The study's theoretical background could be explained as the Radiation Health Risk theory or a theory that seeks to analyze and investigate the correlation between radiation exposure and its effects (Tirmarche et al., 2021). The most popular one is the Linear No-Threshold (LNT) model. In this paradigm, radiation exposure is not of high levels, thus leading to the breaking down of field cells, which might pile up in the future and cause even more cancer development and other health conditions (Azizova et al., 2018; Cherry et al., 2021). The model proposed would be of use when talking about the hazards of working with the element of plutonium when employees of plutonium finishing plants are exceptionally exposed to the element of alpha radiations (the type of ionizing radiation that could cause the emergence of long-term health conditions).

The International Commission on Radiological Protection (ICRP) accentuates that despite small radiation doses during long periods, there is a high possibility that it can pose high health risks and, most especially, cancer. Research conducted by both Wakeford (2021) and Cherry et al. (2021) have proven that employees of nuclear plants, particularly those affected by plutonium, have increased chances of contracting cancers like lung cancer, liver cancer, and bone cancer as the result of the negative effects of alpha radiations (Dumit et al., 2019; Wakeford, 2021). Such a theoretical construct forms the foundation of research studies on the health risk of radiation in the plutonium finishing industries that involve both external and internal radiation (swallowed or inhaled plutonium) (Samuels & Leggett, 2023; Šefl et al., 2021).

This study, according to the theory and other existing research, thus hypothesizes the following:

H 1: Long-term exposure to plutonium in the plutonium finishing plants enhances the occurrence of lung and liver cancer in the worker.

This hypothesis is proved by the works of Azizova et al. (2018) and Cherry et al. (2021). Both researches exhibited a close relationship between the occurrence of plutonium and the risk of cancer among employees. Studies conducted by Azizova et al. (2018) have also indicated the rise of lung and liver cancer-related mortalities among workers in the Sellafield and Cherry et al. (2021) have indicated the rising lung cancer rates among workers in the Hanford Site and have attributed the growing rates to the occurrence of plutonium related activities in their environment.

H2: The more of it and the longer the exposure to plutonium, the more frequent the respiratory diseases such as pulmonary fibrosis and COPD (chronic obstructive pulmonary disease).

This hypothesis is confirmed by such pieces of evidence as supported by Gillies et al. (2017) and Cherry et al. (2021), who document a higher rate of non- malignant respiratory disease cases occurrence as, in the case of pulmonary fibrosis, there is a higher number of instances in people engaged in plutonium production. The study by Gillies et al. (2017) recorded that long-term inhalation of plutonium aerosols increased the occurrence of lung diseases massively, majorly among workers with prolonged exposure.

This study builds upon existing research by examining the long-term health outcomes of workers in plutonium finishing plants. The key variables for this study include:

Radiation exposure: Workers will undergo internal (inhaled or ingested plutonium) and external (gamma) radiation exposure.

Health outcomes: Among the outcomes considered in the study by Priyadarshini, it will evaluate health effects, specifically lung cancer, liver cancer, bone cancer, and lung diseases such as pulmonary fibrosis and COPD. Duration of Exposure: The study will prioritize analyzing workers with 10 years and above of exposure to determine the impact of long-term exposure to health.

Safety Practices: The protocol will explore what safety precautions, including personal protective gear (PPE) and adherence to exposure limits, are effective in reducing the effects of radiation exposure and consequent health issues.

The conceptual framework for this study is based on the hypothesis that increased radiation exposure leads to higher risks of both malignant and non- malignant health outcomes. The framework suggests that the cumulative dose of plutonium exposure, over time, results in cellular damage that can manifest in cancers and respiratory diseases. Safety practices are considered a moderating factor, potentially reducing the severity of health outcomes.

The table below outlines how the radiation in the population group of plutonium finishing plant workers has been evaluated based on key epidemiological studies, the population evaluated, key findings, and the study methodology.

This group of studies highlights the indispensability of multidisciplinary assessment of occupational exposure in plutonium finishing plants. Exact dose reconstruction and sound epidemiological follow-up will continue to be critical in explaining the long-term health outcomes of plutonium exposure and developing ongoing enhancement of safety and health monitoring of workers in the workplace (Rathod et al., 2023).

Internal and external doses of radiation were rebuilt using data on bioassays, urinary measurements and job-exposure matrices (known as JEM) derived in previous research (Riddell et al., 2019; Samuels & Leggett, 2023). The amount of internal plutonium exposure was found from estimates of plutonium-

239 and plutonium-240 in urine, with the help of dose conversion factors discussed in ICRP Publication 150 (Tirmarche et al., 2021). In situations where bioassay data were lacking, the researchers based their predictions on autopsy results and organ exposure models (Šefl et al., 2021).

If records were available, the level of radiation exposure to the individual was determined from personal dosimeters. They divided the total exposure by job area, years of employment and the time period involved since safety and technology standards have changed during the monitored years (Knodel & Wooley, 2018); Ramprasath et al., 2024).

Multivariable Cox regression and Poisson regression were used to calculate relative risks and SMRs related to radiation exposure, adjusting for age, being a smoker and the length of employment (Azizova et al., 2018; Cherry et al., 2021). Statistical methods were applied to check if there was a dose-response relationship and the results were separated based on the specific plutonium exposure in each organ (as explained by Tirmarche et al., 2021). We went over historical documentation and compliance reports to consider any changes in risks workers faced over time (Knodel & Wooley, 2018). Moreover, a look at safety rules and conducting internal audits revealed which risks within operations play a role in exposure differences.

Internal plutonium doses differed a lot between different job classifications. Those who dealt directly with plutonium (such as chemical operators and technicians) were exposed to radiation doses of 100 to 500 mSv or higher, compared to much lower doses received by support staff (Wakeford, 2021); Riddell et al., 2019). Exposure to gamma rays by workers in these mines was about 25 mSv on average, but it could be as high as 150 mSv before new safety standards were set (Knodel & Wooley, 2018).

Regression analysis was used to compute adjusted relative risks (RRs) and standardized mortality ratios (SMRs). Lung cancer was the major type of cancer caused by radiation, with an SMR of 1.76 (95% CI: 1.34–2.12) for highly exposed workers, like the observations made in the Mayak and Sellafield cohorts (Gillies et al., 2017; Azizova et al., 2018). Both liver and bone cancers had some weaker though noticeable links. Exposed workers experienced more non-malignant lung conditions (such as pulmonary fibrosis and COPD) than administrative workers (as shown by Cherry et al., 2021; Suslova et al., 2020).

It was obvious that there was a clear dose-response association once the time from exposure to developing cancer was considered. People who worked for 20 years or more and received a total dose over 400 mSv were more likely to

develop cancer and die from it just as predicted by ICRP Publication 150 (Tirmarche et al., 2021).

Urinary excretion data showed inconsistencies in workers with chronic comorbidities, complicating dose reconstruction for a small subset (Suslova et al., 2020). Autopsy validation confirmed underestimation in several high-dose cases (Šefl et al., 2021), emphasizing the need for multimodal diametric approaches.

The given study has several limitations. First, bioassays and job-exposure matrices or other historical data in general might be inaccurate or incomplete, thus underreporting the exposure level. Also, having adjusted the variables such as age and smoking, other confounding factors might play a role in health outcomes. The relatively wide timeframe of the study would make it difficult to compare the results of different periods because the safety measures would have changed. Finally, health outcomes, especially cancers and respiratory conditions, occur as a result of many causes other than radiation release, so some cases fall short of establishing a causal relationship.

Future research should consider longitudinal samples of plutonium workers using advanced monitoring recording devices to identify long-term effects on these people. More sophisticated exposure assessment methods, such

as genetic analyses and dose-reconstruction models, may be needed to give better risk estimates. Non-malignant diseases like chronic lung disease should also be explored; the researcher should target unexplored research on nascent conditions such as chronic lung disease. A broader radiation risk model, which incorporates genetic and environmental data, might be useful to improve knowledge about individual susceptibility. Lastly, such international collaboration and data sharing will contribute to a more consistent conclusion and better safety standards in nuclear industries worldwide.