Bazlar Rashid

I. Naturally occurring radioactive materials (NORMs) are integral parts of the Earth’s crust and are mainly associated with the decay chains of 238U and 232Th, as well as primordial radionuclides s...

This pioneering study investigates the levels of naturally occurring radioactive materials in soil collected from the vicinity of Srikail gas field, Bangladesh, utilizing a high purity germanium (HPGe) detector. Forty soil samples were systematically collected from concentric circles around the gas well, with approximate radii of 100, 200, 300, 400, and 500 m. The activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K ranged from 12-27, 24-45, and 255-480 Bq/kg, respectively, with most values aligning with global averages of 35, 35 and 400 Bq/kg respectively. Notably, two samples showed the presence of artificial radioactivity (¹³⁷Cs). All the radiological hazard indices are well within the recommended safety limits. However, this study emphasizes the need to establish baseline data for the soon-to-be-commissioned Rooppur Nuclear Power Plant and its nearby areas. It also highlights the importance of regular monitoring to detect any future changes in radioactivity levels that might come from natural processes or human activities.

Environmental radioactivity is significantly elevated by coal combustion, posing risks to communities living near coal-fired thermal power plants (CFTPPs). This study presents the first comprehensive assessment of radiological impacts around the Rampal Thermal Power Plant, a 1320 MW facility located in Rampal Upazila, near the UNESCO World Heritage site of Sundarbans, Bangladesh. Thirty soil samples were systematically collected from distances of 100, 500, 1000, 2000, and 3000 m from the power plant. The activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K in soil ranged from 17-31, 29-51, and 350-670 Bq kg^-1, respectively, with a few samples exceeding the population-weighted global averages for ²²⁶Ra (32 Bq kg^-1) and ²³²Th (45 Bq kg^-1), and almost all the samples exceeding the average for ⁴⁰K (420 Bq kg^-1). The elevated levels of ²²⁶Ra, ²³²Th, and ⁴⁰K in the soil samples can be attributed to several interconnected factors, including the presence of thorium-rich minerals such as monazite and zircon, granitic geological formations, and anthropogenic inputs like bottom ash discharge from the plant and coal combustion byproducts. While the radium equivalent activity and hazard indices generally fell within safety limits, the higher outdoor and indoor absorbed dose rates, effective doses, and increased lifetime cancer risk raised alarms about potential health threats for nearby residents over time. Moreover, the long-term radiological effects on the Sundarbans ecosystem could disturb its fragile balance, impacting both biodiversity and the local communities that rely on its resources. These results highlight the necessity for further evaluations and remediation efforts to ensure the safe use of these soils in agricultural and construction activities. This research also seeks to develop a radiological distribution map, which will provide crucial baseline data for the forthcoming Rooppur Nuclear Power Plant.

Assessing soil radioactivity and associated risks in areas surrounding gas fields is essential due to potential natural radionuclide accumulation during extraction activities. This study investigates the radioactivity levels in surface soil from the Haripur gas field. 21 soil samples were analyzed using a high purity germanium (HPGe) detector. The activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K in the soil samples were found to range between 11-19, 20-38, and 280-500 Bq kg^-1, respectively. All ²²⁶Ra values and the majority of ²³²Th and ⁴⁰K values fell within the global average levels for soil, which are 35, 30, and 400 Bq kg^-1, respectively. Radiation hazard indices were found to be below the internationally accepted safety limits set by organizations such as the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the International Commission on Radiological Protection (ICRP), indicating that the soil poses no significant radiological risks for construction and agricultural applications. This research offers essential baseline data on soil radioactivity at the Haripur gas field, supporting public health, environmental protection, and regulatory compliance efforts.

The people of the coastal parts of Bangladesh are insecure for safe drinking water. Present study is an attempt to delineate the water quality in the coastal parts of Mirsharai, Sonagazi and Companiganj areas. Various parameters of water quality such as free hydrogen (pH), electrical conductivity (EC), total dissolved solids (TDS), oxidation reduction potential (ORP), salinity, turbidity, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), acidity, alkalinity, total hardness and nitrate, phosphate, sulphate, chloride, iron, manganese, cobalt, nickel, arsenic and chromium were determined through field work, available data and laboratory analysis. The results indicate that the arsenic concentration and electrical conductivity in shallow aquifers exceed WHO and Bangladesh standards limit. Additionally, chloride, total hardness, alkalinity, and lead exceed the WHO and Bangladesh standards in both shallow and deep aquifers. In many cases, the turbidity of surface water both inside and outside the coastal embankments also exceeds these limits. The lead, chloride and manganese contents, DO and BOD in the Feni River also exceed the BSTI limits. The analysis reveals that the deep aquifers are free from arsenic, while the shallow aquifers are significantly contaminated. Although, the deep aquifers need precaution for salinity, alkalinity, total hardness and lead contents. Correlation matrix analysis confirms that EC and TDS serve as reliable indicators of salinity levels in both shallow and deep aquifers. Principal Component Analysis (PCA) further supports this, showing that EC, TDS, and salinity are influenced by the saline water intrusion in these aquifers. Additionally, pollutants in both shallow and deep aquifers are positively associated with EC, TDS and salinity. Keywords: Drinking water insecurity, water quality analysis, coastal areas, Bangladesh.

The Bay of Bengal (BoB) is rich in resources (both living and non-living). Marine living resources include fisheries, mangrove forests, coral ecosystems, plankton, sea grass and seaweeds, etc. Whereas, non-living resources are oil, gas, gas hydrates, sea salt, heavy minerals, etc. Present study reveals that the oil and gas fields discovered in the BoB are parallel with exploration activities. Bangladesh part of the BoB includes the low exploration area, consequently only one producing gas field, whereas India and Myanmar discovered many significant gas and oil fields in their territory. India discovered gas hydrates in the BoB in 2016. In the Exclusive Economic Zone (EEZ) of Bangladesh, 0.11 tcf to 0.63 tcf gas hydrates were discovered in 2022, with assessment of 17-103 tcf of natural gas, though gas hydrates exploration at industrial scale is still a big challenge in the world due to stability, composition and distribution of gas hydrates in nature. Different types of heavy minerals are also present in the coastal parts of the country. The Indian Ocean has about 20% of the worldwide tuna production, though Bangladesh contributes very little of it. In the marine part of the country, 475 species of fishes are found compared to 250 species on land. BoB is very important for BIMSTEC countries and also for China and Pakistan in consideration of seaborne trade. Bangladesh can introduce modern cruises like other BoB countries to visit the coastal islands as well as Sundarbans mangrove forest contributing considerably to local employment and economic expansion. Marine organisms have unique nutritional value and contain many kinds of bioactive substances. At present, internationally recognized antibiotics of cephalosporin series, vidarabine antiviral drugs, and a series of sodium alginate marine drugs have been existing. Japan has invested manpower and material resources in seawater by extracting lithium and achieving progress. Japan, Germany, United States and Sweden have also have a certain scale of seawater extracting uranium experiment devices. Despite the challenges like lack of trained personnel, scientific equipment and poor ocean governance, Bangladesh essentially needs to take the opportunity to explore the potential marine areas. Keywords: Oil and gas, gas hydrates, marine organisms, tuna, coastal tourism.

The Bay of Bengal (BoB) is rich in resources (both living and non-living). Marine living resources include fisheries, mangrove forests, coral ecosystems, plankton, sea grass and seaweeds, etc. Whereas, non-living resources are oil, gas, gas hydrates, sea salt, heavy minerals, etc. Present study reveals that the oil and gas fields discovered in the BoB are parallel with exploration activities. Bangladesh part of the BoB includes the low exploration area, consequently only one producing gas field, whereas India and Myanmar discovered many significant gas and oil fields in their territory. India discovered gas hydrates in the BoB in 2016. In the Exclusive Economic Zone (EEZ) of Bangladesh, 0.11 tcf to 0.63 tcf gas hydrates were discovered in 2022, with assessment of 17-103 tcf of natural gas, though gas hydrates exploration at industrial scale is still a big challenge in the world due to stability, composition and distribution of gas hydrates in nature. Different types of heavy minerals are also present in the coastal parts of the country. The Indian Ocean has about 20% of the worldwide tuna production, though Bangladesh contributes very little of it. In the marine part of the country, 475 species of fishes are found compared to 250 species on land. BoB is very important for BIMSTEC countries and also for China and Pakistan in consideration of seaborne trade. Bangladesh can introduce modern cruises like other BoB countries to visit the coastal islands as well as Sundarbans mangrove forest contributing considerably to local employment and economic expansion. Marine organisms have unique nutritional value and contain many kinds of bioactive substances. At present, internationally recognized antibiotics of cephalosporin series, vidarabine antiviral drugs, and a series of sodium alginate marine drugs have been existing. Japan has invested manpower and material resources in seawater by extracting lithium and achieving progress. Japan, Germany, United States and Sweden have also have a certain scale of seawater extracting uranium experiment devices. Despite the challenges like lack of trained personnel, scientific equipment and poor ocean governance, Bangladesh essentially needs to take the opportunity to explore the potential marine areas. Keywords: Oil and gas, gas hydrates, marine organisms, tuna, coastal tourism.