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PubMed2004

Microbial biomass in a soil amended with different types of organic wastes.

Application of different types of organic wastes may have a marked effect on soil microbial biomass and its activity. The objective of this study was to quantify the amount of microbial biomass in a loamy-clayey soil, amended with different types of organic waste residues (composts of municipal solid waste of different ages, sewage sludge and farmyard manure) and incubated for 8 weeks at 25 degrees C and two-thirds of field capacity, using the fumigation-extraction method. Both microbial biomass-C and -N (BC and BN, respectively) appeared to be dependent on the type of organic waste residues, on their degree of stability, and on their chemical characteristics. In general, organic wastes increased the microbial biomass-C content in the soil and the microbial BC was positively correlated with the organic C content, the C/N, neutral detergent fibre/N (NDF/N) and acid detergent fibre/N (ADF/ N) ratios. The microbial biomass content decreased according to the period of incubation, especially when the compost used was immature. The microbial biomass-N was positively correlated with the total N and percentage of hemicellulose. The microbial biomass-C was linearly related with the microbial biomass-N and the ratio BC/BN was exponentially related with the BC.

Bacteria↗
PubMed1989

Patterns of pesticide usage by cereal crop farmers in Western Australia.

In Western Australia there has been an increase in the use of herbicides in recent years due to a change in farming practices. This change, together with more general public concern over exposure to chemicals, has resulted in farmers expressing concern over the possible long term health effects from exposure to herbicides. As part of a long term study of the possible health effects from such exposure, a survey was carried out to establish the extent of pesticide use within the cereal farming community of Western Australia. Of the 9,408 properties surveyed, 2,921 responses were received which represents a 32.2% response rate. The results indicate that a wide range of chemicals are used as insecticides, fumigants, seed dressings, seed pickles, herbicides, and rodent poisons. At the time of the survey in 1985, products containing prespruf and 1,1,1-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) were the most popular insecticide, and products containing diquat, diclofop-methyl, chlorsulfuron and glyphosate as active ingredients represented the four most popular herbicides.

Agriculture↗
PubMed1991

Etiological investigation of farmer's lung disease: a serological study.

To confirm the main etiological antigen of farmer's lung in Dafeng County, Jiangsu Province, People's Republic of China, precipitins in serum from 30 patients with farmer's lung were tested with several strains of antigens. Reactions against two strains of T.vulgaris were shown in 46.7% and 66.7% of the patients group, which were significantly higher than in the controls, while the percentage of reactions against Faenia rectivirgula and A. fumigates were low in the patients group and had no significant difference with the controls. The results indicate that the main etiological agents were some strains of T. vulgaris. This finding was consistent with the microbiological study of sputum of the patients and moldy hay samples from the working area.

Adult↗
PubMedDate not supplied

Greater risks, fewer rights: U.S. farmworkers and pesticides.

Pesticide Action Network, United Farmworkers of America, and California Rural Legal Assistance Foundation analyzed California government data on agricultural poisonings and enforcement of worker safety standards. Nearly 500 pesticide poisonings were reported for California farmworkers every year from 1997 to 2000. The actual number of pesticide-related illnesses is unknown, since many poisonings go unreported. Most poisonings occurred as a result of soil fumigation and pesticide applications to grapes, oranges, and cotton. Pesticide drift accounted for 51% of the cases, and another 25% resulted from exposures to pesticide residues. Violations of worker safety laws were common, contributing to 41% of reported poisonings. No violations occurred in another 38%, indicating that existing laws inadequately protect workers from pesticide exposure. This snapshot of human rights abuse through pesticide exposure in California-the site of some of the world's most stringent pesticide use and worker safety laws-illustrates the global problem of pesticide poisoning among agricultural workers.

Adult↗
PubMed2002

Phosphine toxicity: report of two cases and review of the literature.

Aluminum phosphide is a commonly used fumigant in the agricultural community. This article reviews the toxic effects of phosphine on the lungs and central nervous system in two workers and reviews the available scientific literature. Education for prevention of exposure and more frequent monitoring for exposure are recommended.

Adult↗
PubMedDate not supplied

Herbicides and adjuvants: an evolving view.

The present report examines the in vitro genotoxicity (micronucleus assay) of herbicides and adjuvants and reports on an in vivo human study on potential endocrine effects of pesticides, including herbicides. Adjuvants are used in conjunction with 2,4-dichlorophenoxy acetic acid (2,4-D) and other herbicides. Earlier pesticide applier survey results (n = 709) show that 59% of the applicators used adjuvants, and the majority of this group used paraffinic oils and/or surfactant mixtures. As a beginning effort to explore the role of adjuvants and herbicides in hormonally based reproductive effects, a prospective, controlled study was performed to analyze blood specimens from three different exposure groups (applicators using herbicides only; applicators using both herbicides and insecticides; and applicators using fumigants in addition to herbicides and insecticides; and a control group composed of other agricultural workers including organic farmers). The applicators and controls were age- and smoking-matched. Study subjects (n = 78) were tested before, during, and after completion of pesticide application season for the effects of pesticide products on hormone levels in the bloodstream. Of the applicator exposure groups examined, only the herbicide group showed significant endocrinologic differences from controls. Free testosterone levels were significantly elevated in post-season measurements (p = 0.032), and follicle-stimulating hormone (FSH) was significantly decreased at the height of the season (p = 0.016) and in the post-season (p = 0.010) as compared to controls. These endocrinologic findings are discussed in terms of their possible relationship to potential endocrine effects of herbicides, herbicide contaminants, and adjuvants. In vitro genotoxicity examination compared four different commercially available surfactant mixtures with 12 different commercial herbicide products, including six different chlorophenoxy herbicides. Only one herbicide yielded a significant dose-response curve. All four adjuvants showed positive dose-response effects. These preliminary data suggest that adjuvants are not inert but are toxicologically active components added to herbicide mixtures. Whether adjuvant toxicant effects are additive or are independent of herbicide effects is poorly understood.

Adult↗
PubMed2000

Non-fatal ethylene dibromide ingestion.

Ethylene dibromide (1,2-dibromoethane) is widely used to fumigate grain and fruit in India. However, acute poisoning due to it has rarely been reported in the literature and most of these patients had an fatal outcome. We describe the suicide attempt of a young male who ingested an ampoule (3 ml) of it, developed acute hepatic and renal failure, metabolic acidosis and coagulopathy but survived following supportive measures.

Acute Kidney Injury↗
PubMed1993

Environmental antecedents of young-onset Parkinson's disease.

We conducted an exploratory study of young-onset Parkinson's disease (YOPD) to examine occupational and environmental factors associated with disease risk. This case-control study included 63 YOPD patients (diagnosis on or before age 50); controls (n = 68) were diagnosed with rheumatoid arthritis. Crude odds ratios (ORs) were computed to identify exposure variables for logistic regression analyses. After controlling for the variables of race, educational level, sex, age, age at diagnosis, and family history of Parkinson's disease (PD), PD was positively associated with insecticide exposure (OR = 5.75, p < 0.001), past residency in a fumigated house (OR = 5.25, p = 0.046), herbicide exposure (OR = 3.22, p = 0.033), rural residency at time of diagnosis (OR = 2.72, p = 0.027), and nuts and seed eating 10 years before diagnosis (OR = 1.49, p = 0.021). PD was inversely associated with cigarette smoking at 5 years (OR = 0.50, p = 0.027), 10 years (OR = 0.43, p = 0.012), and 15 years (OR = 0.37, p = 0.005) before diagnosis, farm residency (OR = 0.38, p = 0.018), and exposure to dimethyl sulfoxide (OR = 0.10, p < 0.001). These findings are consistent with hypotheses linking PD to exposure to pesticide agents.

Adult↗
PubMed2004

Assessment of methods of destruction of Syphacia muris eggs.

An investigation was performed to identify methods suitable for decontamination of equipment being transferred from a facility contaminated with Syphacia muris to a new facility. Perianal samples were taken on clear sticky tape from rats known to be infected with S. muris. Tapes and attached worm eggs were treated with ethylene oxide, formaldehyde fumigation, potassium peroxysulphate, chlorine dioxide and didecyl di-methyl ammonium chloride, chlorine dioxide, alcohol/chlorhexidine, 100 degrees C dry heat for 30 min, ultraviolet light (UV), or left for 4 weeks at room temperature. The subsequent viability of the eggs was compared to untreated control samples. Heat and ethylene oxide produced a 100% kill rate of S. muris eggs. Formaldehyde gas and chlorine dioxide treatments showed marked effectiveness, with the number of eggs killed at 94% and 96%, respectively, while the other agents showed less efficacy (36-78% eggs killed). The percentage of eggs not hatching in the controls was 21%. Since so few agents were effective against S. muris eggs, care should be taken when choosing a method for decontaminating a facility.

Anal Canal↗
PubMed2002

Birth defects, season of conception, and sex of children born to pesticide applicators living in the Red River Valley of Minnesota, USA.

We previously demonstrated that the frequency of birth defects among children of residents of the Red River Valley (RRV), Minnesota, USA, was significantly higher than in other major agricultural regions of the state during the years 1989-1991, with children born to male pesticide applicators having the highest risk. The present, smaller cross-sectional study of 695 families and 1,532 children, conducted during 1997-1998, provides a more detailed examination of reproductive health outcomes in farm families ascertained from parent-reported birth defects. In the present study, in the first year of life, the birth defect rate was 31.3 births per 1,000, with 83% of the total reported birth defects confirmed by medical records. Inclusion of children identified with birth or developmental disorders within the first 3 years of life and later led to a rate of 47.0 per 1,000 (72 children from 1,532 live births). Conceptions in spring resulted in significantly more children with birth defects than found in any other season (7.6 vs. 3.7%). Twelve families had more than one child with a birth defect (n = 28 children). Forty-two percent of the children from families with recurrent birth defects were conceived in spring, a significantly higher rate than that for any other season. Three families in the kinships defined contributed a first-degree relative other than a sibling with the same or similar birth defect, consistent with a Mendelian inheritance pattern. The remaining nine families did not follow a Mendelian inheritance pattern. The sex ratio of children with birth defects born to applicator families shows a male predominance (1.75 to 1) across specific pesticide class use and exposure categories exclusive of fungicides. In the fungicide exposure category, normal female births significantly exceed male births (1.25 to 1). Similarly, the proportion of male to female children with birth defects is significantly lower (0.57 to 1; p = 0.02). Adverse neurologic and neurobehavioral developmental effects clustered among the children born to applicators of the fumigant phosphine (odds ratio [OR] = 2.48; confidence interval [CI], 1.2-5.1). Use of the herbicide glyphosate yielded an OR of 3.6 (CI, 1.3-9.6) in the neurobehavioral category. Finally, these studies point out that (a) herbicides applied in the spring may be a factor in the birth defects observed and (b) fungicides can be a significant factor in the determination of sex of the children of the families of the RRV. Thus, two distinct classes of pesticides seem to have adverse effects on different reproductive outcomes. Biologically based confirmatory studies are needed.

Adult↗
PubMed2004

Association of pesticide exposure with neurologic dysfunction and disease.

Poisoning by acute high-level exposure to certain pesticides has well-known neurotoxic effects, but whether chronic exposure to moderate levels of pesticides is also neurotoxic is more controversial. Most studies of moderate pesticide exposure have found increased prevalence of neurologic symptoms and changes in neurobehavioral performance, reflecting cognitive and psychomotor dysfunction. There is less evidence that moderate exposure is related to deficits in sensory or motor function or peripheral nerve conduction, but fewer studies have considered these outcomes. It is possible that the most sensitive manifestation of pesticide neurotoxicity is a general malaise lacking in specificity and related to mild cognitive dysfunction, similar to that described for Gulf War syndrome. Most studies have focused on organophosphate insecticides, but some found neurotoxic effects from other pesticides, including fungicides, fumigants, and organochlorine and carbamate insecticides. Pesticide exposure may also be associated with increased risk of Parkinson disease; several classes of pesticides, including insecticides, herbicides, and fungicides, have been implicated. Studies of other neurodegenerative diseases are limited and inconclusive. Future studies will need to improve assessment of pesticide exposure in individuals and consider the role of genetic susceptibility. More studies of pesticides other than organophosphates are needed. Major unresolved issues include the relative importance of acute and chronic exposure, the effect of moderate exposure in the absence of poisoning, and the relationship of pesticide-related neurotoxicity to neurodegenerative disease.

Dose-Response Relationship, Drug↗
PubMed1977

Biodehalogenation.

Haloorganic biocides are widely employed as soil fumigants to combat the destructive action of plant parasitic nematodes and fungi. These substances are dehalogenated by soil organisms, principally species of Pseudomonas and Flavobacteria, to nontoxic metabolities. The paths of metabolism of a vareity of simply alkyl halides are described with emphasis upon the biodehalogenation step.

1-Propanol↗
PubMed1978

Exploratory monitoring of air pollutants for mutagenicity activity with the Tradescantia stamen hair system.

The Tradescantia genetic system developed by the late Dr. Arnold H. Sparrow for the study of effects of ionizing radiation is applicable to chemical mutagen detection. Early radiobiological data demonstrated that the stamen hairs were sensitive to as little as 0.25 rad of x-rays and that the number of cells showing a phenotypic change in pigmentation from blue to pink plateaus after approximately 21 days of chronic, low-level irradiation. Exposures to the air pollutants SO(2), NO(2), and O(3) and to vapors of mutagens such as 1,2-dibromoethane (DBE) and ethyl methanesulfonate (EMS) demonstrated the usefulness of the system as a detector of chemical mutagens. A significant number of phenotypic changes was observed following exposures to as little as 0.14 ppm of DBE. The maximum sensitivity of the system is obtained with long-term or chronic exposures because the response increases linearly in proportion to the duration of exposure up to 21 days. To monitor industrial sites for atmospheric mutagens a mobile laboratory was designed to support plant culture in the field. Environment-controlled growth chambers were installed in a trailer so that both ambient air fumigations and concurrent clean-air control exposures could be made. Sites monitored by the mobile laboratory were: Elizabeth, N. J.; Charleston, W. Va.; Birmingham, Ala.; Baton Rouge, La.; Houston, Tex.; Upland, Calif.; Magna, Utah; and Grand Canyon, Ariz. The latter site at Grand Canyon served as a clean air control study. Atmospheric contaminants from petroleum and chemical processing plants generated a significant number of phenotypic pigment changes that were 17 to 31% above the control levels; contaminants from steel and copper smelters, automotive combustion products and photochemical compounds were negative. Chemical analyses are underway to identify the atmospheric mutagens at the sites that showed a positive response.

Air Pollutants↗
PubMed2005

Illnesses related to shank application of metam-sodium, Arvin, California, July 2002.

OBJECTIVES: To evaluate the health effects of methyl isothiocyanate (MITC) and other byproducts resulting from the soil-incorporated (shank) application of 25,000 pounds of metam-sodium on July 8, 2002, near the community of Arvin, California. METHODS: Residents in a four-block area were interviewed regarding eye and upper respiratory irritation, non-specific systemic symptoms, and lower respiratory complaints. The distribution of cases was compared to results of Industrial Source Complex (ISC3) air dispersion modeling for the metam-sodium byproduct, methyl isothiocyanate (MITC). The 1-hour 200 ppb no-observed-effect- level (NOEL) and 800 ppb lowest-observed-effect level (LOEL) from a previous human eye irritation study were used to interpret the results of the air modeling estimates. Peak concentrations were compared to the 4-minute NOEL of 600 ppb and the LOEL of 1.9 ppm. RESULTS: Two-hundred-fifty-two cases of irritant, non-specific systemic, and respiratory symptoms were associated with the metam-sodium application. These included 178 community residents or visitors and 74 employees of a carrot packing operation located in the affected neighborhood of Arvin. The most severe reported illness occurred in a community visitor with a history of pre-existing pulmonary disease, who was hospitalized for a week with respiratory distress. ISC3 Modeling indicated 1-hour MITC concentrations in the affected community ranged from 0.8-1.0 ppm, in the range of the LOEL, with peak concentrations between 2.4 and 3.2 ppm. CONCLUSION: Estimated MITC concentrations during the episode exceeded both the 4-minute NOEL and 1-hourNOELby approximately four fold. The high concentrations of MITC present in the affected neighborhood may have been partially attributable to failure to immediately complete a required post-application water-treatment on 15 of the 100 treated acres. However, because of the limited area involved, the violation was unlikely to have accounted for the entire incident. Similar episodes may occur when metam-sodium fumigants are used adjacent to other rural communities.

Adolescent↗
PubMedDate not supplied

Novel metabolism of nitrogen in plants.

Our previous study showed that approximately one-third of the nitrogen of 15N-labeled NO2 taken up into plants was converted to a previously unknown organic nitrogen (hereafter designated UN) that was not recoverable by the Kjeldahl method (Morikawa et al., 2004). In this communication, we discuss metabolic and physiological relevance of the UN based on our newest experimental results. All of the 12 plant species were found to form UN derived from NO2 (about 10-30% of the total nitrogen derived from NO2). The UN was formed also from nitrate nitrogen in various plant species. Thus, UN is a common metabolite in plants. The amount of UN derived from NO2 was greatly increased in the transgenic tobacco clone 271 (Vaucheret et al., 1992) where the activity of nitrite reductase is suppressed less than 5% of that of the wild-type plant. On the other hand, the amount of this UN was significantly decreased by the overexpression of S-nitrosoglutathione reductase (GSNOR). These findings strongly suggest that nitrite and other reactive nitrogen species are involved in the formation of the UN, and that the UN-bearing compounds are metabolizable. A metabolic scheme for the formation of UN-bearing compounds was proposed, in which nitric oxide and peroxynitrite derived from NO2 or endogenous nitrogen oxides are involved for nitrosation and/or nitration of organic compounds in the cells to form nitroso and nitro compounds, including N-nitroso and S-nitroso ones. Participation of non-symbiotic haemoglobin bearing peroxidase-like activity (Sakamoto et al., 2004) and GSNOR (Sakamoto et al., 2002) in the metabolism of the UN was discussed. The UN-bearing compounds identified to date in the extracts of the leaves of Arabidopsis thaliana fumigated with NO2 include a delta2-1,2,3-thiadiazoline derivative (Miyawaki et al., 2004) and 4-nitro-beta-carotene.

Arabidopsis↗
PubMedDate not supplied

Nocturnal uptake and assimilation of nitrogen dioxide by C3 and CAM plants.

In order to investigate nocturnal uptake and assimilation of NO2 by C3 and crassulacean acid metabolism (CAM) plants, they were fumigated with 4 microl l(-1) 15N-labeled nitrogen dioxide (NO2) for 8 h. The amount of NO2 and assimilation of NO2 by plants were determined by mass spectrometry and Kjeldahl-nitrogen based mass spectrometry, respectively. C3 plants such as kenaf (Hibiscus cannabinus), tobacco (Nicotiana tabacum) and ground cherry (Physalis alkekengi) showed a high uptake and assimilation during daytime as high as 1100 to 2700 ng N mg(-1) dry weight. While tobacco and ground cherry strongly reduced uptake and assimilation of NO2 during nighttime, kenaf kept high nocturnal uptake and assimilation of NO2 as high as about 1500 ng N mg(-1) dry weight. Stomatal conductance measurements indicated that there were no significant differences to account for the differences in the uptake of NO2 by tobacco and kenaf during nighttime. CAM plants such as Sedum sp., Kalanchoe blossfeldiana (kalanchoe) and Aloe arborescens exhibited nocturnal uptake and assimilation of NO2. However, the values of uptake and assimilation of NO2 both during daytime and nighttime was very low (at most about 500 ng N mg(-1) dry weight) as compared with those of above mentioned C3 plants. The present findings indicate that kenaf is an efficient phytoremediator of NO2 both during daytime and nighttime.

Aloe↗
PubMed2004

Effects of eucalyptol on house fly (Diptera: Muscidae) and blow fly (Diptera: Calliphoridae).

The effects of eucalyptol were evaluated against the house fly, Musca domestica L., and blow fly, Chrysomya megacephala (F.). The bioassay of adults, using topical application, indicated that M. domestica males were more susceptible than females, with the LD50 being 118 and 177 microg/fly, respectively. A higher LD50 of C. megacephala was obtained; 197 microg/fly for males and 221 microg/fly for females. Living flies of both species yielded a shorter life span after being treated with eucalyptol. The bioassay of larvae, using the dipping method on the third instar, showed that M. domestica was more susceptible than C. megacephala, with their LC50 being 101 and 642 microg/microl, respectively. The emergence of adults, which had been treated with eucalyptol in larvae, decreased only in M. domestica. Having the volatile property, fumigation or impregnated paper test of eucalyptol or the efficacy of repellence or attractiveness merits further investigations to enhance bio-insecticidal efficacy.

Animals↗
PubMedDate not supplied

[Use of new tools for controlling triatomines in different entomologic situations in the American continent].

The field results of new tools for triatomine control developed under the sponsorship of WHO/TDR are reported: a) A slow-release "paint" containing malathion; b) fumigant cans containing cypermethrin and DDVP, and c) sensor boxes for the detection of triatomine infestations. Field assays were performed in Chile, Honduras and Paraguay against Triatoma infestans, T. dimidiata and Rhodnius prolixus, accordingly to a standard protocol designed by a WHO experts committee. Preliminary 6 months post-treatment results for the three countries show an efficient control when insecticide paints were used indoors and in the peridomicilium, keeping reinfestation near zero. The final results presented for Chile two years post-treatment confirmed the superiority of the slow-release "paints". Sensor boxes were less effective than man/hour captures in the detection of infested houses.

Animals↗