Interaction of low-intensity nuclear radiation dose with the human blood: Using the new technique of CR-39NTDs for an in vitro study Asaad H. Ismail n , Mohamad S. Jaafar Research Group of Radiation and Medical Physics, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia article info Article history: Received 8 June 2010 Received in revised form 19 October 2010 Accepted 3 November 2010 Available online 23 November 2010 Keywords: Human blood CR-39 NTDs Radium-226 Low radiation dose In vitro study abstract Complete blood counts were analyzed for 30 samples of human blood with radiation dose rate ranging between 10 and 41 mSv/h using a Radium-226 source with different time of exposure. A new technique involving a nuclear track detector type CR-39(CR-39 NTDs) was used to estimate the alpha particle density incident on the blood samples. The results show that the ranges of alpha particle in blood samples and on the surface of CR-39NTDs vary exponentially with energy of alpha particles. This depends on the restricted energy loss and target density. Changes in the blood components due to irradiation occurred for different durations of irradiation, and the duration of irradiation that influenced the blood samples in this study was 6 min. The change in red blood cell (RBC) was negligible, so it is less affected than other blood components. In addition, most changes in the blood contents began at a low radiation dose (10.38–13.41 mSv/h). For the doses 13.41–21.77 mSv/h, platelet (PLT) counts increased rapidly and adversely with the RBC and white blood cell (WBC) due to chromosomal aberration. Besides, rapid PLT count reduction rapidly at high dose (42.1 mSv h) causes thrombocytopenia; in contrast, WBC increased, which is an indication of cancer caused due to increase in alpha particle dose. Generally, our results are in agreement with the essentials of blood content and the principles of biological radiation interaction. & 2010 Elsevier Ltd. All rights reserved. 1. Introduction Radiation has some effects on the human body, and increased levels can cause injury to tissue systems due to free radical damage. Exposure can be acute or chronic, and the symptom severity depends on many factors like total dose, dose rate, distribution of dose and susceptibility of the person to radiation. Tissue systems with greater rates of cell division, such as the hematopoietic and gastrointestinal systems, typically fare worse than others as the necessary cell turnover is interrupted by widespread cell death. Platelet levels at the time of diagnosis could be a useful prognostic factor in lung cancer (Javier et al., 2009; Jacobs, 1998; Pecaut et al., 2002). In general, high linear energy transfer (LET) radiation (alpha particles and fission fragments) is more efficient in inducing biological damage than low LET radiation (gamma and X-rays, b-particles), because most of the incident energy will be deposited within a short distance, causing dense ionization along the trajectory (Jacobs, 1998; Somosy, 2000). Hematology studies in the field of radiation (long-term expo- sure) have an active role in estimating exposure to ionizing radiation, as it increases the number of chromosomal aberrations in human blood lymphocytes. This increase mainly reflects only the exposure suffered in the previous year, owing to the cell repair mechanism, which limit the usefulness of this parameter as a marker of long-term exposure (Stephan et al., 2005; Elaine et al., 2001). Exposure to ionizing radiation levels higher than those encoun- tered in the natural environment can result in different diseases, of which cancer is one, especially lung and blood (leukemia) cancers. Leukemia is diagnosed from deviation in the blood parameters: white blood cell count (WBC), red blood cell count (RBC) and platelet count (PLT), see Fig. 1. High WBC can be a sign of infection, and it increases in certain types of leukemia. Low white blood cell counts can be a sign of bone marrow diseases or an enlarged spleen. High hemoglobin (Hgb) can occur due to lung disease, living at high altitudes or excessive bone marrow production by blood cells. Decrease in the number of platelets in the blood due to Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/apradiso Applied Radiation and Isotopes 0969-8043/$ - see front matter & 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.apradiso.2010.11.004 n Corresponding author. E-mail address: asadhawlery@hotmail.com (A.H. Ismail). Applied Radiation and Isotopes 69 (2011) 559–566