title: Magnitude of lead intake from respiration by normal man.
abstract: Lead metabolism of five normal men was studied in a hospital metabolic unit in order to measure the daily intake of lead by respiration in urban adults. Subjects ingested a constant diet, and samples of blood, urine, feces, and diet were analyzed periodically for lead isotopic abundances by mass spectrometry. Three men were fed daily a stable isotope tracer of lead for 83 to 124 days in order to distinguish ingested from respired lead. Also, three men lived in rooms with filtered, low-lead air for 25 to 50 days in order to examine the response of blood lead levels to a change in airborne lead exposure. The quantity of respired lead intake was determined from the lead balance data, labeling of blood lead with a dietary lead tracer, and the response of blood lead levels and lead balances to exposure to low-lead air. The results indicate that these men absorbed a mean of 14 +/- 4 (S.D.) microgram/day of lead while exposed to the ambient levels of about 2 microgram/m3 of airborne lead. About twice this amount was absorbed from the diet.
mesh_terms: D000388:Air / Q000032:analysis; D000397:Air Pollution; D002140:California; D004781:Environmental Exposure; D005243:Feces / Q000032:analysis; D005374:Filtration; D006801:Humans; D007554:Isotopes; D007854:Lead / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D009942:Organometallic Compounds / Q000378:metabolism; D012119:Respiration; D012906:Smoke / Q000032:analysis; D014505:Urban Population
chemical_list: D007554:Isotopes; D009942:Organometallic Compounds; D012906:Smoke; D007854:Lead