Increased pulmonary susceptibility to streptococcal infection following inhalation of manganese oxide

Alterations in Macrophage Functions by Environmental Chemicals

“…When these criteria are met, the extrapolation to a similar effect, i.e., increased pulmonary infections occurring in man, becomes reasonable providing the microorganism present is capable of multiplying and invading that host and that the actual dose of the inhaled pollutant reaching these defenses is sufficient to cause an adverse effect. Evidence exists that a number of trace metals which alter either biochemical, physiological, morphological or functional mechanisms of the macrophage also cause a significant increase in susceptibility to infection. Examples of some of the particles that have been shown to cause an enhancement of bacterial pulmonary infection include: Ni2 I, Cd2 +, Zn2 +, Pb2 +, H2SO4 and coal fly ash (35,37,55,62,74,117,132,219,222,225). It is important to note that in many of these studies, dose-response data indicated that an effect could be produced with concentrations similar to those seen in the working environ-ment.…”

“…Exposure to a number of agents reduces the number of free macrophages: lead sequioxide (8), silica (45,50,51), asbestos (50,52), Pb2O3 (8), Sb and Cd fumes (53), MnO2 (54), Mn3O4 (55), 03 (56), chrysotile (57)(58)(59), amosite (60), CdO and CdCl2 (53,61,62), acrolein (63) and NiCl2 (35 100 ,ug/mL but significant cytotoxicity was observed at higher concentrations, > 100 ,ug/mL (60).…”

“…The effects of exposure to NO2 (123,(145)(146)(147), 03 (138,141,(148)(149)(150), S02 (144,151,152), cigarette smoke (5,90,121,137,(153)(154)(155) silica (156), H2SO4 (132), Cd2+ (61,124), alumina (124), Ni2+ (117), Mn2+ (55,157), ethanol (158), PbCl2 (159), and high oxygen tensions (150) have all been investigated using model systems similar to the ones described above. Depressed bactericidal functions has been attributed to exposure to all of these substances except silica, SO2 and 02.…”

Geochemical characteristics of soils in Fezzan, Sahara desert: Implications for environment and agriculture

“…Manganese averaged 865 mg/kg with the maximum concentration up to 9230 mg/kg. Inhalation of airborne Mn compounds could pose a significant health risk (Adkins et al, 1980;Wennberg et al, 1991). The mean concentration of Sr was 231 mg/kg with the maximum concentration as high as 2720 mg/kg.…”

Use of Experimental Airborne Infections for Monitoring Altered Host Defenses

“…Figure 4 illustrates, that with our organism, one can expect that, within the range of2004000 cfu/lung, there is no apparent correlation between number of bacteria deposited in the lung and resulting increase in percent mortality. However, at higher levels of bacterial deposition one can expect that the observed mortality will increase further (6,7).…”