Assessment of Ionizing Radiation Effects on the Hematological Parameters of Radiation-Exposed Workers

Long-term exposure to low doses of ionizing radiation may adversely affect human cells and tissues of hospital radiation workers, especially peripheral blood cell count. Blood cell count analysis is a useful screening test in a routine medical checkup. A high or low blood cells count even in a healthy-looking subject leads to the suspicion of disease and it should prompt further investigations. This study was aimed to assess the effects of ionizing radiation on the hematological parameters of radiation workers at several governmental hospitals in Indonesia and correlation between years of employment and equivalent dose on one hand and the hematological parameters on the other. It included 74 medical radiation workers occupationally exposed to low doses of ionizing radiation at the Unit of Radiology and Radiotherapy and 83 controls. Fourteen hematological parameters were measured by ABX Micros 60 Hematology analyzer and the correlation between years of employment and equivalent doseas well as hematological parameters on radiation-exposed workers were tested by linear regression analysis test. Our study reported that red blood cell and monocyte counts were significantly higher in radiation-exposed workers compared to controls, whereas white blood cells, hematocrit, mean corpuscular volume, and lymphocytes values were significantly lower in radiation-exposed workers. A significant correlation was observed between equivalent dose and red blood cells (RBCs) parameter (P=0.001) with a decline in RBC level of 0.541×106/µL per 1 mSv increase of radiation dose. The present study recommends that further studies shoulduse a larger sample size and include various independent variables (genetic polymorphism, chromosome aberration, micronucleus frequency) to study the long-term effects of low-dose radiation exposure on radiation-exposed workers

Effectiveness of Gamma Rays in Attenuating Rodent Malaria Parasites of Plasmodium berghei in Blood of Mice

Malaria is a major public health problem in Indonesia. Therefore, an effective vaccine against this disease is actively being sought by using gamma rays to attenuate the parasites. However, the safety and efficacy of the resulting vaccine are dependent on the precise irradiation dose. The aim of this research was to determine the exact time when the parasites are attenuated by gamma ray exposure. Mice blood containing Plasmodium berghei of 5,0 X 107 parasites/ml was irradiated with gamma rays at doses of 0, 150, 175 and 200 Gy (doses rate of 380 Gy/h) and then was injected intraperitoneally to mice at 0, 1, 2, 3, and 4 h post irradiation. The parasitemia (parasite density) in mouse blood was observed starting with day 2 and repeated every 2-4 days up to 28 days. The survival of the mice was also observed during the experiment. The results showed that the pre-patent period advanced with exposing infected blood to 150 and 175 Gy irradiations, suggesting some degree of attenuation. The amount of radiation required to render the parasites non-viable is about 175 Gy for an inoculum of a number of parasites, but a delay of 4 h resulted in the death of parasites. There was no difference in the infectivity of irradiated parasite injected 1 h and 2 h post irradiation in terms of parasitemia and the survival of mouse. For a dose of 200 Gy which was injected 2 h post irradiation, no parasitemia was found in the blood and animals which died after times varying from 1 to 4 weeks. We concluded that irradiated parasites should be injected into the host within 1 h after irradiation.Received: 16 January 2013; Revised: 23 April 2013; Accepted: 24 April 201