Transfer of potentially toxic metals and metalloids from terrestrial plants to arthropods—A mini review

Potentially toxic metals and metalloids (PTMs) may become a concern to plant and animal health when soil concentrations exceed toxicity limits. These limits are often exceeded in polluted environments (anthropogenic sources) and may transfer through the trophic system, from contaminated soil to plants, and thereafter to herbivores and predators. The aim of this mini review was to consider trophic transfer of PTMs in terrestrial ecosystems, focusing on arthropods as the endpoint. ScienceDirect® was used as search engine with a set of keywords. The most assessed PTMs were Cd, Pb, and Zn, and 63% of all PTMs considered in research were attributed to anthropogenic sources. Industrial or mining sites were most frequently studied, and agricultural sites the least. Brassica was the most studied plant genus as the main extractor of PTMs from the soil as they are easy growing food plants known to take up PTMs. Research mostly focused on primary consumers, with Coleoptera being the most investigated arthropod order, probably because of the diversity of the order and its common occurrence worldwide. Most research was conducted in Europe, while South America and Africa only contributed 6.8% and 2.6%, respectively. The majority of the investigated articles (61%) assessed trophic transfer. From those, only 24% directly measured PTM transfer with experimental trials and included only one trophic level, that is, primary consumers, while 7% of research directly measured PTM transfer across multiple trophic levels (primary and secondary consumers).