Environmental tobacco smoke and absenteeism related to respiratory illness in schoolchildren

Household environmental tobacco smoke (ETS) exposure accounts for substantial morbidity among young children, but the ETS-associated morbidity burden among school-age children is less well defined. Illness-related school absenteeism is a measure of a broad spectrum of adverse effects of ETS exposure in school-age children. The authors investigated the relations between ETS exposure, asthma status, and illness-related school absenteeism in a cohort of 1,932 fourth-grade schoolchildren from 12 southern California communities during January-June 1996. Incidence rates and adjusted relative risks of illness-related absences were determined by using an active surveillance system. The effects of ETS exposure on absenteeism were assessed by using stratified incidence rates and Poisson regression to adjust for sociodemographic factors. ETS exposure was associated with an increased risk of respiratory-illness-related school absences (relative risk (RR) = 1.27, 95% confidence interval (CI): 1.04, 1.56). Children living in a household with two or more smokers were at increased risk of such absences (RR = 1.75, 95% CI: 1.33, 2.30). Children's asthma status affected their response to ETS. Compared with unexposed children without asthma, children with asthma were at increased risk of respiratory-illness-related school absences when exposed to one (RR = 2.35, 95% CI: 1.49, 3.71) or two or more (RR = 4.45, 95% CI: 2.80, 7.07) household smokers. Children without asthma also had an increased risk if exposed to two or more smokers (RR = 1.44, 95% CI: 1.04, 2.00). Therefore, ETS exposure is associated with increased respiratory-related school absenteeism among children, especially those with asthma.     

Indoor exposure to environmental tobacco smoke and dampness: respiratory symptoms in Sardinian children--DRIAS study

Indoor exposures at home, environmental tobacco smoke (ETS) and mould/dampness adversely affect respiratory health of children. Disturbi Respiratori nell’Infanzia e Ambiente in Sardegna (DRIAS) (Respiratory Symptoms in children and the Environment in Sardegna, Italy) aims at relating the prevalence of respiratory and allergic symptoms to indoor exposures in Sardinian children.DRIAS, a cross-sectional investigation of respiratory symptoms/diseases, used a modified version of ISAAC questionnaire, included 4122 children attending 29 primary schools in the school year 2004-2005.If both parents smoke the prevalence for current wheeze and current asthma is almost doubled in comparison with never smokers, for persistent cough and phlegm a role is suggested when only mother smokes. Among mothers smoking in pregnancy, the prevalence of current wheeze and current asthma is increased. Exposure to ETS and family atopy have a joint effect resulting in an almost tripling of prevalence for current wheeze and more than four times for current asthma. Exposure to “dampness” (mould or dampness) both during the first year of life and currently is associated with increased prevalence of current wheeze, persistent cough or phlegm and current rhino-conjunctivitis; if exposure is only during the first year of life a doubling or more of prevalence is observed for current wheeze, current asthma, and persistent cough or phlegm.DRIAS results add evidence to the causal role of childhood exposure to ETS in the development of respiratory symptoms (cough, phlegm, and wheezing) and asthma. The joint effect of ETS and family atopy is corroborated. The results strengthen the evidence for a causal association between “dampness” and respiratory health, pointing to its possible independent role in causing asthma, a long-lasting exposure entails a doubled prevalence for both asthmatic and bronchitis symptoms.     

祖父母哮喘史与被动吸烟对儿童哮喘的影响效应

目的 探讨祖父母哮喘史与被动吸烟的交互作用对儿童哮喘及哮喘样症状的影响。方法 采用整群随机抽样法在辽宁省7个城市各抽取1所小学和2所幼儿园, 对所选学校所有在此居住时间≥2年且与祖父母居住时间≥3年的儿童的祖父母哮喘史、居住环境、被动吸烟等情况及呼吸系统疾病与症状的信息进行收集。采用Glimmix回归模型分析祖父母哮喘史与被动吸烟的交互作用对儿童哮喘及哮喘样症状(持续咳嗽、持续咳痰、喘鸣现患、过敏性鼻炎)的影响。结果 在调查的3 576名儿童中, 年龄为(8.11±2.87)岁, 祖父母有哮喘史的儿童有224名, 祖父母哮喘史率为6.26%;被动吸烟的儿童有970名, 被动吸烟率为27.13%。祖父母有哮喘史的儿童咳嗽、喘鸣现患和哮喘阳性率分别为16.07%(336/224), 14.29%(32/224)和13.39%(30/224), 祖父母无哮喘史的儿童为10.32%(346/3 352), 5.91%(198/3 352)和5.61%(188/3 352), 祖父母有哮喘史儿童发生咳嗽(OR=1.66, 95%CI:1.15～2.42)、喘鸣现患(OR=2.65, 95%CI:1.78～3.96)和哮喘(OR=2.60, 95%CI:1.72～3.93)的危险性较高。祖父母吸烟的儿童咳嗽和咳痰的阳性率分别为14.02%(136/970)和6.19%(60/970), 祖父母吸烟的儿童发生咳嗽(OR=1.56, 95%CI:1.25～1.96)和咳痰(OR=1.57, 95%CI:1.13～2.18)的危险性较高。Glimmix回归模型分析显示, 祖父母有哮喘史与被动吸烟对儿童哮喘及哮喘样症状存在交互影响:在儿童被动吸烟暴露下, 祖父母有哮喘史的儿童发生咳痰的危险性高于祖父母无哮喘史儿童(P<0.05)。结论 祖父母有哮喘史使被动吸烟的儿童发生哮喘及哮喘样症状的危险性升高。     

Childbearing characteristics of U.S.- and foreign-born Hispanic mothers

This study compares maternal and infant health and sociodemographic characteristics of U.S.-born and foreign- or Puerto Rican-born Hispanic mothers and their babies, using data from the national vital statistics system and the 1980 National Natality Survey. While nearly half of all Hispanic mothers and Mexican and Puerto Rican mothers were born in the United States, less than 10 percent of Cuban and other Hispanic mothers were U.S. born. Compared with foreign- or Puerto Rican-born Hispanic mothers, U.S.-born mothers tended to be younger, to have had fewer high-order births, to be less likely to receive delayed or no prenatal care, to have higher educational attainment, and to be more likely to be unmarried. The incidence of low birth weight among infants born to Hispanic mothers, particularly Mexican and Cuban women, was relatively low. When the proportions of low birth weight were examined by nativity status, infants born to foreign- or Puerto Rican-born women were consistently less likely to be of low birth weight. In an effort to account for these findings, the mother's smoking status before and during pregnancy is examined. Compared with non-Hispanic mothers, Hispanic mothers were much less likely to have smoked before or during pregnancy. These data are examined to see if they account for the better outcome as measured by birth weight for Hispanic births, especially those to foreign- or Puerto Rican-born women.     

Factor analysis of household factors: are they associated with respiratory conditions in Chinese children?

BACKGROUND: We explored methods to develop uncorrelated variables for epidemiological analysis models. They were used to examine associations between respiratory health outcomes and multiple household risk factors. METHODS: We analysed data collected in the Four Chinese Cities Study (FCCS) to examine health effects on prevalence rates of respiratory symptoms and illnesses in 7058 school children living in the four Chinese cities: Lanzhou, Chongqing, Wuhan, and Guangzhou. We used factor analysis approaches to reduce the number of the children's lifestyle/household variables and to develop new uncorrelated 'factor' variables. We used unconditional logistic regression models to examine associations between the factor variables and the respiratory health outcomes, while controlling for other covariates. RESULTS: Five factor variables were derived from 21 original variables: heating coal smoke, cooking coal smoke, socioeconomic status, ventilation, and environmental tobacco smoke (ETS) and parental asthma. We found that higher exposure to heating coal smoke was associated with higher reporting of cough with phlegm, wheeze, and asthma. Cooking coal smoke was not associated with any of the outcomes. Lower socioeconomic status was associated with lower reporting of persistent cough and bronchitis. Higher household ventilation was associated with lower reporting of persistent cough, persistent phlegm, cough with phlegm, bronchitis, and wheeze. Higher exposure to ETS and the presence of parental asthma were associated with higher reporting of persistent cough, persistent phlegm, cough with phlegm, bronchitis, wheeze, and asthma. CONCLUSIONS: Our study suggests that independent respiratory effects of exposure to indoor air pollution, heating coal smoke, and ETS may exist for the studied children.     

Predictors of asthma in young children: does reporting source affect our conclusions?

Both the size and statistical significance of sociodemographic and early health risk factors on childhood asthma vary across studies, in part because some studies rely on parents' retrospective reports of health conditions while others are based on medical records. The authors compare predictors of asthma alternately using maternal reports and medical records for the same set of children. Data are from the 1988 National Maternal and Infant Health Survey and 1991 Longitudinal Follow-up, which collected information from birth certificates, medical records, and mothers of a nationally representative, population-based cohort, allowing comparison across data sources for a consistent sample of young children in the United States. Concordance between maternal reports and medical records on asthma is moderate (kappa = 0.48). The authors find considerable discrepancies in both the estimated prevalence of asthma and the distribution across children with different sociodemographic and health characteristics, depending on the source of asthma data. Black race, male gender, and preterm birth are found to be risk factors for asthma regardless of data source. Poverty, large family size, urban residence, maternal smoking, and breastfeeding are significantly associated with asthma based on maternal reports but not medical records. Lower health care utilization among poor, uninsured, and urban children may account for part of the discrepancy.     

The exposure of nonsmoking and smoking mothers to environmental tobacco smoke during different gestational phases and fetal growth

We studied the impact of maternal exposure to environmental tobacco smoke (ETS) on birth weight (BW), low birth weight (LBW), and intrauterine growth retardation (IUGR) according to self-reported maternal smoking habits in a sample of 6,866 singleton births. We obtained data about parental characteristics and maternal active smoking (AS) and passive smoking at delivery via maternal questionnaires and medical records. We used three categories of smoking habits (nonsmokers and those who smoked 1-10 or >10 cigarettes per day) and defined ETS exposure as greater than or equal to 5 cigarettes per day smoked by others in the mother's presence. We used multiple regression and logistic regression procedures with adjustment for many associated covariates. We observed a significant reduction of the mean BW in infants of AS mothers. This reduction was only marginal for mothers who stopped smoking after recognizing their pregnancy. ETS exposure in 1,797 of 5,507 nonsmoking mothers reduced the mean BW of their infants by 53 g [95% confidence interval (CI), 24-82 g]. ETS exposure also significantly reduced BW in babies of AS mothers by 92 g (CI, 21-113 g) compared with BW of ETS-nonexposed AS mothers. The adjusted odds ratio (AOR) of LBW for ETS-exposed AS mothers was two times the LBW risk of ETS-nonexposed AS mothers(2.02; CI, 1.11-3.67); the AOR of ETS-exposed nonsmoking mothers was 1.51 (CI, 1.02-2.26). The AOR of IUGR for this group did not differ from unity (1.08; CI, 0.82-1.43). However, ETS exposure increased the AOR of IUGR for AS mothers from 1.64 (CI, 1.06-2.53) to 2.13 (CI, 1.70-2.67). ETS exposure reduced the BW of infants of nonsmoking mothers and contributed to additional BW reduction in infants of AS mothers. ETS exposure increased the risk of LBW but not that of IUGR in babies of nonsmoking mothers.     

Birth Outcomes of Immigrant Women in the United States,France, and Belgium

Objectives: To compare maternal characteristics and birth outcomes of Mexico-born and native-born mothers in the United States and those of North African mothers living in France and Belgium to French and Belgian nationals. Methods: We examined information from single live birth certificates for 285,371 Mexico-born and 3,131,632 U.S.-born mothers (including 2,537,264 U.S.-born White mothers) in the United States, 4,623 North African and 103,345 Belgian mothers in Belgium, and a French national random sample consisting of 632 North African and 11,185 French mothers. The outcomes were mean birthweight, low birthweight, and preterm births. Differences between native/nationals and foreign-born mothers in each country were assessed in bivariate and multivariate analyses controlling for maternal risk factors. Results: The adjusted odds for low birthweight were lower for immigrants than native/nationals by 32% in the United States, by 32% in Belgium, and by 30% in France. The adjusted odds for preterm births were lower for immigrants compared with native/nationals by 11% in the United States and by 23% in Belgium. In France, the odds for preterm births were comparable for immigrants and naturalized mothers. Infants of immigrant mothers also had higher mean birthweights in all three countries. Conclusion: Despite their disadvantaged status, Mexico-born and North African-born women residing in the United States, France, and Belgium show good birth outcomes. These cannot be explained solely by traditional risk factors. Protective factors and selective migration may offer further clues.     

Childhood lead poisoning in Washington state: A statewide survey

Although childhood lead poisoning is an important health issue in the United States, it is not distributed evenly across the country. To estimate the prevalence of childhood lead poisoning in Washington State, the authors conducted a birth certificate follow-back survey of 1- to 2-year-old children. Interviewers visited participating families at their homes to conduct blood lead tests with a portable testing device. The estimated prevalence of lead poisoning for all 1- to 2-year-old children in the state was 0.9% (95% confidence interval [CI]: 0.3-2.7); for Hispanic children in central Washington, it was 3.7% (95% CI: 1.3-10.2), and their risk of lead poisoning was significantly higher than that of all other children in the state (relative risk [RR] = 5.8, 95% CI: 1.3-24.9). Lead poisoning prevalence in Washington State children is lower than the US average and is highest among Hispanic children in central Washington.     

Rethinking race/ethnicity, income, and childhood asthma: racial/ethnic disparities concentrated among the very poor

OBJECTIVE: Past studies of the prevalence of childhood asthma have yielded conflicting findings as to whether racial/ethnic disparities remain after other factors, such as income, are taken into account. The objective of this study was to examine the association of race/ethnicity and family income with the prevalence of childhood asthma and to assess whether racial/ethnic disparities vary by income strata. METHODS: Cross-sectional data on 14,244 children aged <18 years old in the 1997 National Health Interview Survey were examined. The authors used logistic regression to analyze the independent and joint effects of race/ethnicity and income-to-federal poverty level (FPL) ratio, adjusting for demographic covariates. The main outcome measure was parental report of the child having ever been diagnosed with asthma. RESULTS: Bivariate analyses, based on weighted percentages, revealed that asthma was more prevalent among non-Hispanic black children (13.6%) than among non-Hispanic white children (11.2%; p<0.01), but the prevalence of asthma did not differ significantly between Hispanic children (10.1%) and non-Hispanic white children (11.2%; p=0.13). Overall, non-Hispanic black children were at higher risk for asthma than non-Hispanic white children (adjusted odds ratio [OR]=1.20; 95% confidence interval [CI] 1.03, 1.40), after adjustment for sociodemographic variables, including the ratio of annual family income to the FPL. Asthma prevalence did not differ between Hispanic children and non-Hispanic white children in adjusted analyses (adjusted OR=0.85; 95% CI 0.71, 1.02). Analyses stratified by income revealed that only among children from families with incomes less than half the FPL did non-Hispanic black children have a higher risk of asthma than non-Hispanic white children (adjusted OR=1.99; 95% CI 1.09, 3.64). No black vs. white differences existed at other income levels. Subsequent analyses of these very poor children that took into account additional potentially explanatory variables did not attenuate the higher asthma risk for very poor non-Hispanic black children relative to very poor non-Hispanic white children. CONCLUSIONS: Non-Hispanic black children were at substantially higher risk of asthma than non-Hispanic white children only among the very poor. The concentration of racial/ethnic differences only among the very poor suggests that patterns of social and environmental exposures must overshadow any hypothetical genetic risk.     

Early-life indoor environmental exposures increase the risk of childhood asthma

We aim to explore the relationships between exposure to dampness, pets, and environmental tobacco smoke (ETS) early in life and asthma in Taiwanese children, and to discuss their links to early- and late-onset asthma. We conducted a 1:2 matched case-control study from the Taiwan Children Health Study, which was a nationwide study that recruited 12-to-14 year-old school children in 14 communities. The 579 mothers of the participants were interviewed by telephone about their children's environmental exposures before they were 5 years old, including the in-utero period. Childhood asthma was associated with exposure to early life environmental factors, such as cockroaches (OR = 2.16; 95% CI, 1.15–4.07), visible mould (OR = 1.75; 95% CI, 1.15–2.67), mildewy odors (OR = 5.04; 95% CI, 2.42–10.50), carpet (OR = 2.36; 95% CI, 1.38–4.05), pets (OR = 2.11; 95% CI, 1.20–3.72), and more than one hour of ETS per day (OR = 1.93; 95% CI, 1.16–3.23). The ORs for mildewy odors, feather pillows, and ETS during early childhood were greater among children with late-onset asthma. Cockroaches, carpet, pets, and in-utero exposures to ETS affected the timing of early-onset asthma. Exposure to these factors led to dose-responsiveness in the risk of asthma. And the earlier exposures may trigger the earlier onset. Interventions in avoiding these environmental exposures are necessary for early-prevention of childhood asthma.     

Disparities in exposure to air pollution during pregnancy

Previous research shows poorer birth outcomes for racial and ethnic minorities and for persons with low socioeconomic status (SES). We evaluated whether mothers in groups at higher risk for poor birth outcomes live in areas of higher air pollution and whether higher exposure to air pollution contributes to poor birth outcomes. An index representing long-term exposure to criteria air pollutants was matched with birth certificate data at the county level for the United States in 1998-1999. We used linear regression to estimate associations between the air pollution index and maternal race and educational attainment, a marker for SES of the mother, controlling for age, parity, marital status, and region of the country. Then we used logistic regression models both to estimate likelihood of living in counties with the highest levels of air pollution for different racial groups and by educational attainment, adjusting for other maternal risk factors, and to estimate the effect of living in counties with higher levels of air pollution on preterm delivery and births small for gestational age (SGA). Hispanic, African-American, and Asian/Pacific Islander mothers experienced higher mean levels of air pollution and were more than twice as likely to live in the most polluted counties compared with white mothers after controlling for maternal risk factors, region, and educational status [Hispanic mothers: adjusted odds ratio (AOR) = 4.66; 95% confidence interval (95% CI), 1.92-11.32; African-American mothers: AOR = 2.58; 95% CI, 1.00-6.62; Asian/Pacific Islander mothers: AOR = 2.82; 95% CI, 1.07-7.39]. Educational attainment was not associated with living in counties with highest levels of the air pollution index (AOR = 0.95; 95% CI, 0.40-2.26) after adjusting for maternal risk factors, region of the country, and race/ethnicity. There was a small increase in the odds of preterm delivery (AOR = 1.05; 95% CI, 0.99-1.12) but not SGA (AOR = 0.96; 95% CI, 0.86-1.07) in a county with high air pollution. Additional risk of residing in areas with poor air quality may exacerbate health problems of infants and children already at increased risk for poor health.     

We have to live in the future

The main purpose of our study was to assess the effects of prenatal tobacco smoke on respiratory symptoms and on doctor consultations in a birth cohort of 445 infants who had no smoking mothers and who had no postnatal exposure to environmental tobacco smoke (ETS). Before and after delivery, questionnaires and interviews with mothers were administered to solicit information on prenatal and postnatal ETS exposure. Newborns were followed‐up over six months of life, and respiratory outcomes such as runny or stuffed nose, cough with or without cold, difficult (puffed) breathing, wheezing or whistling in the chest irrespective of respiratory infection were considered. In addition, medical visits related to the occurrence of respiratory symptoms were recorded for each child over a six‐month study period. In the multivariate Poisson regression analysis, a set of potential confounders has been taken into account such as gender of child, season of birth, gestational age, maternal education, maternal atopy, presence of moulds in households and prenatal level of personal exposure to fine particles. The adjusted rate ratio (RR) estimated for the occurrence of episodes of running nose was significantly higher in infants exposed to prenatal ETS (1.40; 95% confidence interval [CI]: 1.11–1.68) and the corresponding RR estimates for cough, difficult breathing and wheezing were 1.49 (95% CI: 1.15–1.93), 1.96 (95% CI: 1.22–3.16) and 5.12 (95% CI: 2.86–9.16). The rate ratios of doctor consultations attributable to prenatal ETS because of cough was 1.94 (95% CI: 1.49–2.54). The risk estimate for consultations due to difficult breathing was 2.77 (95% CI: 1.76–4.36), and that for wheezing was 5.86 (95% CI: 3.56–9.64). The data strongly support the view about the impact of the in‐utero effect of passive smoking on children’s respiratory health. Higher utilization rates of doctor consultations in infants attributable to prenatal ETS exposure demand the revision of public health policy, which should be focused also on cessation of smoking practices by all household members during and after the pregnancy period.     

Neural tube defects along the Texas-Mexico border, 1993-1995.

In response to a 1991 anencephaly cluster in Cameron County, Texas, a surveillance and neural tube defect (NTD) recurrence prevention project for NTDs was implemented in the 14 Texas-Mexico border counties. For 1993-1995, NTD-affected pregnancies were identified at all gestational ages through active surveillance of multiple case-ascertainment sources. There were 87 cases of anencephaly, 96 cases of spina bifida, and 14 cases of encephalocele for respective rates of 6.4, 7.1, and 1.1 per 10,000 live births. Of the 197 NTD case-women, 93% were Hispanic. The overall, Hispanic, and Anglo NTD rates were, respectively, 14.6, 14.9, and 10.6 per 10,000 live births. The NTD rate for El Paso County (9.8 per 10,000), the most northwestern Texas county, was significantly lower (p = 0.001) than the aggregate rate for the rest of the Texas border (17.1 per 10,000). The overall Texas border rate was significantly higher (p < 0.001) than a recently estimated rate of 9.3 for California and minimally higher than a recently adjusted rate of 11.3 for the Metropolitan Atlanta Congenital Defects Program counties (p = 0.052), both of which now reflect all gestational ages. Of the 197 Texas border cases, 85% (168 cases) reached a gestational age of > or =20 weeks. Excluding cases of <20 weeks' gestation in the rate had a more marked effect on reducing the anencephaly rate (4.9 per 10,000) than the spina bifida rate (6.7 per 10,000). A country of birth was known for 153 (83%) of the 184 Hispanic case-women: 63% were born in Mexico; 24%, in Texas; and 11%, elsewhere in the United States. Rates for Mexico-born Hispanic women (15.1 per 10,000) were significantly higher than rates for United States-born Hispanic women (9.5 per 10,000) (p = 0.006).     

Environmental tobacco smoke exposure in children: parental perception of smokiness at home and other factors associated with urinary cotinine in preschool children

Parental smoking behavior at home and sociodemographic variables may influence exposure to environmental tobacco smoke (ETS) in children. A sample of 115 preschool children aged 3-6 years was enrolled in this study. ETS exposure was evaluated through a questionnaire about parents' smoking behavior and determinations of urinary cotinine -- a biomarker of exposure -- in children. Bivariate and multiple regression analyses were used to evaluate the association between the smoking behavior of each parent at home, sociodemographic factors and cotinine levels in children. The parental perception of smokiness in the home was significantly associated with urinary cotinine in children (r-partial coefficient=0.324; P<0.002). The father's education, mother's smoking status, and day of the week when urine was sampled (Tuesday) were also independently associated with levels of cotinine. These four variables explained 26.4% of the variance in the cotinine levels of children. In designing educational programs to reduce passive smoking among children, it is necessary to take into account those factors related with cotinine levels in children. Our results support the influence of the mothers' smoking status, the fathers' educational level, and the day of the week of sampling on cotinine in children. The perception of parents (smokers and nonsmokers) about the smokiness in the home could also be a useful indicator of the cotinine in children exposed to environmental tobacco smoke in the household.     

Understanding the increased risk of neural tube defect-affected pregnancies among Mexico-born women in California: immigration and anthropometric factors

Mexico-born women in the United States have an unexplained twofold increased risk of neural tube defect (NTD)-affected pregnancies. We examined whether immigration characteristics were associated with the NTD risk and whether anthropometric factors contributed to the increased risk among Mexico-born women. Data were derived from a large population-based case-control study in California. In-person interviews were conducted with mothers of 538 (88% of eligible) NTD-affected fetuses/infants and mothers of 539 (88%) randomly selected non-malformed control infants. The crude odds ratio (OR) for NTDs among all Mexico-born women, women residing <2 years in the US, and women >16 years old at immigration compared with non-Hispanic white women was 2.4 [95% confidence interval (CI) = 1.8, 3.3], 7.2 [95% CI = 3.7, 14.0] and 3.0 [95% CI = 2.0, 4.4], respectively. Risk for second- or third-generation Mexican-Americans was similar to that of white women. The crude OR for all Mexico-born women was reduced from 2.4 to 2.0 [95% CI = 1.3, 3.0] and for those residing <2 years in the US from 8.4 to 7.1 [95% CI = 3.2, 15.3] after adjustment for maternal body mass index (BMI), height, compromised diet, diabetes, and other known risk factors. In term pregnancies, additional adjustment for pregnancy weight gain reduced the OR in all Mexico-born women and recent immigrants by 16% and 25%, respectively. Low pregnancy weight gain (<10 vs. 10-14 kg) was particularly associated with increased NTD risk among Mexico-born women (OR(ADJ) = 5.8; 95% CI = 2.1, 15.8). Findings indicate that recent Mexican immigrants have a sevenfold increased risk for NTDs. Maternal BMI and height contributed very little, and inadequate weight gain contributed modestly to the NTD risk disparity for Mexican immigrants.     

Increased burden of respiratory disease in the first six months of life due to prenatal environmental tobacco smoke: Krakow birth cohort study

The main purpose of our study was to assess the effects of prenatal tobacco smoke on respiratory symptoms and on doctor consultations in a birth cohort of 445 infants who had no smoking mothers and who had no postnatal exposure to environmental tobacco smoke (ETS). Before and after delivery, questionnaires and interviews with mothers were administered to solicit information on prenatal and postnatal ETS exposure. Newborns were followed-up over six months of life, and respiratory outcomes such as runny or stuffed nose, cough with or without cold, difficult (puffed) breathing, wheezing or whistling in the chest irrespective of respiratory infection were considered. In addition, medical visits related to the occurrence of respiratory symptoms were recorded for each child over a six-month study period. In the multivariate Poisson regression analysis, a set of potential confounders has been taken into account such as gender of child, season of birth, gestational age, maternal education, maternal atopy, presence of moulds in households and prenatal level of personal exposure to fine particles. The adjusted rate ratio (RR) estimated for the occurrence of episodes of running nose was significantly higher in infants exposed to prenatal ETS (1.40; 95% confidence interval [CI]: 1.11-1.68) and the corresponding RR estimates for cough, difficult breathing and wheezing were 1.49 (95% CI: 1.15-1.93), 1.96 (95% CI: 1.22-3.16) and 5.12 (95% CI: 2.86-9.16). The rate ratios of doctor consultations attributable to prenatal ETS because of cough was 1.94 (95% CI: 1.49-2.54). The risk estimate for consultations due to difficult breathing was 2.77 (95% CI: 1.76-4.36), and that for wheezing was 5.86 (95% CI: 3.56-9.64). The data strongly support the view about the impact of the in-utero effect of passive smoking on children's respiratory health. Higher utilization rates of doctor consultations in infants attributable to prenatal ETS exposure demand the revision of public health policy, which should be focused also on cessation of smoking practices by all household members during and after the pregnancy period.     

Effect of Maternal Birthplace on Gestational Diabetes Prevalence in Colorado Hispanics

(1) Describe gestational diabetes mellitus (GDM) prevalence time trends in USborn (USWH) and Mexico-born (MWH), white Hispanic Colorado women and (2) Determine effect of maternal birthplace on GDM prevalence. Retrospective population-based study of 1995–2004 Colorado birth certificate data for live, singleton births to white, Hispanic mothers estimated prevalence, trends, and association of GDM and maternal birthplace. Univariate, bivariate and logistic regression analyses were conducted. GDM prevalence in 154,957 births increased in both USWH (1.77–2.53%, P < 0.0001) and MWH (2.38–3.08%, P < 0.0001). Over study years, MWH had higher crude odds (OR = 1.30; 95% CI = 1.22–1.38) for developing GDM than USWH. Adjustment for maternal age and maternal education reduced GDM risk by birth country (OR = 1.05; 95% CI = 0.98–1.13, P = ns). GDM prevalence increased in both US-born and Mexico-born, white, Hispanic Colorado women. Mexico-born immigrant women may have increased risk for GDM compared with their USborn counterparts. Lower education attainment may be determinant of disease risk.     

Salivary Cotinine,Doctor-diagnosed Asthma and Respiratory Symptoms in Primary Schoolchildren

Due to impaired airway function, children are at risk for adverse respiratory symptoms if exposed to environmental tobacco smoke (ETS). A community-based, cross-sectional study of 425 children (5–11 years) attending 15 primary schools in a low socio-economic area of Merseyside/UK was undertaken to investigate the association of adverse respiratory symptoms and ETS exposure using a parent-completed questionnaire and children’s salivary cotinine measurements. Overall, 28.9% of children had doctor-diagnosed asthma (DDA) and 11.3% a history of hospital admission for respiratory illnesses. The symptom triad of cough, wheeze and breathlessness (C+W+B+) occurred in 12.6% of children. The geometric mean cotinine level was 0.37 ng/ml (95% CI, 0.33–0.42 ng/ml) and it was estimated that 45.6% of children were ETS exposed. A history of asthma in the family was reported for 9.2% of fathers and 7.2% of mothers. Salivary cotinine level was significantly increased in children with DDA compared to those without (P = 0.002). Cotinine-validated levels [adjusted odds ratio (AOR), 1.8; 95% CI, 1.4–2.5), low socio-economic (disadvantaged) status (AOR, 1.4; 1.1–2.9), child’s male gender (AOR, 1.6; 1.1–2.5) and maternal smoking (AOR, 2.2; 1.4–3.1) were significantly associated with DDA. The cotinine-validated level (AOR, 1.4; 1.1–2.9) as well as maternal smoking (AOR, 1.8; 1.1–2.5), were also independently associated with C+W+B+. The use of salivary cotinine as an indicator of ETS exposure could be used to inform parents of exposure risk to their asthmatic children and may help re-enforce deterrent efforts to reduce childhood parental smoking exposure.     

Residential mobility patterns and exposure misclassification in epidemiologic studies of birth defects

Many studies of environmental exposures and birth defects use mothers' addresses at delivery as a proxy for the exposure. The validity of these studies is questionable because birth defects generally occur within 8 weeks of conception and the mother's address at delivery may differ from her address early in pregnancy. In order to assess the extent of this bias, we examined the pattern of maternal residential mobility over the span of 3 months prior to conception through delivery, and associated maternal socio-demographic characteristics. We linked Texas subjects from a national case-control study of birth defects with their corresponding records from the Texas Birth Defects Registry and the Texas live birth certificates. Logistic regression analyses were conducted to assess maternal socio-demographic factors related to mobility during pregnancy. Overall, 33% of case and 31% of control mothers changed residence between conception and delivery. The pattern of mobility was similar for both case and control mothers for each pregnancy period. Multivariate analyses indicated that for case mothers, older age (OR=0.39, 95% CI=0.21-0.70), higher household income (OR=0.35, 95% CI=0.18-0.68), Hispanic ethnicity (OR=0.64, 95% CI=0.44-0.92), and higher parity (OR=0.59, 95% CI=0.38-0.94) were indicators of lower mobility during pregnancy. For control mothers, the same pattern of association was present, however, only older age was significantly associated with low rates of mobility. Studies of birth defects using maternal address at delivery as a proxy for maternal environmental exposures during pregnancy may be subject to considerable nondifferential exposure misclassification due to maternal mobility during pregnancy.