No abstract

Abstract-Cadmium (Cd) and zinc (Zn) in surface water, sediment, carp, and crab samples collected from upstream and downstream regions of coastal watersheds along the Chinese Northern Bohai and Yellow Seas were analyzed to provide a comprehensive understanding and assessment of their environmental concentrations and bioaccumulations. The results showed that downstream waters contaminated with Zn would have adverse effects on aquatic organisms. Although nearly all sediments were contaminated with Cd due to human activities, little potential existed for Cd toxicity in sediment-dwelling fauna. Concentrations of Cd and Zn in most water, sediment, carp, and crab were less than published values. The downstream carp and crabs had higher mean bioaccumulation factors and biotasediment accumulation factors for Cd but lower mean biota-sediment accumulation factors for Zn than the upstream carp and crabs. Based on the relationships among Cd and Zn concentrations in water, sediment, and biota, the authors conclude that Cd and Zn in crabs primarily derived from sediment exposure. Although Cd and Zn in water and sediment originated from some of the same sources, the sources of Cd or Zn in water were likely different from those in sediment. Environ. Toxicol. Chem. 2013;32:831-840. # 2013 SETAC

Pig manure (PM) is widely used as an organic fertilizer to increase yields of crops. Excessive application of compost containing relatively great concentrations of copper (Cu) and zinc (Zn) can change soil quality. To clarify the effects of different rates of application and to determine the optimal rate of fertilization, PM containing 1,115 mg Cu kg(-1), dry mass (dm) and 1,497 mg Zn kg(-1), dm was applied to alkaline soil at rates of 0, 11, 22, 44, 88, and 222 g PM kg(-1), dm. Phospholipid fatty acids (PLFAs) were used to assess soil microbial community composition. Application of PM resulted in greater concentrations of total nitrogen (TN), NH4 (+)-N, NO3 (-)-N, total carbon (TC), soil organic matter (SOM) but lesser pH values. Soils with application rates of 88-222 g PM kg(-1), dm had concentrations of total and EDTA-extractable Cu and Zn significantly greater than those in soil without PM, and concentrations of T-Cu and T-Zn in these amended soils exceeded maximum limits set by standards in china. Except in the soil with a rate of 11 g PM kg(-1), dm, total bacterial and fungal PLFAs were directly proportional to rate of application of PM. Biomasses of bacteria and fungi were significantly greater in soils with application rates of 44-222 g PM kg(-1), dm than in the soil without PM. SOM, TC and EDTA-Zn had the most direct influence on soil microbial communities. To improve fertility of soils and maintain quality of soil, rate of application should be 22-44 g PM kg(-1) dm, soil containing Cu and Zn.