Comparative Mineral Profile and Safety Assessment of Arctic Storm-Cast Macroalgae: Implications for Human Health Risk Evaluation

Storm-cast macroalgae represent a vast, underutilized biomass in the Arctic. This study evaluates the mineral composition, safety, and nutritional potential of storm-cast versus attached macroalgae from the Barents and White Seas to determine their suitability for commercial application. Mineral profiles (K, Na, Ca, Mg, As, Zn, Fe, Cu, Hg, Pb, and Cd) were determined by atomic absorption spectroscopy (AAS), while iodine (I) was analysed via iodometric titration. All elemental data were subsequently evaluated using ANOVA, principal component analysis (PCA), and hierarchical cluster analysis (HCA). Human health risks were assessed via Hazard Index (HI) and Lifetime Cancer Risk (LTCR) models based on the inorganic arsenic fraction. Storm-cast macroalgae exhibited a senescent post-detachment profile characterized by significant potassium and iodine leaching (p < 0.05) and iron enrichment from sediment entrapment. Despite leaching, iodine levels (up to 3.8 mg/g d.w.) satisfied pharmacopoeial minimums, though autumn White Sea samples exceeded the upper limit, necessitating blending with lower-iodine material. Toxic heavy metals remained below quantification limits, and total arsenic was well within regulatory thresholds. PCA confirmed that biomass physiological state is the primary driver of elemental variance. Adult consumption of storm-cast macroalgae was safe, whereas the pediatric HI exceeded 1.0. Overall, Arctic storm-cast macroalgae exhibit a high level of elemental purity, representing a promising raw material with a low chemical health risk for potential functional food and pharmaceutical applications.