# Honey as a Bioindicator: Pollution's Effects on Its Quality in Mining vs. Protected Sites
###### Abstract  
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. honey; quality; metal cations; antibacterial and antifungal properties; statistics  
safety of honey, reflecting the local ecological status [4]. Honey is regarded as a complex bioindicator of environmental contamination, particularly in mining-affected areas, as the foraging activity of honeybees facilitates their direct and prolonged exposure to airborne and soil-associated pollutants [5]. Honeybee health is also increasingly compromised by a combination of biotic (parasites, pathogens) and abiotic (pesticides, pollutants, and climate change) stressors. These stressors can weaken bees' innate immune systems, increasing their vulnerability to infections and environmental hazards [6]. Modern strategies to protect colony health aim to reduce exposure and support immune resilience through natural compounds and innovative technologies [7]. Globally, the number of bee colonies has increased by approximately 85% over the past six decades, surpassing 100 million hives according to the FAO [8]. However, this positive trend has been overshadowed by the intensification of industrial and urban pollution, which exposes bees and bee products to increasingly higher concentrations of particulate matter, pesticides, fertilizers, industrial emissions, heavy road traffic, and various atmospheric deposits [9]. Bees are increasingly exposed to environmental contaminants, especially in urban and industrial areas, where air pollution is intense. One of the most important sources of contamination is particulate matter (PM\({}_{10}\) and PM\({}_{2.5}\)), which can carry heavy metals such as lead, nickel, cadmium, and arsenic. These particles settle on the leaves and flowers of plants, where they are then unintentionally collected by bees along with nectar and pollen [10]. The transport of airborne dust containing heavy metals and their deposition onto plant leaves is intensified in areas affected by mining activities, where the lack of vegetation promotes wind erosion. These particles can be carried by wind over considerable distances and may settle on the surfaces of leaves and flowers, which, due to their morphology, more easily retain atmospheric particles [11].