According to the Starfinder rules, the pressurized lungs biotech augmentation has the following effect:
"You can hold your breath for up to 1 hour and are immune to the normal environmental effects of being in a vacuum."
The rules on vacuums are as follows:
The void of space is effectively empty of matter, and this vacuum is perhaps the greatest danger of outer space. A creature introduced to a vacuum immediately begins to suffocate (see Suffocation and Drowning) and takes 1d6 bludgeoning damage per round (no saving throw). Because a vacuum has no effective temperature, the void of outer space presents no dangers from cold temperatures. A creature retains its body heat for several hours in a vacuum. Sound doesn’t travel in a vacuum.
Decompression occurs when a creature suddenly transitions from a pressurized environment to a vacuum, such as by being flung out of an airlock or being inside a sealed structure that becomes heavily damaged. Such a creature takes 3d6 bludgeoning damage (no saving throw) in addition to any suffocation damage.
Most creatures travel the vacuum of space in a starship.
Do the 3d6 points suffered from sudden decompression (discussed in the second paragraph under Vacuum) count as the "normal environmental effects of being in a vacuum"? Or do normal environmental effects only pertain to the suffoction and 1d6 per round?
Here is an article about the real science.
It is logical for lungs that hold an hour’s worth of air to protect you from suffocation in a vacuum, and they theoretically could stop your lungs from bursting (another danger in a vacuum). I don’t see how they would prevent your blood from vaporizing and stopping circulation. Scientifically, even with pressurized lungs, the vacuum should damage/kill you. Granted, it is a fantasy game.