Nasal albumin in a population exposed for the first time to urban pollution

High levels of albumin in some biological fluids are generally associated with abnormal process of permeation during an inflammatory response. In some cases, the nasal albumin levels can be used as an indirect molecular marker of epithelial damage.

We carried out an evaluation study of nasal albumin from a population (14 volunteers), exposed for 15 days to high urban pollution (O(3) 10.644 ppm/h average 10.2 h/day) in Mexico City for the first time, and when they returned to their original non-polluted city (Veracruz, State of Veracruz, Mexico) 13 days later. The nasal albumin samples were fractionated by gel electrophoresis techniques, and albumin determination analyses were done by gel scanning. The densitometry values obtained from the albumin-stained bands were compared with an internal standard and the average values compared with other groups used as reference, under conditions of non-polluted and polluted cities.

Our findings showed in the group exposed to pollution for the first time a significant increment 2 days after entering Mexico City urban pollution. They, subsequently, had a progressive recovery 4 days later up to day 13 in their original place of residence. The reference groups for comparison were from a non-polluted city (at sea level on the Pacific Ocean) Manzanillo, Colima, Mexico, and a very polluted urban metropolis (Mexico City). The group showed a significant difference of protein levels about 2.5 higher apparently at the expense of albumin. These populations were permanent residents of environmental conditions we wanted to evaluate. Our approach was to monitor quantitatively the time course of the change of a biochemical parameter in normal mucus from a population never exposed to Mexico City urban pollution.

Our conclusions from this study point out that pollution causes diverse mucosal damage that can be followed by biochemical monitoring.