What is the minimum age that individuals can purchase tobacco legally in the u. s.?

The minimum age to purchase tobacco legally in the U.S. depends on what each state allows.

The states that allow individuals to purchase tobacco legally at the age of 21 includes: Hawaii. Although, the city of Cleveland in Ohio has banned the sale of tobacco until the age of 21. New York City has also banned the sale of tobacco until the age of 21.

The states that allow individuals to purchase tobacco legally at the age of 19 includes: Alabama, Alaska, New Jersey, and Utah.

The states that allow individuals to purchase tobacco legally at the age of 18 includes: Arizona, Arkansas, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, North Dakota, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, Washington, Washington, D.C., West Virginia, Wisconsin, and Wyoming.

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases. 

20 times a minute is usually the average respritory rate of an adult. additionally the patient is breathing on his own, is clearly maintaining his airway, and is intaking a sufficient amount of air. you shouldn't use a bag valve mask, cpap, or other form of positive pressure ventilation, unless the patient has lost control of his airway, and is not breathing (apneic) or has rapid breathing or slow and shallow respirations. this patient would most likely and should be put on an non-rebreather mask or nrb attached to 100% high flow oxygen at 15 l/min. don't use a nasal cannula, as the amount of oxygen it provides is limited with a rate of 6 l/min.