Trace metal concentrations in soil, leaves, and fruits of red raspberry (Rubus idaeus) cultivated in home gardens.

Red raspberry fruits are widely consumed, and raspberry leaves are used in herbal preparations; therefore, trace-metal occurrence in home-garden plants is relevant to environmental monitoring and food-safety screening. This study characterised Cu, Cd, Pb, Mn, Zn, Ni, and Fe in matched soil, leaf, and fruit samples from Polish sites. Concentrations were determined by flame atomic absorption spectrometry after microwave-assisted digestion. Observations were paired by site and several Cd, Pb, and Ni results were below the method quantification limit (MQL), matrix differences were evaluated with Friedman tests and exact paired Wilcoxon tests, while detection frequencies were analysed separately. Significant matrix effects were found for all elements (Kendall's W = 0.195-0.854). Middle-bound medians for Cu, Mn, Zn, and Fe followed the order soil > leaves > fruits. Quantified-result frequencies differed among matrices for Cd, Pb, and Ni. No targeted soil-plant concentration correlation remained significant after false-discovery-rate correction. Soil pH was negatively associated with the fruit bioaccumulation factor for Mn (Spearman's ρ =  - 0.724, q = 0.004), but not with the other tested factors. For a 100-g portion of fresh raspberries, lower-, middle-, and upper-bound estimates were 0, 2.4, and 4.9 µg for Cd and 0, 13.1, and 26.3 µg for Pb. These estimates are screening scenarios rather than compliance results because moisture was assumed and more than half of the fruit Cd and Pb observations were censored.