Welding fumes composition and their effects on blood heavy metals in albino rats

Toxic substances produced during welding include heavy metals, carbon monoxide, carbon dioxide, and nitrogen oxides. The study aims to evaluate the heavy metals concentration in welding fumes and the blood of the animals exposed to welding fumes. The fumes were collected from a welding site by a skilled welder and part of it was subjected to metals analysis. A total of 130 rats were divided into 13 groups. 12 groups were given doses calculated to correspond to real-life workers exposure regimes and 1 group served as control. The dosages were administered intratracheally after anesthetization weekly for 12 weeks. The animals were sacrificed and whole blood samples were collected for atomic absorption spectrophotometry. The metals in fumes analyzed were decreasing in order of Fe > K > Pb > Co > Cd > Ca > Ni > Mn > Zn > Cr > Al > Cu > Mg. Changes were observed in the behaviour of the test animals compared to the control indicating probable toxicity. The values of Pb, Cr, Fe, Mn, and Ni in the exposed animal's blood were higher than the control and increased relatively across the treatment groups. However, the values of Al and Zn were not significantly different from the control. These indicate that exposure to welding fumes having contained a significant amount of heavy metals has caused noticeable toxicity symptoms with simultaneous elevation in blood metal levels. Monitoring and regulation of these activities should be enforced by relevant authorities in Kano and Nigeria in general.