Blood Lead Secular Trend in a Cohort of Children in Mexico City (1987–2002)

Abstract

We determined the secular trend in blood lead levels in a cohort of 321 children born in Mexico City between 1987 and 1992. Blood lead level was measured every 6 months during a 10-year period. We modeled the effect of yearly air lead concentration nested within the calendar year in which the child was born, family use of lead-glazed pottery, socioeconomic status, year in which the child was born, age of the child at the time of blood lead measurement, place of residence, and an indicator variable for subjects with complete or incomplete blood lead values. The yearly mean of air lead of the Valley of Mexico decreased from its highest level of 2.80 μg/m3 in 1987 to 0.07 μg/m3 in 2002. The contribution of air lead to blood lead according to year of birth was strongest for subjects born in 1987 and fell to nearly zero for children born in 1992. The geometric mean of the entire cohort rose from 8.4 μg/dL in the first year of life to 10.1 μg/dL in the second and decreased thereafter until it reached 6.4 μg/dL at 10 years of age. Children of families who used lead-glazed ceramics had blood lead levels 18.5% higher than did children of nonusing families. Children who belonged to the lowest socioeconomic levels had blood lead levels 32.2% higher than did those of highest socioeconomic levels. Children who lived in the northeast part of the city had blood lead levels 10.9% higher compared with those who lived in the southwest.

Blood lead levels of contemporary Japanese children

“…In a number of cohort studies, in which the same children were followed from birth to school age, peak BPb was observed in the 2nd year of life, followed by decrease thereafter [22][23][24][25]. The present result (Table 2) seemed to be consistent with this finding, although ours is a cross-sectional design.…”

Leaching of Potentially Toxic Metals (PTMs) from Two Nigerian Clays and Related Clay Pottery Used Locally as Foodwares

“…The order of concentrations, Fe>Mn>Zn>Pb>Ni>Cr>Cu>Cd for Kono-Boue Clay Pot is different compared to that of Ara-Ekiti Clay Pot, consistent with previous EDX elemental composition count data on Kono-Boue Clay by Gbarakoro [3]. The presence and elevated levels of the metals in clay deposits and enamels for ceramics have been highlighted in previous studies [10][11][12][13][14]. The presence of the potentially toxic metals, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn is also confirmed by the metal peaks indicated on XRF analysis results Ara-Ekiti (Figure 2) and Kono-Boue (Figure 3) clays.…”

Developmental stress and lead (Pb): Effects of maternal separation and/or Pb on corticosterone, monoamines, and blood Pb in rats

“…Children in such settings face a variety of difficulties that may include impoverishment, family disruption, overcrowding, poor diet, threats, violence, and other challenges that result in elevated cortisol levels and other markers of stress (Gump et al, 2005;Lupien et al, 2000;Lupien et al, 2001). These conditions can co-occur when children live in older housing that tend to have higher levels of Pb paint, dust, and or soil contamination (Goyer, 1996;Jacobs et al, 2002;Lanphear et al, 1998;Levin et al, 2008;Meyer et al, 2003;Muntner et al, 2005;Schnaas et al, 2004). …”