  Many theoretical studies have shown that external photoevaporation from
massive stars can severely truncate, or destroy altogether, the gaseous
protoplanetary discs around young stars. In tandem, several observational
studies report a correlation between the mass of a protoplanetary disc and its
distance to massive ionising stars in star-forming regions, and cite external
photoevaporation by the massive stars as the origin of this correlation. We
present N-body simulations of the dynamical evolution of star-forming regions
and determine the mass-loss in protoplanetary discs from external
photoevaporation due to far ultraviolet (FUV) and extreme ultraviolet (EUV)
radiation from massive stars. We find that projection effects can be
significant, in that low-mass disc-hosting stars that appear close to the
ionising sources may be fore- or background stars in the star-forming region.
We find very little evidence in our simulations for a trend in increasing disc
mass with increasing distance from the massive star(s), even when projection
effects are ignored. Furthermore, the dynamical evolution of these young
star-forming regions moves stars whose discs have been photoevaporated to
far-flung locations, away from the ionising stars, and we suggest that any
correlation between disc mass and distance the ionising star is either
coincidental, or due to some process other than external photoevaporation.
