About the first article, which claims that the amount of helium gas in the atmosphere does support the young earth hypothesis. Creationists claim that the gas can't escape the atmosphere in sufficient amount to no completely fill up the atmosphere with helium gas if the earth has been billions of years old.
This claim neglects the fact that helium gas can easily be heated up in the exosphere and escape into space in large amounts. It doesn't take much to heat up the helium gas because it is so light.
talk origins does a really good job at explaining this.
Here is an explanation by Dr. Dalrymple on other mechanisms that cause the loss of helium gas in large amounts over the years:
The most probable mechanism for helium loss is photoionization of helium by the polar wind and its escape along open lines of the Earth's magnetic field. Banks and Holzer [1969] have shown that the polar wind can account for an escape of 2 to 4 x 106 ions/cm2 sec of Helium-4, which is nearly identical to the estimated production flux of (2.5 1.5) x 106 atoms/cm2 sec. Calculations for Helium-3 lead to similar results, i.e., a rate virtually identical to the production flux. Another possible escape mechanism is direct interaction of the solar wind with the upper atmosphere during the short periods of lower magnetic-field intensity while the field is reversing. Sheldon and Kern [1972] estimated that 20 geomagnetic-field reversals over the past 3.5 million years would have assured a balance between helium production and loss.
Therefore, there are many mechanisms that allow helium gas to escape into space. This explanation completely contradicts Sarfati's claim that "Other escape mechanisms are also inadequate to account for the small amount of helium in the air, about 1/2000th the amount expected after the alleged billions of years."
The Laminator