What does this radioactivity equation mean?

My lecturer gave me the following solution to an equation; 2x10^9Bq x 5.3x10^6eV x 1.6x10^-19 x 86400s all divided by 70kg (avg m of man). All equals 0.8Gy. What is he working out?? And how?? Sorry, very vague. If somone can find the formula to this I'd be very happy.