to follow its abundance with respect to that of oxygen. Unfortunately, oxygen abundance is generally given with a large uncertainty. This is because oxygen abundance is derived from the OI 1302.1685 Å line which has log gf=1.804 and is generally saturated. The other line OI 1355.5977, has log gf=-2.772 and is generally too faint to place useful upper limits. The line saturation leaves the line broadening poorly constrained and leads to the large uncertainty in the oxygen abundance. However, the $b$ value can be inferred from other lines under the assumption that they are formed in the same material and that the origin of broadening is not thermal. Lu et al. (1995a) and Molaro et al. (1995) use the $\it b$ value from the other observed species thus removing the large uncertainty in the oxygen abundance (cfr. Table 1). In Molaro et al. (1995). the broadening value is taken not only from ionized species, which might be sensitive to extra contribution from HII gas along the line of sight, but also from NI which is forming in the same material as neutral oxygen. It is rather striking that in the cases with oxygen abundances with small associated errors, oxygen turns 