NHS is our largest employer (5th in the world apparently, http://www.bbc.co.uk/news/magazine-17429786 - c.5.8% of the working population when coupled with data here http://www.ons.gov.uk/ons/rel/lms/labour-market-statistics/f...) and, despite it's failings, is an area the UK have led in (nationalised health care), and an important element of nearly everyone in the UKs life at one time or another.

Refuse collection is worthy and widespread but not really something the UK leads in I feel nor would it likely provide the visuals the designer was aiming for ...