Age-Specific Risk Factors for Lead Absorption in Children

Abstract

The relationship of blood lead levels to environmental and individual characteristics is analyzed in a large sample of children residing near a lead smelting complex, with particular emphasis on the identification of age-related risk factors. Exceptional variation in both blood leads and its determinants within the study region facilitated the simultaneous detection of several significant risk factors for each year of age from 1 to 9 yr. The strongest predictor of blood lead at all ages was air lead, but the secondary risk factors were age dependent. Household dustiness was significantly related to blood lead in young children, especially those under 2 yr of age; soil lead may be an important source of ingested lead for children between 2 and 7 yr. Other significant effects included that of pica at about 2 yr of age, a slight effect of the occupational category of the fathers of 5- to 8-yr-old children, and a tendency for 8- and 9-yr-old boys to have higher blood leads than girls of the same age. Lead concentration in household paint was not a significant risk factor. These results suggest that a multifactorial approach to the prevention of excessive lead absorption by children is required.

Primary prevention of lead poisoning in children: a cross-sectional study to evaluate state specific lead-based paint risk reduction laws in preventing lead poisoning in children

“…We used the formula: as P F  = C F /T F and P M  = C M /T M , where P F and P M were the proportion of EBLLs, C F and C M were the number of confirmed EBLLs, and T F and T M were the total number tested, for female and male children, respectively. The proportion of cases among male and female children were determined separately because evidence suggests male children are more likely than female children to have EBLLs [11]. To obtain a sample size that mirrored the universe of children in the HHLPPP without sampling all children with EBLL in the program, P F and P M were each multiplied by a constant.…”

Improving Equitability and Inclusion for Testing and Detection of Lead Poisoning in US Children

“…The amount of circulating lead available to be detected is necessarily dependent on the timing of absorption from children's lungs 81‐84 and/or gut 85‐88 and the ratio of lead deposited in organs, 89,90 both of which involve the interaction of dynamic mechanisms influenced by individual developmental differences, developmental stage, and genetics 91‐93 . These processes are in turn influenced by varying environmental factors, including, for example, the route of exposure (inhalation vs. ingestion), 94,95 type of lead hazard source and frequency of exposure, 83 and socioeconomic factors that result in, for example, empty stomachs, 96,97 low calcium stores, 98 and other nutritional deficits that can increase lead absorption and decrease the body's capacity to excrete toxins, depending on the age of the child 25,99,100 . The amount of lead available for detection in blood is also dependent on its half‐life—estimated to be 28‐35 days for single exposures, but it is a far more difficult calculation for children chronically exposed to lead 101‐103 .…”

“… 91 , 92 , 93 These processes are in turn influenced by varying environmental factors, including, for example, the route of exposure (inhalation vs. ingestion), 94 , 95 type of lead hazard source and frequency of exposure, 83 and socioeconomic factors that result in, for example, empty stomachs, 96 , 97 low calcium stores, 98 and other nutritional deficits that can increase lead absorption and decrease the body's capacity to excrete toxins, depending on the age of the child. 25 , 99 , 100 The amount of lead available for detection in blood is also dependent on its half‐life—estimated to be 28‐35 days for single exposures, but it is a far more difficult calculation for children chronically exposed to lead. 101 , 102 , 103 In recent longitudinal studies of 193 children 6 months to 16 years of age residing in neighborhoods previously designated “high risk” for lead exposure, BLLs within individuals varied significantly over a 24‐month period, and with repeated testing, age was not a significant predictor of BLL.…”