It was a really hard work.

работать на износ = to wear oneself out with hard work износ = wear-out to wear out a dress = износить платье all this talking wears me out = я очень устаю от всех этих разговоров his patience wore out = его терпению пришёл конец

Работа = work Шла на = literally "went towards", meaning in context more like "led to" Износ = state/process of being worn out Put those together, and you get something like "the work was tiring", "the work wore <the workers> out". The rest of the sentence basically states that Alla insists the salaries of the medical personnel in her department were the lowest, which makes sense in context. Low pay, hard work.

to be snowed under with work