KashikoiKawai-Darky

Quick follow up (not OP). Along with everything he said above, there's also the issue that Hong Kong's prosperity is was/is heavily dependent on the mainland. The reason HongKong is such a major hub is because it's the gateway to China for many years. Despite this, HK acts like they're above China for the greater part of a century. This along with the sentiment of HK seeing the mainland as lesser people only helps fuel the flames even more.

To the mainland, HK is seen as a spoiled brat who is throwing a tantrum for being contested by other major cities and the pearl river delta. It's no wonder why mainland Chinese are pro-CCP when they're just fed a bit more of the violent parts of the protest/riot.

Mecury in it's pure form is actually not that deadly, although toxic your body isn't that great at absorbing it. In contrast, orgainc mecury (mecury bonded with a carbon based structure) tends to kill you if a drop touches your skin.

Basically, you should be fine.

Not OP but.

As far as I know HK only wants increased autonomy, few people actually want full independence except the some of the younger generation. From what I understand, this talk of independence is purely fictional and talked about by western media and ignorant individuals social media. OP can correct on this.

As for China permitting independence it's a hard no. HK as a city is not only financially meaningful, but symbolically meaningful as a remnant of a colony that represents the humiliation the Chinese had to face due to British imperialism. Unlike the other colonies, HK and Macau are the last two remaining cities with major agreements on how they should be ruled. However unlike Macau, Hong Kongers are distinctly hostile and racist to mainland Chinese, and naturally lack any sympathy or support from the mainland. As a result, the CCP literally can not grant independence to HK demands unless they want far bigger domestic issues within China (think HK levels riots and displeasure, only in every city in China.) since it shows that China is still weak and prone to humiliation from the past century by western powers. This was a colony that treated the Chinese as second class citizens under British rule, and only got to be a financial center due to being the gateway to China and the west, and now they're holding British/American flags and singing foreign national anthems as a form of unity; so you can imagine why they don't get much support within China.

This is also the reason why this conflict is still ongoing, as the 5 demands of HK are completely out of the question when packaged together. Specifically the right for universal suffrage without oversight for the governor position, and full release of all arrested citizens without exception. Keep in mind to the mainland, this city already has it's own legal system, currency, border controls, and most of everything that one might consider a "country", as such any increased autonomy will also lead to heavy resistance from the mainland and internally within the CCP.

As for what lengths China would go to if all of HK suddenly seeks succession? Probably heavy military intervention. By international law (although don't quote me, I'm just a guy that reads books for fun) declaration of independence will allow China to freely roll in as HK is now a rebellion and a rouge state. This is also the reason why Taiwan can not declare independence, and rather accept this limbo state of a country but also not a country and also part of the same China while being a different international border for the foreseeable future.