25 May 2016
04 July 2016
ISEH 2016 & Geoinformatics 2016: Joint International Conference on Environment, Health, GIS and Agriculture
14 August 2016
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Science in the News
Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health
- Alterations in antioxidant defense system of workers chronically exposed to arsenic, cadmium and mercury from coal flying ash 2016-02-01
Humans are exposed to different stress factors that are responsible for over-production of reactive oxygen species. Exposure to heavy metals is one of these factors. The aim of the study was to analyze the effect of chronic exposure to heavy metals through coal flying ash on the efficiency of antioxidative defensive mechanisms, represented by the activity of superoxide dismutase, glutathione peroxidase and ascorbic acid. Nonessential elements such as arsenic and mercury levels showed a significant increase (p¬†>¬†0.001) in the power plant workers rather than in the control subjects. There were no significant differences of blood cadmium between power plant workers and control subjects. We found a significant positive correlation (p¬†<¬†0.05) between BAs/SZn (r¬†=¬†0.211), BAs/BSe (r¬†=¬†0.287), BCd/SCu (r¬†=¬†0.32) and BHg/BSe (r¬†=¬†0.263) in the plant workers. Red blood cell antioxidant enzymes and plasma ascorbic acid were significantly lower in power plants workers than in the control group (p¬†<¬†0.002). We can conclude that levels of mercury, arsenic and cadmium in blood, despite their concentration within the reference values, significantly affect plasma ascorbic acid concentration, superoxide dismutase and glutathione peroxidase activity, which are able to increase the risk of oxidative stress.
- Increase in platinum group elements in Mexico City as revealed from growth rings of Taxodium mucronatum ten 2016-02-01
Tree rings may be used as indicators of contamination events providing information on the chronology and the elemental composition of the contamination. In this framework, we report PGEs enrichment in growth rings of Taxodium mucronatum ten for trees growing in the central area of Mexico City as compared to trees growing in a non-urban environment. Concentrations of PGE were determined by ICP-MS analysis on microwave-digested tree rings. The element found in higher concentrations was Pd (1.13‚Äď87.98¬†őľg¬†kg‚ąí1), followed by Rh (0.28‚Äď36.81¬†őľg¬†kg‚ąí1) and Pt (0.106‚Äď7.21¬†őľg¬†kg‚ąí1). The concentration trends of PGEs in the tree-ring sequences from the urban area presented significant correlation values when comparing between trees (r between 0.618 and 0.98, P¬†<¬†0.025) and between elements within individual trees (r between 0.76 and 0.994, P¬†<¬†0.01). Furthermore, a clear increase was observed for rings after 1997, with enrichment of up to 60 times the mean concentration found for the sequence from the non-urban area and up to 40 times the mean concentration for the pre-1991 period in the urban trees. These results also demonstrate the feasibility of applying T. mucronatum ten to be used as a bioindicator of the increase in PGE in urban environments.
- Heavy metals and parasitic geohelminths toxicity among geophagous pregnant women: a case study of Nakuru Municipality, Kenya 2016-02-01
Geophagia is defined as deliberate consumption of earths‚Äô materials, e.g. soil, clay and soft stones. The practice is widespread among pregnant women, and there are conflicting views as to whether it is beneficial to health or not. Geophagic materials may be a source of micronutrients though the materials may bind the micronutrients thus reducing or hindering their bioavailability in the body. Geophagia is closely associated with geohelminthic infections among pregnant women and heavy metal poisoning, which constitute significant public health problem in many developing countries such as Kenya. In our research, the geophagic materials consumed by the pregnant women were studied. A total of 38 geophagic materials in the possession by different pregnant women were analysed. The collected samples were subjected to standard digestion procedures and analysed for zinc, lead and iron by atomic absorption spectroscopy. Results indicated that the geophagic materials contained elevated levels of Fe at mean concentration value of 80.10¬†ppm, Pb at 3.28¬†ppm and Zn 1.81¬†ppm for a 1.00¬†g sample. An average of 20¬†g of the geophagic materials was being consumed per day. Based on the average consumption, the pregnant women were exposed to 65.52¬†ppm Pb per day, 36.2¬†ppm Zn per day and 1602¬†ppm Fe per day. Lead exceeded the WHO-lead exposure limits of 25¬†ppm/day for pregnant women. The materials were also subjected to microscopic examination for Ascaris lumbricoides, Trichuris trichiura, Taenia Spp., Necator americanus and Ancylostoma duodenale. In conclusion, the women were exposed to heavy metals‚ÄĒiron, zinc and lead, but there was no observable eggs, larvae or adult species of the geohelminths. The key recommendation was that there is need to integrate public health education on geophagia, lead screening and testing with antenatal support care systems. This will enhance maternal and child health, thus reducing infant and maternal morbidity and mortality rates.