These trace concentrations may vary from stone to stone or even within a single slab of granite.
Is black granite radioactive.
It forms as a result of magma cooling over millions of years under intense pressure and heat.
At most only a tiny percentage of them have been tested for radon or radiation levels but a recent test of 13 types of granite typically used for countertops found no radon or very low levels of.
The lowdown on granite radiation.
Radioactive minerals in the granite can decay into radon a colorless odorless radioactive gas which may be released from the surface of the granite over time.
Whether granite countertops could cause lung cancer due to the emission of radon gas has been a matter of some debate.
All granite and most earthen materials contain trace amounts of uranium and radium emit gamma radiation and release radon gas.
With the concern over the radioactive risk potential of granite countertops it is important to remember that we are always exposed to a certain level of background radiation.
However keep in mind that avoiding granite countertops does not mean you avoid radiation or radon gas emissions in your home.
However it is undeniable that granite does contain radioactive materials some more so than others do.
After all there are always exceptions to the rule.
The story here appears to be that some granite countertops have been found to emit high levels of radon a strongly carcinogenic natural radioactive element.
Radiation from granite countertops.
Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture.
Granites can be predominantly white pink or gray in color depending on their mineralogy the word granite comes from the latin granum a grain in reference to the coarse grained structure of such a completely crystalline rock.
It does pay to find out for sure if there are harmful levels of radioactive elements in your granite countertops.
Granite like any other stone may contain veins of naturally occurring radioactive elements like uranium thorium and their radioactive decay products.
Radon is an odorless colorless gas produced by the breakdown of uranium that seeps out of the earth more commonly in some places on the planet than others.
However since the granite is not porous and exposed surfaces are treated with sealant it is harder for the radon escape from the granite than from more porous stones such as.
This concentration is less than.
On one side is that dangerously high levels have been found in some countertops while arguments on the other claim that the amount of radon emitted is very small relative to radon that may occur in homes otherwise.
Assuming a relatively tight house with an air change rate of 0 5 per hour h 1 and using average measured dose rates from granite countertop slabs the estimated radon concentration in kitchen air would be 4 8 becquerels per cubic meter bq m 3.