A total of 520 food samples belonging to 29 food types and 63 drinking water were collected in Chengdu market of China in 2014 to investigate the concentrations of 11 metals, and to assess the related exposure to the local consumers by estimating the hazard quotient and carcinogenic risk (CR). The results showed that metals concentrations in drinking water were below the limit values suggested by the Ministry of Health of the People's Republic of China, and FAO/WHO (Food and Agriculture Organization of the United Nations/World Health Organization). While As, Cd, and Cr were found at concentrations higher than the limit values in some of the foodstuffs. Children in Chengdu intake more metals compared to adults, with the same order of Mn > Zn > Cu > Sr > Cr > Ni > As > Cd > Pb > Co > Sb. Among all of the diverse food, rice, flour, and fish and seafood were the primary sources to intake metals for Chengdu residents. Residents in Chengdu are subjected to both carcinogenic and non-carcinogenic risks based on the calculated HI and CR values, especially for children. Finally, total daily metals intakes for both children and adults were calculated based on the current study and our previous studies, including consumption of food and drinking water and intake of outdoor and indoor dust. Dietary exposure is the predominant exposure route to metals for Chengdu residents, accounting for more than 75.8% of the total daily metals intakes for both children and adults.

Rubus parvifolius L. and R. coreanus Miq. are the two morphologically distinct, endemic wild brambles in East Asia that may be useful in raspberry breeding and cultivar development. In this study, genetic relationships among a total of nine populations of these two species, collected from Sichuan Province in southwestern China, were investigated by cytological and RAPD analyzing. With the exception of ploidy levels, R. parvifolius and R. coreanus had similar cytological features. Six R. parvifolius populations included diploids, triploid, tetraploid, and mixed diploid-tetraploid cytotype plants; among them, the population that produced the fewest seeds was the triploid, while the three R. coreanus populations were all diploid. But obvious genetic differentiation between R. parvifolius and R. coreanus was revealed by RAPD markers, the Euclidean's GS coefficient generated by UPGMA cluster analysis between R. parvifolius and R. coreanus was only 0.442, about half of that observed within species. Both genetic relationships among these populations and the origin of polyploidy in R. parvifolius populations are also discussed.

A total of 28 groundwater, paired farmland soil, lettuce, and its rhizosphere soil samples were collected from Chengdu, China to detect perchlorate levels and to evaluate the relationships of perchlorate concentrations among these matrices. The perchlorate concentrations in the groundwater, farmland soil, lettuce, and rhizosphere soil samples ranged from below detection limit to 60.2 μg L, from below detection limit to 249 μg kg dry weight (dw), from 2.07 to 1010 μg kg wet weight, and from below detection limit to 314 μg kg dw, respectively. Significant correlation was found in the perchlorate levels among the farmland soil, lettuce, and rhizosphere soil, suggesting that they have common pollution sources, or perchlorate might transfer from farmland soil-rhizosphere soil-plant. However, there is no significant correlation between groundwater and the other three matrices, indicating that infiltration from perchlorate contaminated farmland soil was not the predominant source for groundwater pollution in Chengdu. The perchlorate concentrations in the farmland soil and lettuce samples were significantly higher than those in the rhizosphere soil, primarily due to uptake of perchlorate through the rhizosphere micro-environment by lettuce, or accelerated degradation by rhizospheric microorganisms, which contributed more needs further investigation.

No abstract