Transfer from what to what are you interested in? Feed to animals? Water to air? Soil to Water?. Please give more info.

what environmental systems do you mean to investigate transfer factor of heavy metals in? for example , transfer factor of heavy metals in the aqueous system mostly depends on hydrogeochemical condition of the system which is controlled by pH, Eh, Salinity, other ions, Oxidation state of metals, adsorption by Clay-sized particles having free electrons and negative loads on their surface, etc. then please describe the meaning of your question.

Hi

http://www.sciencedirect.com/science/article/pii/S016041201400258X 

doi:10.1016/j.envint.2014.08.010

Physico-chemical variables alter species of metallic compounds and influence transfer to a great extent, like nasty DJ is transferred from CU to PU by financial corruption factor

Please let us know the medium / matrix in which you want to know the metal transfer. In water medium, the physico-chemical parameters affect the transfer. All those chemical parameters which can affect the solubility or can affect the ionization potential will certainly affect the transfer factor of the metals.