Pollution in mining areas represents a major environmental issue, significantly impacting ecosystems and human health. This study highlights propolis as an efficient natural bioindicator for detecting and assessing the degree of contamination in these areas. The objective of this study is to determine the levels of metals (Pb, Cd, As, Cr, Fe, Mn, Cu, and Zn) in propolis from mining exploitation areas in Romania, specifically in the counties of Alba, Hunedoara, Maramureș, and Caraș-Severin. Although mining operations are closed, the anthropogenic impact varies due to differences in the surface areas of the zones affected, the areas occupied by waste heaps, local hydrological conditions, and partial ecological rehabilitation efforts. To highlight the impact of contamination, a reference area considered unaffected by anthropogenic activities was used as a benchmark for each county. The values obtained in the investigated area were compared with those from this control zone to determine the differences and the specific impact of pollution. Maximum values were recorded in Roșia Montană for Pb (9.27 mg·kg⁻¹), Cd (0.17 mg·kg⁻¹), and As (0.87 mg·kg⁻¹); in Băile Borșa for Fe (150.23 mg·kg⁻¹) and Zn (2.9 mg·kg⁻¹); in Certeju de Sus for Cu (6 mg·kg⁻¹) and Cr (7.01 mg·kg⁻¹); and in Moldova Nouă for Mn (25.43 mg·kg⁻¹). The maximum content values of phenols (189.49 mg·kg⁻¹ in Alba County) and flavonoids (88.06 mg·kg⁻¹ in Caraș-Severin) were recorded, as well as the minimum IC₅₀ antioxidant activity (0.33 µg·mL⁻¹). Propolis from these areas showed antimicrobial activity against five bacterial strains (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, and Streptococcus mutans) and five fungal strains (Candida albicans, Aspergillus niger, Aspergillus flavus, Cryptococcus neoformans, and Penicillium chrysogenum), although such antimicrobial and antifungal activities were more intense in unpolluted areas. The present study reveals that propolis is a natural indicator of heavy metal pollution in mining areas. These data support the usefulness of propolis due to its high capacity to accumulate and reflect environmental contaminants.

Microplastic pollution has gained attention in recent years due to its adverse impact on the environment. As a major threat to marine ecosystems and biota, the accumulation of microplastics along coastlines has become a growing concern. This study focused on quantifying and characterizing the presence, distribution, and composition of microplastics along the beaches of Romania and Bulgaria. Microplastics were extracted from beach sand samples using a saturated NaCl solution. The particles were then analyzed through FT-IR and DSC spectral analyses to identify their chemical composition. Sampling was conducted across several resorts along the Romanian and Bulgarian coastlines. The findings revealed varying concentrations of microplastics across different beaches, with Romanian beaches showing concentrations of between 40 and 213 particles per sample (470–2500 microplastics/kg), which were notably higher in areas like Mamaia and Costinești. On Bulgarian beaches, the average concentrations reached up to 137 particles per sample (1612 microplastics/kg), particularly in areas like Sunny Beach and Nessebar. Polyethylene (PE) was identified as the most prevalent polymer (55%), followed by polyamide (PA), polypropylene (PP), polyethylene terephthalate (PET), and polyurethane (PU). These polymers were linked to common sources such as packaging, textiles, and industrial products. Microscopic examination, combined with FT-IR and DSC spectral analysis, confirmed the plastic nature of the particles, revealing distinct chemical structures characteristic of each material type. This study underscores the widespread contamination of Romanian and Bulgarian beaches with microplastics, emphasizing the environmental risks to coastal ecosystems. The presence of synthetic polymers highlights the urgent need for policies targeting plastic waste management to mitigate the growing pollution in marine environments.

Contamination with heavy metal ions from mining activities presents a major environmental issue. This study investigates pollution caused by heavy metals from mining, with a particular emphasis on toxic ions and essential ions for living organisms. It starts by analyzing the sources of pollution and its effects on soil, vegetation, water, and wildlife (propolis produced by honey bees living in natural environments). Propolis is an indicator of environmental contamination by metals, a natural and valuable product of natural ecosystems. As part of the investigation, the contamination with metal cations (Pb²⁺, Cu²⁺, Cd²⁺, Zn²⁺, As³⁺, Fe²⁺, and Sr²⁺) of the soil, cultivated vegetables (carrot, turnip, onion, potato) was monitored in 9 points in the Roșia Montană area, Romania, as well as the river that runs through the area. The maximum values of the parameters investigated were recorded in soil (108.32 mg/kg Pb²⁺, 23.06 mg/kg Cd²⁺, 102.17 mg/kg As³⁺), river water (11.00 µg/L Pb²⁺, 903.47 µg/L Cu²⁺, 60.13 µg/L Cd²⁺, 1903.08 µg/L Zn²⁺, 148.07 µg/L As³⁺, 44,024.08 µg/L Fe²⁺), vegetables (0.72 mg/kg Pb²⁺, 0.17 mg/kg Cd²⁺) and it was followed whether the same heavy metals are found in propolis (maximum values 10.14 mg/kg Pb²⁺, 6.32 mg/kg Cu²⁺, 0.158 mg/kg Cd²⁺, 6.0 Zn²⁺, 1.04 mg/kg As³⁺, 12.06 mg/kg Sr²⁺). The parameters analyzed for the river waters were pH, sulfates, the oxygen and nutrient regime, and microbial load. Additional investigations were carried out into the quality of these propolis samples: water activity, moisture, hygroscopicity, water solubility, volatile oils, oxidation index, measuring point, density, dry matter, material insoluble in ethanol, extractable with ethanol, ash, and wax. The highest values were 189.4 mg GAE/g for phenols, 84.31 mg QE/g for flavonoids, and 0.086 µg/mL for IC₅₀ antioxidant activity. This study indicates that bee products, such as propolis, can be an indicator of pollution in mining areas.

Heavy metal toxicity is an ecological concern in regions affected by processes like mining. This study underscores the potential of honey as a natural bioindicator for monitoring and assessing the levels of environmental contamination in mining-impacted areas. The study evaluated the physico-chemical characteristics, heavy metal content, and antimicrobial activity of honey samples collected from areas adjacent to former mining sites, as well as from protected areas within the same county in Romania. The results revealed significant differences between the two categories of locations. The samples from the protected areas showed higher levels of bioactive compounds (phenols and flavonoids) and exhibited stronger antibacterial activity. The heavy metal analysis indicated significantly higher concentrations of lead, cadmium, and iron in the honey samples from former mining areas compared to those from protected zones, suggesting pronounced industrial-origin contamination. The maximum recorded values were for Pb (0.607 mg/kg), Cd (0.02 mg/kg), Fe (12.131 mg/kg), Cu (0.545 mg/kg), and Zn (6.170 mg/kg). Their antimicrobial activity was tested against several bacterial and fungal strains, including Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Listeria monocytogenes, Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, Rhizopus stolonifer, Fusarium oxysporum, and Alternaria alternata. The antibacterial and antifungal activity were more pronounced in the honey samples from the protected areas. These findings support the use of honey as a bioindicator of environmental quality and highlight the influence of its geographical origin on its therapeutic and chemical properties.

Mining activities have a significant impact on the quality of river water in the Roșia Montană area. This region, known for its gold and other precious metal mining, serves as an example of the interaction between anthropogenic activities and the natural environment. Water from mine drainage is metal-rich and contaminates the environment, inhibiting the growth and reproduction of aquatic plants and animals, while also having corrosive effects on infrastructure. As part of the study, parameters such as pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, sulfates, and heavy metals were monitored for the rivers in the area (Roșia Montană, Săliște, Corna, Abrud, and Arieș). Roșia Montană river shows a decrease in pH to highly acidic values (2.69–3.95), especially in the downstream sections. Sulfate concentrations exceed 3600 mg/L, and heavy metal concentrations (Fe, Zn, As, Mn) increase significantly, indicating severe pollution, primarily originating from the Gura Mine gallery. These frequently exceed the thresholds corresponding to water quality classes I and II, and in some cases even surpass the limits of class V (the most polluted). The presence of As (27.60 µg/L) in Roșia Montană River indicates a significant ecotoxicological risk. In an attempt to treat the acid mine drainage from Roșia Montană, a natural zeolite was used at different doses. The results obtained show good efficiency of zeolite in removing the metal ions (Fe, Zn, and Mn). The results provide valuable information on the quality of river waters in the mining area of Roșia Montană and suggest that zeolite can be used effectively to decontaminate mine waters.

The valorization of waste materials is essential for sustainability, with used cooking oils (UCOs) offering potential for transformation into valuable functional products. The study investigates the oxidative stability of sunflower and olive oils subjected to high temperatures (160–200 °C) and frying on their physico-chemical properties (acidity, peroxide and iodine value, total polar compounds). Significant deterioration occurred above 180 °C, with increased peroxide and polar compounds and reduced iodine values. A technological process for the purification and saponification of UCOs (sunflower, olive, and palm oils) was developed, demonstrating the potential to transform pollutant waste into a valuable and sustainable product—soap. The incorporation of oregano and thyme essential oils (EOs), identified by GC-FID as rich sources of carvacrol, thymol, p-cymene, and limonene, improved the functional properties of the soaps. The antimicrobial activity of soaps largely relates to their alkaline pH, while the incorporation of EOs contributes to additional antimicrobial effects, obtaining zones of inhibition of up to 10.8 mm against Staphylococcus aureus and up to 7.6 mm against Escherichia coli for palm oil. The study highlights a sustainable approach that transforms waste oils into functional soaps with EOs for added antimicrobial benefits.