Exposure to environmental tobacco smoke in pregnant women: the association between self-report and serum cotinine

Effect of gestational smoke exposure on atopic dermatitis in the offspring

The adverse impact of smoking on respiratory diseases and birth outcomes in children is well-known. However, the influence of smoke exposure including environmental tobacco smoke (ETS) and maternal smoking during pregnancy on atopic dermatitis (AD) is not clear. The purpose of this study was to evaluate the effect of gestational smoke exposure on the development of AD in the offspring on the basis of the maternal and cord blood cotinine. We recruited 261 mother and newborn pairs in 2004. Cord blood and information on perinatal factors of children were gathered at birth. At 2 yr of age, information about development of AD and environmental exposures were collected. We compared AD with non-AD children for the concentration of cotinine in cord and maternal blood measured by high performance liquid chromatography-mass spectrometry. Multiple logistic regressions were performed to estimate the relationship of cotinine levels and AD. About 150 mother and child pairs completed the follow-up study and specimen collection with 38 (25.3%) children developing AD. Two (1.3%) out of 150 mothers smoked during pregnancy, while 38 (25.3%) mothers reported having ETS exposure. Cotinine levels in cord blood and maternal blood were highly correlated (r = 0.71, p < 0.001). The risk of AD was found to increase with maternal and cord blood cotinine levels in a dose-response manner (p for trend = 0.01). Children exposed to high levels (>75th percentile) had a significantly increased risk of AD. Smoke exposure during pregnancy might increase the risk of AD in children. Avoidance of prenatal smoke exposure may be warranted for early prevention.

Genetic susceptibilities in the association between maternal exposure to tobacco smoke and the risk of nonsyndromic oral cleft

Maternal tobacco consumption is considered as a risk factor for nonsyndromic oral clefts. However, this risk is moderate and may be modulated by genetic susceptibilities, including variants of the TGFA, TGFB3 and MSX1 developmental genes and polymorphisms of genes of the CYP (1A1, 2E1) and GST (M1, T1) families involved in metabolic pathways of tobacco smoke compounds. This French case-control study (1998-2001; 240 nonsyndromic cases, 236 controls) included a case-parent design (175 triad-families) that made it possible to distinguish the direct effect of the child's genotype and maternally mediated effects. Maternal smoking during the first trimester of pregnancy was not associated with the oral cleft risk in this population, but we observed statistically significant increased risks associated with maternal exposure to environmental tobacco smoke (ETS). No variant of any of the three developmental genes was significantly associated with oral cleft. The fetal CYP1A1*2C variant allele was associated with a statistically significant decreased risk, compared with the homozygous wild-type: relative risk = 0.48, 95% confidence interval: 0.2, 1.0. Suggestive reduced risks were also observed for the maternal CYP1A1*2C allele and the fetal CYP2E1*5 allele. The GSTM1 and GSTT1 deletions appeared to play no role. Our findings suggest some interactions, with the strongest between ETS and CYP1A1 or MSX1 and between maternal smoking and CYP2E1. We did not confirm the maternal smoking-infant GSTT1 null interaction previously reported by other investigators.

Association of environmental toxicants and conduct disorder in U.S. children: NHANES 2001-2004

OBJECTIVE

The purpose of this study was to examine the association of tobacco smoke and environmental lead exposure with conduct disorder (CD).

METHODS

The National Health and Nutrition Examination Survey (NHANES) 2001-2004 is a nationally representative cross-sectional sample of the noninstitutionalized U.S. population. We examined the association of prenatal tobacco, postnatal tobacco, and environmental lead exposure with CD in children 8-15 years of age (n = 3,081). We measured prenatal tobacco exposure by parent report of cigarette use during pregnancy, and postnatal tobacco using serum cotinine levels. We assessed lead exposure using current blood lead concentration. Parents completed the Diagnostic Interview Schedule for Children to determine whether their children met criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV ) for CD.

RESULTS

Overall, 2.06% of children met DSM-IV criteria for CD in the past year, equivalent to 560,000 U.S. children 8-15 years of age. After adjustment, prenatal tobacco exposure was associated with increased odds for CD [odds ratio (OR) = 3.00; 95% confidence interval (CI), 1.36-6.63]. Increased blood lead levels (fourth vs. first quartile) and serum cotinine levels (fifth vs. first quintile) were associated with an 8.64-fold (95% CI, 1.87-40.04) and 9.15-fold (95% CI, 1.47-6.90) increased odds of meeting DSM-IV CD criteria. Increasing serum cotinine levels and blood lead levels were also associated with increased prevalence of CD symptoms (symptom count ratio, lead: 1.73; 95% CI, 1.23-2.43; symptom count ratio, cotinine: 1.97; 95% CI, 1.15-3.40).

CONCLUSIONS

These results suggest that prenatal tobacco exposure and environmental lead exposure contribute substantially to CD in U.S. children.

Comparison of urinary and plasma cotinine levels during the three trimesters of pregnancy

Assays of metabolised cotinine are considered to be an accurate measure of exposure to cigarette smoke among pregnant women. We investigated the association and differences between the cotinine levels in maternal urine and blood, and the umbilical cord blood of three tobacco exposure groups at different stages of pregnancy. A prospective study was conducted among 398 pregnant women undergoing prenatal care in different trimesters at two medical centres and one regional hospital in central Taiwan. All 398 subjects (including 25 smokers, 191 passive smokers and 182 non-smokers) remained in the study up to the time of delivery; 384 of them delivered singleton live births. Cotinine levels were assayed in the maternal plasma and urine of the mothers at each trimester and in the cord blood of the newborns. All specimens were measured using a sensitive high-performance liquid chromatography. Cotinine concentrations in plasma and urine showed a significant dose-dependent difference among the three groups (non-smoker, passive and active smoker) and a trend that increased with gestation among the pregnant women. Significant correlations between cotinine concentrations in plasma and urine among the pregnant women in each trimester were found. In addition, the level of cotinine in umbilical cord blood was significantly correlated with that in maternal blood at term (r = 0.89, P < 0.001). A pattern of elevated cotinine concentrations in the plasma and urine of pregnant women from the beginning to the end of pregnancy was found, and this correlated significantly with the cotinine levels in the umbilical cord blood.

Fetal exposure to secondhand tobacco smoke assessed by maternal self-reports and cord blood cotinine: prospective cohort study in Krakow

OBJECTIVES

While the validity of self-reported smoking habits is generally judged as satisfactory, objective markers of secondhand smoke (SHS) exposure may be more useful in validating the causal links between prenatal SHS and health effects. The cohort study in Krakow provided an opportunity for comparative assessment of fetal exposure to SHS based upon questionnaires and cord blood cotinine measurements.

METHODS

The study sample included 467 newborns born to women recruited in the first and second trimester of pregnancy. To compare the validity of self-reported SHS and cord blood cotinine levels in assessing the association between fetal passive smoking and health effects of newborns, we separately examined the regression coefficients of birthweight on self-reported number of cigarettes smoked by other household members during the entire pregnancy and cord blood cotinine levels.

RESULTS

In the non-exposed newborns the geometric mean of cord blood cotinine was 0.077 ng/ml and was significantly lower than in newborns with a maternal report of SHS. Cord cotinine levels were more highly correlated with a self-reported number of cigarettes smoked daily at home in the third trimester of pregnancy. The two measures of SHS (number of cigarettes and number of hours of daily exposure) were equally well correlated with cord blood cotinine levels. Using cotinine as the exposure variable, overall the association was not significant; but among the subgroup with cord cotinine levels above the median (> or =0.083 ng/ml), the association with birthweight was significant (beta coefficient = -113.65, P = 0.041).

CONCLUSION

The study provides evidence that the assessment of fetal SHS exposure based on cord blood cotinine produced better estimates of the association between exposure and birth outcomes.

Secondhand tobacco smoke exposure, nicotine dependence, and smoking cessation

OBJECTIVE

To explore the association among the number of sources of secondhand tobacco smoke (SHS) exposure, nicotine dependence (ND), and smoking cessation.

DESIGN

A secondary analysis of cross-sectional data. Responses for the main study were obtained in 2001 from a controlled trial of the Quit and Win Tobacco Free Contest in Kentucky.

SAMPLE

822 current smokers.

MEASUREMENTS

Demographic variables (age, gender, educational status, income, and ethnicity) the number of sources of SHS exposure, smoking frequency, length of abstinence from smoking, age of smoking initiation, smoking cessation attempts, intentions to quit smoking, and ND.

RESULTS

The number of sources of SHS exposure was associated with higher ND and smoking frequency, and related to low intentions and attempts to quit smoking. The number of sources of SHS exposure contributed to 11% of the variance in the final ND model, after accounting for control and potential mediating variables.

CONCLUSIONS

The number of sources of SHS exposure may be an important factor influencing ND and intentions and attempts to quit smoking. Further studies are needed to explore the association between SHS exposure and ND among smokers to guide treatment and policy development.

Occult maternal exposure to environmental tobacco smoke exposure

BACKGROUND

Environmental tobacco smoke (ETS) is a recognised air pollutant. Its harmful effects have been found to be implicated in health disorders, including unfavourable pregnancy outcomes. The discrepancy between self-reported environmental tobacco smoke exposure and cotinine levels in pregnant non-smokers in France was examined.

METHOD

Plasma cotinine was determined by a CPG-SM method on women who had answered a self-questionnaire describing their habits and environment during pregnancy.

RESULTS

Of 698 pregnant women reported as non-smokers, 305 (43.7%) claimed not to be exposed to ETS, yet 196 of these (64.3%) had plasma cotinine levels above the limit of detection.

CONCLUSION

Self-reported data on ETS exposure in pregnant women therefore underestimate actual exposure. However, cotinine assay can rectify this misclassification. An accurate identification of this risk factor will help to change attitudes towards ETS and avert its adverse effects on mother and fetus.

Secondhand smoke and nicotine exposure: a brief review

Secondhand tobacco smoke exposure is linked to a number of adverse health outcomes. This paper reviews published studies examining nicotine levels related to exposure to secondhand tobacco smoke. Twenty-two field studies measuring biological levels of nicotine associated with secondhand tobacco smoke exposure were evaluated. Positive associations between self-reported and/or objective measures of secondhand tobacco smoke exposure and concentrations of nicotine and/or biomarkers of nicotine in the body were frequently reported. Two studies indicated that nicotine exposure from secondhand tobacco smoke can engender plasma nicotine concentrations that are equivalent to levels produced by tobacco smoking and that are associated with nicotine-induced changes in behavior. Future research should examine whether nicotine exposure from secondhand tobacco smoke has functional effects on neurobiological and behavioral processes associated with tobacco use.

CYP1A1 gene polymorphisms in modifying the association between passive smoking and primary dysmenorrhea

PURPOSE

This study investigated whether the association between passive smoking exposure and primary dysmenorrhea is modified by two susceptibility genes, cytochrome P450 1A1 (CYP1A1)MspI and CYP1A1HincII.

METHODS

We recruited 1645 female textile workers from 1997 to 2000 in Anqing, China, collecting information about passive smoking and status of primary dysmenorrhea and taking blood samples. We analyzed the association of CYP1A1 gene polymorphisms and passive smoking exposure with primary dysmenorrhea using multiple logistic regression.

RESULTS

In the passive smoking group, women who had the C/C6235 genotype (odds ratio [OR] = 1.8; 95% confidence intervals [CI] = 1.0-3.3) in CYP1A1MspI and Ile/Ile462 genotype (OR = 2.9; 95% CI = 1.1-7.7) in CYP1A1HincII had increased risk of dysmenorrhea. When stratified by genotype, the adjusted OR of dysmenorrhea was 1.6 (95% CI = 1.2-2.1) for the passive smoking group with the Ile/Ile462 genotype and 1.5 (95% CI = 1.0-2.1) with the C/C6235 genotype, compared with the nonpassive smoking group. The data further showed that there was a significant combined effect between passive smoking and the CYP1A1MspI C/C6235 and HincII Ile/Ile462 genotypes (OR = 2.4; 95% CI = 1.2-4.9).

CONCLUSIONS

CYP1A1MspI and HincII genotypes modified the association between passive smoking and primary dysmenorrhea.

Measuring tobacco smoke exposure among smoking and nonsmoking bar and restaurant workers

PURPOSE

This study assesses the validity of hair nicotine as a biomarker for secondhand smoke (SHS) exposure. Although most biomarkers of tobacco-smoke exposure have a relatively short half-life, hair nicotine can measure several months of cumulative SHS exposure.

DESIGN

A cross-sectional study of hospitality-industry workers.

METHOD

Hair samples were obtained from 207 bar and restaurant workers and analyzed by the reversed-phase high-performance liquid chromatography with electrochemical detection (HPLC-ECD) method. Self-reported tobacco use and sources of SHS exposure were assessed.

FINDINGS

Higher hair-nicotine levels were associated with more cigarettes smoked per day among smokers and a greater number of SHS-exposure sources among nonsmokers. Number of SHS exposure sources, gender, number of cigarettes smoked per day, and type of establishment predicted hair-nicotine levels.

DISCUSSION

Hair nicotine is a valid measure of SHS exposure. It may be used as an alternative biomarker to measure longer term SHS exposure.

Preterm delivery and exposure to active and passive smoking during pregnancy: a case-control study from Italy

The aim of this study was to assess the relationship between preterm/early preterm delivery and active smoking as well as environmental tobacco smoke (ETS) exposure in a sample of pregnant Italian women. A case-control study was conducted in nine cities in Italy between October 1999 and September 2000. Cases of preterm birth were singleton babies born before the 37th gestational week; babies born before the 35th gestational week were considered early preterm births. Controls were babies with gestational ages >or= 37th week. A total of 299 preterm cases (including 105 early preterm) and 855 controls were analysed. A self-administered questionnaire was used to assess active smoking and ETS exposure, as well as potential confounders. Multivariable logistic regression analysis showed a relationship between active smoking during pregnancy and preterm/early preterm delivery [adjusted ORs: 1.53; 95% CI 1.05, 2.21 and 2.00; 95% CI 1.16, 3.45, respectively]. A dose-response relationship was found for the number of cigarettes smoked daily. The adjusted ORs were 1.54 and 1.69 for preterm babies and 1.90 and 2.46 for early preterm babies for 1-10 and >10 cigarettes/day respectively. ETS exposure was associated with early preterm delivery [adjusted OR 1.56; 95% CI 0.99, 2.46] with a dose-response relationship with the number of smokers in the home. Smoking during pregnancy was strongly associated with preterm delivery with a dose-response effect. ETS exposure in non-smoking women was associated only with early preterm delivery.

Environmental Tobacco Smoke and Risk of Spontaneous Abortion

BACKGROUND

Studies of exposure to environmental tobacco smoke (ETS) and risk of spontaneous abortion are limited to a few studies of self-reported exposure, and the results have been inconsistent. The aim of this study was to investigate risk of early spontaneous abortion related to ETS and active smoking as defined by plasma cotinine levels.

METHODS

We conducted a population-based case-control study in Uppsala County, Sweden, between January 1996 and December 1998. Cases were 463 women with spontaneous abortion at 6 to 12 completed weeks of gestation, and controls were 864 pregnant women matched to cases according to the week of gestation. Exposure status was defined by plasma cotinine concentrations: nonexposed, <0.1 ng/mL; ETS-exposed, 0.1-15 ng/mL; and exposed to active smoking, >15 ng/mL. Multivariable analysis was used to estimate the relative risk of spontaneous abortion associated with exposure to ETS and active smoking.

RESULTS

Nineteen percent of controls and 24% of cases were classified as having been exposed to ETS. Compared with nonexposed women, risk of spontaneous abortion was increased among both ETS-exposed women (adjusted odds ratio = 1.67; 95% confidence interval = 1.17-2.38) and active smokers (2.11; 1.36-3.27). We could not show a differential effect of exposure to ETS or active smoking between normal and abnormal fetal karyotype abortions.

CONCLUSIONS

Nonsmoking pregnant women exposed to ETS may be at increased risk of spontaneous abortion. Given the high prevalence of ETS exposure, the public health consequences of passive smoking regarding early fetal loss may be substantial.

Environmental tobacco smoke exposure in school children: parent report and urine cotinine measures

BACKGROUND

Environmental tobacco smoke (ETS) in the home continues to be a major health risk for children around the world. Measuring ETS is a central feature of clinical and epidemiological studies, with children's exposure often assessed through parental estimates. The authors examined the relationship between parent-reported estimates of children's exposure to ETS and children's urinary cotinine levels and evaluated the ETS exposure and its effect on respiratory health in children.

METHODS

A total of 188 school children were included in the study. Parents were asked to complete a questionnaire about their smoking habits, their children's respiratory morbidity status and housing conditions. Urinary cotinine levels were measured in children.

RESULTS

According to the responses, 72.3% of the children came from households with smokers, and 34.6% had daily exposure to ETS. When urine cotinine levels of >10 ng/mL were used as the yardstick of exposure, 76% of the children were identified as ETS exposed. No relation was detected between the symptoms of respiratory tract diseases and ETS exposure. To determine the amount of ETS exposure, the contribution of parental reports was low.

CONCLUSION

To evaluate the level of ETS exposure of children, the parents' reports were not reliable. The addition of a biological measure results in a more informative estimate of ETS exposure in children.

Adolescent smoking in pregnancy and birth outcomes

INTRODUCTION

Cigarette smoking amongst pregnant adolescents is a preventable risk factor associated with low birthweight (<2,500 g), preterm birth (<37 weeks) and infant mortality. The aim of this study was to compare birth outcomes of adolescents who smoke during pregnancy with those who do not and to construct their birthweight-for-gestational-age curves.

METHODS

A retrospective cohort analysis of 534 adolescents (<or=19 years) and 8972 adults who delivered singleton births between 1998-2003 at the Liverpool Women's Hospital.

RESULTS

Adolescent pregnancy occurred in 5.6% of deliveries. Mean age of adolescents was 18.1 years (SD = 1.0) and 46.2% smoked during pregnancy including 83.5% light smokers (<10 cigarettes daily). Babies born to adolescent smokers were significantly lighter by -170 g (P = 0.005). The prevalence of low birthweight was almost double in adolescents who smoked (12.1% versus 6.8%, RR = 1.7; CI = 1.0-3.0), and their mean Apgar scores at 5 min were lower (<0.05). A higher prevalence of preterm birth (P < 0.05) and maternal anaemia (P < 0.01) occurred amongst adolescent smokers. Adolescents smoking >10 cigarettes daily had babies with larger birthweight reduction (P = 0.001).

CONCLUSION

Almost half of all adolescents smoked during their pregnancy. Birthweight-for-gestational-age curves of smoking adolescents showed a marked fall-off in weight from 36 weeks of gestation, and at least 10% of adolescent smokers showed fetal growth restriction from before 32 weeks of gestation.

Differences in DNA-damage in non-smoking men and women exposed to environmental tobacco smoke (ETS)

There is much data implicating environmental tobacco smoke (ETS) in the development and progression of disease, notably cancer, yet the mechanisms for this remain unclear. As ETS is both a pro-oxidant stressor and carcinogen, we investigated the relationship of ETS exposure to intracellular and serum levels of DNA-damage, both oxidative 8-hydroxy-2-deoxyguanosine (8OHdG) and general, in non-smokers from non-smoking households, occupationally exposed to ETS. General DNA-damage consisting of single and double strand breaks, alkali-labile sites and incomplete base-excision repair, increased significantly in a dose-dependent manner with ETS exposure in men (P=0.015, n=32, Pearson) but not women (P=0.736, n=17). Intracellular 8OHdG-DNA-damage and general DNA-damage were both greater in men than women (P=0.0005 and 0.016, respectively) but 8OHdG serum levels did not differ between the genders. Neither 8OHdG-DNA-damage nor serum levels correlated with increasing ETS exposure. This is the first study to demonstrate dose-dependent increases in DNA-damage from workplace ETS exposure. Perhaps most interesting was that despite equivalent ETS exposure, significantly greater DNA-damage occurred in men than women. These data may begin to provide a mechanistic rationale for the generally higher incidence of some diseases in males due to tobacco smoke and/or other genotoxic stressors.

Environmental tobacco smoke and pregnancy outcome

BACKGROUND

Recent reviews conclude that environmental tobacco smoke (ETS) leads to diminished birth weight. However, the threshold and magnitude of that effect is uncertain. We aimed to determine the magnitude and shape of the relations between ETS and various adverse pregnancy outcomes using a highly sensitive biochemical assay.

METHODS

Maternal serum specimens were collected from more than 3000 women enrolled in California's prenatal screening program in 1992 and analyzed for cotinine. Information on pregnancy outcomes was obtained from live birth/fetal death records and hospital questionnaires. We conducted analyses on 2777 woman-live birth pairs and 19 woman-fetal death pairs in which the mother was presumed to be a nonsmoker (midtrimester cotinine levels < or =10 ng/mL).

RESULTS

In multiple logistic regression analyses, the odds ratios of fetal death, preterm delivery, and term-low birth weight were 3.4, 1.8, and 1.8, respectively, in the highest cotinine quintile (0.236-10 ng/mL), compared with the lowest quintile (<0.026 ng/mL). In adjusted linear models, there was a linear dose-dependent effect of log cotinine on mean birth weight (-109 g) and mean infant length (-0.84 cm) over the range of cotinine values. Linear relations were not found with respect to infant head circumference or the ratio of brain weight to body weight. Infant's body mass index declined with exposures above approximately 0.5 ng/mL cotinine. We estimated that ETS levels at or above 0.05 ng/mL (experienced by 62% of the study population) accounted for 12% of all adverse outcomes.

CONCLUSIONS

ETS exposure in pregnant women adversely affects pregnancy by increasing fetal mortality and preterm delivery at higher exposure levels and slowing fetal growth across all levels of ETS exposure.

Environmental and occupational factors affecting fertility and IVF success

Reproductive function has been shown to be sensitive to changes in the physical, psychosocial and chemical environments. Although reproductive effects of occupational exposure to hazardous chemicals have been well documented in the literature, the potential effects of chemical contaminants at levels representative of contemporary exposures in the general population are much less certain. Evidence for adverse effects of exposure to environmental contaminants is more conclusive among the lower animals than for humans where considerable controversy remains. In addition to potential reproductive hazards of exposure to environmental contaminants, there is also evidence for adverse reproductive effects of the physical and psychosocial environments. In this review we focus on the difficulties involved in linking exposure to putative hazardous substances in environmental and occupational settings to adverse reproductive outcomes, especially success of IVF procedures. We highlight the plausibility of adverse events through animal and cell studies and the application of these results to the interpretation of human data. We consider both the male and female partners since it is essentially their combined contributions of gametes which may be affected by chemicals, which lead to successful outcomes.

Home smoking restrictions. Problems in classification

BACKGROUND

Evidence of the effectiveness of smoking restrictions in workplaces and other public places is creating awareness of the role of bans in private spaces. The purpose of this study was to examine who is affected by strict home smoking bans at the household level.

METHODS

Using the 1998/1999 Tobacco Use Supplement to the U.S. Current Population Survey, we examined the characteristics of 43,613 households with two or more adults who responded to the home ban question. Analyses were conducted in 2003-2004.

RESULTS

An estimated 12% of sample households provided inconsistent reports about home smoking bans. Multimember households with smokers were substantially less likely to consistently report strict home bans. Discrepancies vary systematically by smoking behavior, socioeconomic status, and race/ethnicity. Children living with smokers are especially at risk of inconsistent adult reports.

CONCLUSIONS

Analyses should not rely on individual reports of home bans, especially in households with smokers and children. Policies should be directed toward educating members of households with smokers and children about the importance of household bans.

Developmental effects of exposure to environmental tobacco smoke and material hardship among inner-city children

Because of the growing concern that exposures to airborne pollutants have adverse effects on fetal growth and early childhood neurodevelopment, and the knowledge that such exposures are more prevalent in disadvantaged populations, we assessed the joint impact of prenatal exposure to environmental tobacco smoke (ETS) and material hardship on the 2-year cognitive development of inner-city children, adjusted for other sociodemographic risks and chemical exposures. The purpose was to evaluate the neurotoxicant effects of ETS among children experiencing different degrees of socioeconomic disadvantage, within a minority population. The sample did not include children exposed to active maternal smoking in the prenatal period. Results showed significant adverse effects of prenatal residential ETS exposure and the level of material hardship on 2-year cognitive development, as well as a significant interaction between material hardship and ETS, such that children with both ETS exposure and material hardship exhibited the greatest cognitive deficit. In addition, children with prenatal ETS exposure were twice as likely to be classified as significantly delayed, as compared with nonexposed children. Postnatal ETS exposure in the first 2 years of life did not contribute independently to the risk of developmental delay, over and above the risk posed by prenatal ETS exposure. The study concluded that prenatal exposure to ETS in the home has a negative impact on 2-year cognitive development, and this effect is exacerbated under conditions of material hardship in this urban minority sample.