Blood‐Lead Levels and Children's Behaviour—Results from the Edinburgh Lead Study

Abstract

The effect of blood-lead on children's behaviour was investigated in a sub-sample of 501 boys and girls aged 6-9 years from 18 primary schools within a defined area of central Edinburgh. Behaviour ratings of the children were made by teachers and parents using the Rutter behaviour scales. An extensive home interview with a parent was also carried out. Multiple regression analyses showed a significant relationship between log blood-lead and teachers' ratings on the total Rutter score and the aggressive/anti-social and hyperactive sub-scores, but not the neurotic sub-score when 30 possible confounding variables were taken into account. There was a dose-response relationship between blood-lead and behaviour ratings, with no evidence of a threshold.

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

“…In the Mexican cross-sectional study using blood as the measure of lead exposure, increased lead body burden was associated with decreased knowledgeability and socialization skills on a teacher's rating scale, as well as impaired performance on the WISC-R (36). In the Scottish cross-sectional study with blood lead as the independent variable (37), a dose-related increase on the aggressive/antisocial and hyperactive measures of the Rutter scale was observed in a group of 6-to 9-year-old children with low blood lead levels, who also exhibited a dose-related decrease in IQ (38) cross-sectional study in Dunedin, New Zealand, significant associations were found between blood lead levels and increased behavioral problems, as assessed by both teachers and parents on the Rutter Behavioral Scale, and increased scores on inattention and hyperactivity scales in the absence of changes in IQ (42). In the Boston prospective study (49), behavior was assessed by a teacher's rating scale when the children were 8 years old.…”

Attention deficit hyperactivity disorder in adults

“…While genetic factors are considered to be most important in the aetiology, a number of other causes are known to contribute to ADHD in a minority of cases : prematurity or low birth weight (Cantwell, 1996), prenatal and\or perinatal insults due to trauma, toxins (maternal smoking or alcohol abuse) and infections (Barkley, 1990), childhood exposure to toxins (e.g. lead) (Thomson et al 1989), fragile X syndrome (Turk, 1992) and possibly generalized resistance to thyroid hormone (Hauser et al 1993). These factors are thought to operate in childhood to either bring out a genetic vulnerability or produce phenocopies of the disorder.…”

Crianças Contaminadas por Chumbo: estudo comparativo sobre desempenho escolar

“…O desempenho cognitivo também piorou, ainda que com índices baixos, quando a exposição era por longos períodos (Tesman, Hills, 1994;Thomson et al, 1989). Bellinger (1995) afirma também que, mesmo em quantidades relativamente pequenas, o chumbo pode causar rebaixamento permanente da inteligência em crianças, resultando em prejuízos escolares e distúrbios psicológicos.…”

“…Os trabalhos apresentados (Vega-Dienstmaier et al, 2006;Bellinger et al, 2005;Canfield et al, 2003;Banks, Ferretti, Shucard, 1997;Tesman, Hills, 1994;Thomson et al, 1989;Stiles, Bellinger, 1993;Bellinger, 1995) relataram prejuízos de ordem cognitiva e comportamental, associados à contaminação por chumbo, que podem acarretar desempenho escolar abaixo do esperado.…”