LEVELS OF MANGANESE AND RADIOACTIVITY IN SOIL AND WATER ASSOCIATE WITH CANCER PREVALENCE IN TWO SECTIONS OF ONDO CITY, SOUTHWEST NIGERIA

Joshua Ojo, Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria (jojo@oauife.edu.ng)

As a preliminary check on possible contribution of environmental factors to the 3.5:1 ratio of cancer prevalence reported for the western and eastern sections of the city of Ondo, levels of some trace elements and radioactivity were measured in soil and water samples collected from the region.

Five representative soil and five water samples were collected from each of five local government areas (LGAs) in Ondo State with different prevalence of cancer. The LGAs included Ondo East and Ondo West LGAs, representing the eastern and western sections respectively of the city of Ondo. The natural radioactivity levels associated with ⁴⁰K, ²³⁸U, and ²³²Th were determined in all the  soil and water samples by gamma spectrometry using a CsI-based facility; while levels of fifteen trace elements (K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Ba, Pb, and Tb) were determined in the twenty-five soil samples using EDXRF.  Furthermore, the levels of three elements (K, Mn, and Pb) were also determined in the ten water samples from Ondo West and Ondo East LGAs, using Flame AAS.

There was no statistically significant correlation between cancer prevalence and the different parameters measured across the five LGAs.  However, comparing results only from Ondo East and Ondo West LGAs, (for which possible confounding socio-economic parameters were virtually absent), mean level of Mn was found to be significantly elevated  while that of radioactivity (all three species) were significantly depressed in both soil and water samples from the Eastern section compared with samples from the Western section.

Manganese is a strong anti-oxidant which could protect against cancer, while radioactivity could promote it. The results obtained therefore suggest that environmental factors, viz manganese and radioactivity levels could be contributing to the disparate cancer prevalence in the western and eastern sections of Ondo, Ondo state, Nigeria.

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Short Biography of Presenting Author

Joshua Ojo is Professor of Health Physics and Environment at the Obafemi Awolowo University, Ile-Ife (www.oauife.edu.ng); as well as the President of the LivingScience Foundation, Ile-Ife, Nigeria. (www.lsfnigeria.org).