radioactive isotopes and pollution

[urza]

so I understand this is a nono for the agriculture industry.

 

or is it that they only apply it to products that are ready to be shipped and not used for "breeding" purposes?

[ecoli]

I wonder if this does anything to the nutritional value of foods?

[jdurg]

People who hear the words 'radiation' and suddenly freak out as if they're going to die because of it, claim that it 'harms the nutritional value of the food' but there has been no solid evidence supporting that claim. Sadly, the vast majority of the public think they know a whole lot about radioactiviyt/radiation but in reality they know very little. As a result, when they hear about their food being irradiated they immediately think that it will glow in the dark and give them cancer.

 

The truth is, it is impossible for their food to become radioactive from the radiation dose it absorbs. In order for something to become radioactive, the nuclei of the atoms inside of it have to change. A gamma ray simply cannot enter a nucleus and cause it to break apart. The copious amounts of electrons on the outside of the nuclei absorb the gamma rays' energy before it can even affect the nucleus. Any alpha and beta radiation is contained within the container of the radiation source.

 

And you are correct urza, the agriculture industry only irradiates the products that are ready to be shipped out to the marketplace. Anything they use to regrow their supply is not irradiated.

[ecoli]

Acutally...I was thinking that the radiation could denature the vitamins and other molecules that provide nutrients. I wasn't suggesting that the food becomes radioactive!

[swansont]

A gamma ray simply cannot enter a nucleus and cause it to break apart. The copious amounts of electrons on the outside of the nuclei absorb the gamma rays' energy before it can even affect the nucleus.

 

Sure it can. People measure (gamma, p) and (gamma, n) cross sections, so it certainly is possible to activate a nucleus with a gamma. To say that it can't happen is too bold a statement. It just isn't the case for the energy of the gammas in question.

[urza]

A gamma ray simply cannot enter a nucleus and cause it to break apart. The copious amounts of electrons on the outside of the nuclei absorb the gamma rays' energy before it can even affect the nucleus. Any alpha and beta radiation is contained within the container of the radiation source.

 

then how are the bacteria killed if you say that a gamma ray cannot peneterate the nucleus and make it break apart?

[YT2095]

bacteria are comprised of MANY Atoms, as is a house made from bricks.

 

I don`t have to destroy each brick to destroy the house

[urza]

but you have to break some of the bricks...

[ecoli]

The radiation eneters the cells and damages the chemical structure of DNA...That's the bonds between atoms and molecules, not the individual atoms, themselves.

[swansont]

but you have to break some of the bricks...

 

The gammas don't have enough energy to activate a nucleus, but they have more than enough energy to break (multiple) molecular bonds. A gamma from decay will typically have of order 1 MeV of energy, while a molecular bond is a couple of eV.

 

So it's more like chipping away at the mortar vs breaking the stones apart.