The residential areas are located around one of the oldest and largest non-nuclear industrial cities in Saudi Arabia, Arabian Gulf. Therefore, it is important to study the radioactivity levels in the urban soil in order to estimate the potential risk of radiation in environment and for public. The activity concentrations of ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs in urban soil around non-nuclear industries were measured using gamma ray spectrometric technique. The mean values of activity concentrations were found to be 7.64 ± 0.4, 3.76 ± 0.2, 174 ± 3.7, and 0.391 ± 0.03 (Bq/kg) for ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs, respectively. Radium equivalent activity (Raₑq), gamma absorbed dose rate in air (D), and annual effective dose equivalent (E) for outdoor were calculated. The mean values of these radiological parameters were found to be less than the allowed limits in soil. The obtained results were compared with other studies from Arabian Gulf and other regions of the world. Consequently, the direct gamma radiation exposure from the urban soil in the study area was found to be safe for public. Additionally, the present study is the first in this area which could be used as a baseline for radioactivity levels in soil nearby industrial areas of the Arabian Gulf region.

The effect of industrial activities on trace metals in farmland of rapidly industrializing regions in developing countries has increasingly been a concern to the public. Here, soils were collected from 13 greenhouse vegetable production (GVP) farms or bases near industrial areas in the Yangtze River Delta of China to investigate the occurrence, speciation, and risks of Cr, Cu, Zn, Cd, Ni, and Pb in GVP soil. The results revealed that the main metal elements causing GVP soil pollution were Cd, Zn, Ni, and Cu, of which contamination levels were generally unpolluted to moderately polluted. Zinc pollution was mainly attributed to heavy fertilization, while Cd, Ni, and Cu pollution may be greatly ascribed to industrial effluents and coal combustion. Metal speciation studies showed that most of Cr, Ni, Cu, and Zn was present in residual fraction while more than half of Cd and Pb was present in non-residual fractions. Additionally, pollution of Cd, Cu, Ni, and Zn in GVP soil increased their corresponding mobile fractions. Risk assessment using potential ecological risk index and risk assessment code showed that Cd was the major risk contributor. Specifically, Cd generally posed moderate or considerable ecological risk as well as displayed medium or high mobility risk in GVP soil. Thus, great attention should be paid to the contribution of both industrial discharges and intensive farming to soil pollution by trace metals, especially Cd, because of its high mobility risk.

The aim of this study was to evaluate the performances of Pichia kudriavzevii CR-Y103 yeast strain for the decolorization, biodegradation, and detoxification of cationic dye C.I. Basic Blue 41, a toxic compound to aquatic life with long-lasting effects. Under optimized cultural conditions (10.0-g L⁻¹ glucose, 0.2-g L⁻¹ yeast extract, and 1.0-g L⁻¹ (NH₄)₂SO₄), the yeast strain was able to decolorize 97.86% of BB41 (50 mg L⁻¹) at pH 6 within 4 h of incubation at 30 °C under shaken conditions (12,238.00-μg h⁻¹ average decolorization rate) and 100% within 12 h. The UV-Vis spectral analysis, high-performance liquid chromatography (HPLC), and Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the complete decolorization and degradation of the BB41 dye by P. kudriavzevii CR-Y103. Also, other seven yeast strains, isolated from soil, as P. kudriavzevii (CR-Y108, CR-Y119, and CR-Y112), Candida tropicalis CR-Y128, Cyberlindnera saturnus CR-Y125, and Candida solani CR-Y124 have shown a promising decolorizing potential of azo-dye BB41 (99.89–76.09% decolorization). Phytotoxicity, cytotoxicity, and genotoxicity assays on Trifolium pratense and Triticum aestivum seedlings confirmed the high toxicity of BB41 dye (500 ppm), with inhibition on germination rate (%), root and shoot elongation, decreasing of mitoxic index value (with 34.03% in T. pratense and 40.25% in T. aestivum), and increasing the frequency of chromosomal aberrations (6.87 times in T. pratense and 6.25 times in T. aestivum), compared to control. The same biomarkers indicated the nontoxic nature of the BB41 degraded metabolite (500 ppm) obtained after P. kudriavzevii CR-Y103 treatment. Moreover, the healthy monkey kidney cells (Vero cells) had a low sensitivity to BB41 biodegraded products (250 μg mL⁻¹) (MTT cell viability assay) and revealed minor DNA damage (comet assay) compared to BB41 dye treatment. These findings show that P. kudriavzevii could be used in eco-friendly bioremediation technologies, applicable for reducing the toxicity of basic azo-dyes containing wastewaters.

Breast cancer is a global public health problem where it is the second most prevalent cancer. Historical cancer treatment with graviola has been reported. This study aimed to investigate the protective effects of graviola on 7,12-dimethylbenz[a]anthracene (DMBA)–induced rat breast cancer. Fifty female Wistar rats were allocated into four groups: control group (gastro-gavaged by sesame oil), DMBA-treated group (gastro-gavaged a single dose of DMBA [50 mg/kg body mass, diluted in 1 ml sesame oil]) at the age 57 days, DMBA+G37-treated group (gastro-gavaged a single dose of DMBA [50 mg/kg body mass, diluted in 1 ml sesame oil]) at the age of 57 days plus graviola (200 mg/kg body mass) two times weekly (p.o.) at the age of 37 days till the end of the experiment, and DMBA+G57-treated group (received a single dose of DMBA [50 mg/kg body mass, diluted in 1 ml sesame oil]) plus graviola (200 mg/kg body mass) two times weekly at the age of 57 days until the end of the experiment. After the 30-week experimental period, blood samples were collected. Then, animals were sacrificed to determine the apoptotic indices, antioxidant status, and mammary gland tumor marker (CA 15-3). The DMBA upregulated the expression of one of the main anti-apoptotic genes: B-cell lymphoma protein 2 (BCL2) and estrogen receptor alpha (ER-α) gene. Moreover, it significantly increased breast lipid peroxidation and serum CA 15-3 but decreased breast antioxidant enzymatic activities (glutathione peroxidase, glutathione S-transferase, catalase, and superoxide dismutase). Nevertheless, administration of DMBA and graviola especially DMBA+G37 induced apoptosis through at least 1.5-fold in gene expression levels of pro-apoptotic genes: BCL2-associated X protein (BAX), tumor suppressor gene (P53), and cysteinyl-aspartic acid-protease-3 (caspase-3). A critical role of P53 in the regulation of the BCL2 and BAX has been reported. These proteins can determine if the cell undergoes apoptosis or cancels the process. Once the BAX gene activates caspase-3, there is no irreversible way toward cell death. Also, graviola ameliorated the DMBA effects on antioxidant enzymatic activities and tumor marker CA 15-3. This study concludes that graviola ameliorated DMBA-induced breast cancer potentially through upregulating apoptotic genes, downregulating the ER-α gene, increasing antioxidants, and decreasing lipid peroxidation levels.

Anaerobic digestion (AD) is an attractive technology for sludge treatment as it stabilizes sludge and produce renewable energy. However, problems such as low organic matter content and high heavy metals level are often encountered which severely limits the effectiveness of AD. In this study, the biochar-supported nanoscale zerovalent iron (nZVI-BC) was synthesized and used as additives during AD of sewage sludge to investigate the enhancement effects for methane production and its impacts on microbial structure at mesophilic temperature. nZVI-BC addition enhanced process stability by improving the generation and degradation of intermediate organic acids, but inhibitory effects were observed at high dosage. The methane content and cumulative methane yields were increased by 29.56% and 115.39%, respectively. Compared with AD without nZVI-BC, the application of nZVI-BC showed positive effect on improvement of metals (Cu, Cd, Ni, Cr, and Zn) stabilization in the digestate. Microbial community analysis illustrated that nZVI-BC addition could significantly increase the Shannon diversity index and Chao1 richness index of archaea, and meanwhile archaea were more diverse in nZVI-BC amended digesters than in control. It was notable that Methanosaeta dominated in all the digesters at genera level, while the relative abundance of hydrogenotrophic methanogens (Methanobacterium and methanospirillum) increased 35.39% in nZVI-BC amended digesters compared to the control, resulting in higher methane production. The results will guide development of microbial management methods to enhance the stability of AD process.

Aeration strategy played an important role in reactor performance. In this study, when superficial upflow air velocity (SAV) decreased from 0.16 to 0.08 cm s⁻¹, low dissolved oxygen concentration (DO) of 2.0 mg L⁻¹ occurred in reactor. The required depth for anoxic microenvironment in biofilm decreased from 902.3 to 525.9 μm, which enhanced the growth of denitrifying bacteria and total nitrogen (TN) removal efficiency. However, decreasing aeration intensity resulted in insufficient hydraulic shear stress, which led to weak biofilm matrix structure. Mass biofilm detachment and reactor deterioration then occurred after 87 days of operation. An end gas recirculation aeration strategy was proposed to separately manipulate DO and aeration intensity. Low DO and high aeration intensity were simultaneously achieved, which enhanced the metabolism of denitrifying bacteria (such as Flavobacterium sp., Pseudorhodobacter sp., and Dok59 sp.) and EPS-producing bacteria (such as Zoogloea sp. and Rhodobacter sp.). Consequently, high TN removal performance (82.1 ± 2.7%) and stable biofilm structure were achieved.

The activity concentrations of naturally occurring and anthropogenic radionuclides in agriculture soils as well as in several food products at four locations within the phosphate area of South Tunisia were investigated. Soil-to-plant transfer factors as well as feed-to-animal products transfer coefficients were determined for the first time for the region. Activity concentrations of ⁴⁰K, ²¹⁰Pb, ²²⁶Ra, ²²⁸Ra and ¹³⁷Cs in soils of agriculture fields were lower than worldwide average values. The soil-to-plant transfer factors (TFs) for ⁴⁰K in leafy vegetables were higher than those in fruit vegetables. Soil-to-grass transfer factor (Fᵥ) values were in the following order: ⁴⁰K > ²¹⁰Pb > ²²⁶Ra. The grass-to-milk transfer coefficient (Fₘ) values for ⁴⁰K and ²¹⁰Pb ranged between 2 × 10⁻³ and 4 × 10⁻³(day L⁻¹). The concentration ratios for the animal products (CRₘᵢₗₖ₋fₑₑd, CRₘₑₐₜ₋fₑₑd and CRₑgg₋fₑₑd) varied in the ranges of 2 × 10⁻²–4 × 10⁻² L kg⁻¹, 1 × 10⁻²–2 × 10⁻¹ (L kg⁻¹) and 5 × 10⁻²–1 (L kg⁻¹)for ⁴⁰K, ²¹⁰Pb and ²²⁶Ra, respectively. Transfer parameters determined in the present study were compared with those reported in International Atomic Energy Agency reports and other published values. The absorbed gamma dose rate in air and the external hazard index associated with these natural radionuclides were computed to assess the radiation hazard of radioactivity in this region, and the results indicated that these areas are within set safety limits.

Aging effects play a crucial role in determining applications of green-synthesised iron-based nanoparticles in wastewater treatment from laboratory scale to practical applications. In this study, iron-based nanoparticles (Ec-Fe-NPs) were synthesised using the extract of Eichhornia crassipes and ferric chloride. Scanning electron microscopy (SEM) revealed that the fresh Ec-Fe-NPs were spherical and had a narrow particle size range (50 to 80 nm). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) demonstrated that the Ec-Fe-NPs were mainly amorphous in nature and consisted of Fe⁰, FeO, Fe₂O₃ and Fe₃O₄. As they aged, the particle size of the liquid Ec-Fe-NPs gradually increased and then tended to stabilise. Ec-Fe-NPs that were aged for 28 days were only 19% less efficient than fresh material at removing Cr(VI). Extracts aged up to 28 days were also tested, and their antioxidant capacity was found to be 15.4% lower than that of the fresh extracts. Furthermore, the removal efficiency of Cr(VI) using iron-based nanoparticles synthesised with the aged extracts was 67.2%. Finally, the active components of the extracts, which were responsible for the reactivity and stability of the iron-based nanoparticles, were identified by liquid chromatography–mass spectrometry. Overall, green-synthesised iron-based nanoparticles show promise for Cr(VI) removal from wastewater in practical applications.

The Norwegian Armed Forces’ shooting ranges contain contamination by metals such as lead (Pb) and copper (Cu) and are often used as grazing pastures for livestock. To determine whether the sheep were at risk from grazing at a shooting range in Nord-Trøndelag (the Leksdalen shooting field), a study was conducted wherein the aim was to determine the amount of soil the sheep were eating, the accumulation of Cu and Pb in the livers of lambs grazing on the shooting ranges, and the accumulation of Pb and Cu in the grass. The grazing behavior of the sheep was mapped using GPS tracking and wildlife cameras. Soil, grass, feces, and liver samples were collected. All the samples were analyzed for Pb, Cu, and molybdenum (Mo), and soil and feces were also analyzed for titanium (Ti). Mean concentrations in grass, soil, feces, and liver was 41–7189, 1.3–29, 4–5, and 0.3 mg/kg Pb, respectively, and 42–580, 4.2–11.9, 19–23, and 273 mg/kg Cu, respectively. The soil ingestion rate was calculated using Ti in feces and soil. From these results, the theoretical dose of Cu and Pb ingested by grazing sheep was calculated. The soil ingestion rate was found to be 0.1–0.4%, significantly lower than the soil ingestion rate of 5–30% usually used for sheep. Little or no accumulation of Cu and Pb in the grass was found. There was no difference between the metal concentrations in the washed and unwashed grass. According to the calculated dose, the sheep were at little or no risk of acute or chronic Pb and Cu poisoning from grazing on the Leksdalen shooting range. The analysis of liver samples showed that lambs grazing on the shooting range did not have higher levels of Cu or Pb than lambs grazing elsewhere. None of the lambs had concentrations of Cu or Pb in their livers indicating poisoning.

This study aims to identify the analytical and radiological characterization of scale TENORM waste produced from oil and natural gas productions in the western desert in Egypt and evaluates their radiological impacts. The mean activity concentration of ²³⁸U, ²²⁶Ra, ²¹⁰Pb, ²²⁸Ra, ²²⁴Ra, and ⁴⁰K measured in scale TENORM samples is 660 ± 63, 1979 ± 435, 1399 ± 211, 645 ± 104, 794 ± 116, and 556 ± 86 Bq/kg, respectively. Radiological hazard parameters (Raₑq, Hex, Hin, etc.) were estimated form the scale TENORM waste sample. All the calculated hazard parameters were found greater than the permissible and recommended safe levels. So the exposure to radiations released from the accumulation of the petroleum scale TENORM waste may cause health risks to the operators and who inhale radioactive radon gases and/or ingest contaminants by radiotoxic nuclides of U, Th, Ra, and Pb. Also, the risks may be extended to the near and/or the general environment.