Environmental radiation and potential ecological risk levels in the intertidal zone of southern region of Tamil Nadu coast (HBRAs), India

Pollution and health risk assessments related to heavy metals on three prominent beaches in Makkah Province, Kingdom of Saudi Arabia: Concerning levels of cadmium pollution

Beach pollution can impact the health of people living in or visiting coastal areas. The primary goal of this research was to investigate the presence of heavy metal pollutants and associated health risks in three distinct coastal cities, Jeddah, Al-Lith, and Al-Qunfudhah, located along Saudi Arabia's Red Sea coast. Forty-three soil samples were collected from different locations, heavy metals including Fe, Zn, Mn, Cu, Cd, and Pb were isolated, and analyzed using inductively coupled plasma optical emission spectroscopy. Various metrics such as pollution indices (PI), integrated pollution indices (IPI), enrichment factors (EF), daily dose averages (ADD), hazard quotients (HQ), and hazard indices (HI), as well as principal component analysis (PCA) and cluster analysis were employed to evaluate the environmental impacts and health risks posed by these heavy metals. The results revealed that Fe, Pb, Cu, Mn, and Zn concentrations in beach zones were below their respective background levels, while concentrations of Cd exceeded corresponding background levels. PCA revealed the highest levels of Pb, Fe, and Mn on Al-Qundudah beach, while Cd and Cu were highest on Al-Lith beach, and Zn was highest on Jeddah beach. PI values highlighted extremely high levels of Cd pollution on all designated beaches. The findings provide a foundational basis for further investigations into health problems potentially related to Cd contamination, such as chronic kidney disease (CKD), osteomalacia, and osteoporosis.

Natural radionuclides and radiological risk assessment in the stream and river sediments of a high background natural radiation area Kanyakumari, India

The Kanyakumari coast is known to be a high background natural radiation area due to the placer deposits of heavy minerals such as ilmenite, monazite, and rutile. The Kanyakumari river sediments that could be the source of the elevated amounts of natural radionuclides in the coastal sands have been studied in this paper. The activity concentrations of primordial radionuclides 226Ra, 232Th, and 40K were determined using high-purity germanium (HPGe) gamma-ray spectrometry. The mean activity concentrations of 226Ra, 232Th, and 40K were found to be 75 Bq kg-1, 565 Bq kg-1, and 360 Bq kg-1, respectively. The mean absorbed dose rate was 395 nGy h-1. Radiological hazard parameters were studied and compared with the world average values. The contribution of 232Th to the total dose rate was found to be higher than that of the two other radionuclides. The high mean ratio of 232Th/226Ra suggested an enrichment of 232Th and the occurrence of 226Ra leaching due to an oxidizing environment. Principal component analysis (PCA) was carried out for the radionuclides in order to discriminate the source of the sediments. This study provides new insights into the distribution of natural radionuclides in sediments of rivers and streams.

Environmental radioactivity assessment of the Brunei Darussalam coastline of the South China Sea

Radioactivity levels of naturally occurring radionuclides at the coast of Brunei Darussalam were evaluated along with their dose rates. Twenty-six berm and intertidal sediment samples were measured using gamma-ray spectrometry. The mean activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in berm sediments were 10.07 ± 1.02 Bq/kg, below the minimum detectable activity, and 21.44 ± 1.23 Bq/kg, respectively, whereas for intertidal sediments they were 7.01 ± 0.87, 1.67 ± 0.15 and 4.99 ± 0.42 Bq/kg, respectively. With respect to the radiological health risk, the average hazard indices, absorbed gamma dose rate, effective dose equivalent, and excess lifetime cancer risk were found to be less than the global average. Calculation of the activity ratio showed that ⁴⁰K is the main source of radiation in the coastal sediments. Furthermore, the difference in radioactivity levels between the berm sediments and intertidal sediments collected at the same location was investigated. Finally, a standard geological terminology of the littoral zone profile is proposed for describing coastal samples for universal communication among researchers.

Assessment of the vertical characteristics and contamination levels of toxic metals in sediment cores from typical Chinese intertidal zones

The heavy metal (As, Cd, Cr, Cu, Hg, Pb, and Zn) contents of 24 sediment cores were obtained and analyzed from 12 typical Chinese intertidal zones. The results revealed a gradual improvement in the environmental quality of the intertidal zone. Enrichment factor and geoaccumulation index analyses demonstrated a generally good environmental quality of intertidal sediment, with some areas of serious contamination, such as the Xiamen Jiulong Estuary, the Yangtze River Estuary, and the Pearl River Delta. Relative to the guidelines for sediment quality, the studied intertidal zones were moderately impacted, with a risk of biotoxic impacts. This research reveals the status of toxic metal pollution in the intertidal zone of China and provides a reference for coastal area development.

The use of total diet study for determination of natural radionuclides in foods of a high background radiation area

The activity concentrations of ⁴⁰K, ²¹⁰Pb, ²¹⁰Po, ²²⁶Ra, ²²⁸Ra, ²²⁸Th, ²³⁰Th, ²³²Th, ²³⁴U, and ²³⁸U were determined in 82 food samples, grouped into 20 food groups according to the Brazilian Total Diet, which reflects the dietary habits of a population, for the rural and urban areas of Poços de Caldas city, a High Background Radiation Area. The highest activity concentration found in the food samples was due to ⁴⁰K being present in all types of food. Among the other radionuclides, high activity concentrations were found for ²¹⁰Pb in beans and salt, ²¹⁰Po in fish, ²²⁶Ra and ²²⁸Ra in nuts and seeds. The main food groups that contributed most to the effective dose, in urban and rural regions, were beans and beverages. The effective doses, due to the ingestion of the analysed food groups, were of 0.44 and 0.60 mSv y^-1 and the lifetime cancer risks were 1.6 × 10^-3 and 2.3 × 10^-3 for the urban and rural Poços de Caldas population, respectively.