My immediate concern would be with damage to eyesight.
https://pubmed.ncbi.nlm.nih.gov/2488031/
"For lower intensities, lens changes may depend on the cumulative dose.
At "nonthermal intensities", microwaves can act as a trigger and
set off changes in the living tissues (e.g. Ca++ efflux). Some
cataract-causing agents (alloxan and galactose) act synergistically
with microwaves. Microwaves also accelerate formation of cataracts due
to diabetes. The corneal endothelium can be damaged by microwaves alone
or in combination with some drugs. Microwave degeneration of retinal nerve
endings and a small increase in retinal permeability were also found in
animals. The effect of long-term low-intensity microwave exposure on
the human lens remains poorly understood."
Smartphones can cause glioma tumors on the side of the head
where you've been sticking the phone. What frequency does
a smartphone work at ?
I don't think leakage from a microwave oven is a joke. Fix it.
Waiting until your eye is all fucked up, that would be sad.
You can get various detectors, like ones that work thermally
and use some kind of liquid crystal material. That would be the
cheapest kind of detector you could get, as a strip of material.
There are also multimeter style devices. One even has a red LED on it which
lights up when the exposure is "too much". These cost 1x to 2x what
a Harbour Freight multimeter would cost. The claim here is "hundreds of dollars",
well, it's just a PIN diode and an ordinary multimeter, so the component
cost should not be expensive.
https://www.wikihow.com/Check-a-Microwave-for-Leaks
Walking away from the machine while it is running, is better than
doing nothing. The penetration of 2.4GHz, reflections and so on,
works just like your Wifi coverage, so the energy can travel some
distance. But then the chemical effects probably fall off at
a different rate, than "receiver sensitivity" would. Walking out
of kitchen and down hallway, is likely good protection. If the
microwave oven door is only held on by one hinge, walk out
into the back yard :-)
One potential way for a microwave to leak, is if a DIY repair person
cuts away the "dome" over the turntable motor, while doing a motor
replacement. Think back to any mods you made.
The door has a "choke" on it. It's a feature on the door, where
the door rests on the metal chassis.
https://www.physicsforums.com/threads/microwave-faraday-cage.650830/
The purpose of the choke, is to "short" the microwave signal.
Apparently even if the door is a bit loose, the choke feature still
works to some degree. The door leaks less, if the choke feature is present.
It's a kind of tuned circuit, designed to work at the microwave oven
frequency.
https://www.physicsforums.com/attachments/microwave2-png.53051/
There's a lot of plastic in microwave ovens now, so it's hard to
say how the choke cavity is implemented.
Paul