Lead, mercury and cadmium in umbilical cord blood and its association with parental epidemiological variables and birth factors.

BACKGROUND: In Spain, few studies have evaluated prenatal exposure to heavy metals. The objective of this study was to describe lead, mercury and cadmium concentrations in blood from a sample of newborn-mother-father trios, as well as to investigate the association between metals in cord blood and parental variables. We also explored the relationship between cord blood metal concentrations and child characteristics at birth. METHODS: Metal correlations among family members were assessed using Spearman Rank Correlation Coefficient. Linear regression was used to explore the association between parental variables and log-transformed cord blood lead and cord blood mercury concentrations. In the case of cadmium, tobit regression was used due to the existence of samples below the detection limit. The association between cord blood metal concentrations and child characteristics at birth was evaluated using linear regression. RESULTS: Geometric means for lead, mercury and cadmium were 14.09 µg/L, 6.72 µg/L and 0.27 µg/L in newborns; 19.80 µg/L, 3.90 µg/L and 0.53 µg/L in pregnant women; and 33.00 µg/L, 5.38 µg/L and 0.49 µg/L in men. Positive correlations were found between metal concentrations among members of the trio. Lead and cadmium concentrations were 15% and 22% higher in newborns from mothers who smoked during pregnancy, while mercury concentrations were 25% higher in newborns from mothers with greater fish intake. Cord-blood lead levels showed seasonal periodicity, with lower concentrations observed in winter. Cord blood cadmium concentrations over 0.29 µg/L were associated with lower 1-minute and 5-minute Apgar scores. CONCLUSIONS: These results reinforce the need to establish biomonitoring programs in Spain, and provide support for tobacco smoke and fish consumption as important preventable sources of heavy metal exposure in newborns. Additionally, our findings support the hypothesis that cadmium exposure might be deleterious to fetal development.

[Micronucleus test: cytome assay and health biomarker]. / Prueba de micronúcleos: análisis citómico y biomarcador de salud.

Micronuclei are structures similar to a nucleus but small size and localized in the cytoplasm. A micronucleus contents chromosome fragments or whole chromosomes. The micronucleus test is considered a biomarker for early induced genetic damage. Micronucleus test with cytochalasin B (CBMN test) is used to evaluate genotoxic effects induced by physical and chemical environmental agents, and to estimate the genetic damage induced in population groups exposed to such agents. After the study of large groups of control population, it is estimated that CBMN test can be used as a marker of health status with ability to establish a cancer risk. Finally, recent studies about the onset of cancer, based on single catastrophic events able to originate a cancer, such as chromothripsis or chromoanagenesis, are going to understand through an anomalous replication of DNA within the micronucleus.

Mercury, lead and cadmium in human milk in relation to diet, lifestyle habits and sociodemographic variables in Madrid (Spain).

BACKGROUND: Although breastfeeding is the ideal way of nurturing infants, it can be a source of exposure to toxicants. This study reports the concentration of Hg, Pb and Cd in breast milk from a sample of women drawn from the general population of the Madrid Region, and explores the association between metal levels and socio-demographic factors, lifestyle habits, diet and environmental exposures, including tobacco smoke, exposure at home and occupational exposures. METHODS: Breast milk was obtained from 100 women (20 mL) at around the third week postpartum. Pb, Cd and Hg levels were determined using Atomic Absorption Spectrometry. Metal levels were log-transformed due to non-normal distribution. Their association with the variables collected by questionnaire was assessed using linear regression models. Separate models were fitted for Hg, Pb and Cd, using univariate linear regression in a first step. Secondly, multivariate linear regression models were adjusted introducing potential confounders specific for each metal. Finally, a test for trend was performed in order to evaluate possible dose-response relationships between metal levels and changes in variables categories. RESULTS: Geometric mean Hg, Pb and Cd content in milk were 0.53 µg L(-1), 15.56 µg L(-1), and 1.31 µg L(-1), respectively. Decreases in Hg levels in older women and in those with a previous history of pregnancies and lactations suggested clearance of this metal over lifetime, though differences were not statistically significant, probably due to limited sample size. Lead concentrations increased with greater exposure to motor vehicle traffic and higher potato consumption. Increased Cd levels were associated with type of lactation and tended to increase with tobacco smoking. CONCLUSIONS: Surveillance for the presence of heavy metals in human milk is needed. Smoking and dietary habits are the main factors linked to heavy metal levels in breast milk. Our results reinforce the need to strengthen national food safety programs and to further promote avoidance of unhealthy behaviors such as smoking during pregnancy.

[Cytogenetic biomarkers and health status]. / Biomarcadores citogenéticos como indicadores de la salud.

Cytogenetic aberrations are a biomarker for early effect that indicate the cell or the organism has undergone chromosomal damage as a result of his exposure to an external mutagenic/carcinogenic agent. The story begins with the description of the cytogenetic effects of ionizing radiation in 1927, but was not until 1956, with the description of the cytogenetic technique in humans, when genotoxic effects induced by mutagenic or carcinogenic chemical and physical agents are known. Induced chromosomal damage in humans by genotoxic agents is analyzed in human cells in vitro to check the genotoxicity of a suspected agent or in vivo in lymphocytes of individuals exposed to a genotoxic agent. The biomarker may be chromosomal breakage, sister chromatids exchanges, or micronucleus when the exposure has been recent, or chromosomal translocations for delayed or continuing exposures. The above, has allowed establishing that genotoxic damage accumulates with age and lifestyles such as smoking or occupational exposures. Recently, after checking the health status and survival of several European cohorts of normal individuals who years earlier were analyzed their cytogenetics biomarkers, has been established the cancer predictive value of the biomarker chromosome aberrations.