Tests on human subjects in Boston in 1965 and 1966, following the era of atomic bomb testing, revealed average quantities of about 2 pCi of plutonium radioactivity in the average person. How many disintegrations per second does this level of activity imply? If each alpha particle deposits 8 * 10^-13 J of energy and if the average person weighs 75 kg, calculate the number of rads and rems of radiation in 1 yr from such a level of plutonium.

Radioactivity refers to the process by which unstable atomic nuclei lose energy by emitting radiation. The activity of a radioactive substance is measured in curies (Ci) or picocuries (pCi), where 1 Ci equals 3.7 x 10^10 disintegrations per second. To find the number of disintegrations per second from a given activity level, one can convert pCi to disintegrations per second using this conversion factor.

When radioactive decay occurs, energy is released in the form of radiation, which can be quantified in joules. The energy deposited by radiation in biological tissues is measured in rads, where 1 rad equals the absorption of 0.01 joules of energy per kilogram of tissue. The rem is a unit that accounts for the biological effect of radiation, factoring in the type of radiation and its impact on human health.

To calculate the total radiation exposure over a period, such as one year, one must consider the continuous activity of the radioactive source and the energy deposited per disintegration. By determining the total number of disintegrations in a year and converting that to energy absorbed by the body, one can then express the result in rads and rems, providing a comprehensive understanding of the potential health risks associated with the exposure.