European Journal of Scientific Research - EuroJournals

Toxicokinetic Studies of Cadmium and Zinc in Goats Following Intratracheal and
Intravenous Administration of Particulate Matter 349
Introduction
Particles in the atmosphere make up the most visible and obvious form of atmospheric pollution. They
are made up of an amazing variety of materials and discrete objects that may consist of either solid or
liquid droplets (Stanley,2005). Exposure of population to these dusts through inhalation is therefore of
environmental concern as particulates often lodge and exert chronic effects on the lungs.
Elemental contents of suspended particulate matter from Maiduguri, Nigeria have been
determined (Ogugbuaja and Goni, 1999; Ogugbuaja and Barsisa, 2001, Moses et al.,2007). These dusts
show appreciable high levels of heavy elements. Biological systems possess mechanisms for
absorption, transportation, storage and excretion of elements. This helps to keep the level in the body
optimal. It is important therefore to understand the distribution of trace elements in biological systems
as elements are known to accumulate in the blood and tissues. (Schwartz,1977). Cadmium (Cd) is a
naturally occurring metallic element that is used for electroplating and galvanization processes, in the
production of pigments, batteries and as a chemical reagent (ATSDR, 1989) It is a known carcinogen.
Zinc is an essential element in the nutrition of human beings, animals, and plants. It is required in the
genetic make-up of every cell and is an absolute requirement for all biologic reproduction (O’Dell,
2000). Its accumulation in the body is harmful.
It has been recognized that measurement of the circulating concentration of metals and their
metabolites can provide useful information on the magnitude and duration of exposure of possible sites
of toxicity (Rosenstock, 2004). Such information on the toxicokinetics of elements provides an
understanding of the extent of absorption, distribution and the pathways and rates of elimination. This
study therefore, was undertaken to add to the knowledge in this area.
Methodology
Collection of dust samples
The study was conducted in Maiduguri, Nigeria. The dust collection technique was carried out
according to the method described by McTainsh and Walker (1982). The technique is designed to
measure the amount of suspended dust falling to the ground from the atmosphere. Samples were
collected from low and high density areas of the town. Sampling was done twice weekly for each
location for a period of one year, pooled and used for subsequent studies.
Experimental animals
The Forty-three (43) adult healthy Sahel goats of both sexes were used for the studies (blood kinetics,
10; tissue kinetics, 30; control, 3). The goats were fed with green leaves and husk of grains and water
was provided ad libidum.
Blood Kinetic Study
Ten adult Sahel goats of both sexes were used. The goats were apparently healthy at the onset of the
experiment. The goats were separated randomly into two equal groups. One group was treated with the
dust sample in phosphate buffered saline (PBS) solution intratracheally at the dose of 50mg/kg body
weight, while the other group was treated with the same dose intravenously. The intravenous
administration was done through the left jugular vein using a syringe and needle. All blood samples
were collected through the right jugular vein.
Sample Preparation
Fifteen minutes before the administration of the dust sample, blood samples were collected as control
from the goats. Following dust, blood samples were again collected at 0.25, 0.5, 1, 2, 3, 4, 6, 8, 12, 18,
24, and 36 hours. All blood samples were collected into plain bottles and allowed to clot. The clotted