Lead in umbilical blood, indoor air, tap water, and gasoline in Boston

Prenatal exposure to lead, delta-aminolevulinic acid, and schizophrenia: further evidence

BACKGROUND

A previously conducted study of prenatal lead exposure and schizophrenia using delta-aminolevulinic acid, a biologic marker of Pb exposure, in archived maternal serum samples collected from subjects enrolled in the Childhood Health and Development Study (1959-1966) based in Oakland, California, suggested a possible association between prenatal Pb exposure and the development of schizophrenia in later life.

OBJECTIVES

In the present study we extend these findings using samples collected from the New England cohort of the National Collaborative Perinatal Project (1959-1966). Using similar methods, in this study we found results that suggest a comparable association in this cohort.

METHODS

We pooled matched sets of cases and controls from both the California and New England sites using a multilevel random-intercept logistic regression model, accounting for matching and site structure as well as adjusting for maternal age at delivery and maternal education.

RESULTS

The estimated odds ratio for schizophrenia associated with exposure corresponding to 15 microg/dL of blood Pb was 1.92 (95% confidence interval, 1.05-3.87; p = 0.03).

CONCLUSION

Although several limitations constrain generalizability, these results are consistent with previous findings and provide further evidence for the role of early environmental exposures in the development of adult-onset psychiatric disorders.

Effects of environmental lead pollution, smoking, and smokeless tobacco (Maras powder) use on blood lead level

One hundred sixty-four adult male volunteers (29 controls [Group 1] and 135 combi drivers) enrolled in the study. The combi drivers were divided into three groups as nonusers of either Maras powder or cigarette (Group 2), smokers (Group 3), and users of Maras powder (Group 4). Blood lead levels (BLLs) were analyzed by atomic absorption spectrophotometer. BLL was detected as 2.8 +/- 2.3 microg/dL in Group 1 (n = 29); however, it was 3.5 +/- 1.6 microg/dL in Group 2 (n = 33), 3.8 +/- 2.4 microg/dL in Group 3 (n = 62), and 3.9 +/- 2.4 microg/dL in Group 4 (n = 40). BLL in Group 1 was found significantly lower than other groups (p < 0.05). The use of cigarette or Maras powder by the drivers did not give rise to a marked difference on the BLLs (p > 0.05). BLL of (combi) drivers was detected to be significantly higher than nondrivers; however, it was still under the hazardous level of 10 microg/dL announced by WHO. Although there are publications reporting that usage of tobacco increases the level of lead in blood, both smoking and use of Maras powder did not affect BLL markedly in our study.

Maternal and umbilical cord blood lead levels: an Istanbul study

Current mean lead concentrations in umbilical cords and in maternal blood in Istanbul were 1.69 +/- 0.91 (standard deviation) microg/dl and 2.37 +/- 0.89 microg/dl, respectively. These levels were much lower than values reported in previous years. Umbilical cord blood lead levels, which correlated significantly with mothers' blood lead levels, were approximately 70% of the latter. The drastic decrease in blood lead levels likely reflects the reduction in use of tetraalkyl lead in gasoline subsequent to 1989.

Limited seasonality effects on blood lead for a small cohort of female adults and children

Many blood lead surveys, especially during the 1970s and 1980s have shown variations of up to 35% in blood lead concentration, with higher values in summer over winter. We have monitored 13 adult females and seven children for periods from 348 to 1337 days as non-pregnant controls in a longitudinal study of mobilization of lead from the maternal skeletal during pregnancy and lactation. Samples of blood, 6-day duplicate diet and environmental samples were analyzed by high-precision thermal ionization mass spectrometry for lead isotope ratios and lead concentrations. There was no statistically significant difference between seasons for blood lead concentrations and dietary intake although there were small differences in the isotopic composition for blood. One explanation for the lack of a seasonal effect in blood lead of our cohort may be the absence of climatic extremes in Sydney. The minimal effects from seasonality observed in this cohort make this an especially useful cohort within which to study effects that could be obscured by seasonal factors.

Analysis of lead body burden in Turkey

Here we report the results of pilot screening for the environmental lead contamination in Turkey. Lead blood concentrations were determined in 342 subjects from 17 cities. The mean lead blood concentration, 3.65 +/- 1.66 micrograms/dl, is much lower than the values reported previously. People smoking tobacco and driving motor vehicles had elevated concentrations of lead in blood. There was also a moderate relationship between the urban population size and the lead in blood values, but no differences were observed, that could be related to distinct geographical locations. Motor traffic was assumed to be the main source of lead pollution in the urban environment in Turkey, and the low lead blood levels were linked to the reduction of lead additives in gasoline, in 1989. Although at present, the environmental lead contamination does not pose a considerable threat to public health, in the near future, when the motorization rate and gasoline consumption will possibly double or triple, the lead content in gasoline might need to be further reduced.

Seasonal variation in paediatric blood lead levels in Syracuse, NY, USA

Venous blood lead values for 2,633 children aged 0-4 years in Syracuse, New York, collected between 1 April 1992 and 31 March 1993 were summarised by census tract for study of geographic variability. A demographic exposure model is presented showing housing stock and SES (socioeconomic status) parameters as the most significant predictor variables. A seasonal trend in blood lead levels was observed with late summer values about 40% higher than late winter values for census tracts with the highest geometric mean PbB levels. Seasonal variation is compared with a biokinetic uptake model to examine hypotheses about temporal variations in soil and dust lead exposure patterns.

Evidence of a fall in cord blood lead levels in South Wales 1984-85

A monitoring scheme for blood lead was based on cord blood samples and maternal blood samples taken in Swansea, South Wales. A fall of around 20% during 1984-85 is described. During this period there was virtually no change in petrol sales in the area and no overall change in air lead levels. Air lead showed large seasonal changes but these were not reflected in blood lead. Water lead levels gave no evidence of changes of any importance during the period of monitoring. These results suggest that petrol lead was at most a minor contributor to blood lead.

Parental occupational lead exposure and lead concentration of newborn cord blood

The purpose of this study was to determine the influence of parental occupational lead exposure on the lead levels of newborn cord blood in the Taipei area. From September 1984 to June 1985, 5,000 pregnant women voluntarily participated in the study at the Taipei Municipal Maternal and Child Hospital. Each woman was interviewed regarding her and her husband's occupational exposures; 2,948 successfully delivered healthy newborns, and cord blood samples were obtained using Terumo Venoject, and 242 samples were analyzed by graphite furnace atomic absorption spectrometry using an Instrumentation Laboratory 251 instrument. Nine cord blood samples were from newborns with both parents exposed, 26 samples had maternal exposure only, 105 samples had paternal exposure only, and 102 were nonexposed. The results showed that the average lead level of cord blood with both parents exposed was 8.9 +/- 2.9 micrograms%, maternal exposure 9.0 +/- 3.8 micrograms%, paternal exposure 8.3 +/- 3.4 micrograms%, and 6.9 +/- 3.2 micrograms% in the nonexposed group. There were significant differences between the nonexposed and the maternal exposure groups, and also between the nonexposed and paternal exposure groups. All 26 maternal exposures were from lead soldering operations. Multivariate analysis revealed that, after control of father's exposure status, newborn cord blood lead level increased 0.27 micrograms% for each hour the mother spent on lead soldering during a normal working day, thus suggesting that soldering during pregnancy may be hazardous to newborns. Paternal contribution to the cord blood lead levels seemed to be through either working at home with the pregnant mother also at home or bringing work clothes home for laundering.

Air lead, blood lead and travel by car

Evidence on the relevance of lead in petrol to lead in blood has come from two main sources. Cross sectional studies of blood lead levels in population samples and in the air to which they are exposed suggest that petrol makes only a very small contribution. However longitudinal studies in the USA in which changes in lead levels in petrol and changes in blood lead have been studied suggest that petrol makes a substantial contribution to blood lead. The possibility that this discrepancy might be explained by the exposure of subjects to very high levels of lead when travelling in motor vehicles is examined, and rejected.

Lead content in abortion material from urban women in early pregnancy

Lead concentration was determined in abortion material obtained from non-professionally exposed women following legal abortions. Furthermore, lead and free erythrocyte porphyrin levels in mother's blood were measured. Under conditions of apparent "normal" lead exposure, we detected lead levels in abortion products which were between 0.07 and 5.29 micrograms/g dry weight with a geometric mean of 1.27. No significant correlation was observed between the parameters measured in mother's blood and lead content in the specimens of the first trimester. The influence of different factors, such as smoking, area of residence, gestational age and parity, was also investigated. None of these factors showed a contributory effect on the total variation of lead in abortion material. From these data, we can conclude that, at least in our population, lead does not accumulate in human embryos/fetuses in the first trimester of pregnancy.