PubMed · 14935680
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
R HENRY, R SORBA. 1951. [Rotating extraction apparatus].. https://pubmed.ncbi.nlm.nih.gov/14935680/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The environmental problems related to the former chemical plant in Tarnowskie Gory, with respect to the Quaternary and Triassic groundwater as main receptors, are described and the eco-toxicological impact is discussed. The historical use of that site included industrial mining of ores (Ag, Pb, Zn) and use of Ba, B, Sr, Al, Cu during production of pigment. The majority of used and produced substances were toxic or hazardous. The applied technologies resulted in generation of waste which were mostly dumped without any elementary protection principles. Hydrodynamic modelling showed potential hazard to water-intakes. The variations of spatial distributions of selected contaminants within the Triassic carbonate series indicate that the chemical waste dumped in vicinity of the plant are the sources of groundwater contamination of boron. The results of soil and groundwater monitoring at the constructed landfill show significant contamination, mainly due to leaching from dumped waste, but also from infiltration of non-operating underground installations, and spills of toxic substances during the plant operation. The Quaternary aquifers are heavily contaminated due to the leaching out of chemical compounds from dumping sites. This is hazardous to the Triassic reservoirs--the main sources of potable water for the region. The characteristics of the key contaminants (As, B, Ba and Sr) are provided, including their transport, fate and toxicity. The spatial and temporal distribution of contaminants in groundwater is presented, and observed trends of groundwater quality decrease, mainly with respect to the Triassic aquifers, are discussed. The groundwater risk assessment being developed for the Tarnowskie Gory site should consider the present situation, and provide an approach towards evaluation and assessment of the required remediation measures.
The aim of this study was: (1) To determine the minimum number of characteristics necessary to discriminate between postural tremor recorded in control subjects (CO), in subjects exposed to manganese (MN), and in patients with Parkinson's disease (PD), and (2) to examine the continuum of changes between the three groups examined. Workers previously exposed to Mn (n = 10), patients with PD (n = 10), and control subjects (CO) (n = 11) underwent a clinical examination. Blood Mn was measured at the end of exposure time for the MN group and 12 months later at the beginning of the experiment for all groups. Postural tremor with visual feedback was recorded in the index finger with a laser system. Statistical criteria were used to reduce computed tremor characteristics to a minimal set of reliable discriminating variables. Two variables were retained namely corrected wobble (CW), describing the morphology of the tremor oscillations, and variability ratio (VR), describing proportional power of tremor. Both variables had an overall correct classification rate of 77.4%. Blood Mn levels at the time of the experiment were similar for all groups and had insignificant correlation with tremor variables. However, blood Mn levels in workers which were also measured at the end of exposure time (i.e., 12 months before) showed significant correlation (Spearman's rank coefficient) with both harmonic index (rho = 0.70, P = 0.03) and first maximum of the autocorrelation function (rho = 0.89, P = 0.001). We conclude that (1) the tremor of workers exposed to Mn could be adequately described with only two variables; (2) a continuum of changes between tremor recorded in control subjects, in subjects exposed to Mn and in patients with PD was observed, with the MN group always found in between the control (CO) and the PD groups; (3) while blood Mn levels in workers were back at control levels at the time of the experiment, the effect of Mn on postural tremor was still detected. Thus our method has the potential to detect the effect of Mn on tremor with only two variables even after Mn level in the blood is back to normal values.