**1. Introduction**

In environment, most of organometallic compounds were found as persistent that do not easily decompose but are easily concentrated and are highly toxic, often more toxic than their elemental form Refs. [1, 2]. These compounds could be characterized as they have a metal or metalloid-carbon bond. Usually the bonds in them are covalent and are reached between soft acid metals and soft ligands. In environment, their fate and pathways occur through interactions with other chemicals and biota from the environmental compartment, their cycling and pathways between multiple environmental compartments and phases are physically, chemically, and biologically mediated [3].

Concerns considering organometallic compounds are accentuated also by that once they accumulate in different environmental compartments can inhibit their functioning and consequently

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affect the ecosystem, plants, and other living organisms (micro and macro), and also contaminate the food chain (including that of humans) [4–6].

As natural components of the Earth's crust and resultant of biogeochemical reactions, organometallic compounds are generally present at low concentrations in natural environmental compartments, as soil or water, but extensive anthropogenic activities over the past 50 years (industrial, mining, agricultural, and urban-extension activities) have greatly increased their inputs in different compartments of our surrounding environment; thus,their presence is becoming a severe problem at worldwide level [7–10].

Among all compartments, soil plays an important role in the distribution and fate of organometallic compounds, since often it serves as a major reservoir and sink of these pollutants due to its large absorption capacity [11, 12]. In the terrestrial and aquatic environment, metals occur in both organic and inorganic forms, including elemental forms, salts, and organometallic compounds. In most cases, the mineral form of metals is insoluble thus rendering these species rather unavailable for transport or plant uptake in the short term [5].

Inorganic species are adsorbed onto soil organic matter and/or metal oxides which can be subjected to biogeochemical processes (e.g., reduction, oxidation, methylation, alkylation, and biomethylation) resulting in highly mobile organic species that further have the ability to form water-soluble complexes in living organism body tissues thus increasing the potential for uptake and accumulation by organisms [13, 14]. Moreover, bond formation between methyl, ethyl, or alkyl groups and metals or metalloids cause changes in their physical properties as solubility or volatility, properties that could significantly affix their fate, pathways, and life cycle both in the original environmental compartment and between interconnected environmental compartments. The rates of all these processes depend greatly on the local conditions, which exist in the relevant ecosystem and the microbial activity, as the pollutant's leaching rate strongly depends on its specific geochemical properties [15, 16].
