A Comparative Study Of Natural Radioactivity And Associated Radiological Hazard In Selected Sanitary Ware Products Sold In Kenya.

TITLE: A Comparative Study Of Natural Radioactivity And Associated Radiological Hazard In Selected Sanitary Ware Products Sold In Kenya.

STUDENT’S NAME: NATANG’AH EDWIN CHEMOS.

SUPERVISORS NAME

1. DR. MICHAEL NAKITARE WASWA
2. DR. PETER KHAKINA NYONGESA

ABSTRACT

Natural radioisotopes are present in all sanitary ware products used in building and construction. The primary source of outdoor radiation that residents of homes or workplaces are exposed to is these radioisotopes. Determining the radiation levels of sanitary wares in terms of production materials (ceramic and porcelain) and countries of importation of these items used in buildings is crucial. In this study, Thallium doped sodium iodide detector NaI(Ti) was used to obtain levels (²²⁶Ra, ²³²Th, and ⁴⁰K) in twenty sanitary ware products. For the studied samples, the activity concentrations for India were 17.75±0.91, 59.83±2.99 and 280.25±14.03, China were 14.75±0.76, 72.95±3.65 and 384.3±19.23 and for Uganda it was 26±1.31, 136±6.81 and 552±27.65 (Bq/kg) for ²²⁶Ra, ²³²Th and ⁴⁰K respectively. The mean concentration based on production material for ceramics was 24.75±1.2425 (Bq/Kg), 66.4±3.3175 (Bq/Kg) and 444.5±22.235 (Bq/Kg) while for porcelain it was 14±0.72 (Bq/Kg), 83.175±4.16 (Bq/Kg) and 401.5±20.135 (Bq/Kg) for ²²⁶Ra, ²³²Th and ⁴⁰K respectively. With the exception of the average of ²³²Th concentration of both countries (India, China and Uganda) and production materials (ceramic and porcelain) that were slightly above the permissible limit of 50 (Bq/kg), the values of   ²²⁶Ra and ⁴⁰K were lower than the global average values of (50, and 500 Bq/kg). The values of ⁴⁰K for Ugandan   samples were slightly higher than GAV. The average of radiological parameters (Ra_eq, l?, H_ex, H _in, ADR, AEDE _in, AEDE _out and ELCR) for three importation countries had all values lower than world limits except for ELCR that was slightly above the global average. The parameters for production materials (Ra_eq, l?, H_ex, H _in, D, AEDE_in, AEDE_out and ELCR) were all below the permissible limits for porcelain and ceramic except for ELCR in both production materials that had a slight high values. All the indices were obtained and compared to the prescribed limits set by commissions (the WHO, ICRP, UNSCEAR, and EC) to ensure the safe use of the sanitary wares. The assessed indices and parameters fall within the recommended values and safety limits except for ELCR that had slightly high values. From obtained results, the samples from both production materials (ceramic and porcelain) and importation countries (India, China and Uganda) pose no risk from using the sanitary wares under investigation in residential facilities but the manufacturers of the products should lower the levels of ²³²Th.