Why is it harder to determine exposure to airborne transmitted diseases than exposure to bloodborne transmitted diseases?

Can you stand 8 to 9 hours when you have mild levoconvex lumbar scoliosis? Can gasoline cause a skin rash? After menstruation between which day to how many day there is chance for pregnancy? Does it hurt a girl to get kicked between the legs? What are the symptoms of dysentry? What could be wrong if you have had small movable lumps on the left side of your neck for about a year now with no other symptoms? What is the diasease caused due to sericulture? Will you die if a mole is ripped open? When people of color have portrayed themselves as white in order to get a part in a film many people of color felt that they were? What is too much sugar in urine indication of? Where can you learn CPR? What is the clear body fluid that pays the cells and transports lymphocytes? Can being around flowers cause a sinus infection? How do I find out if im depressed? What are marsh mellows made of? Do you have an under-active thyroid if you had a clot come out then had brown spotting for two weeks then dark maroon blood? Was Chickenpox deadly in the 19th century? What is the fear of exercise called? What leads to increased erythropoiesis? What behavior is Swift satirizing in this excerpt from Gulliver and Travels?