Apart from the conventional polyethylene and the bio-based or mainly bio-based biodegradable in soil mulching films, polyethylene mulching films of controlled degradation in soil are already used in agriculture. The use of special pro-oxidants as additives is expected to accelerate the abiotic oxidation and the subsequent chain scission of the polymer under specific UV radiation or thermal degradation conditions, according to the literature. The role of pro-oxidants in the possible biodegradation of polyethylene has been theoretically supported through the use of controlled laboratory conditions. However, results obtained in real soil conditions, but also several laboratory test results, are not supporting these claims and the issue remains disputed. Mulching films made of linear low-density polyethylene (LLDPE) with pro-oxidants, after being used for one cultivation period in an experimental field with watermelon cultivation, were buried in the soil under real field conditions. This work presents the analysis of the degradation of the mulching films during the cultivation period as compared to the corresponding changes after a long soil burial period of 8.5 years. The combined effects of critical factors on the photochemical degradation of the degradable mulching LLDPE films with pro-oxidants under the cultivation conditions and their subsequent further degradation behaviour in the soil are analysed by testing their mechanical properties and through spectroscopic and thermal analysis.

Previous research has revealed that agricultural intensification in the Chao Lake Valley since the 1980s has led to significant heavy metal and phosphorus (P) contamination of estuarine sediments in this region. However, the pore water plays a more important role than do sediments in the cycling of nutrients and metals in estuarine ecosystems. Average concentrations of Cd, Cr, Ni, Pb, and P in the pore water of estuarine sediments were 0.634, 3.11, 4.98, 3.98, and 49.9 μg L⁻¹, respectively. Average diffusive fluxes of these elements from the pore water to overlying water were −0.015, 0.058, 0.768, −0.238, and 20.0 μg m⁻² d⁻¹, respectively. Compared with similar studies, the values of heavy metal fluxes were low, indicating minimal diffusion between sediments and overlying waters; however, P diffusion from the sediment pore water to overlying water was high, indicating that the sediments may be a direct source of P to overlying water. Since P is a major cause of algal blooming in agricultural estuaries of Chao Lake, the obtained results could be useful in developing effective management strategies to control pollution in the Chao Lake Valley.

The oxidation of diclofenac (DCF), a non-steroidal anti-inflammatory drug and emerging water pollutant, with chlorine dioxide was investigated under simulated water disinfection conditions. The reaction kinetics as functions of the initial concentrations of DCF, different nitrogenous species, and different pE values were experimentally determined. The results demonstrated that DCF reacted rapidly with ClO₂, where more than 75 % of DCF (≤3.00 μM) was removed by 18.94 μM ClO₂ within 60 s. All of the reactions followed pseudo first-order kinetics with respect to DCF, and the rate constant, k ₒbₛ, exhibited a significant decrease from 4.21 × 10⁻² to 8.09 × 10⁻³ s⁻¹, as the initial DCF concentration was increased from 1.00 to 5.00 μM. Furthermore, the degradation kinetics of DCF was clearly dependent on nitrogen-containing ion concentrations in the reaction solution. Ammonium and nitrite ions inhibited the DCF degradation by ClO₂, whereas nitrate ion clearly initiated its promotion. In contrast, the inhibitory effect of NO₂ ⁻ was more robust than that of NH₄ ⁺. When the values of pE were gradually increased, the transformation of NH₄ ⁺ to NO₂ ⁻, and subsequently to NO₃ ⁻, would occur, the rate constants were initially decreased, and then increased. When NH₄ ⁺ and NO₂ ⁻ coexisted, the inhibitory effect on the DCF degradation was less than the sum of the partial inhibitory effect. However, when NO₂ ⁻ and NO₃ ⁻ coexisted, the actual inhibition rate was greater than the theoretical estimate. These results indicated that the interaction of NH₄ ⁺ and NO₂ ⁻ was antagonistic, while the coexistence of NO₂ ⁻ and NO₃ ⁻ was observed to have a synergistic effect in aqueous environments.

Mining activities result in extensive soil degradation by removing the top soil, disturbing soil structure and altering microbial communities. Rehabilitation of spent mine sites through revegetation thus requires proper soil amendments. In this study, a pot trial was conducted to investigate the effects of a jarrah biochar on the growth and nutrient status of a native legume, Acacia tetragonophylla, grown in a mixture of topsoil and mine rejects. Two biochar application rates (37 and 74 t ha⁻¹) and two types of biochar, namely nutrient-enriched and non-enriched, were tested. We measured the soil pH and electrical conductivity, the carbon (C) and nitrogen (N) contents and C and N isotope composition (δ¹³C and δ¹⁵N) of soil and plants, the foliar phosphorus content and the growth and leaf biomass of the plants. Whilst no significant effect of biochar was observed on plant growth, biochar amendment affected soil properties and plant nutritional status. The highest rate of biochar application increased soil pH, C content and C/N ratio, and decreased soil δ¹³C. Biochar application also enhanced photosynthetic N use efficiency, as showed by the increase in foliar C/N ratio, and biological N fixation rates, as indicated by foliar δ¹⁵N. These positive effects were not observed when biochar was nutrient-enriched due to the associated increase in soil N. Revegetation of mine sites with acacia in combination with biochar amendment constitutes a plausible alternative to the wide use of N fertiliser through the supply of additional N to the system, even though other nutrients may be required in order to enhance plant early growth.

Phthalates may be present in food due to their widespread presence as environmental contaminants or due to migration from food contact materials. Exposure to phthalates is considered to be potentially harmful to human health as well. Therefore, determining the main source of exposure is an important issue. So, the purpose of this study was (1) to measure the release of diethyl phthalate (DEP) in bottled water consumed in common storage conditions specially low temperature and freezing conditions; (2) to evaluate the intake of DEP from polyethylene terephthalate (PET) bottled water and health risk assessment; and (3) to assess the contribution of the bottled water to the DEP intake against the tolerable daily intake (TDI) values. DEP migration was investigated in six brands of PET-bottled water under different storage conditions room temperature, refrigerator temperature, freezing conditions (40 °C ,0 °C and −18 °C) and outdoor] at various time intervals by magnetic solid extraction (MSPE) using gas chromatography–mass spectroscopy (GC-MS). Eventually, a health risk assessment was conducted and the margin of exposure (MOE) was calculated. The results indicate that contact time with packaging and storage temperatures caused DEP to be released into water from PET bottles. But, when comprising the DEP concentration with initial level, the results demonstrated that the release of phthalates were not substantial in all storage conditions especially at low temperatures (<25 °C) and freezing conditions. The daily intake of DEP from bottled water was much lower than the reference value. However, the lowest MOE was estimated for high water consumers (preschooler > children > lactating women > teenagers > adults > pregnant women), but in all target groups, the MOE was much higher than 1000, thus, low risk is implied. Consequently, PET-bottled water is not a major source of human exposure to DEP and from this perspective is safe for consumption.

Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na⁺ uptake and translocation while increased K⁺ uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils.

To contribute to the use of the tropical brown mussel Perna perna as a sentinel species for organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB), the present study reports data on the toxicokinetics of these compounds in P. perna. Specifically, the authors present data on OCP and PCB bioaccumulation for eight sampling months from three bays (SE Brazil) and two transplant experiments (each 1 month long). Although seasonality is observed in the total lipid content of the whole soft tissue, with summer samples showing higher values, no such seasonality is observed in the OCP and PCB concentrations bioaccumulated by the mussel P. perna. Because no seasonal effect is observed in the annual OCP and PCB concentrations bioaccumulated by P. perna, the use of this species as a sentinel organism to monitor organochlorinated compounds is encouraged. One month of transplantation is not enough to allow the transplanted specimens to reach the concentrations observed in animals reared at the destination site. Nevertheless, P. perna showed a clear tendency to depurate the DDT metabolites p,p′-DDD and p,p′-DDE after 1 month of transplantation.

Experimental and epidemiological studies suggest that serum levels of trace elements may be associated with breast cancer risk. We compared serum levels of 15 trace elements between breast cancer patients and normal controls from Shandong, China, for the first time to assess whether serum levels of trace elements were associated with breast cancer risk. Eighty-eight breast cancer patients and 84 healthy controls were enrolled in the study. A Spectraspan V direct current plasma atomic emission spectrometer was used to determine the serum levels of 15 trace elements including Zn, Mn, Al, Cd, Fe, Mg, Ca, Pb, Cu, Se, Ni, Ti, Co, Li, and Cr. Breast cancer patients had significantly higher serum levels of Cd (p = 0.000), Mg (p = 0.001), Cu (p = 0.000), Co (p = 0.006), and Li (p = 0.003) and borderline higher Cr (p = 0.052), while significantly lower Mn (p = 0.000), Al (p = 0.000), Fe (p = 0.000), and Ti (p = 0.000) compared to their matched controls. However, there were no significant differences in serum levels of Zn (p = 0.824), Ca (p = 0.711), Pb (p = 0.274), Se (p = 0.236), and Ni (p = 0.185) between the two groups. Our study showed a possible association between serum levels of trace elements and breast cancer risk in eastern China, though it warrants further investigations to confirm the association. If confirmed, modulation of trace elements may help reduce breast cancer risk.

The paper presents unique data of plutonium²⁴¹Pu study in seabirds from northern Eurasia, permanently or temporally living at the southern Baltic Sea coast. Together, ten marine birds species were examined, as follows: three species that permanently reside at the southern Baltic, four species of wintering birds, and three species of migrating birds; 366 samples were analyzed. The obtained results indicated plutonium was non-uniformly distributed in organs and tissues of analyzed seabirds. The highest²⁴¹Pu content was found in the digestion organs and feathers, the lowest in muscles. Also, the internal radiation doses from²⁴¹Pu were evaluated.

The effect of Phanerochaete chrysosporium inoculation during drum composting of agricultural waste was performed at different composting stages. Three trials were carried out with (5:4:1) combination of vegetable waste, cattle manure, and sawdust along with 10 kg of dried leaves with a total mass of 100 kg in a 550 L rotary drum composter. Trial 1 was a control without inoculation of fungus, while trial 2 was inoculated during the initial day (0th day of composting), and trial 3 was inoculated after the thermophilic phase, i.e., on the 8th day of composting period. The inoculation of fungus increased the volatile solids reduction by 1.45-fold in trial 2 and 1.7-fold in trial 3 as compared to trial 1 without any fungal inoculation. Total Kjeldahl Nitrogen (TKN) was observed with 2.31, 2.62, and 2.59 % in trials 1, 2, and 3, respectively, at the end of 20 days of composting period. Hence, it can be concluded that inoculation of white-rot fungus increased the decomposition rate of agricultural waste within shorter time in drum composting. However, inoculation after the thermophilic phase was found more effective than inoculation during initial days of composting for producing more stabilized and nutrient-rich compost.