The first line of defence against these pro-oxidants is called epithelial lining fluids. From your nose to the tip of your lungs the cells are covered with thick mucous linings. The epithelial cells also have cilia, which form a very fine brush. The brush border sweeps back outside the inhaled foreign particles which may include bacteria and viruses. The mucous, cilia and underlying epithelia form first line of defence and is extraordinary effective in preventing infections. The natural protection of lungs is so effective that most of the time these pollutants do not come in contact with the epithelial line. All these work together to neutralize all the pollutants we inhale and thus protect underlying lung tissue. Vitamin C is the most prominent anti oxidant in this protective fluid lining. It is not only an important antioxidant in this fluid but also has the ability to regenerate the other essential components (Vitamin E and Glucothione).
Exposure to airborne pollutants can overwhelm the antioxidant system found in this protective lining. When this happens an inflammatory immune response occours. The fluids in the lining of the lungs become very thick as the immune response attracts in many white cells that attack the invading pollutants. Initially invaders are quickly cleared out but later on an inability to to terminate or control the inflammatory response can cause marked damage to the lung tissue and impair function. The chronic inflammation is the lung causes significant fatigue and a depleted immune system. Researchs conducted over the past decade has since deduced that the underlying cause of aasthma and many chronic lung disease is the result of oxidative stress.