Exposure to polychlorinated biphenyl (PCB) congeners measured shortly after giving birth and subsequent risk of maternal breast cancer before age 50

Cancers of the lung, head and neck on the rise: perspectives on the genotoxicity of air pollution

Outdoor air pollution has been recently classified as a class I human carcinogen by the World Health Organization (WHO). Cumulative evidence from across the globe shows that polluted air is associated with increased risk of lung, head and neck, and nasopharyngeal cancers--all of which affect the upper aerodigestive tract. Importantly, these cancers have been previously linked to smoking. In this article, we review epidemiologic and experimental evidence of the genotoxic and mutagenic effects of air pollution on DNA, purportedly a key mechanism for cancer development. The alarming increase in cancers of the upper aerodigestive tract in Asia suggests a need to focus government efforts and research on reducing air pollution, promoting clean energy, and investigating the carcinogenic effects of air pollution on humans.

Do statins increase and Mediterranean diet decrease the risk of breast cancer?

BACKGROUND

Physical exercise and healthy dietary habits are recommended to prevent breast cancer.

DISCUSSION

Increased intake of omega-3 fatty acids associated with decreased omega-6 - resulting in higher omega-3 to omega-6 ratio compared with Western-type diet - is inversely associated with breast cancer risk. The modernized Mediterranean diet with high omega-3 to omega-6 ratio, high fiber and polyphenol intake, and consumption of low-glycemic index foods reduces overall cancer risk and specifically breast cancer risk. It has been suggested that consuming no more than one alcoholic drink per day, preferably wine, is preferable. Eliminating environmental contaminants, including endocrine disruptors, and favoring organic foods to increase polyphenol intake and the omega-3 to omega-6 ratios were also shown to be beneficial. Cholesterol-lowering statins may decrease antitumor defenses; are toxic for the mitochondria; decrease the omega-3 to omega-6 ratio; increase body mass index, insulin resistance and diabetic risk; and have been associated with an increased breast cancer risk.

SUMMARY

Therefore, as well as making lifestyle changes to decrease breast cancer risk, we argue that physicians should carefully consider (and often avoid) therapies that may increase breast cancer or diabetes risk in high-risk women and women who wish to decrease their breast cancer risk.

Effects of quercetin on CYP450 and cytokines in Aroclor 1254 injured endometrial cells of the pregnant rats

Polychlorinated biphenyls (PCBs) are widespread persistent residual environmental pollutants, which affect seriously the growth and reproductive alterations in humans and animals. Aroclor 1254 is a commercial mixture of PCBs. Quercetin is a flavonoid, which acts on estrogen receptors and causes the development of estrogen-related diseases. In this paper, the primary cultured endometrial cells in the pregnant rats were isolated and Aroclor 1254 was used to induce the injured endometrial cells model. The cells were treated with gradient quercetin, the viability of the endometrial cells, the expressions of CYP450, the contents of TNF-α, IL-6, estradiol (E₂), and progesterone (P₄) were measured. It showed that the viability of the cultured endometrial cells, the expression of CYP1A1 and CYP2B1, and the contents of TNF-α, E₂, and IL-6 in the injured endometrial cells increased with the treatment of quercetin. It shows that quercetin has protective effect on the injured endometrial cells in the pregnant rats, this provide a basis on herbal medicine protection for animal reproductive diseases caused by environmental endocrine disruptors.

A cohort study evaluation of maternal PCB exposure related to time to pregnancy in daughters

BACKGROUND

Polychlorinated biphenyls (PCBs) remain ubiquitous environmental contaminants. Developmental exposures are suspected to impact reproduction. Analysis of mixtures of PCBs may be problematic as components have a complex correlation structure, and along with limited sample sizes, standard regression strategies are problematic. We compared the results of a novel, empirical method to those based on categorization of PCB compounds by (1) hypothesized biological activity previously proposed and widely applied, and (2) degree of ortho- substitution (mono, di, tri), in a study of the relation of maternal serum PCBs and daughter's time to pregnancy.

METHODS

We measured PCBs in maternal serum samples collected in the early postpartum in 289 daughters in the Child Health and Development Studies birth cohort. We queried time to pregnancy in these daughters 28-31 years later. We applied a novel weighted quantile sum approach to find the bad-actor compounds in the PCB mixture found in maternal serum. The approach includes empirical estimation of the weights through a bootstrap step which accounts for the variation in the estimated weights.

RESULTS

Bootstrap analyses indicated the dominant functionality groups associated with longer TTP were the dioxin-like, anti-estrogenic group (average weight, 22%) and PCBs not previously classified by biological activity (54%). In contrast, the unclassified PCBs were not important in the association with shorter TTP, where the anti-estrogenic groups and the PB-inducers group played a more important role (60% and 23%, respectively). The highly chlorinated PCBs (average weight, 89%) were mostly associated with longer TTP; in contrast, the degree of chlorination was less discriminating for shorter TTP. Finally, PCB 56 was associated with the strongest relationship with TTP with a weight of 47%.

CONCLUSIONS

Our empirical approach found some associations previously identified by two classification schemes, but also identified other bad actors. This empirical method can generate hypotheses about mixture effects and mechanisms and overcomes some of the limitations of standard regression techniques.

Prenatal exposure to the pesticide DDT and hypertension diagnosed in women before age 50: a longitudinal birth cohort study

BACKGROUND

Elevated levels of the pesticide DDT (dichlorodiphenyltrichloroethane) have been positively associated with blood pressure and hypertension in studies among adults. Accumulating epidemiologic and toxicologic evidence suggests that hypertension during adulthood may also be affected by earlier life and possibly the prenatal environment.

OBJECTIVES

We assessed whether prenatal exposure to the pesticide DDT increases risk of adult hypertension.

METHODS

We examined concentrations of DDT (p,p´- and o,p´-) and its metabolite p,p´-DDE (dichlorodiphenyldichloroethylene) in prenatal serum samples from a subset of women (n = 527) who had participated in the prospective Child Health and Development Studies birth cohort in the San Francisco Bay area while they were pregnant between 1959 and 1967. We surveyed daughters 39-47 years of age by telephone interview from 2005 to 2008 to obtain information on self-reported physician-diagnosed hypertension and use of hypertensive medication. We used multivariable regression analysis of time to hypertension based on the Cox proportional hazards model to estimate relative rates for the association between prenatal DDT exposures and hypertension treated with medication in adulthood, with adjustment for potential confounding by maternal, early-life, and adult exposures.

RESULTS

Prenatal p,p´-DDT exposure was associated with hypertension [adjusted hazard ratio (aHR) = 3.6; 95% CI: 1.8, 7.2 and aHR = 2.5; 95% CI: 1.2, 5.3 for middle and high tertiles of p,p´-DDT relative to the lowest tertile, respectively]. These associations between p,p´-DDT and hypertension were robust to adjustment for independent hypertension risk factors as well as sensitivity analyses.

CONCLUSIONS

These findings suggest that the association between DDT exposure and hypertension may have its origins early in development.

Placental transfer of persistent organic pollutants: a preliminary study on mother-newborn pairs

The aim of this study was to characterize the placental transfer of some environmental pollutants, and to explore the possibility of quantitatively predicting in utero exposure to these contaminants from concentrations assessed in maternal blood. Levels of toxic substances such as pesticides (p,p'-DDE, β-HCH, and HCB), polychlorinated biphenyls (PCBs), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA) were determined in serum samples of 38 pregnant women living in Rome and in samples of cord blood from their respective newborns. The study was carried out in the years 2008-2009. PCB mean concentrations in maternal serum and cord serum ranged from 0.058 to 0.30, and from 0.018 to 0.064 ng/g · fw respectively. Arithmetic means of PFOS and PFOA concentrations in mothers and newborns were 3.2 and 1.4 ng/g · fw, and 2.9 and 1.6 ng/g · fw. A strong correlation was observed between concentrations in the maternal and the foetal compartment for PFOS (Spearman r = 0.74, p < 0.001), PFOA (Spearman r = 0.70, p < 0.001), PCB 153 (Spearman r = 0.60, p < 0.001), HCB (Spearman r = 0.68, p < 0.001), PCB 180 (Spearman r = 0.55, p = 0.0012), and p,p'-DDE (Spearman r = 0.53, p = 0.0099). A weak correlation (p < 0.1) was observed for PCBs 118 and 138.