文摘
The objective of this work is to examine associations between blood lead (PbB) and air lead (PbA) in particulate matter measured at different size cuts by use of PbB concentrations from the National Health and Nutrition Examination Survey and PbA concentrations from the U.S. Environmental Protection Agency for 1999鈥?008. Three size fractions of particle-bound PbA (TSP, PMb>10b>, and PMb>2.5b>) data with different averaging times (current and past 90-day average) were utilized. A multilevel linear mixed effect model was used to characterize the PbB鈥揚bA relationship. At 0.15 渭g/m3, a unit decrease in PbA in PMb>10b> was significantly associated with a decrease in PbB of 0.3鈥?.2 渭g/dL across age groups and averaging times. For PbA in PMb>2.5b> and TSP, slopes were generally positive but not significant. PbB levels were more sensitive to the change in PbA concentrations for children (1鈥? and 6鈥?1 years) and older adults (鈮?0 years) than teenagers (12鈥?9 years) and adults (20鈥?9 years). For the years following the phase-out of Pb in gasoline and a resulting upward shift in the PbA particle size distribution, PbA in PMb>10b> was a statistically significant predictor of PbB. The results also suggest that age could affect the PbB鈥揚bA association, with children having higher sensitivity than adults.