Passive smoking, salivary cotinine concentrations, and middle ear effusion in 7 year old children

Smoking Pack Years and Eustachian Tube Dysfunction

Objective

To determine the effect of smoking history on the risk of developing obstructive eustachian tube dysfunction (OETD).

Study Design

Cross-sectional review.

Setting

National database.

Methods

Data from the National Health and Nutrition Examination Survey (1999 to present) was analyzed. OETD was defined as middle ear pressure less than -100 decapascals (daPa). Nonsmokers, current smokers, with tympanometry data were analyzed. Patients under the age of 18, with myringotomy tubes, or with a sinus problem/earache/cold in the past 24 hours were excluded. The relative risks (RRs) for developing OETD were calculated for nonsmokers versus smokers and those with greater versus less than 10, 20, and 30 pack years (py).

Results

A total of 9472 patients met inclusion criteria (54.1% female, 75.9% non-Hispanic, mean age 43, 20.3% smokers). The RR of having OETD for smokers versus nonsmokers was 1.75 [95% confidence interval, CI: 1.45-2.11]. The RR of having OETD for patients with a 10+ py was 1.97 [95% CI 1.57-2.47], 20+ py was 2.29 [95% CI 1.76-2.95], and 30 py or greater was 2.08 [95% CI 1.49-2.90].

Conclusion

In this study, smoking roughly doubled the risk of developing OETD, as represented by a single measurement of negative middle ear pressure less than -100 daPa. The definition of OETD used in this study was limited, as it did not include symptomology, and more work is needed to examine additional covariates. However, these results may guide future research to better counsel and screen patients for OETD.

Secondhand Smoke Exposure Measured in Urinary Cotinine Levels and Severity of Pediatric Sleep Apnea

Importance

Exposure to secondhand smoke has been associated with numerous health problems in children, including obstructive sleep apnea. Secondhand smoke exposure may be a risk factor for increased pediatric sleep apnea severity.

Objectives

To assess the association of secondhand smoke exposure (SHSe), quantified by urinary cotinine levels, with severity of obstructive sleep apnea (OSA) in children.

Design, Setting, and Participants

This was a prospective cohort trial including pediatric patients from 3 to 16 years of age with sleep-disordered breathing who underwent a polysomnogram at a tertiary-level children's hospital in the US in either March 2014 to October 2016 or March 2020 to March 2021. Urine specimens were analyzed for cotinine, an important metabolite of nicotine. Each child's caregiver completed a validated SHSe questionnaire. Data were analyzed from February to June 2023.

Exposure

OSA and secondhand smoke.

Main Outcome and Measures

SHSe and severity of pediatric OSA, quantified by urinary cotinine levels and obstructive apnea hypopnea index (AHI) scores. Secondary outcomes were association of urinary cotinine levels with nadir oxygen saturation, sleep-related quality of life measured by the OSA-18 questionnaire, and caregiver-reported smoking habits (collected through a questionnaire).

Results

The study included 116 patients with a median (IQR) age of 6 (5-9) years, among whom 51 (45%) had obesity. The median (IQR) AHI was 3.0 (1.2-8.0), with 28 children (30.0%) having severe disease (AHI >10). Thirty-four children (29.0%) were found to have a positive result for urine cotinine screening, with a mean (SD) level of 11.7 (9.4) ng/mL. The percentage of children with SHSe was less than anticipated. There was no association identified between urinary cotinine levels and either AHI (ρ = -0.04; 95% CI, -0.22 to 0.15) or nadir oxygen saturation (ρ = -0.07; 95% CI, -0.26 to 0.11). Furthermore, SHSe was not associated with the presence of severe OSA (odds ratio, 0.70; 95% CI, 0.26 to 1.90). Children whose caregivers reported indoor SHSe were more likely to have a detectable urinary cotinine level (odds ratio, 20.3; 95% CI, 6.67 to 61.8).

Conclusions and Relevance

This cohort study did not identify any clinically meaningful association between SHSe, quantified by urinary cotinine level, and pediatric OSA severity. Future research with a larger number of children with SHSe is needed to confirm these findings and determine whether SHSe affects OSA treatment outcomes in children.

Untargeted Urinary Metabolomics and Children's Exposure to Secondhand Smoke: The Influence of Individual Differences

Children’s exposure to secondhand smoke (SHS) is a severe public health problem. There is still a lack of evidence regarding panoramic changes in children’s urinary metabolites induced by their involuntary exposure to SHS, and few studies have considered individual differences. This study aims to clarify the SHS-induced changes in urinary metabolites in preschool children by using cross-sectional and longitudinal metabolomics analyses. Urinary metabolites were quantified by using untargeted ultra high-performance liquid chromatography-mass spectrometry (UPLC^(c)-MS/MS). Urine cotinine-measured SHS exposure was examined to determine the exposure level. A cross-sectional study including 17 children in a low-exposure group, 17 in a medium-exposure group, and 17 in a high-exposure group was first conducted. Then, a before–after study in the cohort of children was carried out before and two months after smoking-cessation intervention for family smokers. A total of 43 metabolites were discovered to be related to SHS exposure in children in the cross-sectional analysis (false discovery rate (FDR) corrected p < 0.05, variable importance in the projection (VIP) > 1.0). Only three metabolites were confirmed to be positively associated with children’s exposure to SHS (FDR corrected p < 0.05) in a follow-up longitudinal analysis, including kynurenine, tyrosyl-tryptophan, and 1-(3-pyridinyl)-1,4-butanediol, the latter of which belongs to carbonyl compounds, peptides, and pyridines. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that 1-(3-pyridinyl)-1,4-butanediol and kynurenine were significantly enriched in xenobiotic metabolism by cytochrome P450 (p = 0.040) and tryptophan metabolism (p = 0.030), respectively. These findings provide new insights into the pathophysiological mechanism of SHS and indicate the influence of individual differences in SHS-induced changes in urinary metabolites in children.

Metabolic Consequences of Concomitant Strongyloides stercoralis Infection in Patients With Type 2 Diabetes Mellitus

BACKGROUND

Human and animal studies have demonstrated that helminth infections are associated with a decreased prevalence of type 2 diabetes mellitus (T2DM). However, very little is known about their biochemical and immunological interactions.

METHODS

To assess the relationship between a soil-transmitted helminth, Strongyloides stercoralis (Ss), and T2DM, we examined analytes associated with glycemic control, metabolic processes, and T-cell-driven inflammation at the time of Ss diagnosis and 6 months after definitive anthelmintic treatment. We measured plasma levels of hemoglobin A1c, glucose, insulin, glucagon, adipocytokines, and T-helper (TH) 1-, 2-, and 17- associated cytokines in patients with T2DM with (INF group) or without (UN group) Ss infection. In INF individuals, we again assessed the levels of these analytes 6 months following anthelmintic treatment.

RESULTS

Compared to UN individuals, INF individuals exhibited significantly diminished levels of insulin and glucagon that increased significantly following therapy. Similarly, INF individuals exhibited significantly diminished levels of adiponectin and adipsin that reversed following therapy. INF individuals also exhibited significantly decreased levels of the TH1- and TH17- associated cytokines in comparison to UN individuals; again, anthelmintic therapy augmented these levels. As expected, INF individuals had elevated levels of TH2-associated and regulatory cytokines that normalized following definitive therapy. Multivariate analysis revealed that these changes were independent of age, sex, body mass index, and liver and renal function.

CONCLUSIONS

Strongyloides stercoralis infection is associated with a significant modulation of glycemic, hormonal, and cytokine parameters in T2DM and its reversal following anthelmintic therapy. Hence, Ss infection has a protective effect on diabetes-related parameters.

Salivary cotinine levels in children with otolaryngological disorders

OBJECTIVE

To determine if salivary cotinine, a biomarker for tobacco smoke exposure, is elevated more often or to a higher degree in children meeting criteria for tonsillectomy or tympanostomy tube insertion.

METHODS

Saliva samples were obtained from 3 groups of children for salivary cotinine measurement. Group 1 served as healthy controls. Group 2 consisted of subjects meeting tympanostomy tube criteria. Group 3 consisted of patients meeting tonsillectomy criteria. Environmental tobacco smoke (ETS) exposure was defined as a salivary cotinine concentration ≥1.0 ng/mL. Demographic data, smoke exposure history, and co-morbidities were also determined.

RESULTS

331 patients were included, with 112 in Group 1, 111 in Group 2, and 108 in Group 3. No differences were encountered for smoke exposure by history or smoker's identity, salivary cotinine level, or frequency of positive cotinine results. 42.6% of Group 1 had positive salivary cotinine compared to 51.8% of Group 2 and 47.7% of Group 3. Group 1 had a mean salivary cotinine level of 2.42 ng/mL compared to 2.54 ng/mL in Group 2 and 2.60 ng/mL in Group 3. The frequency of positive cotinine levels was higher than expected based on parental history. Among subjects with positive cotinine levels, 93 had no ETS exposure, and 64 had ETS exposure by history.

CONCLUSION

Approximately 50% of children who undergo tonsillectomy and tympanostomy tube insertion have objective evidence of ETS exposure. Parental history underestimates passive smoke exposure, which can impact perioperative care.

A case control study to determine the association between Perthes' disease and the recalled use of tobacco during pregnancy, and biological markers of current tobacco smoke exposure

AIMS

It is well established that there is a strong association between Perthes' disease and worsening socioeconomic deprivation. It has been suggested that the primary determinant driving this association is exposure to tobacco smoke. This study aimed to examine this hypothesis.

PATIENTS AND METHODS

A hospital case-control study (n = 149/146) examined the association between tobacco smoke exposure and Perthes' disease, adjusting for area-level socioeconomic deprivation. Tobacco smoke exposure was assessed by parental questionnaire of smoking habits during pregnancy, and by quantitative assay of current exposure using the urinary cotinine-creatinine ratio, which is a widely used and validated measure of tobacco smoke exposure.

RESULTS

The odds of Perthes' disease significantly increased with reported in utero exposure after adjustment for socioeconomic deprivation (maternal smoking odds ratio (OR) 2.06, 95% confidence interval (CI) 1.17 to 3.63; paternal smoking OR 2.09, 95% CI 1.26 to 3.46). The cotinine-creatinine ratio was significantly greater in cases, OR 1.63 (95% CI 1.09 to 2.43), suggesting a greater 'dose' of current tobacco exposure.

CONCLUSION

An association exists between tobacco smoke exposure and Perthes' disease but we remain unable to disentangle the association with socioeconomic deprivation. Cite this article: Bone Joint J 2017;99-B:1102-8.

Tobacco Smoke Exposure and Eustachian Tube Disorders in US Children and Adolescents

OBJECTIVES

To describe the association between active, environmental tobacco smoke (ETS) exposure and the prevalence of eustachian tube dysfunction (ETD) in the U.S. pediatric population.

STUDY DESIGN

Cross-sectional.

SETTING

U.S. representative demographic and audiometric data from the National Health and Nutrition Examination Survey (NHANES);2005-2010.

SUBJECTS AND METHODS

The study consisted of 2,977 children aged 12-19 years. ETD was defined as middle ear pressure <100mm H20. ETS was defined as non-active smoking in individuals with serum cotinine over the limit of detection (≥0.015 ng/mL) and <10 ng/mL(N = 1559).

RESULTS

The prevalence of ETD was 6.1%. After multivariate adjustment for age, sex, body mass index, education level, ethnicity, or having a cold, sinus problem or earache during the last 24 hours, compared to unexposed children, the odds ratios (95% confidence interval) of ETD for those exposed to ETS ages 12-15 in the first, second and third tertile of cotinine concentrations were, respectively, 1.38 (0.53-3.60), 0.99 (0.53-3.60) and 2.67 (1.12-6.34). Similarly, the odds ratios (95% confidence interval) of ETD for those exposed to ETS ages 16-19 in the first, second and third tertile of cotinine concentrations were, respectively, 1.28 (0.48-3.41), 0.99 (0.40-2.48) and 2.86 (1.19-6.88).

CONCLUSION

These data suggest that children and adolescents exposed to high concentrations of ETS may have an increased prevalence of ETD.

Prevalence and risk factors of Otitis Media with effusion in school children in Qassim Region of Saudi Arabia

OBJECTIVE

To determine the prevalence of otitis media with effusion (OME) among school children in Qassim region of Kingdom of Saudi Arabia and to determine relevant risk factors in affected children.

METHODS

Through a cross-sectional study, 1488 children in the age range 6-12 years were randomly selected from 25 primary schools in Qassim region. A questionnaire was used to determine risk factors for OME. Otoscopy and tympanometry were used to diagnose and confirm OME. Pure tone average for children with confirmed OME was measured. Teachers of children were asked to complete a questionnaire evaluating child's level of school performance.

RESULTS

Prevalence of OME in the study population was 7.5% (112/1488). In univariate analysis, it was strongly associated with age less than 8 years (p< 0.0001; OR= 4.23, 95% CI: 2.85-6.29 ), family size more than 4 members in the household((p<0.0001; OR= 4.45, 95% CI: 2.23-8.88), mother education less than secondary school education (p<0.0001; OR=2.2, 95% CI: 1.47-3.29), recurrent acute otitis media (AOM) (p<0.0001; OR=5.73, 95% CI: 3.47-9.45), and hearing loss symptom (p< 0.0001; OR= 3.39, 95% CI: 1.92-5.99). It is less strongly associated with history of preschool AOM (p= 0.002; OR= 3.15, 95% CI: 1.67-5.97), nasal discharge (p= 0.003; OR= 1.91, 95% CI: 1.24-2.93) and snoring (p=0.03; OR= 1.76, 95% CI: 1.06-2.94). OME was significantly higher in schools located in rural districts (p<0.001, OR= 2.82, 95% CI: 1.86-4.28). In multivariate regression model, five of these factors were found to be predictors of OME: age less than 8 years (OR= 5.052, 95% CI:3.289-7.762), family size more than4 members in the household) (OR= 4.192, 95% CI: 2.033-8.643), rural school district (OR=3.037, 95% CI: 1.933-4.772), mother education lower than secondary school education) (OR=2.041, 95% CI:1.602-3.877) and recurrent AOM (OR=4.914, 95% CI: 2.677-9.02). Children with OME tend to have poorer school performance compared to normal children (p=0.067). No significant correlation was found between OME and type of feeding during the first two years of life (p=0.62; OR= 0.87, 95% CI: 0.51-1.49), preschool daycare attendance (p=0.17; OR= 0.71, 95% CI: 0.44-1.16), home exposure to cigarette smoke (p=0.4; OR= 1.34, 95% CI:0.68-2.65), visits to ENT clinic (p=0.13; OR= 0.58, 95% CI:0.29-1.18), and ENT operations (p=0.12; OR= 0.46, 95% CI: 0.17-1.27).

CONCLUSION

Prevalence of OME in Qassim region reaches 7.5% in school children. Age less than 8 years, family size more than 4 members in the household, mother education less than secondary school education, living in rural area and recurrent AOM are found to be predictors of OME in Qassim region. In this population of children, otoscopy and tympanometry should be used as screening tools for OME.

Modeling the effects of indoor passive smoking at home, work, or other households on adult cardiovascular and mental health: the Scottish Health Survey, 2008-2011

Passive smoking has contributed increased risks of cardiovascular disease, mental health, and mortality, but the cumulative effects from work or other households were less studied. Therefore, it was aimed to model the effects of indoor passive smoking from own home, work, and other households in a country-wide, population-based setting. Data in the Scottish Health Survey between 2008 and 2011 after the law banning smoking in public places were analyzed. Information including demographics, lifestyle factors, and self-reported cardiovascular disease and mental health was obtained by household interview. Analyses included chi-square test and survey-weighted logistic regression modeling. After full adjustment, it was observed that being exposed to indoor passive smoking, in particular in more than two places of exposure, was significantly associated with risks of stroke, angina, heart attack, abnormal heart rhythms, and GHQ ≥ 12. The significance remained for angina, GHQ ≥ 12 and probably heart attack in never smokers. The cumulative risks also impacted on sleep problems, self-recognition, making decisions, self-confidence, under strain constantly, depressed, happiness and self-worth. The significance remained for sleep problems, self-confidence, under strain constantly, depressed, and happiness in never smokers. Elimination of indoor passive smoking from different sources should still be a focus in future public health programs.

England's legislation on smoking in indoor public places and work-places: impact on the most exposed children

AIMS

To examine whether English legislation to make virtually all indoor public places and work-places smoke-free on 1 July 2007 displaced smoking into the home and hence increased the proportion of children exposed to levels of second-hand smoke known to be detrimental to health.

DESIGN

Repeated cross-sectional study with data from 10 annual surveys undertaken from 1996 to 2008.

SETTING

England.

PARTICIPANTS

Nationally representative samples of non-smoking children aged 4-15 years old living in private households.

MEASUREMENTS

Salivary cotinine, parental smoking status, whether smoking is allowed within the house, socio-demographic variables.

FINDINGS

The proportion of children exposed to damaging levels of second-hand smoke (defined as those with cotinine levels >1.7 ng/ml) has fallen over time, from 23.5% in 1996 to 12.6% in 2008. The legislation was not associated with further changes in the proportion of children above this threshold-the odds of having cotinine >1.7 ng/ml did not change after adjustment for the pre-legislative trend and confounders (odds ratio: 1.0, 95% confidence interval: 0.78, 1.4). Non-significant associations were also found when examining children by parental or household smoking status.

CONCLUSIONS

Legislation to prohibit smoking in indoor public places and work-places does not increase the proportion of children exposed to damaging levels of second-hand smoke. Even in a country with a strong tobacco control climate, a significant proportion of children remain highly exposed to second-hand smoke and future policies need to include interventions to reduce exposure among these children.

How and why chemicals from tobacco smoke can induce a rise in blood pressure

The primary objective of this article is to analyze the role of tobacco smoke compounds able to damage the cardiovascular system and, in particular, to interfere with blood pressure. They are products of tobacco plant leaves, like nicotine, thiocyanate and aromatic amines, and a chemical derived from cigarette combustion, carbon monoxide. Of the other thousands of chemicals, there is no clear evidence of cardiovascular damage. Nicotine and its major metabolite, cotinine, usually increase blood pressure by a direct action and an action stimulating neuro-humoral metabolites of the body as well as sympathetic stimulation. An indirect mechanism of damage exerted by elevated carboxyhemoglobin concentrations is mediated by carbon monoxide, which, mainly induces arterial wall damage and, consequently, late rising in blood pressure by a toxic direct action on endothelial and blood cells. Thiocyanate, in turn, reinforces the hypoxic effects determined by carbon monoxide. Aromatic amines, depending on their chemical structure, may exert toxic effects on the cardiovascular system although they have little effect on blood pressure. A rise in blood pressure determined by smoking compounds is a consequence of both their direct toxicity and the characteristics of their chemical chains that are strongly reactive with a large number of molecules for their spatial shape. In addition, a rise in blood pressure has been documented in individuals smoking a cigarette, acutely and chronically, with irreversible artery wall alterations several years after beginning smoking. Since cigarette smoking has a worldwide diffusion, the evidence of this topic meets the interest of both the scientific community and those individuals aiming to control smoking.

Passive exposure to smoke results in defective interferon-gamma production by adenoids in children with recurrent respiratory infections

There is evidence that exposure to passive smoke is associated with an increased susceptibility to respiratory infections. Indeed, cigarette smoke extracts may interfere with the immune system, even though the precise mechanism has not been fully understood yet. Recurrent respiratory infections may be sustained by a defective immune response. The aim of the present study was to evaluate whether, in a cohort of children presenting both with recurrent respiratory infections and with a history of exposure to tobacco smoke, these factors were related to a lower local production of interferon-gamma (IFN-gamma) when compared to a similar non-exposed population. The study group included 128 children undergoing adenoidectomy, presenting with more than three respiratory infections per year, independently of exposure to passive smoke at home. The intracellular cytokine profile of lymphocyte subsets in adenoids was evaluated by flow cytometry analysis. Children exposed to tobacco smoke suffered from a significantly greater number of respiratory infections and had a lower percentage of IFN-gamma-producing CD8+ cells in adenoids than non-exposed children, while other T-cell subsets were not affected. The effect of smoke exposure seems to be specific to the IFN-gamma-producing CD8+ cells in adenoids and may contribute to the increased susceptibility to the recurrence of respiratory infections.

Changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales: a repeated cross-sectional study

Background

Smoke-free legislation was introduced in Wales in April 2007. In response to concerns regarding potential displacement of smoking into the home following legislation, this study assessed changes in secondhand smoke (SHS) exposure amongst non-smoking children.

Methods

Approximately 1,750 year 6 (aged 10-11) children from 75 Welsh primary schools were included in cross-sectional surveys immediately pre-legislation and one year later. Participants completed self-report questionnaires and provided saliva samples for cotinine assay. Regression analyses assessed the impact of legislation on children's SHS exposure at the population level, and amongst subgroups defined by parental figures who smoke within the home.

Results

Geometric mean salivary cotinine concentrations were 0.17 ng/ml (95% CI 0.15,0.20) pre-legislation and 0.15 ng/ml (95% CI 0.13,0.17), post-legislation, although this change was not statistically significant. Significant movement was however observed from the middle (0.10-0.50 ng/ml) to lower tertile, though not from the higher end (>0.51 ng/ml) to the middle.

Reported exposure to SHS was greatest within the home. Home-based exposure did not change significantly post-legislation. Reported exposure in cafés or restaurants, buses and trains, and indoor leisure facilities fell significantly.

The proportion of children reporting that parent figures smoked in the home declined (P = 0.03), with children with no parent figures who smoke in the home significantly more likely to provide saliva with cotinine concentrations of <0.10 ng/ml post-legislation.

Amongst children with no parent figures who smoke in the home, the likelihood of 'not knowing' or 'never' being in a place where people were smoking increased post-legislation.

Conclusion

Smoke-free legislation in Wales did not increase SHS exposure in homes of children aged 10-11. Reported SHS exposure in public places fell significantly. The home remained the main source of children's SHS exposure. The legislation was associated with an unexpected reduction in cotinine levels among children with lower SHS exposure pre-legislation. The findings indicate positive rather than harmful effects of legislation on children's SHS exposure, but highlight the need for further action to protect those children most exposed to SHS.

From the American Academy of Pediatrics: Technical report--Secondhand and prenatal tobacco smoke exposure

Secondhand tobacco smoke (SHS) exposure of children and their families causes significant morbidity and mortality. In their personal and professional roles, pediatricians have many opportunities to advocate for elimination of SHS exposure of children, to counsel tobacco users to quit, and to counsel children never to start. This report discusses the harms of tobacco use and SHS exposure, the extent and costs of tobacco use and SHS exposure, and the evidence that supports counseling and other clinical interventions in the cycle of tobacco use. Recommendations for future research, policy, and clinical practice change are discussed. To improve understanding and provide support for these activities, the harms of SHS exposure are discussed, effective ways to eliminate or reduce SHS exposure are presented, and policies that support a smoke-free environment are outlined.

Effects of postnatal parental smoking on parent and teacher ratings of ADHD and oppositional symptoms

To assess the effects of postnatal parental smoking on subsequent parent and teacher ratings of DSM-IV attention deficit hyperactivity disorder (ADHD) symptoms and oppositional behaviors in children diagnosed with ADHD and their siblings. Children between 5 and 12 years of age with ADHD and their siblings were included. DSM-IV ADHD symptom subscales (Inattentive and hyperactive-impulsive), and oppositionality subscale scores from Conners' Rating Scales were predicted on the basis of parental smoking status in the first 7 years after birth using Generalized Estimating Equations controlling for a range of relevant covariates. Postnatal parental smoking was associated with both parent and teacher ratings of ADHD symptoms and oppositional behavior. After controlling for a number of covariates, several of these relationships were still significant. The risk of maternal smoking for the development of ADHD symptoms does not end during pregnancy. Research on the mechanisms underlying the observed associations is needed.

Deficiency of INFgamma producing cells in adenoids of children exposed to passive smoke

Exposure to passive smoke is a very common event associated with increased susceptibility to respiratory tract infections. Many related adverse effects result from the ability of cigarette smoke extracts to interfere with the immune system, but the mechanism is not yet completely understood. The aim of the present study is to evaluate the intracellular cytokine profile in adenoids and peripheral blood cells of children exposed to passive smoke. Children undergoing adenoidectomy exposed or not exposed to passive smoke were studied. The intracellular cytokine profile of lymphocyte subsets in adenoids and in peripheral blood were evaluated by flow cytometry analysis. Children exposed to tobacco smoke showed a significantly lower percentage of INF-gamma producing CD4+ and CD8+ cells in adenoids. Moreover a significant correlation was observed between the quantity of exposure and reduction in Th1 (CD4+INFgamma+ and CD8+INFgamma+) cells in adenoids. This reduction may be a contributing factor in the increasing susceptibility to respiratory tract infection in children exposed to tobacco smoke.

Children's health and the environment: public health issues and challenges for risk assessment

Infants and children are not little adults. They are uniquely vulnerable to environmental toxicants. To protect infants and children against toxicants, the National Research Council in 1993 called for development of an approach to risk assessment that considers children's unique patterns of exposure and their special vulnerabilities to pesticides. Many aspects of that call were codified into federal law in the Food Quality Protection Act (FQPA) of 1996. This report highlights the central elements needed for development of a child-protective approach to risk assessment: a) improved quantitative assessment of children's exposures at different life stages, from fetal life through adolescence, including acute and chronic exposures, exposures via multiple routes, and exposures to multiple agents; b) development of new approaches to toxicity testing of chemicals that can detect unanticipated and subtle outcomes and that evaluate experimental subjects over the entire life span from early exposure to natural death to replicate the human experience; c) development of new toxicodynamic and toxicokinetic models that account for the unique physiologic characteristics of infants and children; d) development of new approaches to assessment of outcomes, functional, organ, cellular and molecular, over the entire life span; these measures need to be incorporated into toxicity testing and into long-term prospective epidemiologic studies of children; and e) application of uncertainty and safety factors in risk assessment that specifically consider children's risks. Under FQPA, children are presumed more vulnerable to pesticides than adults unless evidence exists to the contrary. Uncertainty and safety factors that are protective of children must therefore be incorporated into risk assessment when data on developmental toxicity are lacking or when there is evidence of developmental toxicity. The adequate protection of children against toxic agents in the environment will require fundamental and far-reaching revisions of current approaches to toxicity testing and risk assessment.

Barriers to smoking cessation in pregnancy: a qualitative study

The magnitude of smoking as a public health concern in Britain is reflected in the recent government investment to develop smoking cessation services. Smoking in pregnancy is a priority. This article presents the findings of a small qualitative research study exploring barriers to pregnant women stopping smoking. The research was conducted in deprived areas of South Yorkshire, with levels of smoking-related ill health higher than the national average. The study participants revealed a belief system resulting in a self-fulfilling prophecy of relapse or failure to quit. The role and meaning of smoking for women with a high caring burden and socio-economic problems resonate strongly with earlier studies. Other barriers were the influence of family and friends, how women interpreted facts relating to smoking risks and the nature of smoking cessation service delivery. Community nursing staff have a potential in the delivery of smoking cessation interventions. Effective training should be a priority.

Selecting persistent glue ear for referral in general practice: a risk factor approach

BACKGROUND

Glue ear (otitis media with effusion) is the most common reason for surgical intervention in children.

AIM

To determine the yield and predictive value of a set of risk factors that predict persistence of glue ear over the interval from general practice referral to ear, nose and throat (ENT) consultation to ensure the appropriateness of referrals.

DESIGN OF STUDY

Nested case control study

SETTING

Sixteen ENT departments in the UK.

METHOD

With the aid of audiometry and tympanometry, diagnostic information was collected on 548 children from 16 ENT departments after referral by their general practitioner (GP), as a lead-in to a clinical trial, the Trial of Alternative Regimens in Glue Ear Treatment (TARGET). Using cases and controls, children were classified as either having or not having persistent glue ear. Parental reports on an extensive list of risk factors were also collected.

RESULTS

After adjustment for time waiting to be seen from GP referral and age at referral, four main significant factors emerged for persistence of glue ear. These were: referral between July and December (OR [odds ratio] = 1. 73, 95% CI = 1.15 to 2.6); having a mother who smokes ten or more cigarettes per day (OR = 1.7, 95% CI = 1.1 to 2.8); multiple upper airway symptoms (OR = 2.2, 95% CI = 1.5 to 3.2; and siblings with a history of glue ear (OR = 1.6 for one sibling versus none).

CONCLUSION

For a child who is referred between July and December; who has two or more upper airway symptoms, who has a sibling who has had glue ear, and who has a mother who smokes ten or more cigarettes per day, the odds of having persistent glue ear are over ten times that of a child without adverse values on these factors.

Black-white differences in health care utilization among US children with frequent ear infections

OBJECTIVE

To examine differences in patterns of and barriers to health care utilization between black and white children who have frequent ear infections (FEI).

METHODS

Analysis was conducted using the 1997 and 1998 National Health Interview Survey-Sample Child Files. Data on 25 497 children under 18 years of age and 1985 who were reported by the parent/guardian to have had "3 or more ear infections during the past 12 months" were analyzed. The data were weighted and analyzed to represent all black and white children nationwide, accounting for the complex survey design.

RESULTS

Of white and black children under 18 years of age in the United States, 8.0 and 6.6%, respectively, had FEI in the past year. Among those with FEI, whites and blacks exhibited significantly different patterns in the type of health insurance they had and in the usual source of care. After accounting for sociodemographic factors, health insurance, and usual source of care, there were still significant differences in health care use between whites and blacks. The affected black children had an increased risk of getting delayed care because of transportation problems (odds ratio [OR]: 2.32) and a reduced likelihood of seeing a medical specialist (OR: 0.49) and having surgery (OR: 0.39) in comparison to white children.

CONCLUSION

Although black children with FEI were as likely as white children to be covered by health insurance and have a usual place of health care, they were significantly more likely to face barriers in obtaining the care, especially the more specialized care.

Social determinants of smoking among parents with infants

OBJECTIVES

To estimate the smoking prevalence among parents of infants and examine these parents' socio-demographic characteristics.

METHOD

The sample of all parents of infants (669 mother-father pairs, 90 single parents) was derived from the 1995 Australian Health Survey. Data were collected by face-to-face interview in the respondent's home. Socio-demographic measures include parent's age, family structure, age-left-school, highest post-school qualification, occupation, and family income.

RESULTS

The overall rate of smoking among parents was 28.9% (mothers 24.7%, fathers 33.7%). The lowest rate was observed among mothers with a post-school tertiary qualification (7.6%) and the highest among fathers aged 18-24 (49.0%). In 15.4% of two-parent families both parents smoked, but this rate differed markedly by family income (9.9% vs. 29.7% for high and low-income families respectively). Multiple logistic regression showed that parents who smoked were more likely to be young, minimally educated, employed in blue-collar occupations, and resident in low-income families.

CONCLUSIONS AND IMPLICATIONS

Infants in this sample who were exposed to parental smoking were likely to be at increased risk of experiencing higher mortality and morbidity for childhood conditions related to passive smoking; more likely to experience adverse health consequences in adulthood; and may themselves take up smoking in later life. The study results pose serious challenges to our tobacco control efforts and health interventions more generally. No single policy or strategy can adequately address the problem of parental smoking. We need macro/upstream approaches that deal with the degree of social and economic inequality in society, as well as more intermediate approaches that intervene at the level of communities, families and individuals.

Smoking and tympanoplasty: implications for prognosis and the Middle Ear Risk Index (MERI)

OBJECTIVES/HYPOTHESIS

The objectives of this study are to review the effects of smoking on preoperative middle ear disease severity, long-term surgical outcome, type and extent of surgery required, the need for ossicular chain reconstruction, and the long-term hearing results.

STUDY DESIGN

A retrospective chart review.

MATERIALS AND METHODS

The charts of 74 smokers and non-smokers who underwent over-under tympanoplasty were reviewed. An analysis of the disease severity (using the Middle Ear Risk Index [MERI]) at presentation and type of surgery was performed. A review of graft take and delayed failure (late perforation or atelectasis after 6 mo) and audiologic data were performed.

RESULTS

Fifteen patients smoked a mean of 20 cigarettes daily for a mean of 15 years. The MERI was well matched for both groups. There was a trend toward smokers having a higher incidence of otorrhea preoperatively and requiring a more extensive surgical procedure. All patients had full take of the tympanic membrane graft at 6 months; however, delayed surgical failure was seen in 20% of non-smokers compared with 60% of smokers (P = .050). No statistically significant difference was seen in hearing outcome.

CONCLUSIONS

Cigarette smoking is associated with more severe middle ear disease preoperatively. More extensive surgery is often needed in smokers to eradicate the disease. Most significantly, smoking is associated with a threefold increase in the chance of long-term graft failure. Based on the results of this study, the MERI has been revised to include smoking as a risk factor.

A developmental approach to pediatric environmental health

Children cannot be considered "little adults" in the field of environmental medicine. There are differences in exposures, pathways of absorption, tissue distribution, ability to biotransform or eliminate chemicals from the body, and responses to chemical and radiation. The differences vary with the developmental stages of the child. Children all respond differently to environmental toxicants. Knowledge, although rapidly increasing, is still incomplete regarding the impact of the environment on children. As health care providers, prevention is an ally but must be approached differently at each stage of a child's life.

Evaluation of the effect of passive smoking on otitis media in children by an objective method: urinary cotinine analysis

OBJECTIVES

We aimed to determine objectively the effect of the passive smoking on otitis media with effusion (OME) and recurrent otitis media (ROM) by using the method of cotinine urinalysis.

STUDY DESIGN

We designed a prospective case-control study with follow-up of the case group for 1 year after insertion of tympanostomy tubes to evaluate postoperative complications such as otorrhea and early extrusion (<6 months), in case a significant risk factor was found.

METHODS

One hundred fourteen children between 3 and 8 years of age requiring tympanostomy tubes because of OME and ROM were chosen and compared with 40 age-matched children. Exposure to environmental tobacco smoke was assessed by cotinine urinalysis, which was performed by means of the radioimmunoassay method.

RESULTS

In this study, 73.7% (84 of 114) of the children in the case group and 55.0% (22 of 40) of the children in the control group were found to be "exposed" (P = .0461). This difference was statistically significant. Comparing the cotinine urinalysis results with parental smoking histories, 23.1% (9 of 39) of the children without parental smoking histories were "exposed" to tobacco smoke versus 84.3% (97 of 115) of the children with parental smoking histories (at least one person smoking).

CONCLUSIONS

Our results indicate that sidestream smoking increases the risk of OME and ROM. Legal regulations and guidelines must be established to protect children from passive smoking. Because cotinine urinalysis is a noninvasive and reliable method for the determination of passive smoking, it can be used for that purpose.

HPTLC screening assay for urinary cotinine as biomarker of environmental tobacco smoke exposure among male adolescents

For selective screening determination of urinary cotinine, i.e. (S)-1-methyl-5-(3-pyridyl)-2-pyrrolidinone, the major metabolite of nicotine, the high-performance thin-layer chromatographic (HPTLC) method have been proposed. Prior the final HPTLC analysis the procedure required a solid-phase extraction (SPE) of cotinine from collected urine samples with 1-methyl-2-pyrrolidinone as an internal standard. Densitometrical quantitation of cotinine on the chromatograms have been performed with a 16-grayscale scanner using the specialized software implemented on a desktop microcomputer. The lower detection limit of cotinine was 6 microg/l allowing the method to be applied for the measurement a concentration of this compound in urine samples collected from 35 elementary schoolboys exposed on both moderate and/or significant ETS. The mean recovery of cotinine from urine samples was 93%. The mean intra-day accuracy for the analysis of cotinine in range 6-750 microg/l. including four paralell measurements, was 2.9 %. The results of cotinine measurements by proposed SPE-HPTLC procedure were used in the pilot studies for assessment of hazard from home ETS on the health status of elementary schoolboys, especially an increased risk for infectious respiratory track diseases.

[Study of passive smoking measured by urinary cotinine in maternal and child protective health centers in North-Pas-de-Calais]

BACKGROUND

The aim of the study was to determine the circumstances of exposure to environmental tobacco smoke, to evaluate its importance by measurement of urinary cotinine, and to study the relationship with the children's medical history.

POPULATION AND METHODS

It was a prospective investigation realized in 20 outpatient pediatric clinics. The parents answered a questionnaire to assess the child's exposure as well as the child's medical and surgical history. Cotinine was measured in urine samples collected during the visit. Concentrations > 6 ng/mL were considered to be positive.

RESULTS

Two hundred and one children were included in the study (mean age 17 months, extremes: 1-72 months), 107 of whom were exposed to environmental tobacco smoke. Urinary cotinine was found to be positive in 27 cases (13%). There was a positive relation between passive tobacco exposure and positive urinary cotinine (P < 0.001). Eighty of 201 mothers and 135 of 185 fathers smoked. There was a relation between positive urinary cotinine and the mother's smoking, as well as with a history of upper respiratory tract infection (rhinitis, otitis media) or adenoidectomy. No relation was found between a history of bronchiolitis and passive smoking.

CONCLUSIONS

Passive tobacco exposure is very frequently encountered in our region. Urinary cotinine, which can be easily measured, might constitute an efficient tool in order to convince the parents of the reality of passive smoking.

The aetiology of otitis media with effusion: a review

Otitis media with effusion (OME) is the most common cause of deafness in children in the developed world. In this article we aim to present an overview of current research developments on the aetiology of OME and the resulting implications for treatment. In the model we describe, the primary event is inflammation of the middle ear mucosa, usually due to the presence of bacteria. This leads to the release of inflammatory mediators, which cause secretion of a mucin-rich effusion by up-regulating mucin genes. Prolonged stimulation of the inflammatory response and poor mucociliary clearance lead to persistence of the middle ear fluid, giving rise to the clinical presentation of OME. We describe OME in the following sequence: the initial production of the effusion, the composition of the effusion produced, and factors impairing clearance of the effusion.

Initial tobacco use episodes in children and adolescents: current knowledge, future directions

Approximately three-quarters of adult tobacco users report that their first tobacco use occurred between ages 11 and 17, while many adults who do not regularly use tobacco report that they experimented with it as adolescents. Surprisingly little is known about the effects of these initial tobacco use episodes and their influence on adult tobacco use patterns. In particular, understanding the role that nicotine plays in these early tobacco use experiences may be important in understanding the development of regular tobacco use and concomitant nicotine dependence. One goal of this review is to summarize current knowledge regarding the effects of initial tobacco use episodes in adolescents and to discuss nicotine exposure in initial tobacco use episodes. Another goal is to outline a research agenda designed to learn more about initial tobacco use episodes and the effects of nicotine in children. An ethical rationale and some potential methods for this research agenda are presented.

Environmental tobacco smoke exposure in children: household and community determinants

To determine the most important sources of environmental tobacco smoke exposure to young children, the authors studied the associations among urinary cotinine, reported household smoking habits, and socioeconomic variables in 575 schoolchildren aged 6-11 y. The school children were among a population of prodigious smokers in Cape Town, South Africa. Eighty percent of the children were exposed to environmental tobacco smoke. Maternal smoking, which was adjusted for creatinine, accounted for 21.8% of the variation in urinary cotinine--more than all other sources combined. The male parent and other household smokers accounted for 12.7% of the variation, and socioeconomic indicators explained an additional 4.8%. By defining the ecological variable of smoking prevalence per school, the authors estimated a "community" contribution of 3.3%. The relative importance of different sources of smoke should be taken into account in the prevention of environmental tobacco smoke exposure in young children. Most importantly, of all the sources of environmental tobacco smoke, mothers' smoking habits had the greatest impact on exposure to children.

Risk factors for chronicity in childhood otitis media with effusion

One hundred and ninety-one children who presented to the author's clinic with otitis media with effusion (OME) over a 2-year period (1986-1988) have been studied prospectively. Resolution of their OME was considered to have occurred when they had normal findings on pneumatic otoscopy, tympanometry and audiometry on at least two occasions 6 months apart and had subjectively normal hearing in between. The number of operations performed during the course of the disease was used as a surrogate for chronicity. Children with a history of previous aural discharge at presentation were significantly more likely to have chronic OME (P = < 0.02).

Risk factors of otitis media with effusion during infancy

Associations of possible risk factors with prevalence of otitis media with effusion (OME) were prospectively studied in a cohort of 250 infants, aged 0-2 years. In order to determine OME, otoscopy and tympanometry were performed at 3-monthly intervals beginning at term date. Eighteen epidemiologically relevant features were inventoried by means of standardized questionnaires. Multivariate analysis controlled for possible confounding factors. Prevalence of OME was most strongly associated with age (P-value < 0.001). Other factors significantly associated with the prevalence of OME (P-value < 0.05) were gestational age, birth weight, breastfeeding, day-care attendance, number of siblings, season, and parent-reported ear infection, hearing loss, mouth breathing and common cold. No significance was found for gender, date of birth, passive smoking, family history of otitis media, parental socio-economic status and histories of snoring and consultation of a physician.

IN CONCLUSION

both intrinsic and extrinsic factors appear to play an important role in the prevalence of OME. Some of the risk factors appeared to be time-dependent.

Biomarkers of environmental tobacco smoke exposure

Biomarkers are desirable for quantitating human exposure to environmental tobacco smoke (ETS) and for predicting potential health risks for exposed individuals. A number of biomarkers of ETS have been proposed. At present cotinine, measured in blood, saliva, or urine, appears to be the most specific and the most sensitive biomarker. In nonsmokers with significant exposure to ETS, cotinine levels in the body are derived primarily from tobacco smoke, can be measured with extremely high sensitivity, and reflect exposure to a variety of types of cigarettes independent of machine-determined yield. Under conditions of sustained exposure to ETS (i.e., over hours or days), cotinine levels reflect exposure to other components of ETS. Supporting the validity of cotinine as a biomarker, cotinine levels have been positively correlated to the risks of some ETS-related health complications in children who are not cigarette smokers.

Assessment of the exposure of children to environmental tobacco smoke (ETS) by different methods

1. In order to elucidate the role of exposure to environmental tobacco smoke (ETS) in various acute and chronic illnesses in children, it is important to assess the degree of exposure by suitable methods. For this purpose, we determined the exposure to ETS in 39 children (4-15 years) and 43 adults (16+ years) by questionnaires, personal diffusion samplers for nicotine, and cotinine measurements in saliva and urine. In addition, the influence of the smoking status and the location of the home (urban or suburban) on the benzene exposure of the children was investigated. 2. On average, the 24 children living in homes with at least one smoker were exposed to ETS for 3.1 h/d. This is significantly longer (P<0.001) than the daily exposure time of the 15 children from nonsmoking homes (0.3 h/d). The nicotine concentrations on the personal samplers worn over 7 days were 0.615 and 0.046 microg/m3 for children from smoking and nonsmoking homes, respectively (P<0.001). Average salivary cotinine levels were 1.95 ng/ml in children from smoking homes and 0.11 ng/ml in children from nonsmoking homes (P< 0.01). The corresponding urinary cotinine levels were 29.4 and 4.5 ng/mg creatinine (P< 0.001). There was no difference in the extent of ETS exposure between children and adults from smoking households. Adults from nonsmoking homes tended to have higher ETS exposure than children from nonsmoking homes. 3. Exposure to benzene, which was determined by means of personal samplers, measurements of benzene in exhaled air and of the urinary benzene metabolite trans, trans-muconic acid, was not significantly related to the smoking status of the home but primarily dependent on the location of the home.

Passive smoking, sudden infant death syndrome (SIDS) and childhood infections

1. A number of cohort and case-control studies have shown clear, dose-related associations between maternal smoking and infant death. The strongest relationships were found when the mother smoked during pregnancy as well as postnatally. Maternal smoking during pregnancy increases the risk for SIDS in most studies, whereas it appears that maternal smoking only postnatally also leads to an increase in risk. In addition, smoking only by the father appears to increase the risk for SIDS, but this is not seen in all studies. 2. Exposure of children to environmental tobacco smoke (ETS) increases the risk of having night cough and respiratory infections (bronchitis, bronchiolitis, pneumonia), especially during the first 2 years of life. An increased risk is also seen in studies not distinguishing between upper and lower respiratory diagnoses. Long-term breastfeeding may have a protective effect on ETS-increased risk of lower respiratory tract illness. One study of older children reports that ETS combined with allergy increased the risk of acute respiratory tract infections above that due to ETS alone. 3. The number of new episodes and duration of otitis media with effusion in young children is positively correlated with ETS exposure. Especially infants with lower birth weights had a high risk of recurrent otitis media during the first year of life when the mother was a heavy smoker. 4. Passive smoking has been reported as a risk factor in meningococcal disease and tuberculosis in young children.

Accumulation of factors influencing children's middle ear disease: risk factor modelling on a large population cohort

STUDY OBJECTIVES

Data were analysed from a large national birth cohort to examine cumulative and interactive prediction from various risk factors for childhood middle ear disease, and to resolve conflicting evidence arising from small and incompletely controlled studies. The large sample size permitted appropriate covariate adjustment to give generality, and permit demographic breakdown of the risk factors.

SETTING

A large multi-purpose longitudinal birth cohort study of all births in the UK in one week in 1970, with multiple questionnaire sweeps.

PARTICIPANTS

Over 13,000 children were entered into the original cohort. Data on over 12,000 children were available at the five year follow up.

MAIN OUTCOME MEASURES

For children at 5 years, parent reported data were available on health and social factors including data on two markers for middle ear disease: the occurrence of purulent (nonwax) ear discharge and suspected or confirmed hearing difficulty.

MAIN RESULTS

In those children who had ever had reported hearing difficulty (suspected or confirmed), after control for socioeconomic status, three of the classic factors (male sex, mother's smoking habits since birth, and attending day care) were significantly more frequent. In those who had ever had ear discharge reported, only mother's smoking habit since birth was significantly more frequent. However, it showed an orderly dose response relation. In addition, a derived general child health score was found to be significantly associated with both the middle ear disease markers. Control for this variable in the analysis of those having reported hearing difficulty reduced the effect size of mother's smoking habit, but it remained statistically significant. For reported ear discharge, even after control for the general health score and social index, mother's smoking habits and day care attendance were both significant predictors. Mother's (but not father's) smoking habits and day care attendance were found to be significant risk factors for middle ear disease. Breast feeding effects were weak and did not generally survive statistical control.

CONCLUSIONS

A child having all three risk factors (attends day care, a mother who smokes, and male sex) is 3.4 times more likely to have problems with hearing than a child who has none, based on cumulative risk. Further studies should focus on preventative risk modification and well specified intervention.

Use of health services by children of smokers and nonsmokers in a health maintenance organization

OBJECTIVES

Use of health services by children of smokers and nonsmokers was compared to assess whether exposure to environmental tobacco smoke resulted in greater use of health services among children of smokers.

METHODS

Primary care and emergency room visits, asthma-related prescriptions, and inpatient stays over the 42-month study period were compared for children of smokers (n = 498) and nonsmokers (n = 1062) who were enrolled in a health maintenance organization. Parents of children aged 1 through 11 years were identified from participants in 2 randomized smoking cessation trials.

RESULTS

After adjustment for parental age, education, and health status and for child's age, there were no differences between children of smokers and children of nonsmokers in use of primary care or emergency room visits, asthma-related prescriptions, or inpatient stays. However, among those with any preventive care visits, children of smokers had significantly fewer visits than children of nonsmokers.

CONCLUSIONS

Further study is needed to elucidate whether parents who smoke underutilize health services for their children or use services differently from nonsmoking parents and whether these differences have cost implications.

Health effects of passive smoking. 4. Parental smoking, middle ear disease and adenotonsillectomy in children

BACKGROUND

A systematic quantitative review was conducted of evidence relating parental smoking to acute otitis media, recurrent otitis media, middle ear effusion, and adenoidectomy and/or tonsillectomy.

METHODS

Forty five relevant publications were identified after consideration of 692 articles selected by electronic search of the Embase and Medline databases using keywords relevant to passive smoking in children. The search was completed in April 1997 and identified 13 studies of acute otitis media, nine of recurrent otitis media, five of middle ear effusion, nine of glue ear surgery, and four of adenotonsillectomy. A quantitative meta-analysis was possible for all outcomes except acute otitis media, using random effects modelling where appropriate to pool odds ratios from each study.

RESULTS

Evidence for middle ear disease is remarkably consistent, with pooled odds ratios if either parent smoked of 1.48 (95% CI 1.08 to 2.04) for recurrent otitis media, 1.38 (1.23 to 1.55) for middle ear effusion, and 1.21 (0.95 to 1.53) for outpatient or inpatient referral for glue ear. Odds ratios for acute otitis media are in the range 1.0 to 1.6. No single study simultaneously addresses selection bias, information bias and confounding, but where these have been investigated or excluded in the design or analysis, the associations with parental smoking persist virtually unchanged. Large French and British studies are inconsistent with regard to the association of parental smoking and tonsillectomy.

CONCLUSIONS

There is likely to be a causal relationship between parental smoking and both acute and chronic middle ear disease in children.

Otitis media in 2253 Pittsburgh-area infants: prevalence and risk factors during the first two years of life

OBJECTIVE

As part of a long-term study of possible effects of early-life otitis media on speech, language, cognitive, and psychosocial development, we set out to delineate the occurrence and course of otitis media during the first 2 years of life in a sociodemographically diverse population of infants, and to identify related risk factors.

METHODS

We enrolled healthy infants by age 2 months who presented for primary care at one of two urban hospitals or one of two small town/rural and four suburban private pediatric practices. We intensively monitored the infants' middle-ear status by pneumatic otoscopy, supplemented by tympanometry, throughout their first 2 years of life; we monitored the validity of the otoscopic observations on an ongoing basis; and we treated infants for otitis media according to specified guidelines.

RESULTS

We followed 2253 infants until age 2 years. The proportions developing > or = 1 episode of middle-ear effusion (MEE) between age 61 days (the starting point for data analysis) and ages 6, 12, and 24 months, respectively, were 47.8%, 78.9%, and 91.1%. Overall, the mean cumulative proportion of days with MEE was 20.4% in the first year of life and 16.6% in the second year of life. Tympanostomy-tube placement was performed on 1.8% and 4.2% of the infants during the first and second years of life, respectively. By every measure, the occurrence of MEE was highest among urban infants and lowest among suburban infants; these differences were greatest in the earliest months of life. Overall, unadjusted mean cumulative proportions of days with MEE were higher among boys than girls, higher among black than white infants, and higher among Medicaid than private health insurance enrollees. Cumulative proportions of days with MEE varied directly with the number of smokers in the household and with the number of other children to whom infants were exposed, whether at home or in day care, and varied inversely with birth weight, maternal age, level of maternal education, a socioeconomic index, and duration of breastfeeding. After adjustment, using multivariate analysis, the only variables that each remained independently and significantly related to the cumulative proportion of days with MEE were: during the first year of life, study site grouping, sex, the socioeconomic index, breastfeeding for > or = 4 months, the number of smokers in the household, and an index rating the degree of exposure to other children at home or in day care; and during the second year of life, sex, the socioeconomic index, and the child exposure index. The duration of breastfeeding and the degree of exposure to tobacco smoke contributed little to the explained variance; most was attributable to differences in the socioeconomic index and the child exposure index.

CONCLUSIONS

Contrary to findings in many previous reports, the prevalence of otitis media during the first 2 years of life among lower-socioeconomic-status black infants appears to be as high as, if not higher than among lower-socioeconomic-status white infants, and certainly higher than among middle-class white infants. Among middle-class white infants the prevalence may also be higher than commonly assumed. The most important sociodemographic risk factors for otitis media appear to be low socioeconomic status and repeated exposure to large numbers of other children, whether at home or in day care.

Is there a relationship between proximity to industry and the occurrence of otitis media with effusion in school entrant children?

In a study of the relationship between the prevalence of persistent otitis media with effusion (OME) in school entrant children in Redcar and Cleveland and the distance of the homes of these children from known industrial emission points, 1156 school entrant children were screened for the presence of persistent OME. The social disadvantage scores and map references were determined from the postcode area of each of the study entrants and map references were also obtained of known industrial emission points in the locality. Analyses were conducted on the association between the presence of OME and distance from emission sources and between the presence of OME and disadvantage score. A significantly greater proportion of study entrants with OME lived within 1000 meters of an industrial emission point than further away. However, there was no trend established between the proportion of study entrants with OME and increasing distance from an emissions source, nor was there any significant relationship established between the social disadvantage score of the areas of residence of the study entrants and the presence of OME. Further research is required to establish the effect of confounding variables on this relationship.

The analysis of nicotine in infants' hair for measuring exposure to environmental tobacco smoke

Hair samples were collected from 24 infants (3-36 months) exposed and non-exposed to environmental tobacco smoke. Hair was washed in dichloromethane, digested in NaOH, extracted by solid-phase extraction and analyzed by high-performance liquid chromatography to determine the content of nicotine and cotinine. Nicotine concentration in non-exposed infants (1.3 +/- 1.7 ng/mg hair) was significantly different from that in occasionally exposed infants (6.8 +/- 2.1 ng/mg hair) and that in infants passively exposed to smoke (15.4 +/- 6.7 ng/mg hair). Cotinine could be measured only in passive smokers infants. These findings suggest the possibility of monitoring exposure to environmental tobacco smoke in infants by using nicotine measurement in hair rather than in urine, blood or saliva.