Polychlorinated biphenyls (PCBs) are synthetic organic compounds that were widely used in industrial applications throughout the 20th century. Due to their chemical stability, resistance to degradation and ability to bioaccumulate and biomagnify through food chains, PCBs pose long-term environmental and health risks. Due to these characteristics, PCBs have been globally regulated as persistent organic pollutants (POPs), despite being banned from production in most countries decades ago. This study investigates temporal trends in PCB contamination in urban soils of Bucharest over a 20-year period (2002–2022), focusing on six principal congeners (PCB 28, 52, 101, 138, 153, and 180) sampled from 13 locations, including roadsides and urban parks. Gas chromatography and spatial analysis using inverse distance weighting (IDW) revealed a marked reduction in Σ6PCB concentrations, declining from 0.0159 mg/kg in 2002 to 0.0065 mg/kg in 2022, with statistically significant differences confirmed by Kruskal–Wallis analysis (p < 0.05). This decline is primarily attributed to reduced emissions, source control measures, and natural attenuation. However, the persistence of PCBs in localized hotspots is influenced by secondary dispersion mechanisms, such as atmospheric deposition and surface runoff, which redistribute contaminants rather than eliminate them. Health risk assessments via ingestion, dermal absorption, and inhalation routes confirmed negligible carcinogenic risk for both adults and children. Although measurable progress has been achieved, the persistence of localized contamination underscores the need for targeted remediation strategies and sustained environmental monitoring to protect vulnerable urban areas from recontamination.

Urban rainwater is an increasingly important alternative water resource, but its suitability for harvesting and reuse depends on a water quality that varies strongly with local emissions and season—a variability not previously characterised for Bucharest, the Romanian capital. This study addresses that gap by evaluating the physicochemical quality of directly collected rainwater at six contrasting sites (four traffic-influenced, two urban-green) in District 1, Bucharest, over 37 rainfall events sampled between January and November 2025. Samples were analysed for pH, electrical conductivity, turbidity, true colour, total hardness, chloride, inorganic nitrogen species (NO₃⁻–N, NO₂⁻–N, NH₄⁺–N) and trace metals (Zn, Cd, Pb), and interpreted using descriptive statistics, Pearson’s correlation and Principal Component Analysis (PCA). Traffic-influenced sites were consistently more contaminated than urban-green sites, with mean concentrations higher by 47% for electrical conductivity (EC), 64% for cadmium and 67% for zinc. PCA resolved two factors: traffic-related particulate pollution (Cd, Pb, Zn) and secondary atmospheric nitrogen processing. Cadmium reached the World Health Organisation (WHO) indicative guideline, and lead exceeded the European Union (EU) parametric value at traffic sites, while ammonium exceeded 0.50 mg/L in most traffic-site events. These findings show that harvested rainwater quality is strongly site-dependent and that high-traffic locations require targeted treatment before any potable reuse.

Soil salinity is a major environmental constraint that threatens global food security by significantly inhibiting seed germination and early seedling establishment. Salinity disrupts all three phases of seed germination: Phase I (imbibition), where reduced water absorption capacity reduces seed hydration and delays metabolic reactivation; Phase II (lag phase), where ionic toxicity and oxidative stress impair enzyme activity, reserve mobilization, and cellular metabolism; and Phase III (radicle protrusion), where limited cell division and length prevent radicle emergence and seedling establishment. These disturbances reduce germination percentage, germination rate, germination index, germination energy, and plant vigor, while increasing average germination time. At the morpho-physiological level, salinity impairs water absorption, membrane stability, photosynthetic pigment accumulation, and root–shoot development. Biochemically, excessive accumulation of reactive oxygen species (ROS), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) causes cellular damage and metabolic dysfunction. At the molecular level, salinity alters the expression of the aquaporin gene family (PIPs, TIPs, NIPs, and SIPs), suppresses starch mobilization by reducing α-amylase, enhances abscisic acid (ABA) signaling, and inhibits gibberellic acid (GA) biosynthesis, all of which cause inhibition of germination and early growth. As a result, an effective strategy is needed to improve seed germination under saline conditions. Therefore, the second focus of this review is to critically evaluate the potential of nanoparticles (NPs) and nanobiochar (NBC) as emerging tools to mitigate salinity stress during seed germination. Current evidence suggests that NPs and NBC enhance water absorption, maintain membrane strength, improve nutrient availability, promote antioxidant defense systems, and regulate osmotic adjustment in saline environments. Furthermore, these nanomaterials alter key molecular pathways involved in aquaporin expression, hormonal homeostasis, and reserve mobilization, thereby promoting successful germination and seedling establishment. By combining recent advances in physiological, biochemical, and molecular research, this review provides a comprehensive understanding of salinity-induced germination disruption and highlights the potential of NP- and NBC-based approaches to improve crop establishment under saline conditions.