  We show that element diffusion can produce large fluctuations in the initial
helium abundance of the star-forming clouds. Diffusion time-scale, which in
stars is much larger than the Hubble time, can fall below 10^8 years in the
neutral gas clouds dominated by collisionless dark matter or with dynamically
important radiation or magnetic pressure. Helium diffusion may therefore
explain the recent observations of globular clusters, which are inconsistent
with initially homogeneous helium distribution.
