Welcome @deltamarnix .
Reading about researchers grabbing every package from web made me lough and I am in a field where live is at stake too (cancer research with patients), so here is my answer. First you can read this Why is it reliable to use open source packages for research? - #4 by oheil and perhaps the whole discussion is interesting to you (well, it has a few side tracks 
).
My main argument for using Julia when having security concerns is, that Julia is NOT a black box, in the opposite, Julia code is so much readable and comprehendible, that it is so easy to validate that any concerns are becoming much smaller than using some libraries from some “reliable” manufacturer. The problem with security is not the evil developer who tries to drop a backdoor for example, this is easy to spot, especially with Julia, but the unavoidable bugs which open a system up for malicious intruders in the future. For this scenario open source is better, and readable and comprehendible open source is best.