BIOACCUMULATION OF MANGANESE AND ITS TOXICITY IN FERAL PIGEONS (COLUMBA-LIVIA) EXPOSED TO MANGANESE OXIDE DUST (MN3O4)

Manganese tetroxide (Mn3O4) is a product from the combustion of methyl cyclopentadienyl manganese tricarbonyl. Exposure to high levels of man ganese can lead to serious health effects especially to the central ne rvous and respiratory systems. Very few studies on the effects of long -term low level exposure to Mn3O4 have been reported. The present stud y was therefore conducted to examine the bioaccumulation and toxicity of manganese in various organs of feral pigeons (Columba livia) when e xposed to low levels of Mn3O4 via inhalation and hence to find any pos sible relationship between these two parameters. A total of 22 pigeons was exposed to 239 mu g/m(3) of manganese for 7 h/day, 5 days/week fo r 5, 9, and 13 consecutive weeks. Manganese concentrations in various tissues, e.g., brain (mesencephalon), lung, liver, intestine, pancreas , kidney, muscle, bone, and whole blood, were measured by neutron acti vation analysis. Various biochemical parameters in blood, e.g., hemato crit, total proteins, glucose, uric acid, alanine aminotransferase, to tal iron, blood urea nitrogen and triglycerides, were also measured. M anganese concentrations in brain, lung, and bone were significantly hi gher in Mn3O4-exposed pigeons (0.59, 0.58, and 3.02 mu g/g wet tissue, respectively) than in the control group (0.46, 0.19, 1.74 mu g/g wet tissue, respectively). However, except for total proteins such exposur e did not produce any changes in various biochemical parameters which were within the normal values. Thus these results have shown that, des pite significant bioaccumulation of manganese in some tissues, no sign ificant toxic effects could be seen. (C) 1998 Academic Press.