Assessment of Radiological Hazard Indices from Exposures to Background Ionizing Radiation Measurements in South-South Nigeria
Godwin Ekong,
Timothy Akpa,
Ibrahim Umaru,
Williams Lumbi,
Mbet Akpanowo,
Nsikak Benson
Issue:
Volume 7, Issue 2, April 2019
Pages:
40-47
Received:
5 August 2019
Accepted:
22 August 2019
Published:
5 September 2019
Abstract: Radioactivity in the environment from sources of natural and human activities resulting in planned, emergency and existing exposure to human population, environment and other biota has led to growing apprehensions in Nigeria and the world. The existing exposure situations mainly from natural radionuclides, present in the earth crust from creation emits background ionizing radiation leading to gamma dose exposures. The objective of this study was to assess the background ionizing radiation and associated radiological hazard indices in Itu, Nigeria located at 5010’0” N 7059’0” E, and establish an eco-radiological baseline data prior to the construction of any nuclear fission reaction facility in the area. A systematic random method of measurement was employed within demarcated monitoring zones of entire geological map of Itu, Nigeria. The global positioning system finder (GARMIN Etrex 10) was used for data point location, while RDS-31S/R Multi-purpose survey meter was used for dose rate measurement. The background ionizing radiation measurement obtained ranged from 0.041 ± 0.002 - 0.045 ± 0.002 µSv/hr with overall mean of 0.042 ± 002 µSv/hr, which was lower than the world mean of 0.2 µSv/hr. Radiological hazard indices arising from the background ionizing radiation measurement were also evaluated. The mean estimated Gamma Dose Rate was 9.312 nGy/hr, the terrestrial outdoor Annual Effective Dose Rate arising from gamma was 6.83 mSv/yr, that of indoor was 21.85 mSv/yr and Excess Life Cancer Risk was 0.05 × 10-3. The mean evaluated radiological hazard indices were found to be below admissible limits, and thus poses no significant radiological health threat to the populace. Therefore, the assessment demonstrates that there is no elevated level of dose rate, which is makes it safe for human habitation, but care should be taken to avoid increase radiation level from human activities. It is recommended that constant radiological monitoring be encourage, and the data considered as radiological baseline in Itu, Nigeria.
Abstract: Radioactivity in the environment from sources of natural and human activities resulting in planned, emergency and existing exposure to human population, environment and other biota has led to growing apprehensions in Nigeria and the world. The existing exposure situations mainly from natural radionuclides, present in the earth crust from creation e...
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The Study of Microbial Diversity in Mangrove Wetland Ecological System Based on a 16S rDNA Library
Issue:
Volume 7, Issue 2, April 2019
Pages:
48-55
Received:
3 January 2019
Accepted:
31 January 2019
Published:
10 September 2019
Abstract: The microbial resources in mangrove wetland ecological system are abundant because of their special characteristics. However traditional methods of isolation and culture alone cannot analyze the microbial diversity fully and so, in this study, a 16S rDNA library was constructed to analyze microbial diversity in the Fugong mangrove of the Jiulong River Estuary, Fujian Province, China. The total sediment DNA was extracted, a 16S rDNA library constructed, and the clones analyzed using the restriction fragment length polymorphism (RFLP) method. The 16S rDNA sequences of 50 clones which had a higher display frequency in the RFLP analysis were blasted with the sequences in GenBank. The results showed that the highest similarity of the sequence in clones was 100%, while the lowest was 88%. The dominant microbes from mangrove sediments in the 16S rDNA library belonged to the Proteobacteria (70%) including α-proteobacteria (6.0%), γ-proteobacteria (22.0%), δ-proteobacteria (10.0%) and ε-proteobacteria (32.0%). The other microbes were Bacteroidetes (8.0%), Planctomycetacia (2.0%), Actinobacteria (2.0%) and Verrucomicrobia (2.0%). Additional uncultured microorganisms as well as those whose classification information was unclear were also detected (16.0%). The results of this study indicated that more objective and comprehensive information of microbial diversity in mangrove wetland ecological system had been obtained. There is abundant microbial diversity and a large amount of unknown microbial resources in mangrove wetland ecological system, which could have a very important potential, and so there should be more research to explore and utilize these microbial and functional gene resources in mangrove wetland ecological system.
Abstract: The microbial resources in mangrove wetland ecological system are abundant because of their special characteristics. However traditional methods of isolation and culture alone cannot analyze the microbial diversity fully and so, in this study, a 16S rDNA library was constructed to analyze microbial diversity in the Fugong mangrove of the Jiulong Ri...
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