Intro Env. Engineering

$3$rd ed$.$ problem $4\mathrm{.}11$:Exposure to Cosmic

radiation increases with increasing altitude. At sea level, it is

about $40$mrem$/$yr$,$ whereas at the elevation in Denver it is about $120$

mrem$/$yr$.$ Using the radiation potency factor of $1$ death per $8000$

person$-$rems.b$)$ estimate the

incremental cancer deaths per year caused by the elevated cosmic

radiation exposure in Denver $($pop$.\mathrm{.}57$ million in $2006)$ Compare

that incremental death rate with with the expected cancer deaths

per year at the typical U$.$S$.$ rate of $189$ per $100,000$ per yearc$)$ how long would an

individual have to live in Denver to cause an incremental cancer

risk of $10^-6($compared with sea level$)?$d$)$ If all $300$ million

Americans lived at sea level estimate the total cancer deaths per

year caused by cosmic radiationAnswers: b$)8$

deaths$/$yr$,$ expected $1077$ cancer deaths a year c$)0\mathrm{.}1$ yr d$)1500$

deaths a yearHow do I solve the

problem to get to these correct answ