Report to the General Assembly

Impact of upstream oil extraction and environmental public health: A review of the evidence.

A comprehensive review of water quality monitoring and assessment in Nigeria.

Contrasting distributions of groundwater arsenic and uranium in the western Hetao basin, Inner Mongolia: Implication for origins and fate controls.

Uranium is a heavy metal that is not only radiologically harmful but also a well-known nephrotoxic element. In this study, occurrence of uranium in drinking water samples from locations near the uranium mining site at Jaduguda, India, was studied by Laser-induced fluorimetry. Uranium concentrations range from 0.03 ± 0.01 to 11.6 ± 1.3 µg l(-l), being well within the US Environmental Protection Agency drinking water limit of 30 μg l(-1). The ingestion dose due to the presence of uranium in drinking water for various age groups varies from 0.03 to 28.3 μSv y(-1). The excess lifetime cancer risk varies from 4.3×10(-8) to 1.7×10(-5) with an average value of 4.8×10(-6), much less than the acceptable excess lifetime cancer risk of 10(-3) for radiological risk. The chemical risk (hazard quotient) has an average value of 0.15 indicating that the water is safe for drinking.

Age-dependent dose and health risk due to intake of uranium in drinking water from Jaduguda, India.

The activity concentrations of uranium in well and borehole water samples in the Odeda area were measured using gamma ray spectroscopic system. The results obtained were used to calculate human radiological risk over lifetime consumption by the population in the area.  The activity concentrations of uranium in all the water supplies for drinking and domestic purposes were found to range from 0.51 ± 0.02 to 6.77 ± 0.23 Bq. l-1. The mass concentration was found to range from 20.17 ± 0.79 to 267.80 ± 9.09 µg.l-1. The radiological risks for cancer mortality risk were found to be low, typically ranging from 1.91 × 10-5 to 2.54 × 10-4, while that of the morbidity risk ranged from 2.93 × 10-5 to 3.89 × 10-4.  However, the chemical toxicity was found to vary from 0.56 - 7.47 µg.kg-1.day-1 which is higher than the recommended acceptable safe level by various international organizations. Results of measurements could be of vital importance in radio-epidemiological assessment, diagnosis and prognosis of uranium induced diseases in the local population of the area under investigation.

	 

	Key words: Uranium, radiological risk, toxicity risk, cancer mortality and morbidity risk.

Chemical and radiological risk assessment of uranium in borehole and well waters in the Odeda Area, Ogun State, Nigeria

Water samples from streams, hand-dug wells and boreholes in high background radiation areas in Abeokuta, Nigeria have been collected in order to determine the activity concentrations of 40K, 226Ra and 232Th in the samples as well as their physicochemical characteristics. These parameters were evaluated in order to deter-mine the quality of these water sources to the local population, who use these water resources for drinking and domestic activities. Measurements of radioactivity in the water samples were carried out using γ-ray spectroscopy, while standard chemistry methods were used for the physicochemical determinations of these quality parameters. A total of fourteen representative water samples from streams (7), boreholes (4), and hand dug wells (3) were collected for study. The determined activity concentrations of the radionuclides in these samples were used to calculate the effective dose to the population from due to ingestion of and drink-ing the locally available water. The total annual ingestion effective doses were found to vary between 115.00 ± 1.15μSv and 1362.30 ± 438.02 μSv. The physicochemical parameters where found to be lower than the prescribed standard safe limits in the water sources except for the nitrate and phosphate levels which were particularly high in the water samples from boreholes and hand-dug wells. The radiation effective ingestion dose due to ingestion of water from dug wells and streams was found to be higher than the dose due to inges-tion of water from borehole sources in the studied areas. The results obtained in this study, have been taken as a baselines for physicochemical parameters and activity concentrations of natural radionuclides in water samples within Odeda and Obafemi-owode parts of Abeokuta, Nigeria.

/pdf/radionuclide-contents-and-physicochemical-water-quality-4a4gc1nblf.pdf

Radionuclide Contents and Physicochemical Water Quality Indicators in Stream, Well and Borehole Water Sources in High Radiation Area of Abeokuta, Southwestern Nigeria

Activity concentrations of naturally occurring radionuclides in the soil waste stream in the sedimentation tanks of an oil and gas production well site of a major Petroleum Development Company in Nigeria have been measured using gamma-ray spectroscopy. The gamma-ray peaks observed with reliable regularity in all the samples analysed belong to naturally occurring radionuclides. Radioactive elements such as 137 Cs were not detected in the samples indicating no contamination by radioactive sources in the operations at the site. The concentrations of the radionuclides in the samples ranged from below detection level to 248.2 ± 14.0, 29.9 ± 8.8 to 122.3 ± 13.6 and 12.4 ± 1.2 to 28.6 ± 1.9 Bq · kg-1 for 40K, 226Ra and 232Th respectively. The absorbed dose rates ranged from 25.3 to 73.3 nGy · h-1 with mean 52.6 ± 17.9 nGy · h-1, while the annual outdoor effective dose varied from 31.1 to 89.9 µSv with mean 64.6 ± 21.9 µSv. The cumulative cancer mortality and morbidity risk due to the radionuclides were 8.64 × 10...

Radiological Assessment of Radionuclide Contents in Soil Waste Streams from an Oil Production Well of a Petroleum Development Company in Warri, Niger Delta, Nigeria

The Influence of Selected Soil Physicochemical Properties on Radionuclide Transfer in Cassava Crops

Gross alpha and beta activity concentrations in soil, cassava and fluted pumpkin (leaf and stem) were investigated using a gas flow proportional counter. The gross alpha activity concentrations for the fluted pumpkin were between 3.55 and 13.95 Bq/Kg and 3.53 and 3.61 Bq/Kg for the leaves and stems, respectively. The gross alpha activity concentrations for cassava and soil samples ranged from 0.07 to 0.60 Bq/Kg and 0.35 to 0.53 Bq/Kg, respectively while the gross beta activity concentrations ranged from 0.43 to 0.89 Bq/Kg and 0.46 to 1.04 Bq/Kg for the cassava and soil samples, respectively. The gross alpha and beta activity concentrations in cassava, fluted pumpkin and soils samples have been determined using alpha/beta spectroscopy. The result of thestudy showed that the Iva-valley coal mine area has lower gross alpha and beta activity concentrations compared to other areas of the country. This shows that the coal mining activities in the area may not have increased the radiation burden of the area.

	Key words: Gross, alpha, beta, concentration, activity, food, crop.

/pdf/gross-alpha-and-beta-activity-concentrations-in-soil-and-1hlh66707k.pdf

Chijioke M. Amakom

Papers

Chemical and radiological risk assessment of uranium in borehole and well waters in the Odeda Area, Ogun State, Nigeria

Radionuclide Contents and Physicochemical Water Quality Indicators in Stream, Well and Borehole Water Sources in High Radiation Area of Abeokuta, Southwestern Nigeria

Radiological Assessment of Radionuclide Contents in Soil Waste Streams from an Oil Production Well of a Petroleum Development Company in Warri, Niger Delta, Nigeria

The Influence of Selected Soil Physicochemical Properties on Radionuclide Transfer in Cassava Crops

Gross alpha and beta activity concentrations in soil and some selected Nigerian food crops