Implications of different residential lead standards on children's blood lead levels in France: Predictions based on a national cross-sectional survey

Despite the dramatic reductions in children's blood lead levels (BLLs), there is considerable evidence that low-level lead exposure is associated with intellectual deficits and behavioral problems, without apparent threshold. There are limited data, however, about the contribution of residential sources of lead to contemporary children's blood lead levels. The aim of this study is to calculate the contributions of residential sources of lead to assess the potential impact of setting new standards for lead levels in residential dust, soil and water. We enrolled 484 French children aged from 6 months to 6 years, and collected data on social, housing and individual characteristics. Lead concentrations in blood and environmental samples (water, soils, and dusts) were measured using inductively coupled plasma mass spectrometry. Data were analyzed using a multivariate generalized additive model accounting for the sampling design and the sampling weights. We found that exceedingly low concentrations of lead in dust, soil and water were significant predictors of children's BLLs, after adjustment for potential confounding variables. Lead-contaminated floor dust was the main source of lead in blood. BLLs (GM: 14 μg/L) increased by 65%, 13%, 25%, and 5% when lead content in floor dust, loose soil, hard soil and water increased from their 25th percentile to their 95th percentile, respectively. We also observed that the steepest increase in BLLs occurred at the lowest levels of lead-contaminated floor dust, which indicates that lead contamination should be kept as low as possible. Impact of different possible standards on children's BLLs was also tabulated and indicated that unless standards are set low, they will only benefit a small proportion of children who have the highest exposures.     

Soy milk and dairy consumption is independently associated with ultrasound attenuation of the heel bone among postmenopausal women: the Adventist Health Study-2

Soy milk has become a popular substitute for dairy milk with important health claims. We hypothesized that soy milk, based on its nutrient composition, is comparable to dairy products and, therefore, beneficial for bone health. To test this hypothesis, we examined the benefit of soy milk and dairy products intake on bone health using broadband ultrasound attenuation of the calcaneus. Postmenopausal white women (n = 337) who had completed a lifestyle and dietary questionnaire at enrollment into the Adventist Health Study-2 had their calcaneal broadband ultrasound attenuation measured 2 years later. The association between osteoporosis (defined as a T-score <−1.8) and some dietary factors (soy milk, dairy) and selected lifestyle factors was assessed using logistic regression. In a multivariable model adjusted for demographics, hormone use, and other dietary factors, osteoporosis was positively associated with age (odds ratio [OR] = 1.08; 95% confidence interval [CI], 1.06-1.12) and inversely associated with body mass index (OR = 0.91; 95% CI, 0.86-0.97) and current estrogen use (OR = 0.27; 95% CI, 0.13-0.56). Compared with women who did not drink soy milk, women drinking soy milk once a day or more had 56% lower odds of osteoporosis (OR = 0.44; 95% CI, 0.20-0.98; P_trend = .04). Women whose dairy intake was once a day or more had a 62% reduction in the likelihood of having osteoporosis (OR = 0.38; 95% CI, 0.17-0.86; P_trend = .02) compared with women whose dairy intake was less than twice a week. Among individual dairy products, only cheese showed an independent and significant protection (OR = 0.28; 95% CI, 0.12-0.66; P_trend = .004) for women eating cheese more than once per week vs those who ate cheese less than once a week. We concluded that osteoporosis is inversely associated with soy milk intake to a similar degree as dairy intake after accounting for age, body mass index, and estrogen use.     

Prevalence of type-specific human papillomavirus infection among women in France: Implications for screening, vaccination, and a future generation of multivalent HPV vaccines

To assess human papillomavirus (HPV) prevalence and genotype distribution by age and cervical cytology/histology status among women undergoing routine gynecological examinations, and to discuss the possible impact on preventive strategies. Liquid-based cytology (LBC) samples were tested for HPV DNA, mRNA, and HPV genotypes. Women with atypical squamous cells of undetermined significance or greater (ASC-US+) and/or at least one positive HPV test were referred to colposcopy. Those with normal colposcopy results had biopsies taken at the 6 and 12 O'clock positions of the normal transformation zone. Of the 5002 women, 515 (10.3%) were <25 and 4487 (89.7%) were ≥25years old. Overall HPV prevalence varied between 10.1% and 16.1% depending on the assay. Risk factors for HPV infection included greater number of recent sexual partners, history of abnormal cervical pathology, age <25years, and smoking. HPV prevalence increased with the cytological and histological severity of cervical lesions. Prevalence of HPV 16/18 was 5.2% and 2.7% in women <25 and ≥25years old, respectively. HPV 16 was the type most strongly associated with a diagnosis of cervical intraepithelial neoplasia grade 3 or higher (CIN3+) (odds ratio=11.64 vs. HPV 16 absent, P<0.001). A high proportion of high-grade cervical lesions (60.6% of genotyping assay-positive CIN2+) were associated with HPV types 31, 33, 45, 52, or 58. These data indicate that almost all young women could benefit from HPV prophylactic vaccination, but confirm the need for continued cervical screening and highlight the potential benefit of future vaccines targeting a wider range of HPV types.     

Association of adherence to the seventh report of the Joint National Committee guidelines with hypertension in Korean men and women

Whether the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) guidelines can be applied to the Asian population remains unclear. We aim to test the hypothesis that adherence to the JNC-7 guidelines is associated with hypertension in a representative sample of the Korean population in the fourth Korea National Health and Nutrition Examination Survey. Participants completed a non-quantitative food frequency questionnaire and 24-hour diet recall through interviews. Blood pressure, height, and weight were directly measured, and questions about physical activity and other lifestyle factors were administered. A total of 500 hypertensive and 4567 normotensive participants were identified. We estimated the odds ratio and 95% confidence intervals using a multivariate logistic regression. The following components of the JNC-7 guidelines were considered: dietary approaches to stop a hypertension style diet, moderate consumption of alcohol, adequate physical activity, and a normal body mass index. Those individuals who fell in the low-risk category for all 4 lifestyle components had an odds ratio of 0.48 (95% confidence interval, 0.30-0.78) compared with the remainder of the participants. In conclusion, we found an inverse association between adherence to the JNC-7 guidelines and hypertension prevalence among Korean adults, suggesting the importance of lifestyle modification for the prevention and management of hypertension.     

S-(−)equol producing status not associated with breast cancer risk among low isoflavone-consuming US postmenopausal women undergoing a physician-recommended breast biopsy

Soy foods are the richest sources of isoflavones, mainly daidzein and genistein. Soy isoflavones are structurally similar to the steroid hormone 17β-estradiol and may protect against breast cancer. S-(−)equol, a metabolite of the soy isoflavone daidzein, has a higher bioavailability and greater affinity for estrogen receptor β than daidzein. Approximately one-third of the Western population is able to produce S-(−)equol, and the ability is linked to certain gut microbes. We hypothesized that the prevalence of breast cancer, ductal hyperplasia, and overall breast pathology will be lower among S-(−)equol producing, as compared with nonproducing, postmenopausal women undergoing a breast biopsy. We tested our hypothesis using a cross-sectional study design. Usual diets of the participants were supplemented with 1 soy bar per day for 3 consecutive days. Liquid chromatography–multiple reaction ion monitoring mass spectrometry analysis of urine from 143 subjects revealed 25 (17.5%) as S-(−)equol producers. We found no statistically significant associations between S-(−)equol producing status and overall breast pathology (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.23-1.89), ductal hyperplasia (OR, 0.84; 95% CI, 0.20-3.41), or breast cancer (OR, 0.56; 95% CI, 0.16-1.87). However, the mean dietary isoflavone intake was much lower (0.3 mg/d) than in previous reports. Given that the amount of S-(−)equol produced in the gut depends on the amount of daidzein exposure, the low soy intake coupled with lower prevalence of S-(−)equol producing status in the study population favors toward null associations. Findings from our study could be used for further investigations on S-(−)equol producing status and disease risk.     

Determinants of polychlorinated aromatic hydrocarbons in serum in three age classes—Methodological implications for human biomonitoring

Human biomonitoring provides an integrated measure for individual exposure to environmental pollutants. Better insight in inter-individual variability of biomarkers of exposure may help in the interpretation of biomonitoring studies.The aim was to study the impact of outliers, determine the optimal unit for fat-soluble biomarkers in serum and quantify the major determinants for biomarkers of exposure to polychlorinated aromatic hydrocarbons (PCAHs) in three age groups.Data were obtained from the Flemish Environment and Health Study (2002-2006). Marker PCBs (sum of 138, 153, 180), hexachlorobenzene (HCB) and p,p′-DDE were measured in cord blood samples of 1196 newborns, in serum samples of 1679 adolescents (14-15 years) and 1583 adults (50-65 years).Exclusion of influential outliers in multiple linear regression models lead to models that are better applicable to the general population. In terms of adjusted R², the regression model with the pollutant expressed in volume-based units and blood fat as a separate independent variable was superior compared to models with other units. We found highly consistent relationships between the serum concentration of PCAHs and blood fat, age, changes in body weight, animal fat in the diet, local vegetable consumption (HCB and p,p′-DDE only) and being breastfed as a baby (in adolescents only). The impact of sex and BMI differed by age.For biomarkers of persistent pollutants that reflect long-term exposure, the relation between the covariates and the biomarkers can be well quantified.     

Negative effects of serum p,p′-DDE on sperm parameters and modification by genetic polymorphisms

Objective

Effects of ambient exposure to DDT and its metabolites (DDE-DDT) on human sperm parameters and the role of genetic polymorphisms in modifying the association were investigated.

Methods

Demographics, medical history data, blood and semen samples were obtained from the first 336 male partners of couples presenting to 2 infertility clinics. Serum was analyzed for organochlorines (OC) and DNA for polymorphisms in GSTM1, GSTT1, GSTP1 and CYP1A1. Men with each sperm parameter considered low by WHO criteria (concentration <20 million/mL, motility <50%, morphology <4%) were compared to men with all normal sperm parameters in logistic regression models, controlling for sum of other OC pesticides.

Results

High DDE-DDT level was associated with significantly increased odds for all 3 low sperm parameters. The risk of low motility with high DDE-DDT exposure was increased in men with the GSTT1 null genotype compared to those with GSTT1 intact (odds ratio (OR)=4.19, 95% confidence interval (CI) 1.05-16.78 and OR=3.57, 1.43-8.93, respectively). Risk for low morphology in men with high DDE-DDT and one or both CYP1A1*2A alleles was lower compared to men with the common CYP1A1 alleles (OR=2.18, 0.78-6.07 vs. OR=3.45, 1.32-9.03, respectively). Similar results were obtained for men with low DDE-DDT exposure. Effects of high DDE-DDT on low sperm concentration (OR=2.53, 1.0-6.31) was unaffected by the presence of the polymorphisms.

Conclusion

High DDE-DDT exposure adversely affected all 3 sperm parameters and its effects were exacerbated by the GSTT1 null polymorphism and by the CYP1A1 common alleles.     

Urinary mercury and biomarkers of early renal dysfunction in environmentally and occupationally exposed adults: a three-country study

We conducted a cross-sectional study in Sweden, Italy and Poland to assess environmental and occupational exposure to mercury from chloralkali (CA) plants and the potential association with biomarkers of early renal dysfunction. Questionnaire data and first-morning urine samples were collected from 757 eligible subjects. Urine samples were analysed for mercury corrected for creatinine (U-HgC), alpha-1-microglobulin (A1M), N-acetyl-β-glucosaminidase (NAG) and albumin. Determinants of urinary mercury excretion were examined. Levels of kidney markers were compared in three U-HgC categories, and differences were tested taking age and other covariates into account. In the general population, the median U-HgC was higher in Italian (1.2 μg/g C) than in Polish (0.22 μg/g C) or Swedish (0.21 μg/g C) subjects, and no effect of living close to CA plants could be shown. Dental amalgam, chewing on amalgam, and fish consumption were positively associated with U-HgC. In subjects from the general population, no effects on the kidney markers could be detected, while in men, including workers occupationally exposed to mercury, U-HgC was positively associated with the kidney markers, especially with NAG, but to some extent also with A1M and albumin. Differences in urinary mercury and kidney markers in the general population between three studied countries could possibly be due to dietary factors, increased susceptibility to mercury at low selenium intake or co-exposure to other nephrotoxic metals.