Adipose tissue: another target organ for lead accumulation? A study on Sardinian children (Italy).

OBJECTIVES: This study analyzes the relationship between lead levels and adipose tissue in Sardinian children. As an environmental pollutant, lead occurs in two different chemical forms: inorganic and organic lead; organic lead is present in the environment mainly as lead-alkyls (tetramethyl and tetraethyl lead). The lead-alkyls are characterized by their liposolubility; because of this characteristic, the behavior of organic Pb in the organism is similar to that of persistent organic pollutants (POPs). In fact, the high liposolubility of POPs, synthetic chemical substances highly resistant to biodegradation in both the environment and the human body, gives them a preferential tendency to accumulate in adipose tissue. METHODS: The study sample consisted of 759 children between 11 and 15 years resident in various municipalities of Sardinia. Hair lead levels (PbH) were used as the biomarker of exposure, while several anthropometric indexes were adopted to evaluate the adipose tissue: weight, body mass index, waist circumference, waist to hip circumference ratio, and sum of skinfolds (Σskf). RESULTS: The results of the multivariate ridge regression analysis, controlling for sex and age, show a significant positive relationship between logPbH and logΣskf but not the other adiposity indicators. CONCLUSIONS: This results suggests that organic lead tends to accumulate in adipose tissue, although it would be appropriate to measure lead levels in the adipose tissue itself in order to verify the results. Hence this tissue could be considered a possible new biological matrix for the evaluation of environmental lead exposure.

Growth charts of head length and breadth for regional areas? A study in Sardinia (Italy).

There exist few standards of head length and breadth from childhood to adulthood in Europoid populations. Moreover, such standards are based on samples that cannot be used as references for all populations since they were taken from different ethnic groups and from different periods. The aims of this study were: (1) to test whether standards derived from North Americans of European extraction can be used to assess the Sardinian population; and (2) to produce growth charts for head length and breadth for Sardinian males and females from 3 to 22 years of age. The cross sectional sample consisted of 9,721 subjects of Sardinian origin (4,884 males and 4,837 females), aged 3-22 years, measured from 1998 to 2008. Growth percentiles were produced with the LMS method. The mean values for each sex in each age class (3-18 years) are almost always significantly lower for both head length and breadth than the corresponding North American values. The exceptions are the head length of boys of 14 years and girls of 16-18 years where values for Sardinians are lower, but not significantly so. The results show that the North American standards are not appropriate for the assessment of Sardinian children. For the Sardinian population, specific regional growth charts should be used to correctly evaluate the normal range and the cut-off points of the extreme percentiles.

Evaluation of association between biomarkers of lead exposure in Sardinian children (Italy).

The aim of this work is to verify whether there are statistically significant correlations between the concentrations of lead in blood, urine, and hair in children. The sample collected in 2007 consists of 163 children of both sexes from 11-14-year-olds, living in three municipalities of Sardinia (Italy). Inductively coupled plasma atomic mass spectrometry has been used in the determination of lead concentration in biological material. For the overall sample, there is a non-significant partial correlation among the three matrices. However, for subjects with blood lead levels ≥5 µg/dL, there is a significant positive partial correlation between the lead levels in blood and hair, but not between blood and urine or between urine and hair. The results suggest that blood is the preferred biomarker to ascertain lead exposure in human populations, whereas hair can be used as a tool screening when an area is exposed to medium or high lead pollution.