Journal of Animal Science and Veterinary Medicine
Volume 2. Page 72-78. Published 18th May, 2017
ISSN: 2536-7099. Article Number: JASVM-20.03.17-046
www.integrityresjournals.org/jasvm/index.html
Full Length Research
Assessment of heavy metals in body muscles/organs of
locally reared poultry in cocoa and non-cocoa
producing areas of Cross River State, Nigeria
Williams, Mary Emmanuel
1*
, Igile, Godwin O.
2
, Usoro, Ofoninyene Okon
1
and Offiong, Edem
1
1
Department of Animal Science, Akwa Ibom State University, P.M.B. 1167, Uyo, Nigeria.
2
Department of Biochemistry, University of Calabar, Calabar. Nigeria.
*Corresponding author. Email: mw189742@gmail.com. Tel: +234 8034062727.
Copyright © 2017 Williams et al. This article remains permanently open access under the terms of the Creative Commons Attribution License 4.0,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received 20th March, 2017; Accepted 11th May, 2017
ABSTRACT: There is a growing concern about the impact of increased used of Agro-pesticide on public health and
safety issues especially in farming community who pursue high agricultural productivity. Pesticide pollution is a subject
of global concern and the extent of its poisoning is considered to be grossly under estimated. This study was conducted
to assess the concentration of heavy metals (Cd, Pb, Hg, Cr, As and Ni) in muscle, liver, kidney and lungs of matured
locally reared chickens. Sampling was carried out in two cocoa producing areas (Ikom and Etung) and non-cocoa
producing area (Odukpani) in Cross River State, Nigeria, over a period of one year (November, 2013 to October, 2014).
Determination of heavy metals was carried out using Atomic Absorption Spectrophotometer (ASS). Highest levels of
cadmium (0.11±0.02 μg/g) and lead (0.26±0.11 μg/g) were recorded in liver simples from Etung and Ikom. The highest
levels of chromium concentration (2.95±0.05 μg/g) was observed in kidney of chickens from Etung, while nickel (1.16-
±0.0404 μg/g) was highest in lung samples from Etung and Odukpani recorded the highest nickel concentration values
(1.16±0.04 μg/g). The results show that higher levels of heavy metals can accumulate in the body tissues/organs of
chickens in cocoa producing area. These are no exception since Etung is a cocoa producing area and the metals were
found highest in kidney and lungs of chicken from this area. Generally, livers and kidneys were found to have the highly
significant (P<0.5) levels of the metals than the muscles and lungs the lowest. However, the concentrations of all the
metals studied were within the tolerance limits with exception of chromium and nickel which were respectively higher
than their 0.10 μg/g and 0.5 μg/g tolerance limit. The results obtained in this study will be useful in formulating guidelines
and standards for heavy metals in chicken products in cocoa-producing and non-cocoa producing areas of Nigeria.
Key words: Bio-accumulation, local chicken, tissues, organs.
INTRODUCTION
Cocoa business includes cocoa farming, cocoa seed
processing, warehousing and export. This cocoa value
chain processes is sustained with the application of
various pesticides right from (pre and post-harvest)
inception of cocoa industry in Nigeria, including cocoa
producing areas of Cross River State. Unsafe use of
pesticides has been shown by various studies to be
detrimental to livestock, environment and particularly the
food chain including crops, man and other animals.
Unregulated use of pesticides can generates persistent
organic pollutants (POPS) and leaves pesticide residues
in the environment (Asogwa and Dongo, 2009).
Most pesticides contain heavy metals including those of
global concern such as mercury (Hg), cadmium (Cd) and
chromium (Cr). Others include lead (Pb), Arsenic (As)
and Iron (Fe). These heavy metals are generally known
to elicit deleterious metabolic and endocrine response in
man and animals and also interact adversely with mineral
element to reduce their bioavailability in human nutrition
(Johnson, 2004). Baykov et al. (1996) and Demirezen
and Uruc (2006) indicated that contamination with heavy
metals is a severe health hazard since they are toxic, bio
accumulates and biomagnify in the food chain.
Furthermore, the accumulation of heavy metals varies