Bladeless Fan
Chapter I
INTRODUCTION
Background of the Study
House dust is not simply dirt, but a potent mixture of potentially allergenic materials, which can induce a severe asthmatic attack in prone individuals. Bacteria in household dust can trigger asthma. The greater the exposure to house dust allergens, especially during windy days or during cleaning, the greater is the probability of getting an asthma attack. Their by-products called endotoxins in household dust trigger asthma and asthma related symptoms such as wheezing. Endotoxin exposure worsens asthma symptoms in adults, regardless of whether an individual has an allergy or not. This means that exposure to endotoxin increases asthma risk even in non-allergic individuals. People with asthma have airways that are inflamed. This means that they swell and produce lots of thick mucus. They are also overly sensitive, or hyper reactive, to certain things, like exercise, dust, or cigarette smoke. This hyper reactivity causes the smooth muscle that surrounds the airways to tighten up. A process is set in motion that results in the release of certain substances in the body. One of the substances released is histamine, which causes allergic symptoms that can affect the eyes, nose, throat, skin, gastrointestinal tract, or lungs. When the airways in the lungs are affected, symptoms of asthma (such as coughing, wheezing, or difficulty breathing) can occur. The lungs are constantly exposed to danger from the dusts we breathe. Luckily, the lungs have another function - they have defense mechanisms that protects them by removing dust particles from the respiratory system. For example, during a lifetime, a coal miner may inhale 1,000 g of dust into his lungs. When doctors examine the lungs of a miner after death, they find no more than 40 g of dust. Such a relatively small residue illustrates the importance of the lungs' defenses, and certainly suggests that they are quite effective. On the other hand, even though the lungs can
INTRODUCTION
Background of the Study
House dust is not simply dirt, but a potent mixture of potentially allergenic materials, which can induce a severe asthmatic attack in prone individuals. Bacteria in household dust can trigger asthma. The greater the exposure to house dust allergens, especially during windy days or during cleaning, the greater is the probability of getting an asthma attack. Their by-products called endotoxins in household dust trigger asthma and asthma related symptoms such as wheezing. Endotoxin exposure worsens asthma symptoms in adults, regardless of whether an individual has an allergy or not. This means that exposure to endotoxin increases asthma risk even in non-allergic individuals. People with asthma have airways that are inflamed. This means that they swell and produce lots of thick mucus. They are also overly sensitive, or hyper reactive, to certain things, like exercise, dust, or cigarette smoke. This hyper reactivity causes the smooth muscle that surrounds the airways to tighten up. A process is set in motion that results in the release of certain substances in the body. One of the substances released is histamine, which causes allergic symptoms that can affect the eyes, nose, throat, skin, gastrointestinal tract, or lungs. When the airways in the lungs are affected, symptoms of asthma (such as coughing, wheezing, or difficulty breathing) can occur. The lungs are constantly exposed to danger from the dusts we breathe. Luckily, the lungs have another function - they have defense mechanisms that protects them by removing dust particles from the respiratory system. For example, during a lifetime, a coal miner may inhale 1,000 g of dust into his lungs. When doctors examine the lungs of a miner after death, they find no more than 40 g of dust. Such a relatively small residue illustrates the importance of the lungs' defenses, and certainly suggests that they are quite effective. On the other hand, even though the lungs can