  We present the results of a mid-infrared imaging spectroscopy survey of Young
Stellar Objects (YSOs) and their surrounding environment in four low-mass star
formation regions: RCrA, Rho Ophiuchi, Serpens and Chamaeleon I. This survey
was performed using ISOCAM and its Circular Variable Filters (CVF) and observed
42 YSO candidates. A number of spectral features were measured, most notably
the 9.7um silicate feature, the bending modes of both water and CO2 ices at 6.0
and 15.2um respectively and the well-known unidentified feature at 6.8um. The
strength of the unidentified feature was observed to correlate very well with
that of the water ice bending mode and far less strongly with the CO2 ice
bending mode. This suggests, in a manner consistent with previous observations,
that the carrier of the unidentified feature is a strongly polar ice.
Absorption profiles of the bending mode of CO2 ice are observed to show a
significant long wavelength wing, which suggests that a significant fraction of
the CO2 ice observed exists in a polar (H2O-rich) phase. The sources observed
in RCrA, Rho Oph and Serpens show similar spectral characteristics, whilst the
sources observed in Cha I are somewhat anomalous. However this is consistent
with previous studies of this region of the Cha I cloud, which contains an
unusual cluster of YSOs. We detect an apparent under-abundance of water ice
towards the sources in Rho Oph. This may be indicative of differences in
chemical composition between the different clouds, or may be due to
evaporation. Finally the CO2:H2O ice ratios observed towards the sources in Rho
Oph show significantly greater scatter than in the other regions, possibly due
to varying local conditions around the YSOs in Rho Oph. (Abridged)
