B Y Yu

Yangzhou University, Chiang-tu, Jiangsu Sheng, China

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Publications (4)11.49 Total impact

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    ABSTRACT: This paper reports a study of the distribution of organo-chlorine pesticides (DDT and HCH) between rice plants and the soil system by spraying before the heading stage at four different dosage levels--control, normal dosage (15 kg ha(-1) of 6% HCH and 7.5 kg ha(-1) of 25% DDT), double dosage and four times dosage. Soil and plant samples were taken respectively at the 1st h, 3rd, 10th, 20th, and 40th day after spraying and at the harvest time. The results indicate that less than 5% of HCH and 15% of DDT were absorbed by the surface of rice leaves for normal dosage. Most of both pesticides moved into the soil in solution after spraying. Compared with DDT, HCH was degraded and run off more easily. HCH residues in the surface soil layer (1-3 cm) were already below 6.4 microg kg(-1) at the mature stage, lower than Chinese Environmental Quality Standard for Agricultural Soils: HCH < 0.05 mg kg(-1). However DDT residues in the surface soil layer remained 172 microg kg(-1), higher than the national standard: DDT < 0.05 mg kg(-1). According to the test f OCP residues in rice seeds, it can be concluded that the OCP sprayed onto the surface of rice leaves can move into rice plants and accumulate in the seeds at the mature stage. HCH residues in rice seeds of the double and four times dosage treatments, and DDT residues in all treatments, exceeded the Chinese National Food Standard (HCH < 0.10 mg kg(-1), DDT < 0.20 mg kg(-1)).
    Environmental Geochemistry and Health 05/2004; 26(2-3):253-8. · 2.08 Impact Factor
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    ABSTRACT: The absorption and accumulation of Cd2+, Fe3+, Zn2+, Mn2+, Cu2+ and Mg2+ in the roots and leaves of 20 rice cultivars (Oryza sativa L.) with different genotypes under cadmium (Cd) stress were investigated with pot experiments. The results showed that there existed significant differences among the rice cultivars in the contents of six mineral elements in both roots and leaves at both heading and ripening periods. The statistical analysis showed that, for their contents in roots, significant and positive correlations between Cd2+ and Fe3+, Cd2+ and Zn2+, Cd2+ and Mn2+, Cd2+ and Cu2+ existed, but no significant correlation between Cd2+ and Mg2+, at the two periods. In the leaves, Cd also showed significant and positive correlations with Fe3+, Zn2+ and Cu2+ at the both periods, but a significant and negative correlation with Mn2+ and no significant correlation with Mg2+ at heading, a significant and positive correlation with Mg2+ and no significant correlation with Mn2+ at ripening. These results suggested that there were cooperative absorption between Cd2+ and Fe3+, Mn2+, Cu2+, Mn2+ in rice plants. Genotypic differences in Cd uptake and translocation among the rice cultivars suggested that paddy field of some rice cultivars may be irrigated with partially treated sewage water.
    Chemosphere 10/2003; 52(9):1467-73. · 3.14 Impact Factor
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    ABSTRACT: The use of organo-chlorine (DDT and HCH) has been banned in China for 20 years. A field survey was carried out during 1999-2000 in the Taihu Lake Region. Organo-chlorine pesticide (OCP) residues in soil, water, fish and sediment samples were investigated. DDT was detected in 5 out of 10 samples with concentration ranging from 0.3 to 5.3 microg/kg in the surface (0-15 cm) layer, 6 out of 10 with 0.5 to 4.0 microg/kg in the subsoil layer (16-30 cm), and 4 of 10 with 0 to 2.7 microg/ kg in the deep soil layer (31-50 cm). Results for HCH residues in soil samples were similar to those of DDT. These results indicate that OCP residues in 0-50 cm profile had been leached out or degraded to safe level. In river water DDT was detected in 10 out of 13 samples ranging from 0.2 to 9.3 microg/l, with an average of 1.0 microg/l. While HCH was detected in 12 out of 13 samples ranging from 0.02 to 36.1 microg/l, with an average 5.6 microg/l. DDT residues in sediment ranged from 0.1 to 8.8 microg/kg, while HCH ranged from 0.3 to 66.5 microg/kg. DDT residues in fish body ranged from 3.7 to 23.5 microg/kg and HCH ranged from 3.7 to 132 microg/kg. These results demonstrate an accumulation through food chain (from soil-water-sediment-microbes-crop-fish-... etc.), also that HCH residues are generally more persistent than DDT residues. However, all these data are well below than the state warning standard limit.
    Chemosphere 03/2003; 50(6):683-7. · 3.14 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The use of organo-chlorine (DDT and HCH) has been banned in China for 20 years. A field survey was carried out during 1999–2000 in the Taihu Lake Region. Organo-chlorine pesticide (OCP) residues in soil, water, fish and sediment samples were investigated. DDT was detected in 5 out of 10 samples with concentration ranging from 0.3 to 5.3 μg/kg in the surface (0–15 cm) layer, 6 out of 10 with 0.5 to 4.0 μg/kg in the subsoil layer (16–30 cm), and 4 of 10 with 0 to 2.7 μg/kg in the deep soil layer (31–50 cm). Results for HCH residues in soil samples were similar to those of DDT. These results indicate that OCP residues in 0–50 cm profile had been leached out or degraded to safe level.In river water DDT was detected in 10 out of 13 samples ranging from 0.2 to 9.3 μg/l, with an average of 1.0 μg/l. While HCH was detected in 12 out of 13 samples ranging from 0.02 to 36.1 μg/l, with an average 5.6 μg/l.DDT residues in sediment ranged from 0.1 to 8.8 μg/kg, while HCH ranged from 0.3 to 66.5 μg/kg. DDT residues in fish body ranged from 3.7 to 23.5 μg/kg and HCH ranged from 3.7 to 132 μg/kg. These results demonstrate an accumulation through food chain (from soil–water–sediment–microbes–crop-fish–… etc.), also that HCH residues are generally more persistent than DDT residues. However, all these data are well below than the state warning standard limit.
    Chemosphere 01/2003; 50(6):683-687. · 3.14 Impact Factor