فصلنامه محیط شناسی
سال چهل و نهم شماره 3 (پیاپی 107، پاییز 1402)

Investigating the spatial identity and distribution of sand features depends on knowing the most critical dynamic factor affecting them. For this purpose, it is necessary to investigate the relationship of sand effects with the formation of pressure centers in different potentials, which lead to the creation of the wind, monthly, seasonally, and annually, at different speeds. In this article, the location of dunes relative to the centers of pressure and wind speed is evaluated descriptively. By average wind speed and pressure statistics, maps of wind speed and sea level pressure were drawn over thirty years and analyzed concerning the headquarters of the dunes. The wind speed increased from April, especially in the central, eastern, and southeastern regions of the country, and in May, it reaches 5m/s in the Kavir plain. In June, as the pressure decreases, the wind speed increases in all parts of the east and southeast. With the reduction of pressure in the central areas and internal basins, the wind speed and, as a result, the displacement of sand masses reaches their maximum. In September, the conditions for establishing low thermal pressure or cyclone systems are provided in the headquarters of the dunes. However, due to the minor pressure differences between these areas and their surrounding places, the wind speed is lower than the threshold required to move materials. In the cold seasons, due to the establishment of anticyclonic systems, the wind speed decreases and reaches below the material movement threshold.

In order to develop knowledge about the consequences of perceived greenwashing in the tourism industry, the present study aims to investigate the effect of this phenomenon by tourists on achieving green marketing goals (improving green trust in the brand, green word-of-mouth advertising, green brand image, green ethical commitment, green behavioral tendencies, green satisfaction, green purchasing behavior, green loyalty, and perceived green quality) in eco-lodges. Partial least squares structural equations were used to analyze the data. A statistical sample was selected by a simple random method from the tourists visiting eco-lodges in Isfahan province. The findings showed that perceived greenwashing has the most negative effect on green satisfaction, perceived green quality, green brand image, green brand trust, green word-of-mouth advertising, green ethical commitment, green loyalty, behavioral tendencies, and green purchasing behavior. Therefore, it is expected that along with supporting green tourism businesses and encouraging the adoption of sustainable practices, the issue of greenwashing will be increasingly monitored and legislated. It is also essential that eco-resorts consider the compliance of their performance and environmental commitments beyond a mere regulation and consider the impact of their environmental liability on various aspects of marketing. In order to achieve their marketing goals, review their environmental commitments, identify the existing perceptual and functional gaps and the causes of their occurrence, and take the necessary measures to eliminate them.

Rare Earth Elements (REEs) include a wide range of technological applications due to their unique catalytic, magnetic, and optical properties. The environmental pollution of REEs has increased significantly as a result of their widespread use. Gadolinite, xenotime, samarskite, euxenite, fergusonite, itrotantalite, itrotungstite, and itrialite are minerals that mainly contain yttrium and HREEs. Bastnasite, monazite, allanite, luparite, ansilite, parasite, lanthanite, schwinite, cerite, stylolite, britolite, fluosite, and cerianite are minerals that mainly contain LREE. However, commercial mines around the world mainly extract bastnasite, monazite, and xenotime. This research aims to evaluate the concentration of rare earth elements in the Songun copper mine and their economic and environmental potential. For this purpose, microscopic studies and chemical analyses were performed on the collected samples. Apatite, zircon, carbonate minerals, clay minerals, rutile, sphene, sericite, sausorite, opaque minerals, epidote, limonite, and mullite are among the minerals that have the potential to host rare earth elements in the intrusive mass of Songun copper mine. The average amount of cerium (79 ppm), europium (1.41 ppm), lanthanum (38 ppm), neodymium (29 ppm), and praseodymium (8.47 ppm) in the intrusive mass rocks of Songun copper mine have increased compared to the average amount of crustal rocks. Also, the average amount of dysprosium (2.05 ppm), erbium (1.01 ppm), gadolinium (3.28 ppm), scandium (5.7 ppm), samarium (3.87 ppm), terbium (0.4 ppm), yttrium (7.3 ppm), and ytterbium (0.6 ppm) have decreased compared to Clark's value. REEs include the following important groups based on the cluster analysis diagram: yttrium, ytterbium, erbium, scandium, and terbium; gadolinium, samarium, and dysprosium; neodymium and praseodymium; cerium and lanthanum.

Rivers are one of the most important sources of surface water in the world. The purpose of this research is to investigate the contamination of Karaj River sediments with heavy metals using sediment quality indices, evaluate the effects of pollution on the environment, and provide solutions to reduce pollution and its aftereffects. To achieve this goal, the sediments of the Karaj River bed were sampled at nine stations, and the total concentration of heavy elements in the samples was measured by the ICP device. Eventually, the sediment quality indicators for each of the metals were analyzed separately. The results showed that the Karaj River suffered little pollution in terms of bed sediment contamination with heavy metals, but the role of human activities in producing this amount of pollution cannot be neglected. Urban and rural activities, as a result of their effluents and sewage leaking into the river environment, construction and road construction projects in the region, land use changes in the river's boundaries and margins, and the people's lack of awareness in the region regarding the environmental effects of metal pollution. Inadequacy in proper education and culture in relation to tourism and environmental protection are among the destructive and polluting human factors in the area of Karaj River, which caused an increase in copper contamination up to 2.36 as well as the Pollution Load Index to the point of 0.76 in downstream stations.

Polycyclic aromatic hydrocarbons (PAHs) with their teratogenicity, mutagenicity and carcinogenic characteristics can pose health risks for humans. Therefore, this study was conducted to determine the content and health risk assessment of PAHs in indoor dust samples of some office buildings in city of Isfahan in 2023. In so doing, a total of 84 indoor dust samples were collected from 28 sampling stations. After extraction of the analytes, the gas chromatography/mass spectrometry (GC–MS) method was used to determine the PAHs concentrations in the dust samples. Based on the results obtained, 16 priority PAHs were detected and quantified in the dust samples. The mean values of ∑16PAHs were found to be 9838 µg/kg. Total incremental lifetime cancer risks (ILCRs) of children and adults with average values of 1.06E-01 and 9.36E-02, were both classified in the 'high critical value' category. The cancer risk levels via dermal contact (5.89E-02) and direct ingestion (4.72E-02), indicated that both pathways greatly contributed to the cancer risk for children. Similarly, the risk value of dermal contact (5.99E-02) and direct ingestion (3.37E-02) were found to be important routes that adults could be exposed to contaminated dust with PAHs. Accordingly, the mean values of ILCRs ranked in the following order: dermal contact > direct ingestion > inhalation for both cases (i.e., children and adults). In conclusion, to maintain the health of both the man and the environment, it is recommended that regular and periodic analyses of these pollutants in different environmental matrices including soil, sediment, indoor and outdoor dusts, particulate matter, air, and water be performed to help prevent exposure risks of PAHs.

Decision theory in the gray environment has found wide application in all areas of knowledge. The goal of gray decision-making is to build an advanced predictive model of a system based on data obtained from multiple sensors or independent experts. Multi-criteria optimization methods, trade-off solutions, gray TOPSIS, multi-branch gray decision-making, distance-from-mean evaluation methods, and comprehensive fitness evaluation methods are among the most important techniques in decision theory in a gray environment. One of the most important considerations when planning and implementing a wastewater treatment plant is selecting the best treatment process. This article first collected data by preparing a questionnaire and interviewing subject-matter experts, and then used the evaluation method based on distance from average (G-EDAS) and comprehensive suitability evaluation method (G-COPRAS) to select the best wastewater treatment system. Based on the three criteria “technical”, "economic,” and “environmental-social” and their sub-criteria, the results indicate that, according to experts, the conventional activated sludge system was selected as the best wastewater treatment system in both processes. In addition, the gray hierarchy technique (G-AHP) was used to determine the most important sub-criteria. Based on this technology, resistance to hydraulic shocks has emerged as the most important sub-criterion.

Evaluating the bioavailability of heavy metals and determining the effective parameters of bioavailability play a key role in the management and remediation of contaminated soils. In various land uses with different soil properties (physical, chemical, and biological), there were different factors affecting heavy metals' bioavailability. The present study was conducted in order to investigate the relationship between the heavy metal’s bioavailability with the physical, chemical, and biological properties of soil in agricultural, industrial, and urban land uses in Arak city. One hundred surface soil samples were randomly collected from these three land uses, and their physical, chemical, and biological parameters were measured. By statistical methods, soil properties were compared for agricultural, industrial, and urban land uses. The correlation between heavy metal bioavailability and soil properties was calculated using Spearman's test. Based on the obtained results, there was a statistically significant difference between different land uses in terms of CEC, microbial respiration, CaCO3 and organic matter (p<0.05). Also, there was a statistically significant difference between different land uses in terms of the bioavailability of cobalt, manganese, zinc, copper, nickel and lead and the total amounts of copper, lead and zinc (p<0.05). In agricultural land use, clay percentage, soil pH and EC; for industrial land use, EC, the percentage of clay, sand, silt, carbonate, organic matter, CEC, and microbial respiration, and in urban land use, the percentage of silt, organic matter, microbial respiration, carbonate, CEC, and EC have a significant correlation with the metal’s bioavailability. In all three investigated land uses, EC has a significant correlation with the bioavailability of heavy metals and EC is an effective parameter in all three land uses. Meanwhile, EC, CEC, soil texture, microbial respiration, carbonate, and organic matter are effective parameters in the bioavailability of heavy metals in different land uses and these parameters should be managed in order to remediate the contaminated soils. For this purpose, considering the negative correlation between carbonate and pH and the bioavailability of heavy metals, it is possible to suggest the use of lime for the remediation of the studied soils.