The researchers' quest did not stop at mathematical calculations of the cell numbers. They comprehensively studied the indicators of normal cell functioning. They found that here also all was not well. Rather, far from it. The urban population was found to have 178 per cent more iron deposits in am over its rural counterparts, pointing towards a possible damage of red blood cells that carry oxygen to the different body parts from the lungs. For this also, the worst affected were those exposed to vehicular emissions -- they had 43 per cent of iron-laden am compared to 37 per cent of those exposed to combustion fumes.
Acid phosphatase (acp), a type of enzyme that helps the am digest foreign substances, was found to be 11 times higher among the urbanites as compared to the rural residents. Again, those exposed to vehicular emissions showed highest levels of this enzyme. Although this finding seems to follow from the fact that exposure to pollution causes greater secretion of this enzyme, the scientists found a rider -- a number of am cells were already seen to be disintegrated.
Elastase, an enzyme that damages connective tissues, was found to be almost 12 times higher in the am of the urban group than the rural one, and again highest in the group exposed to vehicular pollution. Under normal circumstances, production of this enzyme by am is negligible. However, air pollutants stimulate production and release of elastase by am. (See Image)
The study also indicated changes in the life cycle of am. While the death of the cells is largely regulated by genes (a process called apoptosis), certain environmental factors also influence the happening. It was found that traffic-related air pollution catalysed apoptosis of am. Moreover, this process was thrice as fast in urban areas compared to rural areas.
According to the researchers, such findings show that the body's natural resistance crashes like a house of cards when faced by air pollution, particularly toxic vehicular fumes. "Although the defence mechanism of the lungs is activated when exposed to high levels of air pollution, it only serves to compound the problems, even leading to genetic disruption," says Twisha Lahiri. The study recounts a gloomy story about intense suffering and slow death, and this is not just Kolkata's story.