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Ecotoxicological effects evoked in hydrophytes by leachates of invasive Acer negundo and autochthonous Alnus glutinosa fallen off leaves during their microbial decomposition
2013
Krevš, Alina | Darginavičienė, Jūratė | Gylytė, Brigita | Grigutytė, Reda | Jurkonienė, Sigita | Karitonas, Rolandas | Kučinskienė, Alė | Pakalnis, R. | Sadauskas, Kazys | Vitkus, Rimantas | Manusadžianas, Levonas
Throughout 90-day biodegradation under microaerobic conditions, invasive to Lithuania species boxelder maple (Acer negundo) leaves lost 1.5-fold more biomass than that of autochthonous black alder (Alnus glutinosa), releasing higher contents of Ntot, ammonium and generating higher BOD7. Boxelder maple leaf leachates were characterized by higher total bacterial numbers and colony numbers of heterotrophic and cellulose-decomposing bacteria than those of black alder. The higher toxicity of A. negundo aqueous extracts and leachates to charophyte cell (Nitellopsis obtusa), the inhabitant of clean lakes, were manifested at mortality and membrane depolarization levels, while the effect on H+-ATPase activity in membrane preparations from the same algae was stronger in case of A. glutinosa. Duckweed (Lemna minor), a bioindicator of eutrophic waters, was more sensitive to leaf leachates of A. glutinosa. Fallen leaves and leaf litter leachates from invasive and native species of trees, which enter water body, affect differently microbial biodestruction and aquatic vegetation in freshwater systems.
اظهر المزيد [+] اقل [-]Effect of hydration status on pesticide uptake in anurans following exposure to contaminated soils
2018
Glinski, DonnaA. | Henderson, WMatthew | Van Meter, RobinJ. | Purucker, SThomas
In this study, the impact of hydration status on dermal uptake of pesticides in two species of amphibians is examined. Absorption of pesticides in anurans occurs primarily through a highly vascularized dermal seat patch; however, pesticides can also enter through the superficial dermis following exposure. Despite the growing body of literature on dermal exposure in amphibians, little is known on how hydration status influences uptake. Thus, the objective of this study was to investigate the influence of hydration status on absorption of pesticides (atrazine, triadimefon, metolachlor, chlorothalonil, and imidacloprid) in southern leopard frogs (Lithobates sphenocephala) and Fowler’s toads (Anaxyrus fowleri). Amphibian treatments included dehydration periods of 0, 2, 4, 6, 8, or 10 h prior to exposure to pesticide-contaminated soils for 8 h. Following exposure, soil and whole-body homogenates were extracted and analyzed by LC-MS/MS. Dehydration time was then regressed against post-exposure concentrations to infer the impact of dehydration on dermal pesticide uptake. Increased dehydration time resulted in significantly lowered pesticide concentrations in both species (F₆, ₂₉₃ = 67.66, p = 0.007) for the five pesticides studied. This phenomenon could be due to an energy and/or dilution effect.
اظهر المزيد [+] اقل [-]Exertional heat illness: knowledge and behavior among construction workers
2018
El-Shafei, Dalia A. | Bolbol, Sarah A. | Awad Allah, Marwa B. | Abdelsalam, Amira E.
Construction workers are considered one of the most vulnerable health group workers. Exertional heat illness (EHI) is a well-recognized health hazard that causes significant sickness and death. The purpose of this study was to assess construction workers’ environment and hydration status and to evaluate the effect of health education program on workers. An interventional study was conducted on 89 construction workers in Port Said City. Assessments of workplace environment and workers’ hydration status were done by using workplace evaluation checklist, wet-bulb globe temperature, urine specific gravity, and urine color chart. A pre-post-test design was used in the evaluation of workers’ knowledge and behavior regarding EHI. A health education program was conducted to improve workers’ knowledge and behavior; then, evaluation was done after 1 month. The most reported symptoms of heat illness were sweating (100.0%), dizziness (98.0%), and muscle pain (82.0%). Most workers showed signs of minimal dehydration (78.7%). There was a significant improvement in workers’ knowledge about EHI and behavioral action for prevention after health education. Construction workers are at high risk of exposure to EHI which raised the attention to provide educational programs which can guide workers to follow healthy behaviors and prevent EHI.
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