Secular trend in blood lead levels in a cohort of Mexico City children.
We determined the secular trend in blood lead levels in a cohort of 104 children born in Mexico City between 1987 and 1993. We grouped children by the calendar year in which they reached 6 mo of age and measured blood lead levels every 6 mo until they attained 36 mo of age. The overall geometric mean blood lead level was 9.6 microg/dl (range = 1.5-59.5 microg/dl). A repeated measures analysis of variance revealed a highly significant linear trend in blood lead level with year (p < .001); there was a maximum decrease of 7.6 microg/dl between 1989 and 1993. There was a highly significant quadratic age effect (p < .001); blood lead levels rose between 6 and 18 mo of age and decreased thereafter. There was a marginally significant interaction between age of the child and year. Family use of lead-glazed pottery significantly elevated blood lead levels (p = .028). The downward trend in blood lead levels during the time period of study corresponded to the reduction in various sources of lead exposure.
Rothenberg
S J
SJ
Center for Research in Population Health, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
Schnaas
L
L
Perroni
E
E
Hernández
R M
RM
Karchmer
S
S
D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007854:Lead / Q000493:pharmacokinetics*; D007855:Lead Poisoning / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008800:Mexico / Q000453:epidemiology; D014504:Urban Health / Q000639:trends*
D007854:Lead