Workers chronically exposed to respirable crystalline silica (CS) are susceptible to adverse health effects like silicosis and lung cancer. This study aimed to investigate potential early peripheral biomarkers of inflammation and oxidative stress in miners. The subjects enrolled in this study were occupationally unexposed workers (OUW, n = 29) and workers exposed to crystalline silica (WECS), composed by miners, which were divided into two subgroups: workers without silicosis (WECS I, n = 39) and workers diagnosed with silicosis, retired from work (WECS II, n = 42). The following biomarkers were evaluated: gene expression of L-selectin, CXCL2, CXCL8 (IL-8), HO-1, and p53; malondialdehyde (MDA) plasma levels and non-protein thiol levels in erythrocytes. Additionally, protein expression of L-selectin was evaluated to confirm our previous findings. The results demonstrated that gene expression of L-selectin was decreased in the WECS I group when compared to the OUW group (p < 0.05). Regarding gene expression of CXCL2, CXCL8 (IL-8), HO-1, and p53, significant fold change decreases were observed in workers exposed to CS in relation to unexposed workers (p < 0.05). The results of L-selectin protein expression in lymphocyte surface corroborated with our previous findings; thus, significant downregulation in the WECS groups was observed compared to OUW group (p < 0.05). The MDA was negatively associated with the gene expression of CXCL-2, CXCL8 (IL-8), and p53 (p < 0.05). The participants with silicosis (WECS II) presented significant increased non-protein thiol levels in relation to other groups (p < 0.05). Taken together, our findings may contribute to help the knowledge about the complex mechanisms involved in the silicosis pathogenesis and in the risk of lung cancer development in workers chronically exposed to respirable CS.

Water fountains are usually present in the urban public places and often draw the attention of citizens and tourists. Their water is often, in various ways, used by adults and children, but water from fountains is not usually a subject of researchers’ interest. This paper describes the analytical procedure and the results of the multi-elemental characterisation of the waters from the selected public water fountains in the city of Zagreb, Republic of Croatia. Twenty-eight chemical elements (Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, S, Sb, Se, Sr, Ti, Tl, V, Zn and Ca, K, Mg and Na) were quantified by means of ICP-AES technique. In addition to the multi-elemental analysis, determination of pH values was performed too. Pearson’s correlation coefficients suggest that Al, Cu, Fe, Mn and Pb originate from the plumbing system and their leaching is strongly negatively correlated with the pH values of the tested samples. On the other hand, alkali and alkaline-earth metals as well as Mo, Ti, Zn and B, P and S are most probably of a natural origin in the water samples tested in this study. The results lead to the conclusions that (i) trace and major element content in squirt of a monumental water fountain is analogous to their content in water of the same origin and (ii) a pool of a fountain which is made of a high-quality stone, in the context of the herein performed testings, generally does not affect the quality of water which is contained in it.

On-site sanitation is the most preferred mode of sanitation due to expensive off-site sanitation. The increasing population especially in the peri-urban areas has led to increasing use of on-site sanitation systems in India. However, the habitations in the vicinity of these systems do not have centralised water supply and are dependent on groundwater sources. However, there is concern about leaching of faecal coliforms and nitrate from the septic tanks to the underlying aquifer. The present study is attempted at two sites in the coastal city of Chennai where on-site sanitation is prevailing. The sample locations (16 nos.) are selected in such a way that groundwater sources are situated in the vicinity of on-site sanitation systems. The groundwater sources are the bore wells installed by the private agencies. It is observed that parameters considered key parameters to study the impact of the on-site sanitation systems, namely Na2⁺, Cl⁻, NO₃⁻, faecal coliform and total dissolved solids, exceed the concentration limits recommended by the Bureau of Indian Standards. The piper diagram analysis identifies that the predominant cations and anions are respectively Na⁺, and Cl⁻, SO₄⁻ and HCO₃⁻.The Gibbs plot shows ground water quality is dominated by the evaporation process in both the seasons. The Cl/HCO₃ ratio in many samples confirms the seawater intrusion in the study area. Elevated concentrations of faecal coliforms in all the samples (16 nos.) confirm the significant amount of groundwater pollution from the on-site sanitation systems. It is desired that policy planners and implementation agencies should undertake detailed scientific and hydrogeological studies of the region in order to examine the feasibility of implementing on-site sanitation systems.

In this study, magnetic bio-adsorbent based on chitosan with high molecular weight was prepared. To stabilize under acidic condition, the synthesized magnetic chitosan was cross-linked with κ-carrageenan (mChitoCar). The magnetic bio-adsorbent was characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicated that mChitoCar had desirable magnetic-sorption properties, and magnetic/bio-adsorbent was successfully synthesized and cross-linked. The present nanocomposite was applied to remove and immobilize Cd²⁺ from water and soil systems. Adsorption and desorption of cadmium by the chitosan bio-adsorbent were investigated using batch experiments. Isotherm data were described by using Freundlich, Langmuir, Dubinin-Radushkevich, and Temkin models, and better fitting was introduced by Freundlich model in both water and soil systems. The maximum adsorption capacity (b) of cadmium onto mChitoCar appeared to increase from the water system to the soil system, from 750.2 to 992.7 μmol/g, respectively. The adsorption mechanism with the help of potential theory indicates the adsorption of cadmium onto the mChitoCar surface is following chemical adsorption type. To evaluate the efficiency of the modified chitosan as a good bio-adsorbent in water and soil system, the difference between adsorption and desorption amounts, Δq, was calculated. By comparing the amounts of Δq, the bio-adsorbent is not economically feasible at high initial concentrations in the water system. But, the bio-adsorbent used can be relatively economic as a soil modifier.

The feasibility of using floating treatment wetlands (FTWs) to treat runoff typical of commercial nurseries was investigated using two 8-week trials with replicated mesocosms. Plants were supported by Beemat rafts. Five monoculture treatments of Agrostis alba (red top), Canna × generalis ‘Firebird’ (canna lily), Carex stricta (tussock sedge), Iris ensata ‘Rising Sun’ (Japanese water iris), Panicum virgatum (switchgrass), two mixed species treatments, and an unplanted control were assessed. These plant species are used for ornamental, wetland, and biofuel purposes. Nitrogen (N) and phosphorus (P) removals were evaluated after a 7-day hydraulic retention time (HRT). N removal (sum of ammonium-N, nitrate-N, and nitrite-N) from FTW treatments ranged from 0.255 to 0.738 g·m⁻²·d⁻¹ (38.9 to 82.4% removal) and 0.147 to 0.656 g·m⁻²·d⁻¹ (12.9 to 59.6% removal) for trials 1 and 2, respectively. P removal (phosphate-P) ranged from 0.052 to 0.128 g·m⁻²·d⁻¹ (26.1 to 64.7% removal) for trial 1, and 0.074 to 0.194 g·m⁻²·d⁻¹ (26.8 to 63.2% removal) for trial 2. Panicum virgatum removed more N and P than any other FTW treatment and the control in both trials. Results show that species selection and timing of FTW harvest impact the rate and mass of nutrient remediation. FTWs can effectively remove N and P from runoff from commercial nurseries.

At the global scale, urban agriculture is increasingly developing in cities due to demographic growth and sustainable food concerns. But, urban soils are frequently polluted with metals. In urban gardens, organic matter is also commonly added both to valorize organic household waste and to promote biophysicochemical fertility. As earthworms promote the decomposition and the recycling of soil organic matter, they can also influence the biogeochemical cycle of metals in urban polluted soils. In order to produce safe vegetables in urban areas, it is crucial to highlight the mechanisms involved in complex soil-earthworm-plant ecosystems. An experiment was set up to examine these relationships using lettuce cultivated in controlled conditions with RHIZOtest® devices. Thanks to the RHIZOtest® devices, metal transfer and bioaccessibility were for the first time compared for urban polluted soil without (1—urban soil polluted with Pb, Cd, Cu, and Zn: essential or toxic metals currently found in environment, SNB) and with bioturbation (2—this metal-polluted soil subjected to earthworm bioturbation, SB) and earthworm casts (3—earthworm casts produced in this polluted soil and naturally enriched in organic matter and microorganisms, T). Metal concentration, phytoavailability, and human gastric bioaccessibility were determined in the different samples. Results showed that earthworm bioturbation increased the phytoavailability of all the metals. For the experimental condition SB, the phytoavailability of metals was increased up to 75% compared to SNB. In addition, surprisingly, metal phytoavailability was always superior in SB compared to earthworm casts (T). Moreover, earthworms led to an increase in Zn gastric bioaccessibility up to 10% in the soils in the same way as for phytoavailability, meaning Zn bioaccessibility in SB > T > SNB, whereas it remained unchanged in the lettuces. These data are important to promote sustainable agriculture activities in urban areas; actually, databases concerning different experimental conditions are needed to develop decision support tools.

Cadmium (Cd) stress is a serious concern in agricultural soils worldwide, and increasing accumulation and subsequent transfer to humans via the food chain can have potentially harmful effects. In this study, field experiments were conducted to examine the uptake and translocation of Cd in rice, changes in the soil Cd speciation, and the subsequent effect on Cd accumulation in rice under combined organic (farmyard manure and crop straw) and inorganic (sepiolite, lime, and calcium-magnesium phosphate) soil amendments. The results showed that farmyard manure combined with sepiolite or lime and straw combined with lime or calcium-magnesium phosphate reduced the Cd translocation from the rice roots to the straw and the grains, significantly decreasing the Cd accumulation in brown rice. In addition, straw combined with sepiolite, lime, or calcium-magnesium phosphate reduced the Cd accumulation in brown rice but increased the Cd translocation from the roots to the straw by 37.8–279.3% compared with the control. Organic-inorganic amendments also decreased the soil exchangeable Cd and increased the organic-bound Cd by more than 40%. Fe-Mn oxide-bound Cd also increased but varied with growth. Cd accumulation in brown rice showed a significant positive relationship with soil exchangeable Cd at 90 days after transplantation, while at 30 days, the increase in Fe-Mn oxide- and organic-bound Cd was found to be the key factor in reducing the Cd accumulation in rice. These findings suggest that straw (under rice-rape rotation) and farmyard manure (under rice-wheat rotation) combined with sepiolite or lime are widely applicable as agronomic control techniques aimed at lowering Cd pollution.

The soil organic carbon accumulation in soda saline-alkaline soil and the humus composition changes with application of aluminum sulfate and rice straw were investigated by the controlled simulative experiments in laboratory. For evaluating the amelioration effect, organic carbon content and humus composition in soda saline-alkaline soil were investigated with different application amounts of rice straw and aluminum sulfate. Potassium dichromate oxidation titration (exogenous heat) method and Kumada method were used to analyze the contents of organic carbon and humus composition, respectively. The transformation of soil organic matter in the saline-alkali soil during the amelioration has been clarified in this paper. The results demonstrated that the contents of soil organic carbon were significantly increased (13–92%) with different application amounts of rice straw and aluminum sulfate. The contents of free fraction and combined fraction of humus and their compositions (humic acid and fulvic acid) were increased with different application amounts of rice straw. The free fraction of humus was increased more dramatically. Due to aluminum sulfate application, free fraction of humus and humic acid (HA) was transformed to combined fraction partially. Free HA was changed to be P type with rice straw application. With aluminum sulfate application, free form of HA was changed from type P to type Rp. For rice straw application, combined HA only was transferred within the area of type A. Aluminum sulfate addition had no significant effect on the type of combined form of HA. With the same amount of rice straw application, the contents of soil organic carbon were increased by increasing the amount of aluminum sulfate application. Both rice straw and aluminum sulfate applications could reduce the humification degree of free and combined fraction of HA. According to the types of HA, it could be concluded that humus became younger and renewed due to the application of rice straw and aluminum sulfate.

The present work is dedicated to the experimental analysis on the influence of fuel-borne additives on ternary fuel blend operated in a single cylinder DI diesel engine. Alumina (Al₂O₃) nanoparticles were chosen as fuel additives at dosing levels of 10, 20, and 30 ppm, respectively, and the ternary fuel (TF) is prepared by blending 70% diesel, 20% Jatropha biodiesel, and 10% ethanol. Performance characteristics like brake thermal efficiency (BTE) and brake-specific energy consumption (BSEC) and emission characteristics like HC, CO, NOx, and smoke along with combustion characteristics like cylinder pressure, HRR (heat release rate), and CHRR (cumulative heat release rate) were considered for analysis. Based on experimentation, it is observed that TF blended with 20 ppm alumina nanoadditive (TF20) resulted in higher BTE and lowered BSEC by 7.8 and 4.93% and lowered HC, CO, NOx, and smoke emissions by 5.69, 11.24, 9.39, and 6.48% in comparison with TF. Moreover, TF20 resulted in higher cylinder pressure, HRR, and CHRR of about 72.67 bar, 76.22 J/°CA, and 1171.1 J, respectively, which are higher than those of diesel and TF. Hence, it is concluded that the addition of 20 ppm alumina nanoadditive in TF can enhance the engine performance and combustion as well as lower the exhaust pollutants simultaneously.

This paper studies the optimization mode of the spatial organization of rural settlements based on the two-way interactive mechanism between the space of rural settlements and quality-of-life theory. It examines three main aspects: the integration of spatial function, the optimization of spatial structure, and the regulation of spatial scale. In this paper, we built an optimization mode and framework of spatial organization, called the road-oriented mode of rural settlements, based on quality-of-life theory. We systematically analyzed the mode’s conceptual connotation, construction principles, frame, type, and spatial scale. At the same time, this paper realized the reasonable proportion and optimized combination of internal spatial type in settlements and focused on a reasonably sized scale of a single settlement and the distance scale between settlements. Our findings can be used as insight into the theoretical development of the spatial structure of rural areas. Results also provide a scientific basis for future spatial optimization and integration of rural settlements to improve quality of life.