BIOLOGICAL EFFECTS OBSERVED IN MAMMALS MAINTAINED IN AN AREA OF VERY HIGH NATURAL RADIOACTIVITY

1981 ◽  
Vol 23 (2) ◽  
pp. 321-326 ◽  
Author(s):  
A. Léonard ◽  
M. Delpoux ◽  
J. Chameaud ◽  
G. Decat ◽  
E. D. Léonard
Keyword(s):  
Natural Radioactivity ◽  
Chromosome Aberrations ◽  
Biological Effects ◽  
Somatic Cells ◽  
Summer Period ◽  
Natural Radiation ◽  
Radon Exposure ◽  
Males And Females ◽  
A Site ◽  
Very High

Male rabbits (Oryctolagus cuniculus) were maintained for a 28-month period on the floor of a hut built at a site in southwestern France where the dose rate from natural radioactivity amounts to about 8 mrad/h. Male and female BALB/c mice (Mus musculus) were also placed in the hut during the summer period. The observations performed on those animals demonstrate that exposure to high natural radiation can increase the frequency of chromosome aberrations in somatic cells and indicate also that fertility in males and females is affected in an inverse manner. Model experiments with radon exposure of laboratory rabbits under controlled conditions have shown that the chromosome aberrations observed in somatic cells are not due to the radon exposure but essentially to gamma irradiation.

Natural radioactivity levels and radiological implications in the high natural radiation area of Wadi El Reddah, Egypt

2021 ◽  
Vol 327 (2) ◽  
pp. 643-652
Author(s):  
A. F. Tawfic ◽  
Hesham M. H. Zakaly ◽  
Hamdy A. Awad ◽  
Hesham R. Tantawy ◽  
Akbar. Abbasi ◽  
...  
Keyword(s):  
Natural Radioactivity ◽  
Natural Radiation ◽  
Radiation Area ◽  
Radioactivity Levels

scholarly journals An Assessment of Metal Contamination Risk in Sediments of the Mohammad Abad River, Northern Iran

2021 ◽  
Vol 2 (8) ◽  
pp. 696-704
Author(s):  
Hassan Malvandi
Keyword(s):  
Heavy Metals ◽  
Biological Effects ◽  
Sediment Quality ◽  
Contamination Factor ◽  
Anthropogenic Source ◽  
Degree Of Contamination ◽  
Northern Iran ◽  
Pollution Levels ◽  
Quality Guidelines ◽  
Very High

Background: Sediments in the aquatic ecosystems can be used as suitable indicators for monitoring contaminants. Then, objectives of this study were to evaluate the concentration of heavy metals in the surface sediments of the Mohammad Abad River, to determine the degree of pollution of heavy metals in sediments using some major contamination indices; to identify the major sources (anthropogenic or natural sources) of the studied metals; and to evaluate the “reference river” of the river under study for ecotoxicology studies. Methods: Samples of sediment were taken from six sites of the river. The present study, eleven heavy metals (chromium, manganese, iron, cobalt, nickel, zinc, selenium, magnesium, silver, aluminum and arsenic) were studied. Results: Comparison of metal concentrations with those of Sediment Quality Guidelines (SQGs) showed no association with harmful biological effects for the heavy metals studied except for Se and As. The results of the contamination factor index showed low pollution levels for most metals (Cr, Mn, Fe, Co, Ni, Zn and Al), moderate pollution levels for As, and very high pollution levels for Se. The degree of contamination (Cd) and modified degree of contamination (mCd), showing the total contamination of elements, demonstrated very high degree contamination status in the study area. According to the index of quantification of contamination, the values of Cr, Mn, Fe, Ni, Zn and Al were derived mainly from geogenic sources of enrichment, while the values for Se and As were enriched by anthropogenic source of enrichment. Conclusion: These findings suggest that continuous monitoring of Se and As in sediment and organisms of the Mohammad Abad River should be directed to evaluate the threat of these elements to the public health and to the ecology of the river under study.

scholarly journals Patterns of Human Papillomavirus DNA and Antibody Positivity in Young Males and Females, Suggesting a Site-Specific Natural Course of Infection

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e60696 ◽  
Author(s):  
Henrike J. Vriend ◽  
Johannes A. Bogaards ◽  
Fiona R. M. van der Klis ◽  
Mirte Scherpenisse ◽  
Hein J. Boot ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Natural Course ◽  
Site Specific ◽  
Young Males ◽  
Antibody Positivity ◽  
Males And Females ◽  
A Site ◽  
Papillomavirus Dna

Current proposals for the Thames barrier and the organization of the investigations

1972 ◽  
Vol 272 (1221) ◽  
pp. 179-185 ◽  
Keyword(s):  
Meteorological Conditions ◽  
The Third ◽  
River Thames ◽  
High Level ◽  
A Site ◽  
Very High

A considerable area of London close to the River Thames is liable to flood if the water in the river reaches an exceptionally high level. The very high waters which occur from time to time due to exceptional meteorological conditions are steadily increasing in level. After considering the possible ways of meeting this threat, by raising the existing flood defences, constructing a barrage across the mouth of the estuary, or the provision of a removeable flood barrier, to be closed only when a dangerous surge tide was liable to occur, the third course has been chosen as the best method. A site in Woolwich Reach has been chosen for a structure with four main openings of 61 m (200 ft), and the rising sectorf gate has been selected as the type of gate to be developed for the main openings.

scholarly journals The Oak Chronology (948-1314 AD) for the Zary Area (Sw Poland)

2007 ◽  
Vol 26 (-1) ◽  
pp. 47-52 ◽  
Author(s):  
Małgorzata Danek ◽  
Marzena Kłusek ◽  
Marek Krąpiec
Keyword(s):  
High Similarity ◽  
Statistical Parameters ◽  
Oak Wood ◽  
Sw Poland ◽  
Site Chronology ◽  
A Site ◽  
Excellent Tool ◽  
Very High ◽  
Lower Silesia

The Oak Chronology (948-1314 AD) for the Zary Area (Sw Poland)The study presents the results of investigations aimed at construction of a site chronology for oak wood from the surroundings of Zary (SW Poland). The 366-year chronology ZY_2006, covering the period 948-1314 AD was determined on the basis of 189 individual ring patterns representing samples of archaeological wooden objects lifted at the excavation works led in the Old Town of Zary in the years 2004-2005. The chronology produced exhibits high similarity to the standards for the neighbouring regions: Wielkopolska and Lower Silesia. The statistical parameters of the chronology are very high and, thanks to the signature years determined, it should be an excellent tool for dating samples of mediaeval timbers from the whole region of Ziemia Lubuska, including some with relatively short dendrochronological sequences.

scholarly journals Heavy Metal Contamination and Ecological Risk Assessment in Fluvial Sediment of San Juan –Taxco River System in Mining Region of Taxco Guerrero, Mexico

2021 ◽  
Author(s):  
Edith R. Salcedo Sanchez ◽  
Manuel Martínez Morales ◽  
Juan Manuel Esquivel Mart ◽  
Oscar Talavera Mendoza
Keyword(s):  
Heavy Metals ◽  
Ecological Risk ◽  
Biological Effects ◽  
Ecological Status ◽  
River System ◽  
Risk Identification ◽  
San Juan ◽  
Mining District ◽  
Geochemical Indices ◽  
Very High

Abstract The hydrological system of San Juan-Taxco Rivers in located inside of one of the oldest and major mining district in Mexico. Several communities in the area use the rivers water along its flow for domestic water supply and crop irrigation. Sediment is an essential, integral and dynamic part of river basins, in polluted environments these act as sink of heavy metals and as a source of contaminants on the fluvial system. The management and sustainability of sediment should be assessed and secured to achieve good ecological status of the basins, for this task, approaches as ecological risk identification and geochemical indices are being used.Superficial sediment samples were collected in San Juan-Taxco river system. The results demonstrated that the degree of pollution from thirteen heavy metals and metalloids studied decreases in the following sequence: Cd> Zn > Pb > Cu > As > B > Mn > Ni > Fe > Co > Ba > Al and Cr. Cd made the most dominant contribution. Geochemical indices revealed important external anthropogenic influences in the rivers. The geochemical indices indicated very high enrichment for As, Cu, Pb and Zn, and extremely high for Cd in the three-rivers. The calculation of Pollution Load Index (PLI) showed in Cacalotenago River and in Taxco River are the sites with the highly contaminated sediments. PLI values were very high in all the samples sites due mining tailings erosion, wastewater and agriculture run off. Cd, Zn, Pb, Cu and As were the main potential risk elements that will cause harmful biological effects in the riverine environment.

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