A followup study of the academic attainment and classroom behavior of children with elevated dentine lead levels

Abstract

To investigate the impact of low-level lead exposure on children's behavior within a natural setting, we assessed the school performance of a sample of 141 elementary school children classified according to dentine lead level. Twenty-two children had "elevated" levels (≥20 parts per million), 71 had "midrange" levels (10.0-19.9 parts per million), and 48 had "low" levels (<10 parts per million). Four types of outcome data were collected: (1) scores on a standardized group intelligence test, (2) teachers' ratings, (3) incidence of academic failure (assignment to remedial aid, grade retention), and (4) observations of classroom behavior. In general, higher dentine lead levels were associated with less favorable school performance, with most covariance-adjustedp-values in the range of 0.05-0.15. The incidence of grade retention was the outcome most strongly related to lead level. The pattern of results suggests a consistent, though weak relationship between children's dentine lead levels and elementary school performance.

Behavioral effects of lead: commonalities between experimental and epidemiologic data.

“…(34,38,49) studies in children. Effects have been (63) observed at blood lead levels similar to those (28,40) in children; a no observable effect level has (28) not been identified in either children or ani- (18) mals. Research in the last decade has often included analyses to identify the behavioral (59) processes underlying the observed lead- (54) induced behavioral deficits (75).…”

“…In the Port Pirie study (52), all scales of the WISC-R were affected when the children were 7 years old, although the information and block design were the most sensitive. (18,28) (29) (30,31) (32) (33)(34)(35) (45), while performance at 10 years of age was most associated with lead levels at 2 years (47). Similarly, early measures in the Port Pirie study were associated with early blood lead levels (51), while performance on the MSCA at age 4 was associated with blood lead at 2 and 3 years of age but not earlier (53).…”

“…In the Danish study, Lyngbye et al (40) found an increased need for special education, especially verbal, in first-graders as a function of increased lead body burden. In a follow-up of the 1979 Boston cross-sectional study, Bellinger et al (28) assessed school performance in sixth-graders as a function of their first-grade tooth lead levels. They found a tendency toward an increased need for remedial education and grade retention as a function of increased lead level ( Table 3).…”

Measuring developmental outcomes of lead exposure in an urban neighborhood: the challenges of community-based research

“…Neighborhood residents welcomed additional studies of the effects of lead on their children. A review of the literature at that time suggested that children experience a one -to three -point (Winneke et al, 1996 ) to a four-to six -point deficit in IQ per 10 g/dl increase in lead burden ( Smith, 1989 ) , as well as a variety of school -performance problems ( Yule et al, 1981;Bellinger et al, 1986;Fulton et al, 1987;Fergusson et al, 1988;Munoz et al, 1993 ). We believe that the construct of IQ is not particularly helpful in understanding lead's neurotoxic effects.…”

Bioavailability of biologically detoxified lead: risks arising from consumption of polluted mussels.

“…The lead level in blood is considered one of the best indicators of current exposure (14,15) and it is usually dose-related to several toxic effects. In children, for example, neurological and neurobehavioral diseases have been reported for blood lead concentrations ranging from 20 to 50 pg/100 ml (16)(17)(18)(19)(20).…”