Problem

(Modeling) Solve the problem. See Examples 5 and 6.Indoor Air Quality and Control (See Exe...

(Modeling) Solve the problem. See Examples 5 and 6.

Indoor Air Quality and Control (See Exercise 41.) For nonsmokers exposed to environmental tobacco smoke (passive smokers), R = 1.5 × 103. (Source: Hines, A., T. Ghosh, S. Loyalka, and R. Warder, Indoor Air: Quality &Control, Prentice-Hall, 1993.)

(a) If the average life expectancy is 72 yr, what is the excess lifetime cancer risk from second-hand tobacco smoke per year?
(b) Write a linear equation that will model the expected number of cancer cases C per year if there are x passive smokers.
(c) Estimate the number of cancer cases each year per 100,000 passive smokers.
(d) The excess lifetime risk of death from smoking is R = .44. Currently 26% of the U.S. population smoke. If the U.S. population is 310 million, approximate the excess number of deaths caused by smoking each year.

Exercise 41

(Modeling) Solve the problem. See Examples 5 and 6.

Indoor Air Quality and Control The excess lifetime cancer risk R is a measure of the likelihood that an individual will develop cancer from a particular pollutant. For example, it R = .01 then a person has a 1% increased chance of developing cancer during a lifetime. (This would translate into 1 case of cancer for every 100 people during an average lifetime.) The value of R for formaldehyde, a highly toxic indoor air pollutant, can be calculated using the linear model R = kd, where k is a constant and d is the daily dose in parts per million. The constant k for formaldehyde can be calculated using the formula

where B is the total number of cubic meters of air a person breathes in one day and W is a person’s weight in kilograms. (Source: Hines, A., T. Ghosh, S. Loyalka, and R. Warder, Indoor Air: Quality &Control, Prentice-Hall, 1993; Ritchie, I., and R. Lehnen, “An Analysis of Formaldehyde Concentration in Mobile and Conventional Homes,” J. Env. Health 47: 300–305.)

(a) Find k for a person who breathes in 20 m3 of air per day and weighs 75 kg.
(b) Mobile homes in Minnesota were found to have a mean daily dose d of .42 part per million. Calculate R using the value of k found in part (a).
(c) For every 5000 people, how many cases of cancer could be expected each year from these levels of formaldehyde? Assume an average life expectancy of 72 yr.

EXAMPLE 5

MODELING THE PREVENTION OF INDOOR POLLUTANTS