Jatinder Kaur Katnoria

The increased demand, driven by a growing population and changing dietary habits, has created immense pressure on agroecosystems throughout the globe. In semi-arid areas, this increased pressure has led to excessive use of agrochemicals in agriculture, which poses a threat of potentially toxic metal (PTM) contamination in agricultural soils. PTMs in agricultural soils result in significant environmental and health threats for humans and livestock. The current study aimed to evaluate the risks associated with five PTMs—nickel (Ni), lead (Pb), chromium (Cr), cadmium (Cd), and cobalt (Co)—in agricultural soils of the semi-arid South Punjab region of India. The study area included sites from district Bathinda of Punjab (3385 km²). Among the PTMs analyzed, the concentration of Cd (0.65–1.85 mg/kg) in several agricultural soil samples was above the international permissible limits (1.0 mg/kg). Principal component analysis (PCA) pointed to parent rock materials as the main sources for Cr, Co, Ni, and Pb, while for Cd, agricultural sources (phosphatic fertilizers) can be a prominent contributor. The values observed for Pollution Load Index (PLI: 0.93–1.64) and Ecological Risk Index (RI: 206.66–584.03) indicated that soil samples were significantly contaminated with the tested PTMs, posing considerable ecological risks. Analysis of other physicochemical characteristics showed that soil samples were alkaline and saline, with low levels of soil organic matter. The human health risk assessment pointed to minimal non-carcinogenic (NCR) and carcinogenic risks (CR) associated with the presence of PTMs in the soil. Spatial distribution analysis revealed a higher level of metallic contamination in the eastern part of the district. Thus, adequate steps must be taken to control the increase in levels of these PTMs in the soils of the study area.

The frequent use of electronic devices in daily lives, predominantly reliant on non-ionizing radiation, has increased the prevalence of electromagnetic radiation (EMR) in natural environment. In light of this, effects of EMR at frequencies of 1800 MHz and 2400 MHz characterized by a power of 10.0 dBm (0.01 W), across varying exposure durations of 1 h/day, 2 h/day, 4 h/day, 6 h/day, and 8 h/day for 7 days, in Allium cepa L. were studied. The effects of the treatment on the morphological features (root length, fresh weight, and dry weight of roots) and biochemical characteristics (protein content and antioxidative enzymes, namely, ascorbate peroxidase (APX), glutathione reductase (GR), superoxide dismutase (SOD), glutathione-S-transferase (GST), guaiacol peroxidase (POD), catalase (CAT), and dehydroascorbate (DHAR)) were studied in roots and bulbs of Allium cepa L. Further genotoxicity for different exposure periods at both frequencies was also conducted. Prolonged exposure to electromagnetic radiation (EMR) at both frequencies was found to reduce root length, fresh weight, and dry weight of plant. Furthermore, significant effects were observed on protein content, indicating a reduction with prolonged exposure duration. Investigation into the activities of antioxidative enzymes such as APX, GR, GST, DHAR, CAT, SOD, and POD at a frequency of 1800 MHz and 2400 MHz in roots and bulbs demonstrated a significant enhancement in enzyme activity during 6 h/day and 8 h/day exposure periods. Additional investigation during genotoxicity studies demonstrated the induction of chromosomal aberrations in the root tip cells of the Allium cepa L. plant test system. The current study revealed the initiation of oxidative stress and genotoxicity resulting from long-term exposure to electromagnetic radiation in the studied plant test systems.

Poor air quality in urban areas increases the exposure of individuals to air pollutants. Hence, it becomes mandatory to grow such plant species that have more potential to tolerate air pollution and can aid in its mitigation. Air pollution tolerance index (APTI) and anticipated performance index (API) are two indices that help in scientific evaluation of plant species before recommending them for plantation. In this study, six plant species from three educational institutions of Amritsar city were screened for their tolerance and performance against air pollution as well as for their capability to act as accumulators of nine metals viz., aluminium (Al), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). On the basis of APTI, Cassia fistula (C. fistula) was categorized as a tolerant species while Alstonia scholaris (A. scholaris), Cascabela thevetia (C. thevetia), Monoon longifolium (M. longifolium), Pongamia pinnata (P. pinnata) and Syzygium cumini (S. cumini) were categorized as intermediately tolerant plant species. API results suggested that A. scholaris, C. fistula, M. longifolium, P. pinnata and S. cumini should be planted for air pollution mitigation. Geo-accumulation Index (Igeo) results showed that soil samples were moderately contaminated with three (Pb, Cu and Zn) metals. Bioaccumulation factor (BAF), for all metals among six plant species, was found to be less than one implying that these plants were absorbers of metals. Metal Accumulation Index (MAI) indicated that C. thevetia, C. fistula and P. pinnata exhibited relatively higher potential for metal accumulation.

Plant growth regulators (PGRs) control signaling networks and developmental processes involved in plant responses to various biotic and abiotic stresses, making it crucial to study PGRs in vitro. The protocol for micropropagation of Solanum lycopersicum L., following callus induction and regeneration through explants such as internodal segments, leaves, and nodal segments, was established during the present study. Explants were inoculated on Murashige and Skoog (MS) medium supplemented with different plant growth regulators like BA (6-benzylaminopurine), 2,4-D (2,4-dichlorophenoxyacetic acid), BA + 2,4-D, IAA (Indoleacetic acid), IBA (Indolebutyric acid), and NAA (Naphthaleneacetic acid). It was observed that among all explants, the nodal segment showed maximum callus induction (83.33%) and multiplication (86.67%) at 0.25 mg/l of 2,4-D; the highest shoot number (3.33) at 0.5 mg/l of IAA + 0.5 mg/l of BA; the greatest shoot length (7.57 cm) at 0.75 mg/l of BA; root induction (80.95%), root number (21.88), and root length (10.62 cm) at 1 mg/l of IAA. Additionally, the maximum fresh weight (2.448 g) was observed at 0.5 mg/l of BA, while the highest dry weight (0.172 g) and dry matter content (14.25%) were noted at 1 mg/l of BA + 1 mg/l of 2,4-D for the internodal segment. Results of the present study revealed that among different explants, the best response was given by nodal segments, followed by internodal segments. Among the different PGRs, 2,4-D resulted in the highest callus induction and multiplication percentage.

The current study assessed the effects of lead (Pb), copper (Cu), and nickel (Ni) in roots and shoots on growth indices, the antioxidative defense system, and metal uptake in Solanum lycopersicum L. variety Punjab Kesar Cherry. For 60 days, S. lycopersicum seeds were exposed to varying amounts of three metals (0-100 μM of Cu and 0-60 μM of Ni and Pb). In comparison to the control, the percentage of germination, root and shoot length, and fresh and dry weight of the roots and shoots all decreased, according to the results. The bioaccumulation factor of both roots and shoots, along with the translocation factor, increased at lower concentrations and decreased at higher concentrations; for Pb, on the other hand, the translocation factor increased with increasing concentrations. At 60 μM, the order of the bioaccumulation factor was Cu>Ni>Pb for roots, and Cu>Pb>Ni for shoots. The antioxidative enzyme activities, including ascorbate peroxidase (APX), catalase (CAT), dehydro ascorbate reductase (DHAR), glutathione reductase (GR), glutathione S transferase (GST), peroxidase (POD), and superoxide dismutase (SOD), were increased at lower concentrations and decreased at higher concentrations under Cu, Ni, and Pb treatments. The order of toxicity in terms of decrease in protein content was observed as Pb>Ni>Cu for both roots and shoots.

The present study aims to assess soil quality and potential health risks associated with soil pollution of the Batala region of Punjab, India. Physico-chemical parameters such as pH (6.69–7.43), electrical conductivity (0.17–0.33 mS/cm), and total organic carbon (1.01–5.94%) were observed to be within permissible limits. The maximum mean content (mg/kg) of heavy metals in soil was found as Fe (4060.93), Zn (444.33), Mn (278.5), Pb (23.16), Cu (21.78), Ni (20.16), Co (7.14), and Cd (1.85) which were below the prescribed limits but beyond the geochemical background limits of world soil. For rice grain samples, metal content (mg/kg) was seen as Fe (307.01) > Zn (12.41) > Mn (7.43) > Cu (4.57) and was below the permissible limits. The mean bioaccumulation factor for various metals was in the order as Zn > Cu > Fe > Mn. Single and integrated soil pollution indices revealed that among 18 sites, six were highly contaminated. The ecological risk index (Er) has shown that contamination of soil with Cd, Zn, and Ni was higher than that of other metals studied. The estimated daily intake of metal (EDI), hazard quotient (HQ), and hazard index (HI) were higher for children than those for adults. Spatial variability based on metal pollution load and soil quality was also determined using cluster analysis (CA) and principal component analysis (PCA). During CA, soil samples from 18 sites formed three statistically significant clusters based on the level of metal pollution at the specific site. PCA showed that all variables were reduced into two main components 1 and 2 with eigenvalues as 3.82 (47% variance) and 1.53 (19.7% variance), respectively. Graphical abstract Spatial distribution and source identification of metal contaminants in the soil and rice grain samples: a study on exploration of soil quality and risk assessment

Considering enormous growth in population, technical advancement, and added reliance on electronic devices leading to adverse health effects, in situ simulations were made to evaluate effects of non-ionizing radiations emitted from three cell phone towers (T1, T2, and T3) of frequency bands (800, 1800, 2300 MHz), (900, 1800, 2300 MHz), and (1800 MHz), respectively. Five sites (S1–S5) were selected near cell phone towers exhibiting different power densities. The site with zero power density was considered as control. Effects of radiations were studied on morphology; protein content; antioxidant enzymes like ascorbate peroxidase (APX), superoxide dismutase (SOD), glutathione-S-transferase (GST), guaiacol peroxidase (POD), and glutathione reductase (GR); and genotoxicity using Allium cepa. Mean power density (μW/cm²) was recorded as 1.05, 1.18, 1.6, 2.73, and 12.9 for sites 1, 2, 3, 4, and 5, respectively. A significant change in morphology, root length, fresh weight, and dry weight in Allium cepa was observed under the exposure at different sites. Protein content of roots showed significant difference for samples at all sites while bulbs at sites S4 and S5 when compared to control. Antioxidant activity for root in terms of APX, GST, and POD showed significant changes at S4 and S5 and GR at site S5 and SOD at S1, S2, S3, S4, and S5. Similarly, bulbs showed significant changes at sites S4 and S5 for APX while at sites S3, S4, and S5 for POD and S2, S3, S4, and S5 for SOD and S5 for GR and GST. Genotoxicity study has shown induction of abnormalities at different stages of the cell cycle in Allium cepa root tips. The samples under exposure to radiation with maximum power density have shown maximum induction of oxidative stress and genotoxicity.