Complex sentence: Ingestion or inhalation of large amounts may cause acute radiation poisoning and death; however no human is known to have died because of inhaling or ingesting plutonium, and many people have measurable amounts of plutonium in their bodies.
Split into simpler sentences: Ingestion or inhalation of large amounts may cause acute radiation poisoning and possibly death. However no human being is known to have died solely because of inhaling or ingesting plutonium, and many people have measurable amounts of plutonium in their bodies.