scholarly journals Herbicides Persistence in Rice Paddy Water in Southern Brazil

10.5772/32727 ◽  
2011 ◽  
Author(s):  
Renato Zanella ◽  
Martha B. ◽  
Sandra C. ◽  
Caroline do A. Friggi ◽  
Osmar D. ◽  
...  
Keyword(s):  
Rice Paddy ◽  
Southern Brazil ◽  
Paddy Water

scholarly journals Mercury methylation in paddy soil: source and distribution of mercury species at a Hg mining area, Guizhou Province, China

2016 ◽  
Vol 13 (8) ◽  
pp. 2429-2440 ◽  
Author(s):  
Lei Zhao ◽  
Christopher W. N Anderson ◽  
Guangle Qiu ◽  
Bo Meng ◽  
Dingyong Wang ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Surface Soil ◽  
Ambient Air ◽  
Rice Paddy ◽  
Guizhou Province ◽  
Mercury Species ◽  
Low Concentration ◽  
Paddy Water ◽  
Hg Mining

Abstract. Rice paddy plantation is the dominant agricultural land use throughout Asia. Rice paddy fields have been identified as important sites for methylmercury (MeHg) production in the terrestrial ecosystem and a primary pathway of MeHg exposure to humans in mercury (Hg) mining areas. We compared the source and distribution of Hg species in different compartments of the rice paddy during a complete rice-growing season at two different typical Hg-contaminated mining sites in Guizhou province, China: an abandoned site with a high Hg concentration in soil but a low concentration in the atmosphere and a current-day artisanal site with a low concentration in soil but a high concentration in the atmosphere. Our results showed that the flux of new Hg to the ecosystem from irrigation and atmospheric deposition was insignificant relative to the pool of old Hg in soil; the dominant source of MeHg to paddy soil is in situ methylation of inorganic Hg (IHg). Elevated MeHg concentrations and the high proportion of Hg as MeHg in paddy water and the surface soil layer at the artisanal site demonstrated active Hg methylation at this site only. We propose that the in situ production of MeHg in paddy water and surface soil is dependent on elevated Hg in the atmosphere and the consequential deposition of new Hg into a low-pH anoxic geochemical system. The absence of depth-dependent variability in the MeHg concentration in soil cores collected from the abandoned Hg mining site, consistent with the low concentration of Hg in the atmosphere and high pH of the paddy water and irrigation water, suggested that net production of MeHg at this site was limited. We propose that the concentration of Hg in ambient air is an indicator for the risk of MeHg accumulation in paddy rice.

scholarly journals Zooplankton community responses to the mixture of imazethapyr with imazapic and bispyribac-sodium herbicides under rice paddy water conditions

2014 ◽  
Vol 44 (8) ◽  
pp. 1392-1397 ◽  
Author(s):  
Geovane Boschmann Reimche ◽  
Sérgio Luiz de Oliveira Machado ◽  
Renato Zanella ◽  
Michele Câmara de Vicari ◽  
Fernando Piccinini ◽  
...  
Keyword(s):  
Half Life ◽  
Zooplankton Community ◽  
Rice Paddy ◽  
Paddy Fields ◽  
Community Responses ◽  
Paddy Water ◽  
Adult Copepod ◽  
Water Conditions ◽  
Rice Paddy Fields

The aim of this study was to assess the effect of concentrations of imazethapyr, imazapic, and bispyribac-sodium herbicides on zooplankton community (Cladocer, Copepod and Rotifer) in rice paddy fields. The decrease of half-life dissipation (DT50) of the herbicides under study in water was: imazethapyr, imazapic, and bispyribac-sodium with an average of 3.75, 3.73 and 1.91 days, respectively. The mixture of imazethapyr with imazapic caused change in the analyzed zooplankton, with an increase in the densities of Cladocer and adult Copepod groups, while bispyribac-sodium caused a reduction of density in Copepod group, both adults and nauplii, in the initial samples. Among the groups, Rotifer was slightly sensitive to the herbicides.

scholarly journals Risk Factors of Leptospirosis in Rice Cultivators as Compared to non Rice Cultivators in Punjab, Pakistan

2018 ◽  
Vol 23 (4) ◽  
pp. 536-539
Author(s):  
Muhammad Athar Khan ◽  
Muhammad Zahid Latif ◽  
Syed Amir Gilani ◽  
Ifrah Bukhari
Keyword(s):  
Public Health ◽  
Paddy Field ◽  
Strong Association ◽  
Rice Paddy ◽  
Rice Cultivation ◽  
Ethical Review ◽  
Body Parts ◽  
Rice Paddy Field ◽  
Paddy Water ◽  
Union Council

Leptospirosis is a global zoonotic infectious disease having alarming public health concerns. Generally this is an occupation related disease and the victims belong to animal slaughtering, owners of pet shops, farm workers, handlers of meat, sewerage and agriculture workers. Leptospirosis affect multiple organs in human body and may lead to myocarditis, renal failure, respiratory distress and hypotension. This disease is an emerging infectious problem in many developing countries like Pakistan. A total of 250 subjects were selected from five different rice growing districts of Punjab, Pakistan after the approval of institutional ethical review board (IERB), 250 subjects were selected for this comparative cross sectional study. Multiple stage probability technique was used for sampling. In the first stage one union council was selected from each district randomly. In the second stage, 25 subjects involved in rice cultivation from the last 10 years wereselected from each union council. Similarly 25 subjects who never worked in the rice paddy field were also randomly selected from each union council as controls. The serum sample of each subject was tested against each of the five antigens against the serovars. A total of 250 subjects were included in the study. Out of these, 125 subjects were exposed to the rice paddy water where as 125 were not exposed to rice paddy water. The cumulative seropositivity among the exposed is (83.2%) as compared to (42%) among the non exposed to rice paddy field water. The calculated cumulative odds ratio is 6.7 which represent a strong association of the risk for the development of disease among the exposed than the non exposed subjects. Leptospirosis is a public health zoonotic disease which is widely present in tropical and sub tropical areas. This study concludes that there is a strong association of rice cultivation with Leptospirosis. It is recommended that rice cultivators should protect their body parts with gloves or boots as prevention is the most appropriate way to control any disease.

Dynamics of the superficial fluxes over a flooded rice paddy in southern Brazil

2019 ◽  
Vol 276-277 ◽  
pp. 107650 ◽  
Author(s):  
Marcelo Bortoluzzi Diaz ◽  
Débora Regina Roberti ◽  
Janaina Viário Carneiro ◽  
Vanessa de Arruda Souza ◽  
Osvaldo Luiz Leal de Moraes
Keyword(s):  
Rice Paddy ◽  
Southern Brazil ◽  
Flooded Rice

Loss of carbofuran from rice paddy water: Chemical and physical factors

1978 ◽  
Vol 13 (2) ◽  
pp. 131-148 ◽  
Author(s):  
J. N. Seiber ◽  
M. P. Catahan ◽  
C. R. Barril
Keyword(s):  
Rice Paddy ◽  
Physical Factors ◽  
Paddy Water

scholarly journals Mercury Methylation in paddy soil: Source and distribution of mercury species at a Hg mining area, Guizhou Province, China

2016 ◽  
Author(s):  
L. Zhao ◽  
C. W. N. Anderson ◽  
G. L. Qiu ◽  
B. Meng ◽  
D. Y. Wang ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Paddy Soil ◽  
Soil Layer ◽  
Ambient Air ◽  
Rice Paddy ◽  
Mercury Species ◽  
Low Concentration ◽  
Paddy Water ◽  
Hg Mining

Abstract. Rice paddy plantation for human consumption is dominant land uses throughout Asia. Rice paddy fields have been identified as important sites for methylmerucry (MeHg) production in the terrestrial ecosystem, and a primary pathway of MeHg exposure to human in mercury (Hg) mining areas. We compared the source and distribution of Hg species in different compartments of the rice paddy during a complete rice-growing season at two different typical Hg-contaminated mining sites: an abandoned site with high Hg concentration in soil but low concentration in atmosphere, and a current-day artisanal site with low concentration in soil but high concentration in atmosphere. The contribution of new Hg to the ecosystem from irrigation and atmospheric deposition was insignificant relative to the pool of old Hg; the dominant source of MeHg to paddy soil is in situ methylation of inorganic Hg. Elevated MeHg concentrations jointly with the high proportion of Hg as MeHg in paddy water and the surface soil layer at the artisanal s ite demonstrated active Hg methylation at this site only. We propose that the in situ production of MeHg is dependent on elevated IHg in the atmosphere, and the deposition of new Hg into a low pH anoxic geochemical system. In contrast, the absence of depth-dependent variability in the MeHg concentration in soil cores collected from abandoned Hg mining site, consistent with the low concentration of Hg in atmospheric deposition and high pH of the paddy water/irrigation water, suggested that the net production of MeHg was limited. We also propose that the concentration of Hg in ambient air is an indicator for the risk of MeHg accumulation in paddy rice.

Photodegradation of Imidacloprid and Fipronil in Rice–Paddy Water

2011 ◽  
Vol 86 (5) ◽  
pp. 548-553 ◽  
Author(s):  
Dang Quoc Thuyet ◽  
Hirozumi Watanabe ◽  
Kenichi Yamazaki ◽  
Kazuhiro Takagi
Keyword(s):  
Rice Paddy ◽  
Paddy Water

scholarly journals Checklist of amphibians in a rice paddy area in the Uruguayan savanna, southern Brazil

Check List ◽  
2014 ◽  
Vol 10 (5) ◽  
pp. 1014-1019 ◽  
Author(s):  
Leonardo Moreira ◽  
Débora Knauth ◽  
Leonardo Maltchik
Keyword(s):  
Rice Paddy ◽  
Southern Brazil ◽  
Paddy Area
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