  Using lattice field simulations of the Abelian-Higgs model, we characterize
the simultaneous emission of (scalar and gauge) particles and gravitational
waves (GWs) by local string loops. We use {\it network} loops created in a
phase transition, and {\it artificial} loops formed by either crossing
straight-boosted or curved-static infinite strings. Loops decay via both
particle and GW emission, on time scales $\Delta t_{\rm dec} \propto L^p$,
where $L$ is the loop length. For particle production, we find $p \simeq 2$ for
artificial loops and $p \lesssim 1$ for network loops, whilst for GW emission,
we find $p \simeq 1$ for all loops. We find that below a critical length,
artificial loops decay primarily through particle production, whilst for larger
loops GW emission dominates. However, for network loops, which represent more
realistic configurations, particle emission always dominates, as supported by
our data with length-to-core ratios up to $L/r_\text{c} \lesssim 3500$. Our
results indicate that the GW background from a local string network should be
greatly suppressed compared to estimations that ignore particle emission.
