Research Article
Trace Element Soil Quality Status of Mt. Cameroon Soils
Veronica E. Manga,
1
Christopher M. Agyingi,
2
and Cheo E. Suh
2
1
Department of Environmental Science, University of Buea, Buea, Cameroon
2
Department of Geology, University of Buea, Buea, Cameroon
Correspondence should be addressed to Veronica E. Manga; ebotmangav@gmail.com
Received 15 April 2014; Revised 27 August 2014; Accepted 8 September 2014; Published 23 September 2014
Academic Editor: Wayne Stephenson
Copyright © 2014 Veronica E. Manga et al. his is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
he concentrations of Cu, Co, Zn, Ni, V, and Cr in topsoils at six sites located along the lower slopes of Mt. Cameroon were assessed
for their potential toxicity to humans and the ecosystem. Soils were collected from horizons down to a depth of 70 cm and analysed
for trace element concentration by ICP-MS technique. he Dutch soil quality standards which use %clay/silt and organic matter
content to derive target values were used to assess the contamination levels of the soils. he content of these soils was also compared
to the United Kingdom ICRCL “soil trigger” values. Zinc and Cu values were persistently below the normal value (A) and occurred
in the lower elevation, the region of extreme weathering, while Cr and V values were above the intervention (C) values. he high
content of Cr in common fertilisers poses a potential risk in toxicity in the higher elevations experiencing lower weathering rates,
where soil Cr levels are elevated.
1. Introduction
Many trace elements are essential macro- and micronutrients
for humans, plant growth, and the maintenance of healthy
ecosystems. Micronutrients like Cu, Mn, Se, and Zn can
be toxic at high concentrations in the soil. Trace elements
unknown to be essential to plant growth, such as barium
(Ba), cadmium (Cd), chromium (Cr), lead (Pb), and nickel
(Ni), are toxic at high concentrations or under certain
environmental conditions in soils. One of the major factors
controlling soil trace element content is the parent rock
material. Soils vary across landscapes and rock weathering
and other soil-forming processes may result in the addition
or removal of these elements from the soil. High background
concentrations of trace elements, whether from natural or
anthropogenic sources, could result in mobilization and
release into surface and subsurface waters and subsequently
incorporation into the food chain. Soil factors such as organic
matter, type and amount of clay, pH, and cation exchange
capacity (CEC) inluence the quantity of trace elements
available for mobilization and release or sorption in a soil [1].
Regulations to protect humans and the environment
from toxicities and deiciencies related to trace elements are
primarily based on soil quality reference values which are
being developed in many countries. Many countries that
have not developed their own formal guidelines follow the
“Dutch standard” to support decision-making in assessing
and monitoring soil quality. he Dutch are improving their
soil quality in light of new scientiic work particularly with
regard to the impact of listed substances on living species
and ecosystems [2]. Two values are particularly important
in decision-making in regulating trace metals in soils. hese
are the target value (the A-value, the normal or natural level)
and the intervention value (the C-value the clean-up level)
[3]. Cameroon has not started working on soil standards;
consequently, any level of information that can serve as
indicators remains of immense importance in the fertile
areas of Mt. Cameroon for reasons such as (i) identiication
of particular elements for further research on TE (trace
elements) and health and (ii) identiication of target soils
(spatial) for further studies. he present study examines the
potential risks associated with selected trace elements in the
Mt. Cameroon region. he bulk concentration of selected
trace metals (Cu, Co, Cr, Ni, Zn, and Pb) in surface soils in Mt.
Cameroon is compared with world averages, ICRCL (UK)
“trigger” values for open space, and the Dutch standard for
assessing soil contamination.
Hindawi Publishing Corporation
Advances in Geology
Volume 2014, Article ID 894103, 8 pages
http://dx.doi.org/10.1155/2014/894103