Environmental radioactivity near the central coast of Venezuela and its radiological impact

Abstract

The concentrations of 4~ 226Ra, 232Th and |37Cs were determined in the upper layers of soils in the central coastal region of Venezuela. The activities of 137Cs are higher in the areas where the forest is well developed, oriented towards the wind and at higher elevations. The origin of the |37Cs deposition is from water input from the clouds directly in the cloudforest and rainfall from the northeast trade winds. Even though the values of 137Cs are much higher in these areas, there is little or no significant increase in the health risk. The natural radioactivity is correlated with the geology in the region except in the area of Urama. The values for the natural radiation background are as follows: for potassium between 1-3%, for radium between I-3 ppm and for thorium the range was 6-39 ppm. The corresponding amounts of absorbed dose rates in air, the exposure rates and the annual effective dose equivalents are in the following ranges respectively: 11-39 pGy/s, 4-16 uR/h and 0.25-0.86 mSv/y. The annual effective dose equivalents include the contribution of the global average (2.57 mSv/y) of the rest of the natural sources of radiation. Finally, the largest natural radioactivity background, was found near Chichiriviche as a result of the massive granite deposits in this area, but again there is no significant health risk.

Radioactivity concentration and heavy metal content in fuel oil and oil-ashes in Venezuela

“…The ion lenses were optimised simultaneously monitoring isotopes of low ( 9 Be) middle ( 115 In) and high ( 238 U) masses so that the count rate is suited to achieve the best possible compromise across the mass range considered. The dynamic range of the technique allows linear calibration curves over five or six orders of magnitude, therefore quantification was performed for all the elements by using external standard calibration curves drawn through the blank and 5 more points, using multielement aqueous standard solutions in 2% HNO 3 . Each sample determination was the mean of three separate sequential determinations.…”

“…Gamma dose and the radon concentrations indoors, in drinking water, in caves and in artificial cavities including the effect of radon transported to the surface with the earth gas have been studied [2][3][4][5]. To continue this task the oil and its related products should be considered.…”

Environmental radioactivity measurement in soils of an abandoned potash deposit at Holle, Republic of Congo

“…Then, the Republic of Congo does not have standards or guidelines for the maximum level of radioactivity in soils. However, soils from abandoned mine sites have been the subject of many studies worldwide: [1][2][3][4][5][6] It is also disturbing to note that this abandoned mine is actually turned into economic site by some of the villagers, who engaged activities such as the selling of those potash-salts to those who made salted-fish, to farmers, etc. It is also consumed by the surrounding populations.…”