Excess Lifetime Cancer Risk Values Research Articles

Assessment of natural radioactivity levels and hazard indicators in Tarakeshwor Municipality, Nepal through in-situ technique and multivariate analysis

The evaluation of primordial radionuclide concentrations in rapidly urbanized and concrete-laden areas through the importation of construction materials from various regions of Nepal is both important and essential. This study utilized a portable gamma-ray spectrometer (PGIS 2) to analyze the distribution of three natural radionuclides: uranium (238U), thorium (232Th), and potassium (40K) in Tarakeshwor Municipality, Kathmandu, Nepal. The measured dose rates ranged from 70.22 nSv hr−1 to 163.66 nSv hr−1, with an average of 124.65±20.29 nSv hr−1, surpassing the global average of 59 nSv hr−1. The activity concentrations of 40K, 238U, and 232Th exceeded global averages, indicating relatively higher natural radioactivity concentrations in the region. Specifically, the average values for 40K, 238U, and 232Th were 935.26±172.30 Bq kg−1, 80.47±15.53 Bq kg−1, and 80.44±18.58 Bq kg−1, respectively. The calculated radium equivalent (Raeq) ranged from 132.26 to 351.22 Bq kg−1, and the annual gonadal equivalent dose (AGED) varied from 372.61 to 1028.81 μSv yr−1. The annual effective dose rates for indoor and outdoor environments were 0.54±0.09 mSv yr−1 and 0.15±0.03 mSv yr−1, respectively, both exceeding the global average. The representative level index (RLI) within the study area averaged 1.96±0.32, indicating an elevated radiation risk. The excess lifetime cancer risk (ELCR) values for outdoor and indoor environments were 0.52×10−3 ±0.09 ×10−3 and 1.87 ×10−3 ±0.31×10−3, respectively, surpassing the world average. Additionally, external hazard indices (Hex) ranged from 0.36 to 0.59, while internal hazard indices (Hin) ranged from 0.38 to 1.20, both indicating values higher than UNSCEAR recommendations. These findings underscore the necessity for further experimental analysis employing ex-situ equipment. The data generated in this study can provide a valuable baseline for future assessments and interventions in radiation risk management guidelines within the country.

Evaluation of Indoor and Outdoor Radiation Levels and its Health Hazard at Dennis Osadebay University, Asaba, Delta State, Nigeria

This research designed at evaluating the indoor and outdoor background ionizing radiation dose equivalent levels at Dennis Osadebay University, Asaba Delta state. The study was carried out at fifteen different locations around the university campus using a portable GQ GMC-320 detector to measure outdoor and indoor equivalent dose rate of the university campus. The mean values of outdoor and indoor equivalent dose rate obtained are 0.135 μSv/hr and 0.142 μSv/hr respectively. These mean values are vaguely lower compared to 0.274 µSv/hr world average limit. The mean values of annual effective radiation equivalent (AEDE) of outdoor and indoor are 0.788 mSv/y and 0.142 mSv/y respectively. Similarly, 2.153 and 0.716 are the obtained values for excess lifetime cancer risk (ELCR) outdoor and indoor around the university respectively. The calculated dose to organs showed that the testes have the highest organ dose of (0.533 and 0.039) mSv/y for indoor and outdoor respectively. The estimated AEDE around the university are below the permissible limit, while ELCR average values for both outdoor and indoor around the university exceeded the standard value. The implication of equivalent dose rate, AEDE and ELCR values is that the university environment appears to be safe from immediate radiation-related health effects due to BIR exposure. Nevertheless, the possibility that an individual may develop cancer over their lifetime within university environment.

Determination Of Heavy Metals and Radon Concentration in Soil and Water Samples from Wadi-B Jere Oil Exploration Sites in Maiduguri, Northeast Nigeria

Radon gas and heavy metals are two significant risk factors that can cause lung cancer. Wadi B, a locality in Jere local government of Borno state, is an area where oil exploration is underway. There is a potential health risk of contamination of the drinking water and soil samples in the area. To investigate radon concentration and heavy metal contamination, several samples of water from wells and boreholes, as well as soil samples, were collected for analysis. The analysis was conducted using liquid scintillation (LSC) and atomic absorption spectrometry. The result of radioactivity analysis using LSC shows that water samples have varying levels of radon concentration ranging from 17.77 Bql-1 to 22.50Bql-1 which exceeded the maximum contaminant levels of 11.1Bq/L set by the USEPA 1999 and the world average value of 10Bq/L set by the World Health Organisation (WHO 2004). The mean annual effective cancer risk of radon intake varied across sampling points, ranging from 0.164, 0.246, 0.287 to 0.130, 0.218, and 0.227 for adults, children, and infants, respectively, with mean values of 0.146, 0.219, and 0.255. The mean values of excess lifetime cancer risk (ELCR) associated with radon inhalation and ingestion for adults, children, and infants were 0.0005110, 0.0007660, and 0.0008930, respectively. Moreover, elevated conductivity and total dissolved solids in water samples suggest potential contamination, exceeding the recommended limits set by the World Health Organization. On the other hand, Heavy metals analysis shows a mean value of ELCR 0.125009 for adults and 0.000063 for infants. Results showed that heavy metal concentrations in soil samples exceeded permissible limits for all metals except chromium and lead, with the order of concentration being Cr < Cd < Pb < Cu < Zn. These findings underscore the need for ongoing monitoring and remediation efforts to mitigate environmental and health risks in Wadi B

Biomonitoring and health risk assessment of exposure to phthalate esters in waste management workers

Humans are at risk of exposure to phthalates due to the widespread use of plasticized plastics, and one of the major concerns is occupational exposure. The present study investigated occupational exposure to phthalates at one of the greatest solid waste management sites in the second-largest country in the Middle East. Carcinogenic and non-carcinogenic health risks were assessed by human biomonitoring (HBM). The concentration of phthalate esters was determined using gas chromatography-mass spectrometry (GC–MS), and the daily intake (DI) of phthalate was calculated based on the adjusted urinary creatinine concentrations. Moreover, carcinogenic and non-carcinogenic risks were assessed. Monte Carlo simulations were performed for uncertainty and sensitivity analysis. The highest concentration recorded was 130.80 µg/g creatinine for mono-ethyl phthalate (MEP) among the composting group, while the lowest concentration was 0.49 µg/g creatinine for Monobenzyl phthalate (MBzP) among the office group. All estimates of daily intake were below the reference concentration, and differences between the DI at site sections were statistically significant (p < 0.05). The non-carcinogenic risk level was negligible. The excess lifetime cancer risk (ELCR) values corresponding to di-(2-ethylhexyl) phthalate (DEHP) exposure were 2.07E-04 among the composting group and 2.07E−04 among the processing group, posing a definite risk. The carcinogenic risk value among the office group was in a possible risk category with ELCR values of 9.75 E−05. The on-site workers of waste management sites can be highly exposed to phthalates, and their health risk is considerable. Appropriate measures and interventions should be considered to reduce occupational exposure to phthalates.

Environmental radioactivity around a mining site and its impact on the populace within specified distances from the site in southwest Nigeria

In this study, we quantify specific activity of 238U, 232Th, and 40K, from soils, water, and vegetables around limestone mining sites because of the dense urban settlement with high agricultural activities around the area. Annual effective dose (AED) was evaluated and used to estimate radiological hazard impact. Mean values of internal radiation hazard index (Hin) for soils, water, and vegetation are calculated and compared with those from literatures. The estimated mean excess lifetime cancer risk (ELCR) was obtained, too. The values of ELCR are under the world average value as recommended by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) one of the world regulatory bodies. For this reason, health related issues may occur at long time of living in this environment.

The radioactive contamination of ground and surface water near a uranium mine in Malawi

Ground and surface water in the uranium mining area of Kayelekera in Malawi was assessed for concentration levels of radioactive metals. Potential health risks associated with the intake of these metals in drinking water from various sources were also estimated. Surface, groundwater and mine discharge water samples were collected and analysed for radio elemental concentration using inductively coupled plasma mass spectrometry analytical technique. The results indicated a high concentration of 238U in water samples from lower Sere river. The activity concentrations of 238U, 232Th and 40K were however below WHO recommended limit. Health risk assessment using average committed effective dose were below the global average. Excess lifetime cancer risk values with an average of for borehole water was calculated and found to be below the global average. Radiologically, the water quality of Kayelekera area post uranium mining activities has not been compromised, however close monitoring and treating of drinking water is recommended

Natural radionuclide content in horticulture plants from former tin mining land and health risk assessment: A case study on Bangka Belitung Island, Indonesia

As a tin producer in Indonesia, Bangka Belitung has abandoned tin mining land containing natural radionuclides, and its use for cultivating horticultural crops has health risks. The aim of the research was to determine the contribution of former tin mining land to natural radionuclide contamination in horticultural products and to assess the radiation hazards by determining the annual effective dose and excess lifetime cancer risk (ELCR). The methodology includes sampling vegetables, fruit, and tubers from several villages in Bangka. Measurement of natural radionuclides using a Gamma Spectrometer at their specific energy. The research results showed that the radionuclides Ra-226, Th-232, K-40 were found in vegetables, fruit, and tubers samples. The highest Ra-226 was found in bitter melon and spinach, Th-232 in cassava leaves, spinach, and bitter melon, while K-40 in bitter melon, spinach, cassava leaves, papaya leaves, mustard greens. The activity rank of Ra-226, Th-232, and K-40 is shown in tubers > vegetables > fruit. The total annual effective dose (AED) from vegetable and fruit consumption is 0.6330 mSv/year, as recommended by UNSCEAR (1 mSv/year), except consumption of tubers (galangal). The ELCR value of vegetable, fruit, and cassava (tubers) consumption is 1.08x10−3; 0.75x10−3; and 0.42x10−3, as recommended by the ICRP.

Radiological landscape of natural resources and mining: Unveiling the environmental impact of naturally occurring radioactive materials in Ghana's mining areas

This study provides a general observation of the status of naturally occurring radioactive materials (NORMs) distribution in mining and industrial areas of Ghana in order to establish regional and national data on NORMs. The study includes data on radioactivity concentrations of U-238, Th-232, and K-40 in soils and for water concentrations of Ra-226, Th-228, and K-40 from various mining, oil, and gas communities, as well as water sources used for crop farming and farmlands. The average activity concentrations of U-238, Th-232, and K-40 in the soil samples were found to be 59 ± 16 Bq/kg, 48 ± 15 Bq/kg, and 286 ± 57 Bq/kg, respectively. The average concentration of Ra-226, Th-228, and K-40 in the water samples were found to be 1.62 ± 0.33 Bq/L, 2.08 ± 0.53 Bq/L, and 22.36 ± 3.44 Bq/L, respectively. The estimated average annual effective doses from external and internal exposure pathways in soil and water samples were 0.09 mSv/y and 0.54 mSv/y, respectively. The total annual effective dose resulting from both exposure pathways was calculated to be 0.63 mSv/y, which is below the 1 mSv/y dose limit recommended by the International Commission on Radiological Protection (ICRP) for controlling public radiation exposure. Based on the radiological hazard indices, the majority of the soil samples were found to be suitable as building materials as their respective indices were below the limits except for two sample locations and the sludge and scale samples. The average Excess Lifetime Cancer Risk (ELCR) value of the water samples was 1.6 times greater than the recommended value of 1.16 × 10−3, presenting a relatively higher risk to the public of developing cancer. No significant regional differences in the levels of radioactive elements. The regression models demonstrate strong interrelationships between the studied elements, with high R-squared values suggesting a predictable nature of one element’s concentration based on others.

Assessment of Natural Background Radiation Exposure in the Federal Capital Territory of Nigeria

The detrimental effects of environmental contamination and deterioration on health are a worldwide concern and Nigerian environmental and public authorities continue to be concerned about the risk to public health. The water, the sky, construction materials and the earth's crust all release natural background radiation that contaminates the environment around us. Additionally, people are exposed to background radiation that comes from internal, cosmic, and terrestrial sources, although, the altitude determines the amount of cosmic radiation exposure, and high altitudes result in large radiation doses. Monitoring the amounts of radiation to which humans are exposed, either directly or indirectly, requires an understanding of the natural background radiation in the environment. The current study attempted to create a baseline of outdoor background radiation in FCT for exposure rate, absorbed dose rate, annual effective dose equivalent, and excess life cancer risk. The study used a very sensitive survey meter to measure the BIR. The average BIR value found in the research areas is marginally below the 0.013mRh-1 global BIR level, indicating an almost high BIR level for the FCT while the absorbed dose rates of 105.85nGy/hr was greater than the 59nGy/hr global population weighted average gamma dose rates estimate. The obtained annual effective dosage equivalent value is greater than the global average normal annual effective dosage level for outdoor environments, and the excess lifetime cancer risk values were higher than the 0.29×10-3 allowable level as reported by UNSCEAR &amp; ICRP. Therefore, the general people and those who live in environmentally sensitive areas may experience immediate health effects from contamination and radiation levels at the current rates.

Assessment of Environmental Background Gamma Radiation Variation in Minna Area of Nigeria

Radiation has been acknowledged to be responsible for deleterious conditions in living tissues. Hence, environmental background gamma radiation (BGR) measurement is crucial from an environmental and health perspective. In this study, due to the absence of comprehensive background gamma radiation data and the increasing numbers of anthropogenic activities that could increase the BGR level, such as where mining activities are active. The BGR in the Minna area of Niger State, Nigeria, was measured and analyzed in this study. In-situ measurement of the background gamma radiation level was carried out using a well-calibrated portable handheld GQ GMC-500 Plus nuclear radiation detector at an elevation of about 1.0 m above ground level. A global positioning system from Garmin (GPSmap 78s) was adopted for identifying geographical locations. A total of 1172 points were surveyed across the study area for background environmental radiation. The BGR values ranged from 0.102 to 0.147 μSv/h, with an overall mean value of 0.126 μSv/h. The average measured dose rate was more than twice the reported world average value of 0.059 μSv/h. The annual effective dose equivalent (AEDE) for the research area was calculated to be 0.221 mSv/y on average. The mean AEDE is lower than the ICRP recommended limit. This shows that the population of the Minna area is radiologically safe based on the estimated AEDE value. Similarly, the excess lifetime cancer risk (ELCR) value ranged from 0.626 × 10−3 to 0.901 × 10−3 mSv/y with a mean value of 0.774 ± 0.09 × 10−3 mSv/y. The mean value of AEDE is below the 0.24 mSv/y permissible limits as recommended by the International Commission on Radiological Protection (ICRP). The mean ELCR value exceeds the average world value of 0.29 × 10−3. Also, the mean organ dose values estimated for the whole body, liver, kidney, testes, bone marrow, ovaries, and lungs are 0.150 ± 0.02, 0.102 ± 0.01, 0.137 ± 0.02, 0.181 ± 0.02, 0.152 ± 0.02, 0.128 ± 0.02 and 0.141 ± 0.02 mSv/y respectively. The differences in the calculated mean of BGR were attributed to natural and human factors. Geological variation is a fundamental factor that influences the changes in BGR. Human activities, mining, building materials, and the use of phosphate fertilizers in agricultural practices are responsible for the differences in BGR. The ELCR implies that terrestrial gamma radiation does not pose any immediate radiological health effects on residents of the area, but there is a tendency for long-term health hazards in the future, such as cancer, due to the dose accumulated.

Measurement of ambient particulate matter (PM1.0, PM2.5 and PM10) in Khulna City of Bangladesh and their implications for human health

Atmospheric particles have been significantly affecting urban air quality and urban-oriented living in an increasing share of the population in Bangladesh. This study assessed the concentration of PM1.0, PM2.5, and PM10 in Khulna, one of the largest cities in Bangladesh located near the Bay of Bengal. The maximum average concentrations were recorded 415 ± 184.01 µg/m3 for PM10, 302 ± 109.89 µg/m3 for PM2.5, and 143 ± 45.05 µg/m3 for PM1.0. These values are several times higher than the World Health Organization air quality standard and Bangladesh National Ambient Air Quality Standard. According to the size and fractional distribution of PM, most of the monitoring locations were dominated by fine particles. Carcinogenic and non-carcinogenic risks due to exposure to ambient PM1.0, PM2.5 and PM10 were also quantified to illustrate the relevant potential human health risks. The excess lifetime cancer risk (ELCR) values of PM1.0 ranged from 8.6E0–4 to 6.0E–07 and PM2.5 varied between 8.6E–04 and 6.0E–07 exceeded the allowable limit at every location indicating the potential cancer-developing risk to the urban population. The health quotient (HQ) values also crossed the least permissible value at most of the locations depicting strong non-carcinogenic risks. Average HQ values of PM2.5 varied from 1.07 to 20.13 while PM10 ranged from 0.44 to 8.3. This research revealed children and elderly people as the most vulnerable age groups with the highest carcinogenic risks through exposure to atmospheric PM in Khulna city. Therefore, air pollution reduction plans and risk mitigation strategies should be developed and implemented by the government authorities.Graphical

Sewage treatment plant dust: An emerging concern for heavy metals-induced health risks in urban area

Metal-related pollution from dust is a significant source of toxic elements in urban areas. The present study aimed to assess the health risk posed by heavy metals present in dust samples to the people residing near the Sewage Treatment Plant (STP). Dust samples were collected from an STP with a capacity of 130 mega litres per day (MLD). Data analysis indicated highly contaminated STP dust with Enrichment Factor (EF) suggesting an anthropogenic origin of selected metals (As, Co, Al, Cu, Cr, Cd, Ba, Pb, Ni, Mn). The contamination factor values of metals highlighted a greater degree of contamination in the selected area. Notably, a strong correlation (>0.5) was observed between metals. The EF value was found to be >40 indicating high enrichment for all the metals except Fe. In-depth chemical analysis and health risk assessments were conducted, revealing an Excess Lifetime Cancer Risk (ELCR) value of 1 × 10−6 and HQ (Hazard Quotient) value of 1. These values are significantly exceeding the safe limits for both children and adults which could develop cancerous properties in human beings. In an effort to reduce toxicity, dust samples were also subjected to vermicomposting treatment to assess the potential effectiveness of the earthworms. The EF value of vermicomposted dust came out to be lower than the untreated one. The Hazard Quotient (HQ) values for adults exhibited the following pattern of HQing > HQder > HQinh (indicating that the Hazard Quotient from ingestion is greater than that from dermal contact, which is in turn greater than inhalation). This investigation offers crucial insights into the increased risks of cancerous and non-cancerous ailments for individuals living or working in proximity to STPs. This research also highlights the pressing need to implement effective measures for safeguarding public health and mitigating environmental pollution in urban areas.

Assessment of Radiological Risks due to Indoor Radon, Thoron and Progeny, and Soil Gas Radon in Thorium-Bearing Areas of the Centre and South Regions of Cameroon

Indoor radon, thoron and thoron progeny concentrations, along with the equilibrium factor for thoron progeny and soil gas radon concentrations, have been measured to assess radiological risks in the centre and south regions of Cameroon. Indoor radon and thoron concentrations were estimated using radon–thoron discriminative detectors (RADUET), while thoron progeny monitors measured the equilibrium equivalent thoron concentration (EETC). Radon concentrations in the soil were determined using a MARKUS 10 detector. It was found that radon, thoron and thoron progeny concentrations range between 19 and 62 Bq m−3, 10 and 394 Bq m−3 and 0.05 and 21.8 Bq m−3, with geometric means of 32 Bq m−3, 98 Bq m−3 and 4.9 Bq m−3, respectively. The thoron equilibrium factor ranges between 0.007 and 0.24, with an arithmetic mean of 0.06 ± 0.03; this is higher than the world average value of 0.02 provided by the United Nations Scientific Commission on the Effects of Atomic Radiation(UNSCEAR, New York, USA). The level of the soil radon concentration ranges from 4.8 to 57.3 kBq m−3, with a geometric mean of 12.1 kBq m−3 at a depth of 0.7 m. Of the sampling points, 66% fall within normal radon risk areas, and 3% of the sampling areas are high radon risk areas exceeding 50 kBq m−3. The annual effective dose was found to be 0.03 ± 0.01 mSv for radon, 0.08 ± 0.05 mSv for thoron, 0.63 ± 0.12 mSv for radon progeny and 1.40 ± 0.84 mSv for thoron progeny. The total dose is estimated to be 2.14 mSv y−1. The mean estimated indoor excess lifetime cancer risk values due to radon, thoron, radon progeny and thoron progeny are 0.12 × 10−3, 0.31 × 10−3, 2.51 × 10−3 and 5.58 × 10−3, respectively. Thoron progeny contributed 60% to the effective dose. Thus, thoron progeny cannot be neglected in dose assessments, in order to avoid biased results in radio-epidemiological studies.

Assessment of radioactivity levels and radiation hazards in building materials in Egypt

Different degrees of natural radioactivity found in quartz can have negative consequences on health. Quartz vein along the investigated Abu Ramad area, Egypt, had its natural radioactivity assessed. The HPGe spectrometer was used to determine the role played by the radionuclides 238U, 232Th, and 40K in the gamma radiation that was emitted, and the results showed that these concentrations are 484.64 ± 288.4, 36.8 ± 13.1 and 772.2 ± 134.6 Bq kg−1 were higher than the corresponding reported global limits of 33, 45, and 412 Bq kg−1 for each radionuclide (238U, 232Th, and 40K). Among the radiological hazard parameters, the excess lifetime cancer risk (ELCR) is estimated and it's mean value of ELCR (1.2) is higher than the permissible limit of 0.00029. The relationship between the radionuclides and the associated radiological hazard characteristics was investigated based on multivariate statistical methods including Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). According to statistical research, the radioactive risk of quartz is primarily caused by the 238U, 232Thand 40K. Finally, applying quartz to building materials would pose a significant risk to the public.

Elevated radon level in drinking water of Ajodhya Hill Area of West Bengal, India: probable health impact on lung and stomach.

A screening survey has been carried out to measure the radon concentration in drinking water at various locations of Ajodhya hill and surrounding areas in Purulia district of West Bengal, India, using AlphaGUARD radon monitor. The obtained 222Rn concentration in ground water varies from 5.71 ± 0.29 to 579.47 ± 23.18Bq/l with an average of 110.00 ± 6.61Bq/l. Comparison between our results with the internationally recommended reference levels reveals that drinking of water from the majority of these tube-wells can pose significant health risks to the local people. Correlation study indicates that tube-well depth has significant influence on the radon level in water samples. Using 60l/yr and 1642.50l/yr water consumption estimated annual effective radon doses for most of the samples (almost 70% and 96%, respectively) are high compared to the World Health Organization (WHO) and the European Union (EU) Commission prescribed reference dose limit of 100 μSv/yr. Also, the evaluated Excess Lifetime Cancer Risk (ELCR) values associated with the tube-wells are showing serious threat to the health of the locals.The primary goal of this work is to develop a radon profile map of this area and to find out the possible reasons behind the elevated radon level in ground water. This type of work may play a very crucial role to aware the locals in perspective of human exposure to radon. The local health officials and the water quality regulators of India are requested to take necessary steps for protecting the local people from water radon hazard.

Baseline radioactivity in the five candidate sites for the second nuclear power plant in Bangladesh and concomitant hazards assessment

ABSTRACT To meet the increasing energy demands and foresee the shortage of fossil fuels as a source of energy, the Government of the People’s Republic of Bangladesh has decided to install a second Nuclear Power Plant in the southern region of Bangladesh. This study was conducted to assess the baseline radioactivity using the High Purity Germanium (HPGe) detector of the five candidate sites to construct a nuclear power plant in the southern regions of Bangladesh and to evaluate the associated radiological hazard parameters. This pioneering study demonstrates that the mean activity concentrations (range) of 226Ra, 232Th, and 40K in forty-five soil samples collected from the five candidate sites were 28.95 ± 2.72 (2.65–48.75), 30.10 ± 2.95 (10.35–46.65), and 278.82 ± 25.78 (126.05–418.61) Bqkg−1. The evaluated area poses insignificant radiological concerns regarding mean absorbed dose rate, radium equivalent activity, annual effective dose, external and internal hazard indices, and excess lifetime cancer risk values. This study revealed a thorough picture of radioactive dispersion in soil samples from Bangladesh’s southern areas, allowing policymakers to take appropriate measures in identifying viable candidate sites for constructing a Nuclear Power Plant. Moreover, the data of this study can be used as a reliable source of baseline radioactivity in the particular area.

EVALUATION OF HAZARD INDICES OF BACKGROUND RADIATION IN SOME MAJOR TOWNS OF GOMBE STATE, NIGERIA

Interest for the determination of naturally occurring radiation and environmental radioactivity has led to the interest of extensive surveys in many countries including Nigeria. This work was carried out to ascertain the indoor and outdoor background ionizing radiation in Gombe state as a precautionary measure due to recent development of radioactive activities in the State. RDS-31 Survey meter placed 1m above the earth surface was used for taking readings. The measured average exposure rates ranged from 0.007 to 0.017 mR/h for indoor and 0.007 to 0.015 mR/h for outdoor with a total mean of 0.010 ± 0.003 mR/h, which are within the limit of world average of 0.013 mR/h. The indoor absorbed dose rate ranged from 61.34 ± 7.52 nGy/h in Kwami to 149.21 ± 57.35 nGy/h in Billiri with a total mean value of 88.47 ± 32.64 nGy/h, which is higher than World’s average of 84.00 nGy/h, while the outdoor ranged from 61.34 ± 17.45 nGy/h in Shongom to 134.42 ± 38.61 nGy/h in Kaltungo with a mean total value of 90.24 ± 29.88 nGy/h, which is 31.24 nGy/h higher than the standard average of 59.00 nGy/h. Equivalent dose rate was calculated to be in the range of 0.59 ± 0.07 mSv/yr to 1.44 ± 0.55 mSv/yr with a total mean of 0.86 ± 0.32 mSv/yr, which is within the International Commission on Radiological Protection(ICRP)recommended limit of 1 mSv/yr. The AEDE shows a range of 0.33 ± 0.08 to 0.73 ± 0.28 mSv/yr for indoor and 0.08 ± 0.02 to 0.16 ± 0.05 mSv/y for the outdoor respectively. The sum is found to be 0.54 mSv/yr which is 0.02 mSv/yr higher than the world’s average of 0.52 mSv/yr. Estimated life-time cancer risk ranges from 1.20 x 10-3 to 2.56 x 10-3 mSv/yr, while outdoor ranges from 0.30 x 10-3 to 0.58 x 10-3mSv/yr with a total mean of 2.08 x 10-3 mSv/yr which is larger compared with the resulting worldwide average of 1.45 x 10-3. The excess lifetime cancer risk values indicated that the probabilities of contracting cancer for residents of Gombe, Kwami, Dukku, Yamaltu Deba, Bajoga, Shongom, Balanga, Funakaye, Kaltungo are low but higher in Billiri, and Akko (Mai-Ganga). These values may not constitute any immediate health risk to the residents of Gombe state but precaution should be taken in order to avoid stochastic effect.

Spatiotemporal Analysis and Health Risk Assessment of Nitrate in Kan River Basin, Tehran: Application of IRWQI and Monte Carlo Simulation

Introduction: Monitoring and controlling water resources and using health risk assessment approaches for water pollutants are essential for health promotion programs. This study aims to determine the water quality status and its spatiotemporal variation across the Kan River Basin, explore the interrelationship between surface and groundwater quality indices, and assess the nitrate health risk in drinking water.&#x0D; Materials and Methods: The water quality index (WQI) was calculated based on the guideline of the Iran Environmental Protection Organization, and spatiotemporal distribution maps were prepared using ArcGIS in 2020. To determine the correlation between IRWQISC and IRWQIGC indices, Spearman's non-parametric test was applied. Furthermore, Hazard Quotient (HQ), Excess Lifetime Cancer Risk (ELCR), and Monte-Carlo Simulation techniques were used to determine the carcinogenic and non-carcinogenic risks of nitrate in three age groups.&#x0D; Results: The water resources were classified into three groups of medium quality, relatively good, and good during the study period. All parameters complied with the Iranian water quality standards. Furthermore, the statistical analysis revealed no significant relationship between the surface and groundwater quality indices. The calculated HQ values for infants, children, and adults were 0.661, 0.620, and 0.236, respectively. The ELCR values for infants, children, and adults were 1.06 × 10-4, 0.99 × 10-4, and 0.38 × 10-4, respectively, which, for the infants' group, was higher than the guideline limit of the United States Environmental Protection Agency (USEPA) (10-4).&#x0D; Conclusion: The water resources are suitable for drinking purposes. However, more attention is needed to prevent water contamination in the coming years.

Environmental Assessment of Friable Asbestos from Soil to Air Using the Releasable Asbestos Sampler (RAS).

The objectives of this study are to examine the feasibility of the releasable asbestos sampler (RAS) equipment for laboratory tests as an alternative to activity-based sampling (ABS), and to apply the equipment controlled by wind velocity and water contents in the field to asbestos-contaminated soils. Two asbestos-contaminated mines (the Jecheon mine and the Jongmin-ri mine) were selected. At each mine, 21 surface soils (0~15 cm) were sampled, the asbestos concentrations were analyzed, and then three representative sites, containing 0.25%, 0.50%, and 0.75% of asbestos in soils, were chosen to evaluate the amount of releasable asbestos by the modified RAS with wind velocity and water contents. The results showed that the levels of releasable asbestos from soil to air increased with higher wind velocities and lower water content. In addition, the application of risk assessment of releasable asbestos in the soils as an alternative to the activity-based sampling (ABS) method was established at each site, and an estimation of the excess lifetime cancer risk (ELCR) was also calculated. According to the calculation, the estimated ELCR values did not exceed the threshold value (1 × 10-4) in the Jecheon mine for all the soils, while some samples from the Jongmin-ri mine exceeded the threshold value. Therefore, proper remediation work is needed to control friable asbestos from soils to air in the vicinity of the mines.

Radiological health risks assessment of vegetable and fruit samples taken from the provincial borders of Adıyaman in the south-eastern Anatolia region, in Turkey

In this study, the natural radionuclide activity concentrations such as 238U, 232Th and 4 K were measured in 65 vegetable-fruit samples taken from fields within provincial borders of Adıyaman in the south-eastern Anatolia region of Türkiye. An HPGe detector having the energy resolution of 1.85 keV at 1332.5 keV and 40% relative efficiency, p-type coaxial, covered with 10 cm thick lead shield was used to measure 238U, 232Th, and 4 K radionuclide activity concentrations of the samples of plant and fruit.238U, 232Th and 4 K radionuclide activity concentrations in vegetable and fruit samples are varied from 0.04 -2.39 Bk/kg, 0.08–2.14 Bq/kg and 28–252 Bq/kg, respectively. The mean radionuclide activity concentrations of 238U, 232Th and 4 K measured in fruits (peppers, tomatoes, eggplants, cucumbers, pumpkins, figs, and their stalks) and vegetables (leek, parsley and basil) were also calculated. For 238U and 4 K, the average radionuclide activity concentrations calculated in fruit stalks are generally higher than those calculated in fruits. However, this cannot be said for the 232Th. The measured mean radionuclide activity concentrations are smaller than the Worldwide mean value of 35 Bqkg−1, 30 Bqkg−1 and 400 Bqkg−1 for 238U, 232Th and 4 K, respectively, which is defined by UNSCEAR in 2000 year. The rate of absorbed dose measured in vegetable and fruit samples is much smaller than the World safety limit value defined by the ICRP in 1993. The calculated excess lifetime cancer risk (ELCR) values are higher than the world safe limit value (2.9 × 10−4 mSvy−1). Therefore, it can be said that there is a radiological risk.