Sources and health risks of heavy metals in soils and vegetables from intensive human intervention areas in South China.

Heavy metal pollution greatly harms the soil environment and poses threats to food safety and human health. This study aimed to quantify and analyze the sources of heavy metals and assess the health risks associated with the human intake of contaminated vegetables in South China. Heavy metals (Cd, As, Hg, Cu, Ni, Pb, Zn, and Cr) in soil and vegetables (leaf vegetables, legume vegetables, and cucurbits) were investigated and evaluated for contamination. By combining the correlation analysis (CA), positive matrix factorization (PMF), and GeoDetector model, source apportionments were comprehensively identified. Results showed that Cd was the predominant element in soils throughout the study area. Industrial (28.36 %, 20.24 %, 31.50 %), agricultural (27.19 %, 46.50 %, 27.30 %), besides traffic, atmospheric deposition and natural sources were identified as the dominant sources of heavy metals in GD01, GD02, and GD03, respectively. The human health risk assessment showed that the total non-cancer risk of heavy metals (i.e., Cr, Ni, As, Cd, and Pb) ingested through vegetables was 2.3E+00 for children and 9.67E-01 for adults, and the total cancer risk for children was 2.54E-02 and 1.07E-02 for adults, both of which exceeded acceptable levels. It is worth noting that children are more susceptible to health risks due to the consumption of contaminated vegetables than adults.

Socio-demographic characters, distribution and transformation of iodine in soil, plant and wheat grains at District Diamer, Gilgit-Baltistan, Pakistan.

Iodine deficiency in soils and plants is a common problem in the hilly areas and has still been ignored. The aim of the current study is to investigate associated health issues, socio-economic characteristics and people's perception regarding iodine deficiency. Furthermore, a follow-up study was conducted to determine iodine and nutrients concentration in soil and crops at District Diamer, Gilgit-Baltistan, Pakistan. A descriptive and empirical analysis was examined. Most importantly, male was significantly observed as more affected for iodine deficiency than female, as contrary to the literature, socio-economic factors such as households' income and awareness (education) are reported as negative and significant contributor to reduce the iodine deficiency among the people irrespective of the gender. Majority of people (84%) heard about the iodine, but about 51.6% people argue that iodine has no effect on the human body and 56% of the respondents do not know why iodine is necessary for human. It was found that 11.5% of the community was affected from the IDD and majority of them were females. Wheat crops were the principal crop since it supplies 75% of calorific energy in an average Pakistani diet. The concentrations of iodine in soil samples range from 4.21 to 5.45 mg kg-1. The concentration of iodine in wheat crop plant sampled were considerably varied as Boner > Gais > Goher Abad with 1.12, 0.91 and 0.81 mg kg-1. respectively. Likewise, grain iodine concentration was varied as Gais > Boner > Goher Abad with 0.126, 0.102 and 0.078 mg kg-1, respectively. This study exposed that community using the cereal crops could face iodine deficiency in their diet which can cause endemic goiter among the population and control the iodine deficiency by empowering the rural community to raise the income level and providing the awareness to the people.

Analyses of Arabidopsis ecotypes reveal metabolic diversity to convert D-amino acids.

For a long time D-enantiomers of proteinogenic L-amino acids were assumed to be physiologically irrelevant for plants. But there is growing evidence that D-amino acids (D-AAs) also fulfil important physiological functions in these organisms. However, the knowledge about the metabolic fate of D-AAs in plants is still scarce and more information about it is needed. To close this gap we established an optimized protocol for the processing and analysis of D- and L-AAs from large numbers of Arabidopsis lines. This included the application of 18 different D-AAs to seedlings, the extraction of free amino acids from the samples and the determination of 16 L-AAs and their corresponding D-enantiomers. To validate our approach we searched for genetic accessions with aberrant amino acid metabolism. Therefore we applied D-AAs on 17 ecotypes of Arabidopsis thaliana and analysed their free amino acid contents. These analyses confirmed the suitability of the system for the analysis of large sets of plant samples with enhanced velocity and improved accuracy. Furthermore, the resulting data led to the definition of standard amino acid profiles in response to D-AAs of Arabidopsis seedlings. Within these analyses the ecotype Landsberg erecta was found with aberrant metabolic patterns like drastically reduced capabilities to convert different D-AAs to D-alanine and D-glutamate. The presented experimental setup and results of this study offer starting points to dissect the metabolic pathway of D-AAs in plants.