In adult humans, _______ of lead or less in the blood is considered to be normal HomeCirculatory System MCQsIn adult humans, _______ of lead or less in the blood is considered to be normal Share your love WhatsApp Facebook Telegram Twitter Pinterest Q. In adult humans, _______ of lead or less in the blood is considered to be normal. A. 40µg/dL B. 20µg/dL C. 10µg/dL D. 50µg/dL Answer: 10µg/dL