Lead Intoxication in Infancy

Abstract

Four years of experience in the evaluation and management of lead intoxication in the first year of life were reviewed. This study was conducted in a lead referral program within the state of Massachusetts, whose comprehensive lead laws include extensive (and now mandatory) lead screening of all children. Over the period of study, 50 (14%) of 370 new patients enrolled in the program were Infants aged 12 months or younger. Median age of these infants was 11 months (range 1 through 12 months). Mean peak lead level was 39.0 µg/dL while the mean peak erythrocyte protoporphyrin concentration was 111.9 µg/dL of whole blood. Thirty-two percent of infants were ambulatory at the time lead intoxication was diagnosed; only 24% had a history of pica. Twenty-six percent of parents were welfare dependent. Apparent sources of plumbism included household renovation (n = 20), direct ingestion of paint chips (n = 10), formula preparation with lead-contaminated water (n = 9), lead dust importation (n = 1), and congenital exposure to elevated maternal lead level (n = 1). In 9 cases the source was not found. When this profile was compared with that of a randomly selected group of 47 children aged 18 through 30 months, who were seen in the lead program during the same interval, apparent sources of intoxication in the older group were paint chip ingestion (n = 41), household renovation (n = 2), and unknown (n = 4) (P < .0001). On the basis of these data, it is concluded that lead intoxication in infants is common and has significantly different origins from that in toddlers. Lead intoxication from infant formula reconstituted with contaminated water may account for many of these cases. These findings support recommendations that lead screening begin at the age of 6 months for children with any likelihood of lead exposure.