I always replace causal " as " (and causal " since ") with " because ", or else I rewrite the sentence. That's because I believe that there should not be ambiguity in biomedical or other technical writing. It isn't poetry or detective fiction (well, sometimes it's criminal fiction). Clarity, brevity, and plain-style are what I strive for in formal written prose . Ambiguity and other types of unclear writing convey a "Gee, Officer Krupke. Krup you!" attitude to the reader/listener. That's just my personal bias , of course, but no journal copy-editor, editor-in-chief, or reviewer anywhere in the world has ever changed " because " back to " as " or " since " in the thousands of manuscripts that I've revised. For what that's worth.
In that context, a national survey of 1,520 adults conducted March 7-April 4, 2016, finds that Facebook continues to be America’s most popular social networking platform by a substantial margin: Nearly eight-in-ten online Americans 1 (79%) now use Facebook, more than double the share that uses Twitter (24%), Pinterest (31%), Instagram (32%) or LinkedIn (29%). On a total population basis (accounting for Americans who do not use the internet at all), that means that 68% of all . adults are Facebook users, while 28% use Instagram, 26% use Pinterest, 25% use LinkedIn and 21% use Twitter.