Rodríguez-Rodríguez et al. (2026) investigate whether the use of Sargassum-based biofertilizer in tomato cultivation introduces trace element contamination into tomato fruit, given that Sargassum seaweed can contain elevated levels of heavy metals including arsenic, cadmium, lead, nickel, and chromium. The study reports ICP-OES and ICP-MS measurements of As, Cd, Pb, Ni, and Cr in tomato fruits from greenhouse experiments comparing Sargassum biofertilizer-treated and control (conventional fertilizer) plots.
Key numbers
All five metals — As, Cd, Pb, Ni, and Cr — were below the limit of quantification (LOQ) in tomato fruits from both the biofertilizer-treated and control groups. This finding indicates that even when Sargassum biofertilizer with its known heavy metal load is applied to the soil, the transfer of these metals into the edible fruit tissue of tomato is negligible under the study conditions. The metals were measurable in the Sargassum material and in the soil, but fruit-to-soil transfer appeared to be effectively blocked or diluted below detection.
Methods (brief)
ICP-OES and ICP-MS for multi-element trace analysis. Tomato fruit tissue, wet weight. Spanish greenhouse trial conditions. Comparison of biofertilizer and conventional fertilizer treatments. The key finding is the complete absence of detectable As, Cd, Pb, Ni, and Cr in the fruit even under Sargassum application, suggesting the tomato fruit matrix is a low-risk pathway for these metals even when the soil amendment source contains them.
Limitations: Single-location greenhouse study; Spanish conditions; number of samples and LOQ values not confirmed from abstract content; generalizability to field conditions or higher-application-rate scenarios is uncertain.
Implications
Certification: Supports the interpretation that fresh tomato fruit is a low-risk matrix for heavy metals Pb, Cd, As, Ni, and Cr under conventional and biofertilizer-amended growing conditions. Relevant for products containing tomato or tomato-derived ingredients.
Courses: Illustrates the soil-to-fruit transfer question for seaweed-based biofertilizers — a topic of growing importance as circular agriculture practices expand. The below-LOQ result for all five metals in the fruit is a notable finding for risk communication.
App: Reinforces near-zero contamination estimates for fresh tomato fruit for Pb, Cd, tAs, Ni, and Cr. Supports existing lower-risk positioning of tomato compared to root vegetables or leafy greens.