Examination of honeys and flowers as soil element indicators

Honey Bee Products as Bio Indicator of Heavy Metals Pollution and Health Risk Assessment Through the Consumption of Multifloral Honey Collected in Azad Kashmir, Pakistan

The study assessed the health risks associated with heavy metal ingestion and explored the use of honey bee products as a bio-indicator for heavy metal pollution. All honey bee products tested showed heavy metals, but some honey samples had concentrations exceeding permissible limits for Cd, Pb, Ni, and Cr. The mean concentrations of heavy metals (mg/kg) in the honey, propolis, bee wax, and bee pollen were Fe (1.32) > Zn (1.31) > Pb (0.46) > Ni (0.18) > Cr (0.16) > Cu (0.14) > Co (0.12) > Mn (0.05) > Cd (0.03), Fe (8) > Zn (1.13) > Mn (0.59) > Pb (0.13) > Ni (0.07) > Cu (0.06) > Co (0.05) > Cr (0.03) > Cd (0.02), Fe (1.31) > Pb (0.41) > Ni (0.407) > Zn(0.25) > Mn (0.12) > Co(0.10) > Cu (0.07) > Cr (0.05) > Cd (0.002), and Fe (2.2) > Zn (0.75) > Ni (0.25) > Pb (0.16) > Cu (0.05) > Mn (0.045) > Co (0.04) > Cr (0.01) > Cd(0.002), respectively. Similarly, the mean concentration of heavy metals (mg/kg) in the soil, flowers and pine pollen was Fe (539.08) > Zn (89.53) > Mn (66.91) > Ni (58.5) > Co (19.2) > Cr (11.42) > Pb (6.58) > Cu (5.71) > Cd (0.19), Fe (3.12) > Zn (0.95) > Mn (0.72) > Ni (0.29) > Cu (0.16) > Cr (0.14) > Pb (0.059) > Co (0.057) > Cd (0.003) and Fe (2.59) > Zn (1.75) > Mn (0.43) > Pb (0.34) > Co (0.1) > Cr (0.07) > Cu (0.06) > Cd (0.039) > Ni (0.03), respectively. The atomic absorption spectrophotometry procedure was validated through a recovery study and achieved accuracy through the limit of detection (LOD) and limit of quantification (LOQ). The mean Bio concentration factor (BCF) indicated that the transfer from soil to honey was higher than from soil to flower. The metal pollution index (MPI) of the selected indicators was in descending order: soil > honey > flowers > propolis > pine pollen > beeswax > bee pollen. The hazard quotient (HQ) and hazard index (HI) were below one, showing no chronic health risk. The carcinogenic risk (CR) of Cd, Cr, and Ni in honey for children, male and female adults for the consumers exceeds the acceptable level, making Cd, Cr, and Ni the most concerning heavy metals in honey. The study suggests that regular monitoring of heavy metal pollution is essential.

Honey Bees and Associated Matrices as Biomonitors of Soil Trace Elements: Assessment of their Sensitivity in a Regional Rural Environment

Honey bees (Apis mellifera L.) represent a random biosampler integrating pollutants over space and time. An effective biomonitor for trace element (TE) pollution should provide a linear response to TE levels in the environment. However, uncertainties in detecting TEs originating in soil limit their use. To address this, nine experimental sites with multiple apiaries were established in the Upper Palatine Forest, Czech Republic. The soils surrounding the hives were characterized by estimations of the pseudototal and (bio)available pools of TEs. Our study aimed to (1) quantify the linear relationships between soil TE indices and TE contents in bees, bee bread, honey, and wax, and (2) verify the biobarrier function protecting honey from TE contamination. Lead (0.046-0.140 µg g-1 ) and nickel (0.12-4.30 µg g-1 ) contents in bees showed strong linear correlations with (bio)available Pb (0.012-0.254 µg g-1 ) and pseudototal Ni (17.1-36.4 µg g-1 ) in soil (Pearson's r = 0.95 and 0.88, p < 0.005), providing high spatial resolution. A weaker, insignificant correlation was observed for chromium (Cr; r = 0.65) and vanadium (V; 0.44), while no correlation was found for cadmium (Cd). However, the lack of associations for Cr, V, and Cd may result from the low soil TE levels in the region, negligible differences among the majority of sites, and temporal concerns related to different time scales of the biomonitors, impacting the linear model's sensitivity. Biochemical traits in bees, such as the biobarrier function, and different bioavailability of TEs from ingested matter may affect the matrix-to-matrix transfer of TEs in an element-dependent manner. Consequently, the linear response of bee-related biomonitors to TE levels in the environment may significantly deteriorate. Environ Toxicol Chem 2024;43:288-298. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Graphical Discrimination of New Zealand Honey from International Honey Using Elemental Analysis

This study investigated the potential of utilising the elemental fingerprinting of honey to differentiate New Zealand (NZ) honey from that of international origin. Twenty elements were analysed by ICP-MS in 352 honeys from 34 various countries. Of these, 323 honeys (245 New Zealand honeys, 78 international) and two subsets of data (NZ and European origin, n = 306, and, NZ and Denmark/Germany, n = 280) were visualised using principal component analysis (PCA). For the NZ/Europe subset, 42.2% of data was explained in the first two principal components. Statistical classification rules were also derived using linear discriminant analysis (LDA) and decision tree analysis. Various combinations of elements were explored for classification, considering the effect of soil-derived elements and those from anthropogenic sources. A high degree of accuracy (at least 90%) for the characterisation of New Zealand honey was observed for all statistical models, showing the robustness of these analyses. When using decision tree analysis to distinguish New Zealand samples from international samples, a tree with five terminal nodes (using Cs, Ba and Rb) was created with 92.4% accuracy. This work has demonstrated that elemental fingerprints of honey are a promising tool for categorising New Zealand honey from other geographical locations.

Chemical Elements and the Quality of Mānuka (Leptospermum scoparium) Honey

Soil properties in the foraging range of honeybees influence honey composition. We aimed to determine relationships between the antimicrobial properties of New Zealand mānuka (Leptospermum scoparium) honey and elemental concentrations in the honey, plants, and soils. We analyzed soils, plants, and fresh mānuka honey samples from the Wairarapa region of New Zealand for the chemical elements and the antimicrobial activity of the honey as indicated by methylglyoxal (MGO) and dihydroxyacetone (DHA). There were significant negative correlations between honey MGO and the concentrations of Mn, Cu, Mg, S, Na, Ba, K, Zn, and Al. These elements may provide a low-cost means of assessing mānuka honey quality. For individual elements, except for K, there were no correlations between the honeys, plants, and soils. Soil nitrate concentrations were negatively correlated with concentrations of MGO and DHA in the honey, which implies that soil fertility may be a determiner of mānuka honey quality.

Honey authentication using rheological and physicochemical properties

The aim of this study was to evaluate the influence of honey botanical origins on rheological parameters. In order to achieve the correlation, fifty-one honey samples, of different botanical origins (acacia, polyfloral, sunflower, honeydew, and tilia), were investigated. The honey samples were analysed from physicochemical (moisture content, fructose, glucose and sucrose content) and rheological point of view (dynamic viscosity-loss modulus G″, elastic modulus G', complex viscosity η*, shear storage compliance-J' and shear loss compliance J″). The rheological properties were predicted using the Artificial Neural Networks based on moisture content, glucose, fructose and sucrose. The models which predict better the rheological parameters in function of fructose, glucose, sucrose and moisture content are: MLP-1 hidden layer is predicting the G″, η* and J″, respectively, MLP-2 hidden layers the J', while MLP-3 hidden layers the G', respectively. The physicochemical and rheological parameters were submitted to statistical analysis as follows: Principal component analysis (PCA), Linear discriminant analysis (LDA) and Artificial neural network (ANN) in order to evaluate the usefulness of the parameters studied for honey authentication. The LDA was found the suitable method for honey botanical authentication, reaching a correct cross validation of 94.12% of the samples.