摘要:

The electrophoretic protein profile and residue levels of selected persistent insecticides were investigated in 160 mother's milk samples representing 20 different locations in Egypt. Nine major protein bands were detected in all of the samples. These protein bands were designated as lactoferrin, albumin, SIgA heavy chain, casein I, casein II, SIgA light chain, casein III, lysozyme and α‐lactalbumin. Residue levels of DDT and its metabolites as well as lindane and its other hexachlorocyclohexane isomers were determined using electron capture gas chromatography and confirmed by gas chromatography/mass spectrometric analysis. Samples containing relatively higher residue levels of the DDT group (DDT, DDE and DDD) showed significant effects on the levels of lysozyme and a‐lactalbumin bands relative to samples with low or no residue levels. On the other hand, the casein subunits were mostly affected by the residue levels of hexachlorocyclohexane isomers (α, β,γand δ isomers). The two patterns showed characteristic dose response correlation suggesting that the protein profile of human milk may serve as a quick biomarker for exposure to persistent insecticides.

ISSN:0360-1234    

DOI:10.1080/03601239809373169

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

This study paper reports on two cases of poisoning with the organophosphorus insecticides, fenthion and omethoate. The two victims were admitted in the Intensive Care Unit (ICU) a few hours after ingestion of the two insecticides. They received appropriate treatment for organophosphorous poisoning (gastric lavage, activated charcoal, atropine and pralidoxime) and supportive care. Both patients survived. Organophosphate blood levels were determined on admission (fenthion 2.9 (ig/ml, omethoate 1.6 Hg/ml) and during the hospitalisation and proved to be considerably high. Slow elimination rate of the poison already distributed in the body was indicated for both pesticides. The patient with omethoate poisoning remained clinically well (Glasgow Coma Scale : 15) and was discharged three days later. The patient with fenthion poisoning, who had also ingested 30 mg of bromazepam and 720 mg of oxetoron, developed cholinergic crisis six hours after admission and was intubated for 24 days, with concomitant complications.

ISSN:0360-1234    

DOI:10.1080/03601239809373170

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Atrazine and metolachlor co‐application to soil created competitive sorption between the two herbicides, producing smaller partitioning coefficients than for separate atrazine and metolachlor applications. The partitioning coefficients for both compounds were also less when applied in a commercial formulation, compared with separate analytical‐grade applications. Since the Freundlich slope of the isotherms was less than unity (0.83 to 0.87), the sorption strength of the herbicides decreased with increasing solution concentrations. Based on the Freundlich adsorption values obtained, this study concludes that atrazine and metolachlor co‐applications on agricultural fields have the potential to increase the mobility of these herbicides in soil, thereby also increasing the risk for groundwater contamination.

ISSN:0360-1234    

DOI:10.1080/03601239809373171

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The objective of this study was to determine if atrazine (2‐chloro‐4‐ethylamino‐6‐isopropyl‐1,3,5‐triazine), alachlor [2‐chloro‐N‐(2,6‐diethylphenyl‐N‐(methoxymethyl)acetamide], or inorganic nitrogen was present on wind‐eroded sediments collected from road ditch areas in mid to late winter. Sediment samples that had been deposited in ditches on top of snow were collected during the winters of 1994, 1995, and 1996 at randomly selected sites in eastern South Dakota and western Minnesota. Atrazine, atrazine metabolites [deethylatrazine (DEA)(6‐chloro‐N‐l‐methylethyl‐l,3,5‐triazine‐2,4‐diamine], and deisopropylatrazine (DIA) (6‐chloro‐N‐ethyl‐l,3,5‐triazine‐2,4‐diamine), and alachlor were determined by gas chromatography. Total inorganic N (NO3‐+ NH4+) concentration was determined with a nitrogen analyzer. In all years, atrazine was detected in at least 72% of the samples, with a mean concentration of 8.9 ug kg‐1and, while DEA was detected in at least 18% of the samples. Alachlor was detected in at least 27% of the soil samples for all three years with mean sediment concentration of >5 ug kg‐1. Inorganic N concentration of all samples averaged 33 mg kg‐1. These data suggest that deposition of wind‐eroded sediment contributes to nonpoint source contamination of nontarget areas by agrichemicals.

ISSN:0360-1234    

DOI:10.1080/03601239809373172

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Biodegradation of chlorpyrifos was studied in liquid culture media amended with either single or combined eight different plant pathogenic fungi isolated from the continuous cropping wheat fields. The average recovery of chlorpyrifos from the liquid media was found to be 86.1%. The detection limit of chlorpyrifos by the analytical method used was 19 ppb. Data showed that the growth of mixed fungi at concentrations up to 200 ppm of chlorpyrifos was higher than in the control treatment. Chlorpyrifos concentrations declined in the medium of combined fungi more than it did in the medium of any single fungus with increase in the incubation period. The amount of chlorpyrifos recovered was 79.8 ppm (39.9%) in the combined fungal cultures after 21 days. However, those recovered from the media ofFusarium graminearum, F. oxysporum, Rhizoctonia solani, Cladosporhim cladosporiodes, Cephalosporium sp., Trichoderma viridi, Alternaria alternata, and Cladorrhinum brunnescens,ranged from 48.0 to 74.8%. The half‐life value (T1/2) for chlorpynfos was 15.8 day in the medium amended with mixed fungi. However, for the single cultures it ranged from 19.3 to 33.0 day.

ISSN:0360-1234    

DOI:10.1080/03601239809373173

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The rate and extent of trichloroethylene (TCE) degradation by three cultures of phenol oxidizing bacteria grown from two chemostats and one from rotating biological contactors was investigated. Batch experiments were performed to measure the disappearance of TCE both with the resting cell alone and with the formate added. Experimental data were then compared with mathematical predictions from a model describing TCE transformation. Through nonlinear regression analysis, a best fit between the measurements and predictions was achieved when residual sum of squares reached a minimum. Based on the resultant parameters of transformation capacity and reaction rate, the suspended cells with a mean cell retention time (MCRT) of 3.8 days were the most active in degrading TCE, while the attached bacteria had the least activity. Based on the results presented herein, it is recommend that using suspended‐growth reactors operated at short MCRT to produce desirable cells for cometablic transformation of TCE.

ISSN:0360-1234    

DOI:10.1080/03601239809373174

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Research of 2,4‐chlorophenol and 2,4,6‐trichlorophenol in aqueous solution using the photo‐Fenton process was conducted in two parts. The first part of the study explored the treatment efficiency and reaction rate expression of 2,4‐chlorophenol and 2,4,6‐trichlorophenol. With respect to the simulated experimental data, the relationship between the reaction rate for 2,4‐chlorophenol and 2,4,6‐trichlorophenol and H2O2concentration was expressed as a first‐order reaction and that between the reaction rate and the Fe(II) concentration was a saturation‐type reaction. In the second half of this study, chlorohydroquinone, catechol, dichlorocatechol, and dichlororesorcinol were found in the photo‐Fenton process by GC/MS. Some of these identified intermediates were more toxic than the primary compound.

ISSN:0360-1234    

DOI:10.1080/03601239809373175

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

This study was undertaken to develop a method for the extraction of trifluralin (α,α,α, trifluoro‐2,6 ‐ dinitro‐N,N ‐ dipropyl‐p‐toluidine) from soil and humic acid. The adsorption‐desorption constants were evaluated through Freundlich isotherms. The studies were carried out with a Podzolic soil from Pindorama, SP, with the humic acid (HA) extracted from the same soil, with the same soil free of organic matter by calcination, and finally with the same soil fortified with 2% of humic acid. The results indicated that the quantity of organic matter was a key factor for the adsorption of the herbicide trifluralin in soil. The order followed by trifluralin with respect to its adsorption was: humic acid > soil spiked with 2% of humic acid > soil > calcinated soil.

ISSN:0360-1234    

DOI:10.1080/03601239809373176

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Glutathione content and glutahione‐dependent enzymes were measured in the liver of two fish species, gudgeon(Gobio gobio)and roach(Rutilus arcasii),from the river Bernesga (Spain) caught downstream and upstream of the waste site of several chemical industries. Animals from contaminated sites display a reduced glutathione concentration and a tendency to the decrease of glutathione S‐transferase activity. Glutathione peroxidase activity was significantly elevated only in the liver ofGobio gobioand glutathione reductase activity in that ofRutilus arcasii.Our data indicate that the glutathione system constitutes a sensitive biochemical indicator of chemical pollution. Relative changes of glutathione and glutathione‐dependent enzymes in both fish species suggest a different susceptibility to toxins.

ISSN:0360-1234    

DOI:10.1080/03601239809373177

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Acute and chronic toxicity tests with diazinon (diethyl 2‐isopropyl‐6‐methyl‐4‐pyrimidinyl phosphorothionate) were conducted onDaphnia magna.The 24‐hr static LC50 was 0.86 μL.L‐1. The sublethal effects of 0.05, 0.1, 0.5, 0.75 and 1.0 ngL‐1of diazinon concentrations on the survival, reproduction and growth ofD. magnawere monitored for 21 days. The algaeNannochloris oculata(5 x 105cellsmL‐1) was used to feed the daphnids. The parameters used to determined the effect of the pesticide onD. magnawere: mean total young per female; mean brood size; days to first brood; intrinsic rate of natural increase (r); growth; and survival. Reproduction as well as survival was significantly reduced at diazinon concentrations of 0.10 ngL‐1and higher. The intrinsic rate of natural increase (r) decreased with increasing concentrations of diazinon. Growth, as measured by body length, was depressed significantly at 0.05 ngL‐1of diazinon and higher concentrations. The maximum acceptable toxicant concentration (MATC) was calculated. The chronic data was used to formulate an acute/chronic ratio.

ISSN:0360-1234    

DOI:10.1080/03601239809373178

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor