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The aim of this study was to assess probabilistic human health risk due to ethnobotanical usage of Avicennia officinalis , Porteresia coarctata and Acanthus ilicifolius . The study was conducted at the tannery outfall near Sundarban (Ramsar wetland, India) mangrove ecosystem  affected by potentially toxic elements (Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn). Total metal concentrations (mg kg -1 ) were considerably higher in the polluted rhizosphere namely, Cd (1.05–1.97), Cu (36.3–38.6), Cr (144–184), Hg (0.04–0.19), Mn (163–184), Ni (37.7–46.4), Pb (20–36.6), and Zn (97–104). Ecological risk index indicated low to moderate ecological risk in this site, whereas the ecological risk factor showed high potential ecological risk due to Cd pollution. BCR Sequential extraction of metals showed more exchangeable fraction of Cd (47–55%), Cr (9–13%), Hg (11–13%), and Pb (11–15%), at the polluted site. Mercury, though present in trace amount in sediment, showed the highest bioaccumulation in all the three plants. Among the toxic trio, Hg showed the highest bioaccumulation in A. officinalis , Cd in P. coarctata but Pb has the lowest bioaccumulation potential in all the three species. Occasional fruit consumption of A. officinalis and dermal application of leaf, bark of A. officinalis (antimicrobial), A . ilicifolius (anti-inflammatory, pain reliever when applied on wounds) indicated negligible human health risk. However, long-term consumption of P. coarctata (wild rice variety) seeds posed health risk (THQ>1) both in adults and children age groups. This study concludes that nature of ethnobotanical use and metal contamination levels of the mangrove rhizosphere can impact human health. The transfer process of potentially toxic elements from rhizosphere to plants to human body should be considered while planing pollution mitigation measures. Graphical Abstract

Usage of native plant species for traditional medicine or nutritional supplement is a popular practice among various cultures. But consumption of plants growing on polluted soil can cause serious human health hazard due to bioaccumulation of toxic heavy metals. Present study deals with the ecological and human health impact of heavy metals, in six native plant species with ethnobotanical significance growing at the largest chromite mine of India. Exchangeable, oxidizable, reducible and residual fractions of the metals in plant rhizosphere were analyzed. Only 2–6% of total Cr (270–330 mg/kg) and Ni (150–190 mg/kg) at the mining site is bioavailable. Cd showed highest bioavailability (~ 60%) in mining site posing very high ecological risk (1055–5291) followed by Ni (1297–2124) and Cr (309–1105). The heavy metals in the shoot of the targeted plants were about 0.7 to 80 times higher than the standard limit as per Indian statutory body. The total hazard quotient (THQ) by the consumption of plants growing in mining region was very high (> 1) and varied from 2.6 to 5.9 in adult and 0.6–1.3 in children, while in non-mining region the THQ of same plants indicates low risk (< 1). This study indicates THQ (adult) in the order of, Euphorbia hirta (5.9) > Calotropis procera (4.9) > Argemone mexicana (3.6) > Vernonia cinerea (3.5) > Pteridium latiusculum (3.4) > Tridax procumbens (2.6) through consumption pathway growing in mine soil. This study concludes that consumption of plants growing in heavy metal polluted soil should be avoided due to their potential health hazard.Graphic abstract

Sundarban is the world’s largest mangrove wetland. This study, conducted in 2016, to compare blue carbon sequestration with different natural metapopulations and a four-year-old Avicennia marina (30% area)-Rhizophora mucronata (70% area)-mixed mangrove plantation under anthropoganic stress. The aims of the study is to find out the variations in soil ecological function indicators (pH, electrical conductivity, bulk density, soil texture, available nitrogn, phosphorus and soil organic carbon) and key ecological service indicator (soil blue carbon pool) between sites. Simpson’s Index of dominance, diversity and Shannon-Weiner Index revealed that all the sites are under ecological stress, with the Suaeda maritima-dominated mudflat having the least biodiversity. It is also revealed that pH and electrical conductivity were highest in Suaeda maritima and Phoenix padulosa-dominated metapopulations, whereas organic carbon was the highest under the mangrove plantation and Avicennia marina-dominated site. Available nitrogen was recorded highest in the community with the Sonneretia sp.-Avicennia marina association. The mixed mangrove plantation had the highest blue carbon pool. The species diversity was not found to be related with the distance from the nearby conserved mangrove forest, contrary to the island biogeography theory. This study concludes with a recommendation of mixed mangrove plantations to restore the degraded saline mudflats along the human settlements across the globe.

Phosphorus (P) is an important nutrient for terrestrial ecosystems like grassland and plays a critical role in influencing primary productivity and hence ecosystem dynamics. The deposition of airborne dust, particularly from arid and semiarid regions, has been recognised as a significant source of phosphorus input in distant ecosystems. The study area, the Banni grassland, is a semiarid ecosystem with a unique geological history that has experienced degradation for various natural and anthropogenic reasons. It is located in the arid tract of western India. Soil samples were collected from 10 × 10 km grid locations in the grassland before, 48 h after, and 20 days after a cyclonic storm, Biparjoy, which hit the region in June 2023. Statistical analyses (Shapiro‒Wilk normality and Kruskal–Wallis H test) were performed on the data to assess the differences in phosphorus concentrations in terms of PAC (Phosphorus Activation Coefficient) among the phases. To examine the long-range transport of dust-borne phosphorus and its subsequent deposition in the target grassland, we employed an interdisciplinary approach that integrated satellite imagery and ground-based measurements. Spatial and temporal variations in dust emissions were assessed using satellite remote sensing data, while ground truthing was performed for phosphorus content analysis using standard protocols. The aerosol data from MERRA-2 for the past 40 years were used to examine the relationships between aerosol concentrations and wind direction and speed. Our findings revealed that the Middle East, North Africa, and Thar Desert significantly contributed to phosphorus deposition in the target grassland during specific seasons. The SW cyclone ‘Biparjoy’, which followed the same track of aerosol loading (MENA), made landfall in this zone (June 16, 2023) and affected the P depositional patterns. The pre-cyclone, post-cyclone and 20 DAC (days after cyclone) had AP values of 15.15, 22.54 and 24.06, respectively. However, the TP values were 45.81 ± SE = 1.73, 60.95 ± SE = 1.39 and 61.98 ± SE = 1.40, respectively. The highest TP values were in phase 3 (20 DAC phase) (61.89 ± SE = 1.40). Similarly, the transformation of locked forms of P to bioavailable forms was coincidental with higher PSM (Phosphate Solubilising Microorganisms) in soil samples. Dust storms and other atmospheric circulation patterns were found to play pivotal roles in facilitating the long-range transport of phosphorus-laden dust particles from these source regions to the target grassland. Ultimately, our research contributes to the broader understanding of global nutrient cycling and land‒air interactions, enabling informed decision-making for the conservation and sustainable management of terrestrial ecosystems.

Sundarban is the world’s largest contiguous mangrove forest but is under threat from anthropogenic interventions. Plantations are the favored method to restore degraded mudflats. In this study, ecological functional soil indicators (available N, soil organic C, available P, salinity) and service (Blue carbon pool) of the iteroparous tree Avicennia marina (Forssk.) Vierh. (Acanthaceae family), plantation has been compared with a natural mudflat dominated by mangrove semelparous grass Proteresia coarctata (Roxb.) Tateoka (Poacease family). Both sites were under anthropogenic pressure. It was observed that the P. coarctata dominated natural site has gone through fluctuations in species population between 2012 and 2016 with higher Simpson’s dominance, and lower value of the Shannon–Weiner Index. A one-way Analysis of Variance (ANOVA), Principal Component Analysis (PCA), indicated that soil indicators have significantly varied and linearly increased across the years at the A. marina plantation site. Blue carbon pool increased by four times (10 cm soil depth) at the plantation site since 2012 compared to only one time in the mangrove grass dominated community within the study period (2012–2016). This study concludes that plantation with iteroparous mangrove species can improve ecosystem function and services at degraded mudflats dominated by semelparous grass and aid in achieving the Sustainable Development Goal 13 (Climate action).

Climate change-induced frequent cyclones are pumping saline seawater into the Sundarbans. Fani, Amphan, Bulbul, and Yaas were the major cyclones that hit the region during 2019–2021. This study represents the changes in the soil parameters, mangrove biodiversity and zonation due to the cyclone surges in the Indian Sundarbans between 2017 and 2021. Increasing tidal water salinity (parts per thousand) trends in both pre-monsoon (21 to 33) and post-monsoon (14 to 19) seasons have been observed between 2017 and 2021. A 46% reduction in the soil organic blue carbon pool is observed due to a 31% increase in soil salinity. Soil organic blue carbon has been calculated by both wet digestion and the elemental analyzer method, which are linearly correlated with each other. A reduction in the available nitrogen (30%) and available phosphorous (33%) in the mangrove soil has also been observed. Salinity-sensitive mangroves, such as Xylocarpus granatum, Xylocarpus moluccensis, Rhizophora mucronata, Bruguiera gymnorrhiza, and Bruguiera cylindrica, have seen local extinction in the sampled population. An increasing trend in relative density of salinity resilient, Avicennia marina, Suaeda maritima, Aegiceras corniculatum and a decreasing trend of true mangrove (Ceriops decandra) has been observed, in response to salinity rise in surface water as well as soil. As is evident from Hierarchical Cluster Analysis (HCA) and the Abundance/Frequency ratio (A/F), the mangrove zonation observed in response to tidal gradient has also changed, becoming more homogeneous with a dominance of A. marina. These findings indicate that cyclone, climate change-induced sea level rise can adversely impact Sustainable Development Goal 13 (climate action), by decreasing organic soil blue carbon sink and Sustainable Development Goal 14 (life below water), by local extinction of salinity sensitive mangroves.

Exposure to potentially toxic elements (PTE) from various sources seriously threatens the ecosystem in the modern era. Fly ash produced from coal and solid waste combustion contains a high concentration of PTE. Fly ash is a major by-product of coal-based thermal power plants and municipal solid waste incineration units. Due to the high demand for fly ash reuse due to its unique properties, fly ash is now in demand for manufacturing of various building materials and geo-liner for landfills. Brick is the primary building material used in construction. Fly ash bricks are very popular nowadays due to their low cost and high durability. This study reveals the ecological risk index through the exposure of heavy metals in fly ash reported in various studies. Results indicate extremely high ecological risk mainly due to Cd content in fly ash followed by Hg, As, Cu, and Pb. Fly ash is one of the causative agents for several diseases affecting the nervous system, skin, circulatory system, digestive system, reproductive system, and immune responses in the human body.

This study is on the outskirts of the rapidly growing city of Jaipur, located in the semiarid region of India and gateway to the ‘Great Indian Thar’ desert, and focused on potentially toxic elements (PTE) pollution in the farmlands around the city. Concentrations of PTE, along with associated soil parameters such as pH, available nitrogen, organic carbon, phosphorus, and potassium, were estimated in agricultural soil samples near an industrial region on the outskirts of the capital city of the largest state of India. The PTE concentrations in the soil were in the following order: Mn > Pb > Ni > Cr > Cu > Cd. Soil pollution indices, such as the geochemical accumulation index (Igeo), contamination factor (CF), and ecological risk index (ERI), indicated that the soil was moderately to highly polluted. The result of BCR extraction techniques showed Cd is found mainly in the exchangeable and residual fractions, Pb, Mn were found in the reducible as well as residual fractions, while other PTE were mostly bound to residual fraction. All other PTEs are primarily found in the residual fraction, tightly linked with the silicate lattice of soil minerals. Multivariate analysis and the Pearson correlation matrix indicate a common source apportionment for Pb and Cd. Cd, and Pb concentrations in agricultural soil indicate ecological harm that warrants immediate attention and policy-level intervention.

ABSTRACT The recent estimates suggest that South Asia is the least urbanized region in the world, however, Pakistan is one of the most urbanized countries in this region. Rural-urban migration is considered the main cause of urbanization and an inherent part of economic development process. Therefore, this study examines the determinants of rural-urban migration in Pakistan and utilizes two waves of Labour Force Survey of Pakistan (2006 and 2018). The study finds that there are various determinants of migration such as age, gender, marital status and education but higher levels of education appear to be important determinants of migration. This finding suggests that migration decision is positively linked to the human capital embodied in the individual. Therefore, policy makers should focus on the provision of higher education institutions. So, people may contribute to their own development as well as to the development of the country.

This study accessed the levels of Cd, Cr, Fe, Mn, Ni, Pb and Zn concentration in soils of different locations (mine, roadside, agricultural and control sites) of Sukinda chromite mine (the India’s largest Chromite mine and listed among the world’s ten most polluted regions). Geo-accumulation (Igeo) index indicates that the mine, agricultural and roadside soils are ‘heavily to extremely contaminated’ due to Cr, Ni, Pb and Cd, hence human residing/working in this region can have health hazards due to contaminated soil via different exposure pathways. The concentration of heavy metals (mg/kg) in mine site vary between 52.35 and 244.8 (Cr6+), 12,030.2 and 31,818.6 (Cr3+), 5460.4 and 8866.0 (Ni), 70.02 and 208.6 (Pb), 0.95 and 5.3 (Cd), 209.1 and 360.4 (Mn), 21,531.8 and 28,847 (Fe) and 221 and 349.3 (Zn). Fe, Cr6+, Cr3+ and Ni concentration in soil follows an order of mine site > road sites > agricultural lands > control forest sites. Principal component analysis and hierarchical cluster analysis indicate Cd, Cr, Fe, Ni and Pb as major pollutants in the region. Cancer Risk is ‘high’ in both adult (5.38E−04) and children (4.45E−04) in mining sites and ‘low’ to ‘very low’ in agricultural and road side soils. The hazard index for all the heavy metals in a mining areas is varied from 2.9 to 5.2 in adult and 2.8–5.1 in children, indicating ‘high’ to ‘very high’ non-cancer risk due to significant contribution of Ni, Pb and Cr6+ concentration (73, 11 and 10%, respectively).