Complex sentence: Unfit for active wartime service, Francis volunteered for civil defence and worked full-time in the ARP (Air Raid Precautions) rescue service; the fine dust of bombed London worsened his asthma and he was discharged.
Split into simpler sentences: Unfit for active wartime service, Bacon volunteered for civil defence and worked full-time in the ARP (Air Raid Precautions) rescue service. But the fine dust of bombed London worsened his asthma and he was discharged.