I live at a mile above sea level, and decided to use a spirometer to measure my intake of air. I recorded it at 2500ml, should I be concerned?

Not sure. Not sure what was measured or how correctly it was done. Lung function and capacity is very dependent upon age / sex and height AND not upon altitude. If you measured Vital Capacity AND measured it correctly you may be at the low end of normal. Vital Capacity is not generally measured without a clinical indication. If you have lung symptoms you should see your doc.