Abstract:
Welding is a fabrication process used to join materials, usually metals that
generates a complex airborne mixture of metal fume, other particulates and gases.
This study aims at simultaneous estimation of chromium and nickel in biological
samples of stainless steel welders and risk estimation of physical and chemical
hazards at workplace. Eight physical hazards are identified at two working sites which
are temperature, noise, electrocution, slip/trip/fall, fire, confined works area,
ventilation and ergonomics during a walk through survey. Both of the sites were
found to be at high risk with respect to these hazards. Atomic absorption spectroscopy
(AAS) was used for the estimation of Nickel (Ni+2) and Chromium (Cr+6) in the
biological fluids of fourteen (14) welders at the chosen sites. The concentrations are
found to be as follows: Urinary Ni and Cr at site one (1) 0.009-0.0385μg/mL and
0.001-0.0103μg/mL and blood Ni and Cr 0.012-0.031μg/mL and 0.001-0.0085μg/mL
respectively, whereas at site 2 concentrations of Ni and Cr in urine are 0.001-0.009
μg/mL and 0.001-0.002μg/mL and that in blood Ni and Cr are 0.019-0.029μg/mL and
0.001-0.0032μg/mL respectively. Concentrations of Ni and Cr in majority of the
individuals were greater than the prescribed reference values for healthy individuals.
Correlations are calculated between age and the levels of Ni and Cr in the biological
fluids. All the correlations had positive values varying from insignificant 22% to
positive and strong value of 74%. The correlation of urinary Ni with age, however,
revealed a negative 26% correlation at site one (1). Moreover, the urinary
concentrations of Cr and Ni were found to be more than that of blood but the risk
factors are observed to be reverse since urine is an excretory product hence the trace
metals are eliminated each time an adult urinates contrary to the case of blood which
is a non-excretory essential fluid. Therefore, the workforce was declared to be at a
potent level of risk with respect to trace metal concentrations in blood, and on a
potential to lower level of risk with respect to the urinary metal concentrations.
