Richard Lansdown

The Relationship between Blood Lead Concentrations, Intelligence and Attainment in a School Population: a Pilot Study

One‐hundred‐and‐sixty‐six children whose blood lead levels had previously been determined were assessed on a battery of psychometric tests. Blood lead levels ranged from 7 to 33μg/100ml, and the group performed within the average range on all tests of attainment and intelligence. There were significant associations between blood lead levels and attainment scores on tests of reading, spelling and intelligence, but not on mathematics. These differences in performances largely remained after social class was partialled out. Partial correlation and multiple regression analyses suggest that while only a small proportion of the variance in intelligence is explained by blood lead levels, this relationship, is independent of social class. Caution is necessary in interpreting these findings, in view of the crude measure of social factors available.

The relationship between blood-lead concentrations, intelligence, attainment and behaviour in a school population: the second London study

SummaryThis study replicates an earlier one carried out in London in which an association was found between lead and intelligence, reading and spelling. In the present study 194 children living near an urban motorway were given the same battery of tests as well as an extensive family interview to determine background variables. Before social factors were taken into account there were no significant associations between lead and outcome variable. Possible reasons for the negative results from this study are discussed.

Exploring children's perceptions of health: does drawing really break down barriers?

A study was conducted in primary schools in London to explore the idea that involving children in drawing as well as writing provided greater insights into their health perceptions than writing alone. Three approaches were used: write only, draw-and-write and label-and-write. All methods provided roughly the same number of categories of response but write-only identified categories more quickly while draw-and-write revealed more on how ideas were interlsnked. Label-and-write provided more information on physical signs of health or ill health and the appearance and use of drugs and foodstuffs. Drawings helped to decipher poor hahdwriting. These findings imply that no single method is best in all contexts and that an imaginative combination of drawing and writing can balance the strengths and limitations of each method. However, the choice of methods must be determined primarily by the questions to be answered and the situational constraints.

Automated testing of reaction time and its association with lead in children

SummaryFollowing Needleman et al.s (1979) report of a correlation between tooth lead estimates in children and reaction time as measured by Rodnick and Shakows (1940) delayed reaction time paradigm, a version of the procedure with two delay periods of 3 s and 12 s was developed for automated presentation and scoring on a VIC-20 microcomputer. Data are presented from a study of 300 children aged 6–14 years. Mean reaction time over six trials for each delay period related in a curvilinear fashion with age, but no relationships were found with sex or intelligence. Age-adjusted reaction time related significantly with blood-lead levels, but accounted for only about 1 per cent of the variance. The effect was mainly observed in younger (6–10 years) children in whom higher lead was associated with slower reaction time.