Determination of uranium concentration in blood samples of women with breast cancer in Babylon Province of Iraq using CR-39 nuclear track detector

Radioactive elements such as uranium and its daughter nuclides have the potential to harm humans due to their toxicity and emission of ionizing radiation. Uranium, found abundantly in nature, is primarily composed of the uranium-238 isotope. This isotope dominates the uranium present in the natural world and serves as the starting point for a series of radioactive decays, leading to the formation of stable lead-206. This process involves the formation of 13 intermediate radionuclides that emit beta or alpha particles, with some also emitting gamma particles at lower energy levels [1, 2]. Human activities, including phosphate fertilizer application, phosphate mining, atomic testing, uranium mining, and the entire nuclear fuel cycle, have significant consequences on the environment in terms of radionuclide pollution. Radionuclides are radioactive isotopes that result from these activities and can have detrimental effects on ecosystems and human health [3–5]. Rocks and soils contain various naturally occurring radionuclides, albeit in relatively low concentrations [4]. Depleted uranium (DU) is a uranium compound that is generated as a result of uranium enrichment. It is called “depleted” because it contains a lower proportion of the uranium-235 isotope compared to natural uranium. DU is mildly radioactive, with an activity level of approximately 60% of natural uranium. Its production is primarily associated with the nuclear fuel cycle and the manufacture of nuclear weapons. Understanding the background of DU is crucial to comprehending its properties, applications, and potential environmental and health concerns [6].

During the Gulf War and Iraq War 2003, the use of munitions containing DU by the Coalition Forces raised international concerns. The fallout from these conflicts resulted in DU contamination of cars and soil in specific areas. As a result, global communities became worried about the potential health consequences posed by DU residues. The international concerns surrounding DU contamination stem from the fear of long-term health risks for individuals living near these damaged regions. The potential for environmental implications is also a significant factor contributing to these concerns [7]. Uranium exposure can occur through various routes, including inhalation, ingestion, and skin puncture. These routes are the most common pathways for uranium to enter the body [8]. The release of uranium from the bones and other organs into the bloodstream is linked to a wide variety of diseases and conditions [9, 10], including cancer, skin diseases, congenital abnormalities, respiratory disorders, leukemia, kidney failure, and even some diseases for which no cure has yet been discovered. Recent studies reveal that heavy metals such as the radioactive nucleotide uranium cause oxidative stress by increasing the production of reactive oxygen species (ROS) [11, 12]. This oxidative stress is a fundamental contributor to genotoxicity, autophagy, apoptosis, and DNA damage.

On the other hand, a few circumstantial indications indicate that uranium may impede the DNA repair process. Exposure to uranium has been linked to DNA damage induction and repair disruption [13, 14]. When determining the uranium content in a patient’s blood, it is common practice to use a solid-state nuclear track detector [15]. According to Fleischer et al. [16] hypotheses, solid-state track recording materials that were squeezed together and in contact with both films were exposed to thermal neutron irradiation, known as the fission-track technique. This method seems ideal for analyzing uranium levels in human blood for precise quantification. In this investigation, the CR-39 nuclear track detector will be used to compare the amounts of uranium in the blood of women diagnosed with breast cancer and a healthy control group.

The study investigated the uranium concentrations in blood samples from 16 women diagnosed with breast cancer. The findings, summarized in Table 1, indicate that the highest recorded uranium concentration was 3.259 ± 0.20 ppb, detected in sample CB02 from a woman aged 36 years. Conversely, the lowest recorded uranium concentration was 1.918 ± 0.21 ppb, observed in sample CB03 from a woman aged 46 years. In analyzing the data from Table 1, it is evident that there are notable differences in uranium concentrations between younger and older women. Young women display elevated levels of uranium compared to their older counterparts. This observation suggests that age might have an influence on uranium accumulation within the body. The exact reasons for this disparity require further investigation, but it is worth noting that uranium exposure can occur through various pathways, including ingestion, inhalation, and external contact. Therefore, it is possible that the variations in uranium concentrations could be attributed to differences in lifestyle, occupational exposure, and dietary habits [25].

Additionally, the uranium-concentration analysis was conducted in 20 blood samples collected from women without breast cancer, as presented in Table 2. The recorded uranium concentrations in Table 2 varied between 0.59 ± 0.22 ppb and 2.105 ± 0.27 ppb. The mean uranium concentration across all the samples was found to be 1.205 ± 0.30 ppb. These results provide valuable insight into the presence and distribution of uranium in the human body. As mentioned earlier, no significant correlation was observed between the age of women and the levels of uranium present. Similarly, this lack of observed relation was also present in women without a diagnosis of breast cancer. Various factors can influence the concentration of uranium in human blood. These factors include lifestyle choices, dietary habits, contamination exposure levels, and other potential influencing factors [26, 27]. The spread of radiation contamination in Iraq after the 2003 invasion was a significant consequence of the military intervention. The invasion resulted in the destruction of institutions and research centers, including the Al-Tuwaitha nuclear site, which played a crucial role in the dispersal of radioactive materials and isotopes. These sources of radiation became uncontrolled and posed a serious threat to both the environment and the population [28, 29].

The comparison of uranium concentration in women with breast cancer to those without cancer, as shown in Tables 1 and 2, clearly indicates a significant increase in uranium levels in women with breast cancer as shown in Fig. 5. This finding suggests a potential link between uranium toxicity and the development of breast cancer. The data presented in Table 1 show the measured uranium concentration in women diagnosed with breast cancer, providing a baseline for comparison. Table 2, on the other hand, presents the uranium concentration in women without breast cancer, serving as a control. By examining both tables, it becomes evident that women with breast cancer exhibit higher levels of uranium compared to those without the disease. This comparison provides valuable evidence supporting the notion that elevated uranium levels may play a role in the development of breast cancer. Figure 5 demonstrates a significant finding that the average uranium concentration in the blood samples of cancer patients is notably higher in comparison to that of healthy individuals. This statistical distinction (P <0.001) has been determined using an independent sample t-test, providing compelling evidence of a clear connection between uranium levels and the development of cancer. Within the human body, uranium undergoes metabolic processes, including the conversion of tetravalent uranium to hexavalent uranium, resulting in the formation of uranyl ions. Moreover, uranium forms complexes with proteins, plasma, citrate, and bicarbonates, indicating the intricate interaction between uranium and the human body. These interactions may contribute to the toxic effects observed in women with breast cancer [30–32].

Fig. 5.

Table 3 highlights the comparison of the research results obtained in this work with those from previous studies conducted in Iraq–Babylon and different countries. According to the results, the mean uranium concentrations identified in the present research and in previous studies conducted in Iraq–Babylon are greater than those reported in different countries. Military actions in Iraq, especially depleted uranium munitions, may have contributed to this elevated element level.

Noticeably higher concentrations of uranium have been detected in the blood samples of female patients, raising concerns about associated health risks. This discovery highlights the importance of understanding the causes, effects, and impacts of elevated uranium levels. Further research is essential to comprehensively examine the potential toxicity of uranium, increased risk of cancer, and reproductive effects. By identifying the underlying factors and exploring gender-specific impacts, proactive measures can be developed to minimize uranium exposure and safeguard public health.