Study on Peripheral Blood Lymphocytes ChromosomeAbnormality of People Exposed to Cadmium in Environment

Chromosome aberration (CA) and micmnucleus (MN) tests were appied to investigate Peripheral blood lymphocytes in 56 people environmentally exposed to cadwhum (Cd) for a period up to 30years, and in 10 unexposed People as controls. As indicator of body-load of Cd, urineq Cd (UCd)concentrations were measured simultaneously. The People in polluted villages were divided into four groups according to vallous levels of UCd concentrations: ~ 2 .5, 2 .5 ~, 5 .0 ~, 10.0 ~ (μg/l).There was significant difference in MN rates between the exposed and control groups (3 .47, 5 .06,8.06, 12 .75‰ for the exposed groups respectively, and 3. 10‰ for the controls), and significant correlation between MN rates and UCd was observed. Although no markesd difference in CA rates was noted between UCd 5 .0 ~ and 10 .0 ~ groups, there was significant difference in CA rates between the exposed and control groups (3. 07,5. 21, 7. 21, 8. 50% for exposed groups respectively, and2 .33% for the controls) and significant correlation between CA rates and UCd. CA was presented mainly in the form of chromatid and chromosome gaps and breaks. Together with our another study 'An Investigation on Human Health Effects by Envimnmental Cadmium Pollution', the results suggest that Cd may injure human chromosomes and that the damage appears to be concentrated on cytogenetic material and may happen earlier than renal disfunction

Oyster Cementation as Protective Covers for Exposed Marine Concrete

Cored concrete specimens from seawall exposed to marine environment for 22 years were evaluated by carbonation depth test,rapid chloride permeability test,absorption of water test and microstructure examination.The results show that concrete exposed to marine environment has smaller carbonation depth and carbonation depth of concrete exposed to tidal zone is less than that in splash zone.There are similar water absorption rate and chloride permeability for concrete exposed to splash zone compared with concrete exposed to splash zone removed 3mm surface layer.However,concrete exposed to tidal zone with bio-films has lower chloride permeability and water absorption rate than those of concrete exposed to tidal zone removed 3mm surface layer.In addition,Results of FE-SEM and EDAX indicate that concrete exposed to splash zone has loose structure,exposed finer aggregate and concrete exposed to tidal zone covers by dense structure of oyster cementation and shell.Microstructures analysis further verified that concrete covered with oysters and their cementation has beneficial effects to durability of concrete.