Increase of Histamine Concentration in the Sputum of Exposed Workers a Case-control Study

Background: The key aim of this study was to determine the relation between possible changes in the lung function and the concentration of histamine in the sputum of exposed workers and control group. The research aimed to establish possible correlation between participants exposed to air pollutants at workplaces, especially participants who are smokers and non-smokers, workers in industrial - mining basins and mines. This case-control study assessed the COPD risk attributable to occupational exposures among mine workers.

Methods: The participants in this case control study included 420 workers out of which 60 represented the control group. The study determined, histamine concentration in the sputum, pH, arterial partial oxygen pressures (PaO2) and carbon dioxide (PaCO2) in capillary blood and, spirometric parameters FVC/FEV1 using "Godart" pulmo-test model spirometer. Airways resistant (Rt) and intrathoracic gas volume (ITGV) were measured using a ‘Siemens’ model Body Plethysmograph. Specific resistance (SRt) was calculated using the formula (SRt=Rt x ITGV). Qualitative exposure indicators were developed based on both, work duration and exposure histories.

Results: Histamine presence in sputum was at a significant level (F=10, 59, p<0.0001) just for the whole group of exposed workers compared to the control group. However, significant values were found for the smokers’ category only in the case of Leposavić participants, respectively at the level (p<0.05). Apparently the obtained values for partial pressures at level PaO2 (F = 13,387, p<0.001) and PaCO2 (F = 10,79, p<0.001), where the lowest value of PaO2 was at participants of Leposavić basin, namely 8.91 kPa, whereas the highest was at the control group, RS 10.04 kPa (SD5.3). PaCO2 was also the lowest to the workers in Leposavić, 4.53 kPa (SD2.6), while the highest was in Ajvalia 5.01 kPa (SD5.4). Hence we consider that these findings are not just casual but they are rather in a direct correlation with increased values of histamine in sputum of the participants. At the same time spirometric parameter values were at a significant level [Tiffneau Index (p<0.001), FEV1 (p<0.0001), SRt (p<0.0001)]. Hence, these results suggest that histamine might participate in the pathogenesis of functional disorders in exposed workers.

Conclusions: Mine workers are at increased risk for COPD as a result of broad and complex effects of many exposures acting independently or interactively. Control methods should be implemented to prevent workers’ exposures, as well as smoking cessation should be promoted. “Hermetization” of technology processes, which is currently a world trend in “dirty” technologies, practically disables pollutants' emission at working places and the atmosphere.