RADIATION EXPOSURE LEVELS AND THEIR POTENTIAL EFFECTS ON DOMESTICATED ANIMALS IN WEST POKOT, KENYA

Abstract

Radioactive matter in the earth’s crust and celestial bodies are the main sources of natural radioactive exposure to man and animals. The main contribution to external exposure comes from gamma-emitting radionuclides present in trace elements in the soil. This study aimed at investigating absorbed dose and annual effective dose rate from radiations emitted by radionuclides from Atulya and Mtembur in West Pokot. Purposive sampling was used to identify points for soil sampling. A 500 g of each of the soil samples were collected. Rock samples were chipped off from caves and bones and hides collected from a slaughter house. The samples were then transported to the National Radiation Protection Board laboratory (Nairobi), for radioactivity analysis. Soil was ground with a grinder to powder then sieved through 100μm mesh wire. An LB 200 Bequerel Monitor, measured gamma activity (Bqkg-1) in solid samples. The values were subjected to statistical analysis and from t- test results, the corresponding p-values of soil and rock licks were (P=0.000, df=3, t=-41.288) and (P=0.005, df=3, t=7.398) which differed significantly (P≤0.05). However, the results of crushed rocks (P=0.731, df=3, t=-0.378) didn’t differ significantly. Samples from Mtembur showed negative correlations between radiation activity levels within soil and leaves, rock licks and skin, rock licks and bones, leaves and skin and between leaves and bones, since p˃0.05 and r <1. The same negative correlation was noted for Atulya except for a positive correlation between radiation activity levels within crushed rocks and bones (0.050, p≤0.05). Ratemeter in counts per second results showed elevated radioactive exposure in soils 0.5651 mSv/y, rock lick 0.8599 mSv/y, animal parts 0.4029 mSv/y and crushed rock 0.7421 mSv/y. Leaf samples showed up to 0.573 mSv/y. Evidently, animals in West Pokot County are exposed to harmful radiations which could lead to deformities like fragile limbs, misplaced organs and multiple organs. This leads to poor economic returns to the pastoral community. The two areas showed exposure limits beyond the WHO standards and policy to reduce the exposure levels is recommended.