| January 2017
Read about VicFalls 2018 and fieldwork in the Copperbelt continue reading...
SEGH was established in 1971 to provide a forum for scientists from various disciplines to work together in understanding the interaction between the geochemical environment and the health of plants, animals, and humans. We recognise the importance of interdisciplinary research. SEGH members represent expertise in a diverse range of scientific fields, such as biology, engineering, geology, hydrology, epidemiology, chemistry, medicine, nutrition, and toxicology.
Stay informed of new impact factor journal issues! Sign up for the Table of Contents Alert here.
Follow updates on Twitter @SocEGH
Victoria Falls, Zimbabwe
02 July 2018
Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.
Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health
Atrazine is one of the most widely applied and persistent herbicides in the world. In view of limited information on the regional contamination of atrazine in soils in China, this study investigated the spatial distribution and environmental impacts of atrazine in agricultural soils collected from the Yangtze River Delta (YRD) as an illustrative analysis of rapidly developing regions in the country. The results showed that the concentrations of atrazine in the YRD agricultural soils ranged from <1.0 to 113Â ng/g dry weight, with a mean of 5.7Â ng/g, and a detection rate of 57.7Â % in soils. Pesticide factory might be a major source for the elevated levels of atrazine in Zhejiang Province. The contamination of atrazine was closely associated with land use types. The concentrations and detection rates of atrazine were higher in corn fields and mulberry fields than in rice paddy fields. There was no significant difference in compositions of soil microbial phospholipids fatty acids among the areas with different atrazine levels. Positive relationship (RÂ =Â 0.417, pÂ <Â 0.05, nÂ =Â 30) was observed between atrazine and total microbial biomass. However, other factors, such as soil type and land management practice, might have stronger influences on soil microbial communities. Human health risks via exposure to atrazine in soils were estimated according to the methods recommended by the US EPA. Atrazine by itself in all the soil samples imposed very low carcinogenic risks (<10âˆ’6) and minimal non-cancer risks (hazard index <1) to adults and children.
Î±-Endosulfan and some polycyclic aromatic compounds (PAHs) are persistent in the environment and can reach crop products via contaminated agricultural soils. They may even be present as mixtures in the soil and induce mixture toxicity in soil organisms such as earthworms. In this study, the combined toxicities of PAHs with Î±-endosulfan were determined in Eisenia fetida adults using an artificial soil system. Î±-Endosulfan and five PAHs were tested for their acute toxicity toward E. fetida in artificial soils. Only Î±-endosulfan, fluorene, and phenanthrene showed acute toxicities, with LC50 values of 9.7, 133.2, and 86.2Â mgÂ kgâˆ’1, respectively. A mixture toxicity assay was conducted using Î±-endosulfan at LC10 and fluorene or phenanthrene at LC50 in the artificial soils. Upon exposure to the mixture of fluorene and Î±-endosulfan, earthworms were killed in increasing numbers owing to their synergistic effects, while no other mixture showed any additional toxicity toward the earthworms. Along with the acute toxicity results, the biochemical and molecular changes in the fluorene- and phenanthrene-treated earthworms with or without Î±-endosulfan treatment demonstrated that enhancement of glutathione S-transferase activity was dependent on the addition of PAH chemicals, and the HSP70 gene expression increased with the addition of Î±-endosulfan. Taken together, these findings contribute toward understanding the adverse effects of pollutants when present separately or in combination with other types of chemicals.
Pyrolyzing sludge into biochar is a potentially promising recycling/disposal solution for municipal wastewater sludge, and the sludge-derived biochar (SDBC) presents an excellent sorbent for metal immobilization. As SDBC is composed of both mineral oxides and carbonized organic compartment, this study therefore compared the sorption behaviour of Pb and Zn on SDBC to those of individual and mixture of activated carbon (AC) and amorphous aluminium oxide (Al2O3). Batch experiments were conducted at 25 and 45Â Â°C, and the metal-loaded sorbents were artificially aged in the atmosphere for 1â€“60Â days followed by additional sorption experiments. The Pb sorption was generally higher than Zn sorption, and the co-presence of Pb reduced Zn sorption on each studied sorbent. Higher sorption capacities were observed at 45Â Â°C than 25Â Â°C for SDBC and AC, while the opposite was shown for Al2O3, indicating the significance of temperature-dependent diffusion processes in SDBC and AC. Nevertheless, metal sorption was more selective on Al2O3 that showed a greater affinity towards Pb over Zn under competition, correlating with the reducible fraction of sequential extraction. Furthermore, significant amounts of Pb and Zn were additionally sorbed on SDBC following 30-day ageing. The X-ray diffraction revealed the formation of metal-phosphate precipitates, while the X-ray photoelectron spectroscopy showed a larger quantity of metalâ€“oxygen bonding after 30-day ageing of metal-loaded SDBC. The results may imply favourable long-term transformation and additional sorption capacity of SDBC. In conclusion, SDBC resembles the sorption characteristics of both organic and mineral sorbents in different aspects, presenting an appropriate material for metal immobilization during soil amendment.