1.
Sex-Specific Differences in Cognitive Abilities Associated with Childhood Cadmium and Manganese Exposures in School-Age Children: a Prospective Cohort Study.
Zhou, T, Guo, J, Zhang, J, Xiao, H, Qi, X, Wu, C, Chang, X, Zhang, Y, Liu, Q, Zhou, Z
Biological trace element research. 2020;(1):89-99
Abstract
To examine sex-specific associations of neonatal and childhood exposure to eight trace elements with cognitive abilities of school-age children. The association between exposure and effects was assessed among 296 school-age children from a population-based birth cohort study, who had manganese (Mn), cadmium (Cd), and lead (Pb) exposure measured in cord blood and chromium (Cr), manganese, cobalt (Co), copper (Cu), arsenic (As), selenium (Se), cadmium, and lead exposure quantified in spot urine. Cognitive abilities were assessed using the Wechsler Intelligence Scale for Children-Chinese Revised (WISC-CR). Generalized linear models were performed to analyze associations of intelligence quotient (IQ) with trace element concentrations in cord blood and urinary trace element levels. General linear models were used to evaluate association between exposure fluctuation and children's IQ. Urinary Cd concentrations were negatively associated with full-scale IQ (β = - 3.469, 95% confidence interval (CI) - 6.291, - 0.647; p = 0.016) and performance IQ (β = - 4.012, 95% CI - 7.088, - 0.936; p = 0.011) in girls; however, neonatal Cd exposure expressed as Cd concentrations in cord blood was in inverse associations with verbal IQ (β = - 2.590, 95% CI - 4.570, - 0.609; p = 0.010) only in boys. Positive association between urinary Mn concentrations and performance IQ (β = 1.305, 95% CI 0.035, 2.575; p = 0.044) of children was observed, especially in girls. In addition, inverse association of urinary Cu concentrations with verbal IQ (β = - 2.200, 95% CI - 4.360, - 0.039; p = 0.046) was only found in boys. Childhood Cd exposure may adversely affect cognitive abilities, while Mn exposure may beneficially modify cognitive abilities of school-age children, particularly in girls.
2.
Optimization of Xhhh strain biodegradation with metal ions for pharmaceautical wastewater treatment.
Sun, SL, Wu, B, Zhao, DY, Zhang, XX, Zhang, Y, Li, WX, Cheng, SP
Journal of environmental biology. 2009;(5 Suppl):877-82
Abstract
Effects of three ions, Mn2+, Cu2+ and Zn2+ on biological treatment of pharmaceutical wastewaterby a functional strain Xhhh were investigated. Through orthogonal tests, Cu2+ was determined to be the most important factor influencing Xhhh biodegradation performance. Biodegradation kinetic experiments demonstrated that with Cu+ concentration at about 200 mg l(-1), the maximum of specific growth rate and specific degradation rate were obtained to be 0.033 and 0.075 d(-1), respectively. The optimal levels of Mn2+ (5.00 mg I(-1)), Cu2+ (2.00 mg l(-1)) and Zn2+ (5.00 mg l(-1)) were achieved based on experimental results of their effects on the activities of manganese peroxidase and lignin peroxidase, and biodegradation kinetic parameters. Among three types of biodegradation kinetic models (Monod, Tessier and Contois), Tessier model was found most reasonable for kinetics description of Xhhh growth (R2 = 0.995) and pollutants degradation (R2 = 0.970) in the case of metals optimization. Both kinetics evaluation and experimental results demonstrated that optimization with the three metals made a great contribution to Xhhh growth and COD removal for pharmaceutical wastewater treatment.