Question

Man-made radio-active element $Sr^{90}$ accumulates in the body through
A. Air
B. Food Web
C. Water
D. Contaminated Soil

Answer 1

The Strontium-90 is an isotope of Strontium. Sr-90 was one of the main components in the Chernobyl disaster. It can occur naturally, which could be non-toxic and non-radio-active or can be the result of various human activities.

Complete answer:
Strontium-90 can be found almost everywhere in small amounts as a resultant product from the nuclear incidents or spread due to nuclear explosions. It can be absorbed by the humans while consuming food or water, or by accidentally consuming soil or dust particles containing Sr-90.
The major part of Sr-90 in dietary is available to humans through dairy products, grains or leafy vegetables. It is mostly consumed through ingestion and most of it gets out of the body through egestion, but if any remains get dissolved in bones.
Strontium-90 is also known as bone seeker as it possesses similar chemical properties with calcium. Sr-90 gets deposited in bones or bone-marrow. The internal exposure of the Sr-90 could lead to cancer in bones, soft tissues located near bones and leukaemia.
Thus, our answer is option B, as in the world each kind of species is somehow exposed to Strontium-90 because of its nature, which can pass from one to another in the form of a food chain.

Note:
Sr-90 is the major product of nuclear fission. Nuclear fission is a process of breaking up of atom nucleus in two or more new nuclei. The half-life of Sr-90 is approx. 28-29 years. The Sr-90 can vary with the age in humans because of metabolism in bones.