We have compared the helium isotope ratio of samples of Pacific marine air collected over the 30-year period from 1973 to 2003 against a secondary geothermal gas standard and also against a running air standard. The results are consistent with zero rate of change for atmospheric 3He/4He. When the errors are taken into account, the rate of change in the air 3He/4He ratio is between -0.0102 and +0.0019 %/year. At the most this corresponds to a 0.3% change in the air 3He/4He ratio over the past 3 decades, which is at or below the detection limit of most laboratories. While there may be a small decrease in air 3He/4He due to anthropogenic release of 4He associated with use of fossil fuels, this decrease is not large enough to prevent the use of air helium as an isotopic standard.