Is this arthropod non-intrusive and recommended to be left alive?
This appears to be a silverfish, a very common household "pest" in the Lepismatidae family of insects. 



 Photo Credit: Dong-Hwan Choe. Source: UC IPM 

Silverfish are silver/grey and (like all members of the Zygentoma order) have three distinct, tail-like caudal appendages from their posterior end -- really, two large cerci with a central long filament.
 [Sources: 1, 2, 3].

According to Wikipedia, you can find them all arround the world: 


  Silverfish are a cosmopolitan species, found in Africa, the Americas, Australia, Eurasia, and other parts of the Pacific.[8] They inhabit moist areas, requiring a relative humidity between 75% and 95%.[9] In urban areas, they can be found in attics, basements, bathtubs, sinks, kitchens, old books, classrooms, and showers.[3]


They are relatively harmless due to their weak jaws [source], and their presence is typically a larger nuisance than the damage or disruption that they cause. 

We have a number of posts already identifying silverfish and asking about management advice. Try yping "silverfish" into the Search bar at the top of the page to search for more information.