Mathematically, the human alimentary tract organs were simplified in the model structure as separate compartments with
pathways of transfer that are kinetically homogenous and equally distributed. The development of gastro-compartment
model follows the first order kinetics of differential equations to describe cadmium absorption, distribution and elimination
in the human digestive system. With the aid of in vitro DIN assay, an artificial gastric and gastrointestinal fluid were
prepared using water leach purification (WLP) residue as a sample that contained toxic metals cadmium. The Simulation,
Analysis and Modelling II (SAAM II) V2.1 software is employed to design models easily, simulate experiments quickly and
analyze data accurately. Based on the experimental inputs and fractional transfer rates parameter incorporated to the
gastro-compartment model, the concentration of cadmium against time profile curves were plotted as the model output.
The curve presented concentration of cadmium in both gastric and gastrointestinal fluid where initially absorption phase
(first hour) occurred followed by the distribution phase (second to third hours) and elimination process (third to fifth
hours). The concentration of cadmium obtained from the simulated model structures was in good agreement with the
fitted model predicted measurements as statistical t-test conducted showed the values were not significantly different.
Therefore, modeling approach with SAAM II software gave realistic and better estimation of cadmium dissolution into
the human gastrointestinal tract.
Electricity has become one of the necessities for human daily activities. The presence of electric
current produces electromagnetic fields (EMF) at extremely low frequency (ELF). The problem arises
when scientists suggests a possible connection between ELF exposure to human health and safety.
Concerned about the safety and health of students and staff, Universiti Kebangsaan Malaysia (UKM)
took the initiative to identify possible ELF sources and measure their exposure in various locations
around the UKM main campus in Bangi. This paper reports the results obtained from the monitoring
of the magnetic flux density at three identified locations in the vicinity of the overhead high-voltage
transmission line which transverses the university compound and compare the maximum value results
with the exposure limit suggested by the International Committee on Non Ionising Radiation
Protection (ICNIRP) for ELF. Measurements were done with an (Extech) Three Axis
Electromagnetic Field (EMF) Meter (Model 430826) to determine the magnetic flux density. The
lateral profile method was applied as the standard measurement methodology. Results showed that the
maximum value of the magnetic flux density was 12.5 mG, which is below the suggested ICNIRP
public exposure limit of 1000 mG, or in percentage ratio, 1.25% of ICNIRP public exposure limit.
Results from the statistical Kruskal-Wallis test showed that there is a significant difference in the
distributions of the magnetic flux densities at the different locations (P < 0.05). In conclusion, the
measured locations are still safe for people in short-term exposure. However, long-term exposure
measurements still need to be done to provide concrete data on the ELF-emission levels in UKM.