The worst case scenario is instant death, which has happened to a family member. It's just a risk that is accepted in Brazil that wouldn't be in Europe or the US.
The same is true of many gas appliances sold in Brazil. My CO alarm regularly goes off in Brazilian homes when cooking - another death of a family member of a friend is why I carry that now.
Again a perfectly acceptable risk in Brazil that also kills Brazilians, but that isn't accepted in some other countries. For now, at least.
One mitigation for the gas risk in Latin America is that houses are rarely fully sealed with shut windows like they are in US and Europe. Because of the high electricity prices, windows are often open for ventilation.
Pictures of that are some of the most horrifying things you'll see. Fortunately this does not happen anymore due to residual-current devices and safety mechanisms in the shower heads.
Source: Brazilian police forensics expert in the 90s
"All of latin American uses them" and all of latin America is wrong (and anywhere else, IHMO. Yes, even Ireland, those ring circuit having heathens). Case and point: your mom would rather tell you to wear flip flops in the shower to prevent the POTENTIALLY DEADLY ELECTRIC SHOCK FROM A SHOWER IN A RENTAL PROPERTY than demand better conditions to raise their children.
Im not saying your mom is a bad person, shes not (well, she still could be, but it would be for reasons beyond the scope of this comment that I am not privy to). Gotta raise them kids, yo! There is nothing wrong with that. Im saying systemic dangerous conditions is not indicative of an acceptable infrastructure. And if the people have such little power they cannot demand a simple enforceable improvement to something as basic as a warm shower that doesn't threaten to electrocute you (not even in rental/vacation units which should be under more scrutiny due to the liabilities involved...oh sorry, you see a "liability" refers when you are responsible for the harm caused to another, say for instance by renting out a property without a properly functioning grounded electrical system and shower heads of death)...well, mate, I'm sorry but all of anywhere using them doesn't count for a hill of beans...
And I dont say this to shame you. You dont control where you are born or are raised. I say this so that these little hints of the overarching sociopolitical issues do not become white washed (or pink, or green, or yellow, all the colors of carnival!) into obscurity at the hands of 'playing nice', 'being polite', 'being non-offensive'. We tried that, it failed, it lead us here, here sucks, its time to start calling crappy things crap again. We need to remember the fear of being publicly shamed for our actions so our actions are acted upon with more forethought, and not simply at the expectation of getting a pat on the back for 'trying really hard'. Maybe then our politicians, our law makers, law enforcement, code enforcement, builders, architects, engineers, ...psychologists... (read up on the stanford issues as of late if you dont get this one), our fellow countrymen, our fellow humans will regrow that integrity and backbone we have been sorely lacking for too long...Toxic positivity has allowed the toxic to thrive. Time to be mean again, folks!
PS - im serious when I said this is not against you or your mom, im sure you're both lovely people. But you opened the door, and I had to bust through it. Sorry about your door...Ill get them to install a new one. With proper grounding.
Despite the clickable name, they are perfectly fine. If they weren't, the entirety of latin america wouldn't be using them. The worst case scenareo is if the house doesn't have grounding. In that case you can get a lil' zap when closing turning the shower off while wet. I remember when growing up, my mom would rent cheap apartments in the beach for us to stay a few days during the holidays, and she always made us shower while wearing flip flops to avoid getting the lil' zap. I'm not entirely convinced this worked.