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Introduction: The United States Centers for Disease Control and Prevention (CDC) issued behavioral recommendations to limit the spread of the novel coronavirus disease-2019 (COVID-19). No studies have examined the influence of various factors on adherence to COVID-19 preventive measures. Among individuals with co-morbidities, such as cardiovascular disease (CVD) and residing in rural communities, adherence is essential as they are at an increased risk of COVID-19 infection and increased disease severity. Objective: This study aims to explore factors influencing adherence to evidence-based recommendations for preventing COVID-19 among patients/family caregivers with CVD in rural Central Appalachia. Methods: During March-April 2020, 102 CVD Stakeholders - patients/family caregivers, community leaders, and providers from six states across Appalachia participated in a survey administered through REDCap. This study used a subsample (n=73) that excluded providers. Adherence score was defined as the rate of compliance with health authorities’ guidelines, including handwashing, physical distancing, staying home if sick, wearing a face mask, disinfecting and cleaning daily, and cough and sneezing etiquette. Simple and multiple linear regressions were performed to examine associations between adherence scores and variables of interest. Results: Over half (53.42%) of participants complied with all guidelines. Gender, employment status, hypertension, smoking, no insurance, getting information about COVID-19 from Government/CDC website, and getting information about COVID-19 from worship place/club were significantly associated with adherence to CDC recommendations (p Conclusion: Moderate and high perceptions of COVID-19 threats are associated with higher adherence, whereas no perception was associated with lower adherence with health authority recommendations for COVID-19 prevention. These factors should be considered in order to develop effective adherence interventions for CVD stakeholders in rural communities. Results should be confirmed in a larger study.

Bronchial thermoplasty (B.T.) is a therapeutic bronchoscopic procedure in which controlled thermal energy is applied to the airway wall to decrease smooth muscle mass. Immediate complications of B.T. include acute exacerbation of bronchial asthma, upper and lower respiratory tract infection, hemoptysis, among others. Our study assessed these immediate adverse events and the changes in forced expiratory volume in one second (FEV1%) measured four hours after each procedure from baseline. The study also aimed to examine the number of activations during each cycle of treatment and its correlation to the corresponding change in FEV1% from baseline.A case-series analysis of 17 patients who underwent B.T. between 2014 and 2019 was done. Demographic, clinical characteristics, including pre and post-BT FEV1% measures, and the number of activations were obtained.Acute exacerbation of asthma was the commonest complication accounting for 33%, 57%, and 75% after BT1, BT2, and BT3, respectively. There was deterioration in FEV1% after each treatment phase, the most significant being in BT3. There was no correlation between the number of heat activations with the change in FEV1% from baseline.The number of activations in B.T. does not correlate with the immediate deterioration in FEV1%, although exacerbation of asthma is the commonest complication post-B.T.

Background A long term of unhealthy lifestyles can lead to many health problems, especially type 2 diabetes (T2D). This study is to determine the associations of lifestyle factors (smoking, alcohol consumption, physical activity and diet) with type 2 diabetes in American adults (≥20 years) in a nationally representative sample. Methods Data were from 12987 American adults who participated in National Health and Nutrition Examination Survey (NHANES) 2005-2014. Weighted multiple logistic regression models were used to examine the associations of the four lifestyle factors with T2D after adjusting for demographics and socioeconomic status (SES). The prevalence trend of T2D was examined with Cochran-Armitage test. Results There is a significant increasing prevalence trend of T2D among American adults over 10 years. Smokers and individuals having more than 12 drinks last year were less likely to report having type 2 diabetes than non-smokers and those having less than 12 drinks with OR= 0.41 (95% CI= 0.35-0.48) and 0.46 (95% CI= 0.39-0.55), respectively. Participants with light physical activity have greater likelihood to have T2D than those engaging in vigorous physical activity (OR=5.72, 95% CI=4.30-7.60). Individuals consuming a poor diet were more likely to report having T2D than those eating excellent diet with OR=1.18 (95% CI=1.02-1.41). All these relationships remained significant after adjustment for demographics and SES. Conclusion All four behavior factors are significantly associated with T2D among American adults. The findings of this study provided useful information for healthcare providers that may help them inform patients to promote specific lifestyle modifications. Significant findings of the study: The quality of diet, physical activity intensity, smoking status and alcohol consumption are significantly associated with T2D with different directions among U.S. adults using NHANES 2005-2014 survey. What this study adds: This study used up to date U.S. NHANES survey and reported the latest 10 years’ prevalence trend of T2D among American adults. Different directional association between four lifestyle factors and T2D which indicates the direction of campaigns to reduce T2D patients.

Introduction: Epidemiologic data supporting the role of organochlorine pesticides in pubertal development are limited. Methods: Using a nested case-control design, serum collected during pregnancy from mothers of 218 girls who reported menarche before 11.5 years of age (cases) and 230 girls who reported menarche at or after 11.5 years of age (controls) was analyzed for 9 organochlorines and metabolites. We analyzed the association between in utero organochlorine concentrations and early menarche using multivariate logistic regression controlling for mother's age at menarche, or mother's prenatal BMI. Results: We did not observe an association between in utero exposure to HCB, β-HCH, ϒ-HCH, p,p′-DDT, p,p′-DDE, oxychlordane or trans-nonachlor and early menarche. Conclusions: This study is the first to examine the association between in utero exposure to HCB, β-HCH, ϒ-HCH, oxychlordane or trans-nonachlor and early menarche. In utero exposure to organochlorine pesticides does not appear to have a role in the timing of menarche in this study. Keywords: ALSPAC, Endocrine disrupting compounds, Organochlorine pesticides, Puberty, Menarche

Background Prenatal exposure to perfluoroalkyl substances (PFAS) has been associated with lower birth weight in epidemiologic studies. This association could be attributable to glomerular filtration rate (GFR), which is related to PFAS concentration and birth weight. Objectives We used a physiologically based pharmacokinetic (PBPK) model of pregnancy to assess how much of the PFAS–birth weight association observed in epidemiologic studies might be attributable to GFR. Methods We modified a PBPK model to reflect the association of GFR with birth weight (estimated from three studies of GFR and birth weight) and used it to simulate PFAS concentrations in maternal and cord plasma. The model was run 250,000 times, with variation in parameters, to simulate a population. Simulated data were analyzed to evaluate the association between PFAS levels and birth weight due to GFR. We compared simulated estimates with those from a meta-analysis of epidemiologic data. Results The reduction in birth weight for each 1-ng/mL increase in simulated cord plasma for perfluorooctane sulfonate (PFOS) was 2.72 g (95% CI: –3.40, –2.04), and for perfluorooctanoic acid (PFOA) was 7.13 g (95% CI: –8.46, –5.80); results based on maternal plasma at term were similar. Results were sensitive to variations in PFAS level distributions and the strength of the GFR–birth weight association. In comparison, our meta-analysis of epidemiologic studies suggested that each 1-ng/mL increase in prenatal PFOS and PFOA levels was associated with 5.00 g (95% CI: –21.66, –7.78) and 14.72 g (95% CI: –8.92, –1.09) reductions in birth weight, respectively. Conclusion Results of our simulations suggest that a substantial proportion of the association between prenatal PFAS and birth weight may be attributable to confounding by GFR and that confounding by GFR may be more important in studies with sample collection later in pregnancy. Citation Verner MA, Loccisano AE, Morken NH, Yoon M, Wu H, McDougall R, Maisonet M, Marcus M, Kishi R, Miyashita C, Chen MH, Hsieh WS, Andersen ME, Clewell HJ III, Longnecker MP. 2015. Associations of perfluoroalkyl substances (PFAS) with lower birth weight: an evaluation of potential confounding by glomerular filtration rate using a physiologically based pharmacokinetic model (PBPK). Environ Health Perspect 123:1317–1324; http://dx.doi.org/10.1289/ehp.1408837

Background: In some cross-sectional epidemiologic studies the shape of the association between serum concentrations of perfluoroalkyl acids (PFAAs) and lipids suggests departures from linearity. Objectives: We used statistical approaches allowing for non-linearity to determine associations of prenatal exposures of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) with lipid concentrations. Methods: PFAAs were measured in serum from pregnant women collected in 1991–1992 at enrollment in the Avon Longitudinal Study of Parents and Children and lipids in serum from their daughters at ages 7 (n = 111) and 15 (n = 88). The associations of PFAAs with lipids were first explored by cubic splines, followed by piecewise linear regressions by tertiles to obtain regression coefficients (β) and their 95% confidence limits (95% CL) (in mg/dL per 1 ng/mL). Results: At age 7, total cholesterol was positively associated with prenatal PFOA concentrations in the lower tertile (β = 15.01; 95% CL = 2.34, 27.69) but not with PFOA concentrations in the middle (β = −3.63; 95% CL = −17.43, 10.16) and upper (β = −1.58; 95% CL = −4.58, 1.42) tertiles. At age 15, a similar pattern was noted as well. Positive associations between LDL-C and prenatal PFOA concentration in the lower tertile were observed in daughters at ages 7 (β = 14.91; 95% CL = 3.53, 28.12) and 15 (β = 13.93; 95% CL = 0.60, 27.26). LDL-C was not associated with PFOA concentrations in the middle or upper tertile at any age. Neither HDL-C nor triglycerides was associated with prenatal PFOA exposure. Non-linear patterns of association of total cholesterol and LDL-C with prenatal PFOS were less consistently noted. Conclusion: Exposure to low levels of PFOA during prenatal development may alter lipid metabolism later in life. Given the small sample size further replication of the association in large independent cohorts is important. Keywords: Lipid metabolism, Endocrine disruption, PFOA, PFOS, Perfluoroalkyl acids, ALSPAC, Fetal origins of adult disease

Over the long term, unhealthy lifestyles can lead to many health problems, especially type 2 diabetes (T2D). The aim of the present study was to determine associations between lifestyle factors (smoking, alcohol consumption, physical activity, and diet) and T2D in American adults (aged ≥20 years) in a nationally representative sample.Data for 12 987 American adults participating in the National Health and Nutrition Examination Survey 2005-2014 were evaluated. Weighted multiple logistic regression models were used to examine associations between the four lifestyle factors and T2D after adjusting for demographics and socioeconomic status (SES). Prevalence trends for T2D were examined using Cochran-Armitage tests.There was a significant increasing prevalence trend for T2D among American adults. Smokers and individuals consuming12 alcoholic drinks in the past year were less likely to report having T2D than non-smokers (odds ratio [OR] 0.41; 95% confidence interval [CI] 0.35-0.48) and those consuming12 alcoholic drinks (OR 0.46; 95% CI 0.39-0.55). Participants with light physical activity have a greater likelihood of having T2D than those engaging in vigorous physical activity (OR 5.72; 95% CI 4.30-7.60). Individuals consuming a poor diet were more likely to report having T2D than those eating an excellent diet (OR 1.18; 95% CI 1.02-1.41). All these relationships remained significant after adjustment for demographics and SES.All four lifestyle factors were significantly associated with T2D among American adults. The findings of the present study provide useful information for healthcare providers that may help them promote specific lifestyle modifications.

Background: Prenatal exposures to polyfluoroalkyl compounds (PFCs) may be associated with adverse changes in fetal and postnatal growth. Objective: We explored associations of prenatal serum concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorohexane sulfonate (PFHxS) with fetal and postnatal growth in girls. Methods: We studied a sample of 447 singleton girls and their mothers participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Data on weight and length were obtained at birth and at 2, 9, and 20 months. Serum samples were obtained in 1991–1992, from mothers during pregnancy. We explored associations between prenatal PFC concentrations and weight at birth as well as longitudinal changes in weight-for-age SD scores between birth and 20 months. Results: PFOS (median, 19.6 ng/mL), PFOA (median, 3.7 ng/mL), and PFHxS (median, 1.6 ng/mL) were detected in 100% of samples. On average, girls born to mothers with prenatal concentrations of PFOS in the upper tertile weighed 140 g less [95% confidence interval (CI): –238, –42] at birth than girls born to mothers with concentrations in the lower tertile in adjusted models. Similar patterns were seen for PFOA (–133 g; 95% CI: –237, –30) and PFHxS (–108 g; 95% CI: –206, –10). At 20 months, however, girls born to mothers with prenatal concentrations of PFOS in the upper tertile weighed 580 g more (95% CI: 301, 858) when compared with those in the lower tertile. No differences in weight were found for PFOA and PFHxS. Conclusions: Girls with higher prenatal exposure to each of the PFCs examined were smaller at birth than those with lower exposure. In addition, those with higher exposure to PFOS were larger at 20 months.

This study examines the timing of menarche in relation to infant-feeding methods, specifically addressing the potential effects of soy isoflavone exposure through soy-based infant feeding. Subjects were participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Mothers were enrolled during pregnancy and their children have been followed prospectively. Early-life feeding regimes, categorised as primarily breast, early formula, early soy and late soy, were defined using infant-feeding questionnaires administered during infancy. For this analysis, age at menarche was assessed using questionnaires administered approximately annually between ages 8 and 14.5. Eligible subjects were limited to term, singleton, White females. We used Kaplan-Meier survival curves and Cox proportional hazards models to assess age at menarche and risk of menarche over the study period. The present analysis included 2920 girls. Approximately 2% of mothers reported that soy products were introduced into the infant diet at or before 4 months of age (early soy). The median age at menarche [interquartile range (IQR)] in the study sample was 153 months [144-163], approximately 12.8 years. The median age at menarche among early soy-fed girls was 149 months (12.4 years) [IQR, 140-159]. Compared with girls fed non-soy-based infant formula or milk (early formula), early soy-fed girls were at 25% higher risk of menarche throughout the course of follow-up (hazard ratio 1.25 [95% confidence interval 0.92, 1.71]). Our results also suggest that girls fed soy products in early infancy may have an increased risk of menarche specifically in early adolescence. These findings may be the observable manifestation of mild endocrine-disrupting effects of soy isoflavone exposure. However, our study is limited by few soy-exposed subjects and is not designed to assess biological mechanisms. Because soy formula use is common in some populations, this subtle association with menarche warrants more in-depth evaluation in future studies.

Introduction: Polyfluoroalkyl chemicals (PFCs) are commercially synthesized chemicals used in consumer products. Exposure to certain PFCs is widespread, and some PFCs may act as endocrine disruptors. We used data from the Avon Longitudinal Study of Parents and Children (ALSPAC) in the United Kingdom to conduct a nested case-control study examining the association between age at menarche, and exposure to PFCs during pregnancy. Methods: Cases were selected from female offspring in the ALSPAC who reported menarche before the age of 11.5 years (n=218), and controls were a random sample of remaining girls (n=230). Serum samples taken from the girls' mothers during pregnancy (1991–1992) were analyzed using on-line solid-phase extraction coupled to isotope dilution high-performance liquid chromatography-tandem mass spectrometry for 8 PFCs. Logistic regression was used to determine association between maternal serum PFC concentrations, and odds of earlier age at menarche. Results: PFOS and PFOA were the predominant PFCs (median serum concentrations of 19.8 ng/mL and 3.7 ng/mL). All but one PFC were detectable in most samples. Total PFC concentration varied by number of births (inverse association with birth order; p-value

This study describes the timing of puberty in 8- to 14-year-old boys enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) and identifies factors associated with earlier achievement of advanced pubic hair stages. Women were enrolled during pregnancy and their offspring were followed prospectively. We analysed self-reported pubic hair Tanner staging collected annually. We used survival models to estimate median age of attainment of pubic hair stage >1, stage >2 and stage >3 of pubic hair development. We also constructed multivariable logistic regression models to identify factors associated with earlier achievement of pubic hair stages. Approximately 5% of the boys reported Tanner pubic hair stage >1 at age 8; 99% of boys were at stage >1 by age 14. The estimated median ages of entry into stages of pubic hair development were 11.4 years [95% confidence interval (CI) 11.3, 11.4] for stage >1, 12.7 years [95% CI 12.7, 12.8] for stage >2 and 13.5 years [95% CI 13.5, 13.6] for stage >3. Predictors of younger age at Tanner stage >1 included low birthweight, younger maternal age at delivery and being taller at age 8. Associations were found between younger age at attainment of stage >2 and gestational diabetes and taller or heavier body size at age 8. Being taller or heavier at age 8 also predicted younger age at Tanner stage >3. The results give added support to the strong influence of pre-adolescent body size on male pubertal development; the tallest and heaviest boys at 8 years achieved each stage earlier and the shortest boys later. Age at attainment of pubic hair Tanner stages in the ALSPAC cohort are similar to ages reported in other European studies that were conducted during overlapping time periods. This cohort will continue to be followed for maturational information until age 17.

OBJECTIVES: The objective of this study was to explore the influence of maternal prenatal characteristics and behaviors and of weight and BMI gain during early childhood on the timing of various puberty outcomes in girls who were enrolled in the Avon Longitudinal Study of Parents and Children. METHODS: Repeated self-assessments of pubertal development were obtained from ∼4000 girls between the ages of 8 and 14. Data on prenatal characteristics and weight at birth and 2, 9, and 20 months of age were obtained from questionnaires, birth records, and clinic visits. Infants' weights were converted to weight-for-age and BMI SD scores (SDSs; z scores), and change values were obtained for the 0- to 20-month and other intervals within that age range. We used parametric survival models to estimate associations with age of entry into Tanner stages of breast and pubic hair and menarche. RESULTS: Maternal initiation of menarche at age CONCLUSIONS: Many of the maternal prenatal characteristics and weight and BMI gain during infancy seemed to have similar influences across different puberty outcomes. Either such early factors have comparable influences on each of the hormonal processes involved in puberty, or processes are linked and awakening of 1 aspect triggers the others.

Purpose Patterns of pubertal development reflect underlying endocrine function and exposures, and could affect future health outcomes. We used data from a longitudinal cohort to describe factors associated with breast and pubic hair stage and estimate average duration of puberty. Methods Data from the Avon Longitudinal Study of Parents and Children were used to describe timing and duration of pubertal development in girls. Self-reported Tanner stage of breast and pubic hair and menarche status were collected from ages 8–14 through mailed questionnaires. Factors associated with breast and pubic hair stage were identified using ordinal probit models. Age at entry into breast and pubic hair stages, and duration of puberty were estimated using interval-censored parametric survival analysis. Results Among the 3,938 participants, being overweight or obese, of non-white race, being the firstborn, and younger maternal age at menarche were associated with more advanced breast and pubic hair stages. Having an overweight or obese mother was associated with more advanced breast stages. Time spent in breast stages 2 and 3 was longer (1.5 years) than time spent in pubic hair stages 2 and 3 (1 year). The average age at menarche was 12.9 (95% CI, 12.8–12.9) years, and average duration of puberty (time from initiation of puberty to menarche) was 2.7 years. Conclusions Girls in Avon Longitudinal Study of Parents and Children had a slightly longer duration of puberty compared to an earlier British cohort study. Various maternal and child characteristics were associated with breast and pubic hair stage, including both child and maternal body mass.

Purpose The timing of breast and pubic hair development in girls are related, but the degree of correlation has not been well characterized. Periodic observations also are complicated by interval censoring. Methods Data used were from the Avon Longitudinal Study of Parents and Children. Mean age at entry into breast and pubic hair development was determined by the use of parametric survival analysis. The bivariate normal cumulative distribution function was evaluated over the region containing the paired event times; the likelihood was maximized with respect to the correlation coefficient ρ. Results Among 3938 participants, estimated mean ages at entry into Tanner stage 2 for breast and pubic hair development were 10.19 and 10.95, respectively. The likelihood was maximized at ρ = 0.503 to 0.506. This value remained relatively constant among subgroups, although some heterogeneity was observed by maternal and child body mass index and birth order. Conclusions The timing of breast and of pubic hair development is moderately correlated and remain so when it is stratified by characteristics associated with puberty.

Background: Exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have been associated with higher circulating concentrations of total cholesterol (TC) and low density ...

We evaluated the relation between term low birth weight (LBW) and ambient air levels of carbon monoxide (CO), particulate matter up to 10 microm in diameter (PM(10)), and sulfur dioxide (SO(2)). The study population consisted of singleton, term live births (37-44 weeks of gestation) born between 1 January 1994 and 31 December 1996 in six northeastern cities of the United States: Boston, Massachusetts; Hartford, Connecticut; Philadelphia, Pennsylvania; Pittsburgh, Pennsylvania; Springfield, Massachusetts; and Washington, DC. Birth data were obtained from National Center for Health Statistics Natality Data Sets. Infants with a birth weight < 2,500 g were classified as LBW. Air monitoring data obtained from the U.S. Environmental Protection Agency were used to estimate average trimester exposures to ambient CO, PM(10), and SO(2). Our results suggest that exposures to ambient CO and SO(2) increase the risk for term LBW. This risk increased by a unit increase in CO third trimester average concentration [adjusted odds ratio (AOR) 1.31; 95% confidence interval (CI) 1.06,1.62]. Infants with SO(2) second trimester exposures falling within the 25 and < 50th (AOR 1.21; CI 1.07,1.37), the 50 to < 75th (AOR 1.20; CI 1.08,1.35), and the 75 to < 95th (AOR 1.21; CI 1.03,1.43) percentiles were also at increased risk for term LBW when compared to those in the reference category (< 25th percentile). There was no indication of a positive association between prenatal exposures to PM(10) and term LBW. Increased ambient levels of air pollution may be associated with an increased risk for LBW.

Background. Lead is a persistent, toxic substance and its exposure has been associated with later puberty onset and maturity. Current literature on the role of lead on puberty timing of girls is li...

This study examines the timing of menarche in relation to infant-feeding methods, specifically addressing the potential effects of soy isoflavone exposure through soy-based infant feeding. Subjects were participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Mothers were enrolled during pregnancy and their children have been followed prospectively. Early-life feeding regimes, categorised as primarily breast, early formula, early soy and late soy, were defined using infant-feeding questionnaires administered during infancy. For this analysis, age at menarche was assessed using questionnaires administered approximately annually between ages 8 and 14.5. Eligible subjects were limited to term, singleton, White females. We used Kaplan-Meier survival curves and Cox proportional hazards models to assess age at menarche and risk of menarche over the study period. The present analysis included 2920 girls. Approximately 2% of mothers reported that soy products were introduced into the infant diet at or before 4 months of age (early soy). The median age at menarche [interquartile range (IQR)] in the study sample was 153 months [144-163], approximately 12.8 years. The median age at menarche among early soy-fed girls was 149 months (12.4 years) [IQR, 140-159]. Compared with girls fed non-soy-based infant formula or milk (early formula), early soy-fed girls were at 25% higher risk of menarche throughout the course of follow-up (hazard ratio 1.25 [95% confidence interval 0.92, 1.71]). Our results also suggest that girls fed soy products in early infancy may have an increased risk of menarche specifically in early adolescence. These findings may be the observable manifestation of mild endocrine-disrupting effects of soy isoflavone exposure. However, our study is limited by few soy-exposed subjects and is not designed to assess biological mechanisms. Because soy formula use is common in some populations, this subtle association with menarche warrants more in-depth evaluation in future studies.

Background and Aims:POPs have been shown to affect the endocrine system, particularly during critical windows of development. We examined the effect of in utero exposure to two different classes of...

Background and aims: Polyfluoroalkyl chemicals (PFCs) are commercially synthesized chemicals used in consumer products. Exposure to PFCs is widespread and some PFCs may disrupt signaling processes ...

Data from the Avon Longitudinal Study of Parents and Children were used to describe initiation of secondary sexual characteristic development of girls. Tanner stages of breast and pubic hair and menarche status were self-reported via mailed questionnaires, administered from ages 8–14. Initiation pathway was categorized as breast [thelarche] or pubic hair [pubarche] development alone, or synchronous. Average ages at beginning breast and pubic hair development were estimated using survival analysis. Factors associated with initiation pathway were assessed using logistic regression. Among the 3938 participants, the median ages at beginning breast and pubic hair development were 10.19 (95% CI: 10.14–10.24) and 10.95 (95% CI: 10.90–11.00) years. Synchronous initiation was the most commonly reported pathway (46.3%), followed by thelarche (42.1%). Girls in the pubarche pathway were less likely to be obese or overweight at age 8 or have an overweight or obese mother. Girls in the thelarche pathway were less likely to be of nonwhite race or be the third born or later child.

This study describes the timing of puberty in 8- to 13-year-old girls enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) and identifies factors associated with earlier achievement of menarche. Women were enrolled during pregnancy and their offspring were followed prospectively. We analysed self-reported Tanner staging and menstrual status information collected annually from daughters up to age 13. We used survival models to estimate median age of attainment of stage >1 and stage >2 of breast and pubic hair development and of menarche. We also constructed multivariable logistic regression models to identify factors associated with earlier achievement of menarche. About 12% of girls reported Tanner breast stage >1 at age 8; 98% of girls were above stage 1 by age 13. For pubic hair, 5% and 95% of girls had attained a stage >1 by 8 and 13 years, respectively. The estimated median age of entry into stage >1 of breast development was 10.14 years (95% confidence interval [CI], 10.08, 10.19), and for pubic hair development the median age was 10.92 years [95% CI, 10.87, 10.97]. One girl (out of 2953) had attained menarche by age 8; 60% had attained menarche by age 13. The estimated median age at menarche was 12.93 years [95% CI, 12.89, 12.98]. Prenatal predictors of menarche by age 11 (12% of girls) included earlier maternal age at menarche, high maternal pre-pregnancy body mass index, smoking during the third trimester, and non-white race; the single postnatal predictor was the girl's body size at 8 years. Age at attainment of breast and pubic hair Tanner stage and age at menarche in the ALSPAC cohort are similar to ages reported in other European studies that were conducted during overlapping time periods. The results also give added support to the strong influence of maternal maturation, pre-adolescent body size and race on the timing of a girl's menarche. This cohort will continue to be followed for maturational information until age 17.

A systematic review of the literature on the effects of air pollution on low birth weight (LBW) and its determinants, preterm delivery (PTD) and intrauterine growth restriction (IUGR), was conducted. Twelve epidemiologic investigations that addressed the impact of air pollution on four pregnancy outcomes were identified. Results were analyzed separately for each perinatal outcome because of differences in pathogenic mechanisms. Effects of air pollution were apparent on PTD and IUGR, but not on LBW. Most of the associations reported were rather small. The estimation of summary effects was not meaningful because of the heterogeneity of the effect estimates arising from differences in the measurements of outcome, exposure, and confounders and the small number of studies per outcome (four studies for PTD and six for IUGR). Current scientific knowledge on the impact of air pollution on fetal growth is still limited; thus, several issues should be examined further.

Objective: A pair-matched, case-control study was conducted to identify if risk factors or behaviors suspected to affect childhood blood lead levels, were more prevalent among children with elevated blood lead levels living in the vicinity of a defunct mining and smelting facility. Methods: Study individuals were recruited from the 1992 Silver Valley blood lead screening participants. The cases were children with a blood lead level >10 micrograms per deciliter (μg/dL). The controls were children with a blood lead level

This study assesses the degree of impairment of children's IQ scores due to exposure to lead from a storage site. In 2005, we studied 192 children in Antofagasta, Chile, age 7-16 years who had been exposed to a lead storage site from birth until its removal in 1998. We used past (1998) and current (2005) blood lead levels as explanatory variables for IQ, which was measured once in 2005 using the WISC-r test. Multilevel mixed-effects linear regression models were constructed, adjusting for potential confounders. Current blood lead level (BPb, 2005) was associated with a significant decrease in full-scale IQ (P value = 0.03), whereas blood lead level measured in 1998 (BPb, 1998) showed an inverse but not significant association with full-scale IQ (P value = 0.35). The findings provide evidence that exposure to an open source of environmental lead can exert an effect on IQ. Policy efforts should be targeted to prevent lead exposure to avoid children's intellectual impairment.