Refer to Exercise 51. High concentrations of carbon monoxide (CO) can cause coma and death. The time required for a person to reach a COHb level capable of causing a coma can be approximated by the quadratic model 

T = 0.0002x² - 0.316x + 127.9, 

where T is the exposure time in hours necessary to reach this level and 500 … x … 800 is the amount of carbon monoxide present in the air in parts per million (ppm). (Source: Indoor Air Quality Environmental Information Handbook: Combustion Sources.)

(a) What is the exposure time when x = 600 ppm?

(b) Find the concentration of CO necessary to produce a coma in 4 hr. Round to the nearest tenth part per million.

Exercise 51

Carbon monoxide (CO) combines with the hemoglobin of the blood to form carboxyhemoglobin (COHb), which reduces transport of oxygen to tissues. Smokers routinely have a 4% to 6% COHb level in their blood. The quadratic model 

T = 0.00787x² - 1.528x + 75.89 

approximates the exposure time in hours necessary to reach this 4% to 6% level, where 50 … x … 100 is the amount of carbon monoxide present in the air in parts per million (ppm). (Source: Indoor Air Quality Environmental Information Handbook: Combustion Sources.)

(a) A kerosene heater or a room full of smokers is capable of producing 50 ppm of carbon monoxide. How long would it take for a nonsmoking person to start feeling the above symptoms? Round to the nearest tenth.

(b) Find the carbon monoxide concentration necessary for a person to reach the 4% to 6% COHb level in 3 hr. Round to the nearest tenth.