the effects are clear.
my point was if the monster activation for hazard spaces also cover lava spaces.
i think the new rtl rulebooks makes this clear: all spaces with yellow lines are "hazard spaces".
In the normal rule book this is also made quite clear:
Any space defined by a yellow line surrounding it is a hazard space. Hazard spaces follow the same rules as lava spaces as described on the page 18 of the Descent: Journeys in the Dark Second Edition rule book. Any effect or ability that applies to the lava spaces applies to hazard spaces, and any effect or ability that applies to hazard spaces applies to lava spaces.