Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium ( ISM ) .
Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks , however that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant ( SNR ) shock .
In this paper we present new calculations of grain destruction in evolving , radiative SNRs .
To facilitate comparison with the previous study by Jones et al .
( 30 ) , we adopt the same dust properties as in that paper .
We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock .
This occurs in shocks with velocities \gtrsim 200 km s ^ { -1 } for which the remnant is just beginning to go radiative .
Assuming SNRs evolve in a warm phase dominated ISM , we find dust destruction timescales are increased by a factor of \sim 2 compared to those of Jones et al .
( 30 ) , who assumed a hot gas dominated ISM .
Recent estimates of supernova rates and ISM mass lead to another factor of \sim 3 increase in the destruction timescales , resulting in a silicate grain destruction timescale of \sim 2 –3 Gyr .
These increases , while not able resolve the problem of the discrepant timescales for silicate grain destruction and creation , are an important step towards understanding the origin , and evolution of dust in the ISM .