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200 <br /> 5. POTENTIAL FOR HUMAN EXPOSURE <br /> 11.7 million children less than 7 years old are exposed to lead in dust and soils from a variety of sources: 5.6 PC <br /> 5.9 million children are exposed from lead paint; 5.6 million children are exposed from leaded gasoline and <br /> lead emissions in cities; and 0.2 million children are exposed from stationary emission sources such as N additi, <br /> smelters and battery plants. In addition, 6.6 million children may be at risk from exposure to lead in It risk f <br /> drinking water as a result of lead solder and pipes used in plumbing (Mushak and Crocetti 1989). ppulatic <br /> The lead content of dusts can be a significant source of exposure, particularly for young children. Baseline young c <br /> estimates of potential human exposure to dusts including intake due to normal hand-to-mouth activity are ontamin <br /> 0.2 g/day for children 1-6 years old and 0.1 g/day for adults when both indoor and outdoor ingestion of lay. If t <br /> believed that ingestion of dust by children most Mielke <br /> soil including dust are considered (EPA 1989c). It is <br /> commonly occurs as the result of the mouthing of hands, toys, and food that have come into contact with ire unust <br /> lead-containing surface dust, and less commonly by deliberate ingestion of soil (Bornschein et al. 1986). regnane <br /> Although ingestion of lead-containing paint may lead to elevated blood lead levels in young children, the esult in <br /> major source of moderately elevated blood lead levels (30-80 µg/dL) in inner city children is mostly likely posed t <br /> to he contaminated household dust and subsequent hand contamination and repetitive mouthing (Charney ay be t <br /> et al. 1980). Lead levels of indoor dust and outdoor soil were found to be strongly predictive of blood ;educed t <br /> lead levels in over 200 urban and suburban infants followed from birth to 2 years of age; however, the <br /> blood lead levels were not correlated with indoor air or tap water lead levels, nor the size of nearby General <br /> roadways. Indoor dust lead levels and soil lead levels in the homes of children with high blood lead levels zntamin, <br /> (>8.8 µg/dL) were 72 µg/wipe (windowsill dust) and 1,011 jig/g, respectively; children with low blood lead cad in tt <br /> levels (<3.7 µg/dL) were exposed to 22 µg/wipe and 380 ug/g, respectively. In addition, 79% of the homes ittempt t <br /> of the children with high blood lead levels had been refinished while only 56/0 of the homes had been removed <br /> refinished among the children with low blood lead levels, suggesting that refinishing the interior of homes uen fours <br /> with leaded paint may increase, at least temporarily, a child's exposure to lead dust (Rabinowitz et al. additic <br /> 1985). Blood lead levels in children have been found to increase during the summer months when children 70fession <br /> play outdoors and soil dust is more common. After interior and exterior lead dust cleanup procedures Chisolm <br /> were instituted around areas known to have high soil lead levels, the blood lead concentrations dropped iotn hour <br /> in 521/1tof the children (Mielke et al. 1992). and toxic; <br /> ocumenti <br /> Secondary occupational exposure may occur among families of workers who inadvertently bring home lead <br /> dusts on clothing worn at work. Blood lead levels of children in households of occupationally exposed Young chi <br /> workers were almost twice those of children in neighboring homes whose parents were not occupationally lectronic <br /> exposed to lead, median range of 10-14 Ag/dL and 5-8 Ag/dL, respectively (Grandjean and Bach 1986). tad levels <br /> 3 the ele( <br /> Another source of dietary lead is the use of inadequately glazed earthenware vessels used for food storage ead toxici <br /> and cooking. Due to the number of incidences of lead poisoning that have resulted from the use of <br /> earthenware vessels, the FDA has established action levels of 0.5 µg/mL lead for pitchers to 5.0 Ag/mL for .acreased <br /> cups and mugs soaked for 24 hours in a 4"%- acetic acid solution (FDA 1992a). However, inadequately I.ppears th <br /> glazed pottery manufactured in other countries continues to pose a significant health hazard. Likewise. !98 ,a). <br /> homemade or craft pottery and porcelain-glazed vessels have been found to release large quantities of lead, <br /> particularly if the glaze is chipped, cracked, or improperly applied. In addition, glaze on vessels that are 'opulation <br /> washed repeatedly may deteriorate, and a vessel that previously met FDA standards may become unsafe k4ia may <br /> (CDC 1985; EPA 1986a). �Dw char <br /> posed. <br /> r <br />