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PubMed2001

Isomeric effects on thiosulfate transformation and detoxification of 1,3-dichloropropene.

The fumigant 1,3-dichloropropene (1,3-D) is one of the most heavily used pesticides but also a suspected carcinogen. Previous research has shown that 1,3-D was rapidly transformed and detoxified by ammonium thiosulfate (ATS), a sulfur and nitrogen fertilizer. As common formulations contain cis and trans isomers at roughly equivalent ratios, this study was conducted to understand isomeric differences in thiosulfate transformation and detoxification of 1,3-D. Under the same conditions, reaction of cis-1,3-D with thiosulfate was more than three times faster than trans-1,3-D, which was correlated with a lower reaction activation energy for the cis isomer. The trans isomer was considerably more toxic to the luminescent bacteria Vibrio fisheri than the cis isomer, but the toxicity was reduced by 14 times after thiosulfate transformation. Mutagenic activity to strains of Salmonella typhimurium was observed for trans-1,3-D but was not detected after thiosulfate transformation. These results suggest that thiosulfate transformation detoxifies 1,3-D primarily by deactivating the trans isomer, and the reaction is toxicologically beneficial, as it negates the potential harmful effects of 1,3-D to the environment and human health.

Allyl Compounds↗

PubMedDate not supplied

A dynamic two-dimensional system for measuring volatile organic compound volatilization and movement in soils.

There is an important need to develop instrumentation that allows better understanding of atmospheric emission of toxic volatile compounds associated with soil management. For this purpose, chemical movement and distribution in the soil profile should be simultaneously monitored with its volatilization. A two-dimensional rectangular soil column was constructed and a dynamic sequential volatilization flux chamber was attached to the top of the column. The flux chamber was connected through a manifold valve to a gas chromatograph (GC) for real-time concentration measurement. Gas distribution in the soil profile was sampled with gas-tight syringes at selected times and analyzed with a GC. A pressure transducer was connected to a scanivalve to automatically measure the pressure distribution in the gas phase of the soil profile. The system application was demonstrated by packing the column with a sandy loam in a symmetrical bed-furrow system. A 5-h furrow irrigation was started 24 h after the injection of a soil fumigant, propargyl bromide (3-bromo-1-propyne; 3BP). The experience showed the importance of measuring lateral volatilization variability, pressure distribution in the gas phase, chemical distribution between the different phases (liquid, gas, and sorbed), and the effect of irrigation on the volatilization. Gas movement, volatilization, water infiltration, and distribution of degradation product (Br-) were symmetric around the bed within 10%. The system saves labor cost and time. This versatile system can be modified and used to compare management practices, estimate concentration-time indexes for pest control, study chemical movement, degradation, and emissions, and test mathematical models.

Agriculture↗

PubMedDate not supplied

An apparatus for measuring the gas permeability of films.

The gas permeability of plastic films is important in packaging, containment, and agricultural fumigation. Recently, an approach for estimating the mass transfer coefficient of vapors across a film was presented by Papiernik et al. (2001). The mass transfer coefficient is an intrinsic property of a film-chemical combination, independent of the concentration gradient maintained across the film. Here we describe an apparatus useful for obtaining permeability data; the model of Papiernik et al. (2001) may be fitted to the data to determine mass transfer coefficients. The assembled equipment provides a sealed permeability cell, where a sample of the film to be tested is sandwiched between two static half-cells. Vapor is spiked to one side of the film and the concentrations in the spiked and receiving chamber are monitored until equilibrium. A sealed system is required for this approach; the permeability cells described here were gas-tight for >40 d. This approach produces reproducible measures of mass transfer coefficients that are not dependent on the size of the experimental apparatus. Model parameters were similar when fitted simultaneously as when determined independently from the same data set.

Agriculture↗

PubMed2006

Modeling methyl isothiocyanate soil flux and emission ratio from a field following a chemigation of metam-sodium.

Metam-sodium had become the most heavily used soil fumigant in recent years as the deadline approached for methyl bromide to phase out in January 2005. After application, metam-sodium decomposes rapidly to methyl isothiocyanate (MITC), a highly toxic compound capable of killing a wide spectrum of soil-borne pests. Inhalation risk of MITC ranked high among airborne agricultural pesticides in California. Information about off-gassing intensity and percentage of emission is essential for exposure risk assessment and mitigation measures, but is limited, especially for new application methods such as drip chemigation. Air concentrations of MITC were monitored around a field treated with metam-sodium through surface drip irrigation system. The field was tarped with plastic films before the chemigation. The air concentrations at receptor locations were simulated for the period of air monitoring with the Industrial Source Complex (ISC3) Dispersion Model, and soil flux density of MITC at various periods after chemigation was estimated through a back-calculation procedure. The estimated soil flux density of MITC showed a diurnal pattern, with the daytime flux stronger than nighttime. However, the average air concentration at nighttime was higher than that at daytime. Soil flux density peaked at 4.30 microg m-2 s-1 in the first 12-h period after chemigation, then declined with time. The MITC emission percentage in the first 60-h was 2.65% of applied mass, of which 57% occurred in the first 24-h after chemigation. The study indicated that the tarped bed drip application method of metam-sodium had a relatively good control of MITC emission from soil.

Isothiocyanates↗

PubMed1988

Effects of 1,2-dibromoethane on isolated hepatocytes: functional alterations and induction of lipid peroxidation.

1. Isolated rat hepatocytes were exposed to the fumigant 1,2-dibromoethane (DBE) and cytotoxicity was evaluated by studying parameters of cellular function and lipid peroxidation. 2. DBE caused plasma membrane damage, as determined by leakage of lactate dehydrogenase, and was more severe in shaken suspensions than stationary suspensions, suggesting that cells were more fragile after DBE exposure. 3. DBE decreased hepatocyte glycogen content and stimulated albumin synthesis in hepatocyte suspensions. 4. Lipid peroxidation resulted from DBE exposure and was greater in cells isolated from phenobarbital-pretreated rats. Shaking the suspensions enhanced lipid peroxidation. Ethane production did not parallel formation of thiobarbituric acid reactants, suggesting that these parameters of lipid peroxidation reflect different mechanisms of molecular interaction of DBE.

Animals↗

PubMed1991

The effects of exercise following exposure to bis(trifluoromethyl) disulfide.

Bis(trifluoromethyl) disulfide (TFD) was originally designed for use as an agricultural fumigant. Inhalation of toxic doses of TFD results in varying degrees of pulmonary edema. The purpose of this study was to determine if exhaustive exercise would potentiate the toxic effects of TFD. One group of treadmill-acclimated rats was exercised to exhaustion following a 10-minute whole-body exposure to TFD. A second group was similarly exposed but not exercised. Two other groups of rats were sham exposed; one was exercised while one remained sedentary following the sham exposure. Twenty-four hours after exposure, the animals were sacrificed; the lungs were removed and weighed, and a portion was collected for histopathologic examination. The remaining lung tissue was allowed to dry to constant weight. There was no difference in endurance times between exposed and sham-exposed rats. There was a significant increase in the amount of pulmonary edema and associated pulmonary pathology in rats exercised following exposure to TFD. Eleven of twelve animals exercised following exposure to TFD and three of twelve animals which remained sedentary following exposure died by 24 hours. The degree of pulmonary pathology in all rats exposed to TFD was profound.

Administration, Inhalation↗

PubMed1999

Ethylene dibromide poisoning with acute renal failure: first reported case with non-fatal outcome.

Ethylene-di-bromide is a popular fumigant. Delayed long-term effects of this chemical include carcinogenicity and genotoxicity in animals. Only a few cases of acute ethylene-di-bromide toxicity have been reported and all of them have resulted in a fatal outcome. We report the first case of ethylene-di-bromide poisoning presenting with acute renal failure and toxic hepatitis that was managed successfully.

Acute Kidney Injury↗

PubMed1987

The toxicology of bromide ion.

Inorganic bromide is widely distributed in nature. Its natural physiological role in animal life is unknown. More than a century ago bromide was introduced in medicine as an antiepileptic drug. Nowadays, man is primarily exposed to bromide via food as the result of use of bromide-containing fumigants in intensive horticulture and in the treatment of food stocks. In this review exposure of man to bromide is described, and the pharmacological and toxicological effects of bromide ion are discussed.

Animals↗

PubMed1991

Effect of some environmental pollutants on the superoxide dismutase activity in Lemna.

Exposure of Lemna sp. to SO2 resulted in an increased activity of superoxide dismutase. About 3 to 4 fold increase in the activity was observed within 30 minutes after the plants were fumigated with 10 ml/l of SO2. Paraquat, a well known superoxide generator, doubled the enzyme activity after 1 hour of treatment with 0.1 mM paraquat. Superoxide dismutase activity was also enhanced by cadmium treatment but the response was not immediate. Optimum increase in the activity of enzyme was observed after 4 days of treatment with 40 mg/l of cadmium in the medium. Treatment with H2O2 very clearly inhibited the activity of superoxide dismutase in Lemna.

Cadmium↗

PubMed1981

Cyanide poisoning.

In recent years, the increasing use of laetrile has been added to the traditional sources of exposure to cyanide in industry, chemistry labs, and fumigation. The events in Jonestown in 1978 were a grim reminder of the lethality of cyanide. Nonetheless, advancement in new modes of treatment has been slow. The traditional method of treatment used in the United States is effective, but not without its own morbidity and mortality. Using two case reports as models, we review here the topic of cyanide poisoning including sources of exposure, pathophysiology, clinical manifestations of both acute and chronic exposure, and modes of treatment. Although there is currently no accepted alternate treatment in this country, review of the literature shows promise in other modalities being investigated in Europe, including hydroxocobalamin, cobalt salts, and particularly aminophenols.

Adult↗

PubMed1996

Aluminum phosphide ingestion--a clinico-pathologic study.

BACKGROUND: Aluminum phosphide is widely used in India as a fumigant to protect stored grain from pests and rodents. It is marketed in India as 3 g tablets under several brand names as Celphos, Phostek, Quickphos, and Phosphume. If ingested, it is acutely toxic with a high mortality. The present study was undertaken to define any factors which could predict the outcome after an ingestion. METHODS: Between March 1989 and March 1994, 195 patients with aluminum phosphide ingestion were admitted to Nehru Hospital of the Postgraduate Institute of Medical Education and Research, Chandigarh in Northwest India. The information regarding demography, time elapsed between ingestion and arrival in the hospital, nature of ingestion, dose ingested, symptoms and signs at admission and course during hospital stay was recorded on a proforma. RESULTS: Of 195 patients, 115 died. The deaths could be related to the dose ingested but not to the time elapsed between ingestion and arrival at the hospital. The nonsurvivors had more severe hypotension and metabolic acidosis than the survivors who had more severe vomiting. Autopsies conducted in 115 subjects revealed congestion of liver, spleen, kidneys, adrenals, gastrointestinal tract and brain that correlated with the severity of hypotension. Histopathology did not reveal any specific changes beyond visceral congestion and patchy necrosis of the liver. CONCLUSION: Aluminum phosphide when ingested is highly toxic with fatal dose as low as 1.5 g. The dominant clinical feature is severe hypotension refractory to dopamine.

Adolescent↗

PubMed2006

Acaricidal effects of herb essential oils against Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae) and qualitative analysis of a herb Mentha pulegium(pennyroyal).

This experiment was undertaken to screen the acaricidal effects of herb essential oils (pennyroyal, ylang ylang, citronella, lemon grass, tea tree, and rosemary) at different doses (0.1, 0.05, 0.025, 0.0125, and 0.00625 microliter/cm(2)) and exposure times (5, 10, 20, 20, 30 and 60 min) on house dust mites Dermatophgoides farinae and D. pteronyssinus. The most effective acaricidal components of pennyroyal (Mentha pulegium) were analyzed using a gas chromatography-mass spectrometer (GC-MS). Of these essential oils, the most effective was pennyroyal, which is composed essentially of pulegone (> 99%), at a dose of 0.025 microliter/cm(2), which at an exposure time of 5 min killed more than 98% of house dust mites. In the pennyroyal fumigation test, the closed method was more effective than the open method and maximum acaricidal effect was 100% at 0.025 microliter/cm(2), 60 min. The results show that herb essential oils, in particular, pennyroyal was proved to have potent acaricidal activity.

Animals↗

PubMed1976

Experimental procedure for testing the effects of low level antibiotic feeding and therapeutic treatment on Salmonella typhimurium var. copenhagen infection in broiler chicks.

Procedures are described for determining the effects of low level antibiotic feed additives in broiler chick rations when chicks are artificially infected with Salmonella typhimurium var. copenhagen and the effectiveness of the same antibiotics used therapeutically for salmonellosis. These procedures also permit study of development of antibiotic resistant enteric flora related to antibiotic feeding and the transferability of the resistance. Measures should be taken to monitor and assure minimal extraneous bacterial contamination of eggs, chicks, feed and facilities and minimize baseline antibiotics resistance. Facilities and equipment should be fumigated extensively, chicks should be from primary breeder flocks off antibiotics for two generations, handled minimally, and fed all-vegetable protein rations. Optimum procedures for oral induction of salmonellosis with a chick-virulent strain of Salmonella typhimurium var. copenhagen are reported. Effects of low level antibiotic feeding and subsequent therapeutic level feeding of infected and control birds are measured by mortality, feed efficiency and weight gain, and microbiological analyses of fecal samples, intestinal samples and necropsied dead chicks. Gathering all data possible from all facets of the trials is imperative for ascertaining antibiotic effects.

Animal Feed↗

PubMed1976

Effect of formaldehyde on disinfection of filtered air under positive pressure (FAPP) type house.

Effect of formaldehyde liberated from formalin on disinfection of the surface of a filtered air under positive pressure (FAPP) house and the surface of equipment placed in the house was studied. Escherichia coli, Staphylococcus aureus and avian adenovirus were used in this study as a indicator to evaluate degree of disinfection. Satisfactory degree of disinfection of the house and equipment was obtained when formaldehyde was liberated from 40 ml. of formalin per 1 m.3 capacity. Bacteria and virus used in the experiments, as well as air-borne organisms in the house, were perfectly inactivated by fumigation for 24 hours at the level of formalin mentioned above.

Air Microbiology↗

PubMed1989

Biocidal activity of ozone versus formaldehyde against poultry pathogens inoculated in a prototype setter.

Ozone was evaluated as an alternative hatchery disinfectant to replace formaldehyde in the event that the Environmental Protection Agency regulates the use of formaldehyde under the Toxic Substances Control Act. Cultures of Staphylococcus, Streptococcus, and Bacillus species previously isolated from poultry hatcheries and selected culture collections of Escherichia coli, Pseudomonas fluorescences, Salmonella typhimurium, Proteus species, and Aspergillus fumigatus were spread-plated on open petri plates and independently fumigated with ozone or formaldehyde in a prototype laboratory poultry setter. Ozone (1.52% to 1.65% by weight) resulted in bacterial reductions of greater than 4 to 7 log10 and fungal reductions of greater than 4 log10, whereas formaldehyde achieved reductions of greater than 7 log10 and greater than 5 log10, respectively, after 8 min of exposure to either disinfectant. Potential mutagenic effects were observed in ozonated E. coli colonies resulting in decreased superoxide dismutase activity and increased catalase activity when compared with nonozonated control colonies. In this study ozone reduced microorganism counts but not as much as formaldehyde. Ozone may be used as a disinfectant against selected microorganisms, although further testing under actual hatchery conditions is needed before making recommendations to the industry.

Animals↗

PubMed1989

Effect of hatching egg sanitizers on embryonic survival and hatchability of turkey eggs from different lines and on egg shell bacterial populations.

Three experiments were conducted to examine the effect of hatching egg sanitizers on embryonic survival, hatchability, and microbiological populations of turkey eggs. Each experiment consisted of two trials. Experiments 1 and 2 were designed to examine embryonic survival and hatchability following sanitization. Experiment 3 examined postsanitization levels of bacteria on the shell surface and inside the egg at Day 7 of incubation. In Experiment 1, formaldehyde fumigation (FF) was compared to quaternary ammonium (QA). In Trial 1, eggs of 359 hens representing 10 lines were randomly assigned to one of the two treatments. In Trial 2, 3,890 eggs produced from a cross of randombred control line (RBC2) females with commercial sire line (C) males were randomly assigned to one of the two treatments. Differences due to sanitizing treatment were nonsignificant in both trials. Line was significant for 7-day embryonic survival and hatch of surviving embryos in Trial 1. In Experiment 2, QA was compared with QA plus U.S.P. Formalin (QAF). In Trial 1, eggs of 288 hens representing 10 lines were randomly assigned to one of the two treatments. In Trial 2, 1,058 eggs produced from the cross of RBC2 females with C males were randomly assigned to one of the two treatments. Differences due to sanitizing treatment were significant only for 7-day embryonic survival in Trial 2; embryonic survival was highest for QA. Line differences in Trial 1 were significant (P less than .01) for 7-day embryonic survival and hatch of surviving embryos.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Long segmented filamentous organisms in broiler chicks: possible relationship to reduced serum carotenoids.

Over the past several years, broiler-flocks at the author's laboratory have exhibited low serum carotenoid levels. This phenomenon has not been related to exceptionally low carotenoids in the feed or to known protozoan or viral infections. However, long segmented filamentous organisms (LSFO) have been identified in the pale chicks. An inverse correlation between LSFO counts and serum carotenoid levels was not observed, but prevention of LSFO infection consistently resulted in higher carotenoid values. Young chicks were very susceptible to naturally acquired LSFO infection, but the organisms decreased in number with time and became very difficult to find by the time the chicks were 7 wk old. Segments of LSFO containing endospores were detected in mucosal smears. This observation, along with the extreme ease of natural infection, suggests that LSFO are transmitted by dust-borne spores. Transmission can be prevented by fumigation of housing with formaldehyde vapors.

Animals↗

PubMedDate not supplied

"Spray, Spray, Spray!": insecticides and the making of applied entomology in Canada, 1871-1914.

As insecticides were adopted by Canadian farmers and fruit-growers after 1871, the resources conferred on economic entomology by the Dominion and Ontario governments grew. In 1886, with the establishment of the Experimental Farms system, James Fletcher, the Dominion entomologist and botanist, and his colleagues inherited the task of promoting insecticides to orchardists and others. In 1898-1900, in response to the arrival in Ontario of the San Jose scale, Canada and Ontario adopted laws mandating the use of insecticides, as sprays and fumigants, in orchards and at plant quarantine stations. To meet the resulting demand for trained technicians and scientifically-minded farmers, the institutions of applied entomology federally and at the Ontario Agricultural College were further developed. In 1910, after a decade of rapid diffusion of insecticides, Parliament adopted the Destructive Insects and Pest Act, thus creating a national system of horticultural hygiene.

Agriculture↗