22 páginas, 2 figuras, 5 tablas.-- The final publication is
available at www.springerlink.comBackground, aim, and scope In this work, an environmental
risk assessment of reusing organic waste of differing
origins and raw materials as agricultural fertilizers was
carried out. An inventory of the heavy metal content in
different organic wastes (i.e., compost, sludge, or manure)
from more than 80 studies at different locations worldwide
is presented.
Materials and methods The risk analysis was developed by
considering the heavy metal (primarily Cd, Cu, Ni, Pb, and
Zn) concentrations in different organic residues to assess
their potential environmental accumulation and biotransfer
to the food chain and humans. A multi-compartment model
was used to estimate the fate and distribution of metals in
different environmental compartments, and a multi-pathway
model was used to predict human exposure.
Results The obtained hazard index for each waste was
concerning in many cases, especially in the sludge samples
that yielded an average value of 0.64. Among the metals,
Zn was the main contributor to total risk in all organic
wastes due to its high concentration in the residues and high
biotransfer potential. Other more toxic metals, like Cd or
Pb, represented a negligible contribution.This work was supported by the Spanish
Government (Science and Innovation Ministry) through the Project
INDIE (CTM2010-18893). Marta Herva wishes to thank the University
of Santiago de Compostela for her pre-doctoral contract. Dr.
Amaya Franco-Uría would like to thank MICINN for the support
provided by the “Juan de la Cierva” Subprogram.Peer reviewe
