazine were adsorbed by the high molecular weight humic fraction. The adsorption processes involve ionic bonds between simazine and humic acids. In addition it is likely that hydrogen bonds and physical forces are also involv...

Residues of dicofol on cucumber grown under plastic covers in Jordan.

Abstract: Residues of dicofol were determined on cucumber leaves and fruits under plastic house (PH) and plastic tunnels (PT). Five sprays, 8 d apart, were applied at 0.15% concentration. initial deposits on leaves were 48 and 58 ppm under PH and PT, respectively. In the last sampling date of leaves, the amounts of 191 and 135 ppm were detected under both cultures, respectively. There was a continuous increase in the initial residue after each spray. The highest amount of dicofol (401) was determined 1 d after the fifth spray under PH. The exposure to high residues may pose a risk to fieldworkers. On cucumber fruits, residues of 0.95 and 1.60 ppm were determined 1 d after the fourth spray under PH and PT, respectively. These residues decreased after 4 d to 0.40 and 1.49 ppm, respectively. Almost no detectable residues could be determined 8 d after sprays number 4 and 5 under both cultures. All dicofol residues on the fruits were below the tolerance level of 2 ppm.

Minimizing environmental exposure of 1,2-dibromoethane (EDB) by cold trapping in a fumigation chamber

Abstract: A new approach for fumigating citrus with EDB was recently investigated with the dual objective of reducing exposure to the atmosphere following its use and for recycling the fumigant after an operation for continued use. The principle is based on cold trapping the EDB vapors out of the air following the fumigation process. Three progressive studies were undertaken starting from a simple laboratory investigation to evaluate it technical feasibilitv and enventually a 12 m3 field model fumigation chamber equipped with a conventional 2.72 ton (metric) air conditioning was assembled to verify its technical feasibility into a commercial operation. Using this less than optimum model system, it was shown that up to 78% of ?D? vapors were trapped onto cold coils followed by recycling of the vapors with air movement and warm temperatures. It was also observed that EDB decomposes rapidly in the presence of hot metallic surfaces and that special precautions are necessary in order to prevent decomposition in...

A comparative evaluation of dislodgable and penetrated residues, and persistence characteristics of aminocarb and fenitrothion, following application of several formulations onto conifer trees

Abstract: A comparative evaluation of dislodgable and penetrated residues, and persistence patterns of aminocarb and fenitrothion, was made using several formulations containing diluents with different physi‐cochemical characteristics. Spray was applied onto single spruce trees in a tree farm in Shawville, Quebec, using a dosage rate of 90 g AI (active ingredient)/ha for aminocarb and 340 g AI/ha for fenitrothion. Droplet and deposit data were also obtained simultaneously on sampling units. The data indicated that, with both insecticides, low‐volatility diluents provided larger droplets, higher deposits and foliar residues than high‐volatility diluents. The rate of dissipation and persistence patterns of the dislodagable and penetrated residues were also related to the type of diluents used. However, the penetrated residues dissipated slower than the dis‐lodgable residues, indicating their tendency to resist environmental loss by volatilization, photodegradation and leaching by rain. The amounts of dislodg...

Diazinon treatment effects on heart and skeletal muscle enzyme activities.

Abstract: The effects of low levels of diazinon treatment on four marker enzymes in rat heart and skeletal muscle have been investigated. Adult male Wistar rats were treated twice a week with a dose of 0.5 ml‐kg‐1day‐1 diazinon for 28 weeks. Diazinon treated rats gained significantly less weight than Sham‐treated controls. Typical differences in Succinate dehydrogenase (SDH), Lactate dehydrogenase (LDH), Phosphofructo kinase (PFK) and Hexokinase (HK) activities were observed between heart and skeletal muscles. Diazinon feeding had no effect on heart, soleus, gastrocnemius and plantaris SDH, LDH and PFK enzyme activities after 28 weeks. HK activity was significantly increased in sham‐control soieus and plantaris muscles after 28 weeks. Diazinon feeding inhibited HK activity in plantaris muscle after 28 weeks treatment These results demonstrate that chronic low levels of diazinon have little effect on the glycolytic and oxidative activity in heart and skeletal muscle.

Regulation of aflatoxin biosynthesis: effect of adenine nucleotides, cyclic AMP and N6-O2' -dibutyryl cyclic AMP on the incorporation of (1-14C)-acetate into aflatoxins by Aspergillus parasiticus NRRL-3240.

Abstract: Adenosine triphosphate (ATP) was found to inhibit the incorporation of labelled acetate into aflatoxins while adenosine diphosphate (ADP) and adenosine mono‐phosphate (AMP) stimulated the process. Exogenous cyclic AMP and its derivative, N6 ‐O2‘ ‐dibutyryl cyclic AMP produced efficient (1‐14C)‐acetate incorporation into aflatoxins at all the concentrations tried (0.1 , 0.5 and 1 mM) . The stimulation of incorporation of labelled acetate into aflatoxins was significant at 0.1 and 1 mM concentration of the cyclic nucleotide but was found to be maximum at 0.5 mM concentration.

Evaluation of Beta‐naphthoxyacetic Acid for Mutagenic Activity in the Salmonella/mammalian Microsome Assay

Abstract: Beta-naphthoxyacetic acid (BNOA) is used as a plant growth regulator on tomatoes and strawberries. It is the active ingredient in Blossom-Set and Berry-Set, two plant hormone sprays for fruit-set. The mutagenic activity of BNOA was evaluated in four strains of Salmonella typhimurium (TA97, TA98, TA100 and TA1535) in the presence and absence of liver microsomal and cytosolic enzymes derived from Aroclor induced rats. BNOA did not produce any significant increase (p less than 0.05) in the reversion of any of the four tester strains in the standard plate incorporation assay. Results of the agar overlay toxicity tests indicates that the chemical shows toxic effects at concentrations above 500 micrograms/plate. It was concluded that under the conditions of these tests, BNOA did not exhibit any mutagenic activity.