Number 202 . June 18, 1991 

Advance


Data


From Vital and Health Statistics of the National Center for Health Statistics 

Children’s Exposure to Environmental Cigarette Smoke 

Before and After Birth 

Health of Our Nation’s Children, United States, 1988 

by. Mary. D. Overpeck, National 

Introduction 

The effects of environmental 

exposure to cigarette smoke for the 

preschool child are primarily the 

result of two phenomena: The 

mother’s prenatal smoking practices 

and the child’s subsequent family 

environment (l). Because strong 

evidence exists that exTosed infants 

and children are at higher risk for 

specific health and developmental 

problems (2,3), the vulnerability of 

some children may be increased 

according to differences in exposure 

to cigarette smoke among various 

demographic and socioeconomic 

groups, 

The pattern of cigarette smoking 

in the United States has shifted over 

the years among sex, race, 

educational, and socioeconomic 

groups (2,4-6), Although overall 

prevalence rates of smoking have 

declined among men and women over 

the past decade, smoking has 

decreased at a slower rate among 

Institute of Child Health and Human Development, and Abigail J. Moss, 

Division of Health Interview Statistics 

women. Until recently, smoking 

initiation was increasing for the least 

educated young females. Also, the 

onset of smoking for females is 

occurring at younger ages. In 1987, 

26 percent of women 18–24 years of 

age and 31 percent of those 25-44 

years of age smoked (7). About twice 

as many women these ages with less 

than a high school education smoked 

as did college graduates (31 

compared with 15 percent). 

Forty-one percent of those smoking 

during these childbearing years 

smoked about a pack a da% an 

additional 11 percent of women 

18-24 years and 21 percent of women 

25-44 years smoked more than this 

amount, 

As a result, differential risk of 

exposure for children may have 

changed because of smoking patterns 

among persons with higher than 

average birth rates and those who 

spend more time with the developing 

child (8,9). This report describes 

differences in exposure, both 

prenatally and postnatally, by 

demographic and socioeconomic 

characteristics for U.S. children 

5 years of age and under. Their 

respondent-assessed health status 

according to exposure and selected 

characteristics is also shown. 

Background 

Maternal smoking during 

pregnancy and its adverse effects on 

infant health have been the subject of 

numerous research studies over the 

last three decades (2). Considerable 

evidence has been amassed to 

indicate that cigarette smoking during 

pregnancy increases the risk of 

various adverse prenatal 

consequences and postnatal health 

conditions in infants. Prenatal 

exposure from a mother who smokes 

may cause intrauterine growth 

retardation, low birth weight, preterm 

delivery, and other complications of 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES ~-

Public Health Service r“­

Centers for Disease Control 

National Center for Health Statistics CENTERS 

c “UL FOR DISEASE CONTROL 

Manning Feinleib, M.D., Dr. P.H., Director 
2 Advance Data No. 202. June 18, 1991 

pregnancy and delivery. Recent 

estimates suggest that elimination of 

smoking during pregnancy could 

reduce about 5 percent of perinatal 

deaths (10–12). In a prospective 

study, it was demonstrated that 

nonsmokhg mothers exposed to 

environmental tobacco smoke for at 

least 2 hours a day had an increased 

relative risk of 2.17 for delivering a 

baby of low birth weight (less than 

2,500 grams) (13). 

Morbidity in older children, at 

least through the preschool years, 

also has been found to be higher for 

children whose mothers smoked 

during pregnancy than for those 

whose mothers did not smoke during 

this period (3). A number of studies 

have found increases in lower 

respirato~ tract infections (bronchitis 

and pneumonia) in smokers’ children 

under 2 years of age, with the 

strongest associations shown for 

maternal smoking (14-16). Other 

studies have found increased 

respiratory-related hospitalizations, 

wheezing, asthma, middle ear 

infections, febrile seizures, and 

reduction in physical growth (17–24). 

Behavioral and cognitive 

abnormalities affecting mental 

development also have been 

associated with maternal smoking 

during pregnancy (25,26). The 

associations with prenatal maternal 

smoking have held in all of these 

studies when controlled or stratified 

by socioeconomic and demographic 

factors related to poor health. With 

some of these findings, however, the 

effects of prenatal maternal smoking 

may be confounded with children’s 

exposure to environmental smoke 

after birth. 

In 1981, the National Health 

Interview Survey (NHIS) Child 

Health Supplement (CHS) included 

one question on prenatal maternal 

smoking. Competing priorities 

established for that survey dictated 

that the focus of the question be 

limited to obtaining data on the 

effects of low birth weight and 

intrauterine growth retardation. 

Subsequent analysis of data from 

this cross-sectional representative 

survey of U.S. children, however, 

revealed multiple adverse health


outcomes among children up to


3 years of age whose mothers smoked


while pregnant (27). Prenatal


maternal smoking was associated with


subsequent poorer health and with


higher levels of restricted-activity


days, bed days, hospitalizations, and


number of chronic conditions. A large


part of what was being measured,


however, may have been potential


adverse effects from sidestream


smoke in the household after the


children were born. Unfortunately,


questions about the presence of


household smoke following birth were


not included in the 1981 CHS.


To sort out the different stages of 

exposure to smoke for the young 

child, the 1988 NHIS on Child Health 

(NHIS-CH) contained an expanded 

set of cigarette smoking questions 

about children’s potential exposure 

both before and after birth. In 

particular, questions were included 

about the cigarette smoking practices 

of the sample child’s mother during 

her pregnancy as well as the presence 

of cigarette smokers in the household 

following the child’s birth. 

This report compares the rates of 

exposure to smoke at various stages 

from the prenatal period to the time 

of the survey. Exposure estimates are 

shown according to the following 

demographic, socioeconomic, and 

health status indicators: Race, 

Hispanic origin, family income, 

poverty status, maternal education, 

place of residence, and respondentassessed health status. 

Table 1 shows the number and 

percent of children 5 years of age and 

under in the United States by 

whether they were ever exposed to 

cigarette smoke and the period(s) of 

exposure. Estimates of children’s 

exposure to smoke during the 

prenatal period and the sources of 

that exposure are shown in table 2. 

In table 3, the estimates shown are 

by exposure to household smoke since 

birth. Table 4 shows the percent of 

children assessed in fair or poor 

health, according to selected exposure 

periods. Table 5 contains population 

denominators needed to derive 

various estimated frequencies for the 

percentage estimates presented in 

tables 1-4. 

Data and methods 

In 1988 the National Center for 

Health Statistics, in collaboration with 

the National Institute of Child Health 

and Human Development and the 

Health Resources and Services 

Administration and as part of its 

ongoing NHIS, collected detailed 

information about the health of 

children. The National Health 

Interview Survey is a continuous, 

cross-sectional survey representing 

the household population of the 

United States. Each year, basic health 

and demographic information is 

collected in NHIS by means of 

face-to-face interviews with a sample 

of about 122,000 family members in 

about 47,000 families. In addition to 

the basic questionnaire, questions on 

one or more special topics are also 

included. Interviews are conducted by 

interviewers employed by the US. 

Bureau of the Census, Topics covered 

in the 1988 NHIS-CH include child 

care, marital history of the child’s 

parents, geographic mobility, 

circumstances of the pregnancy and 

birth, injuries, impairments, acute 

conditions, chronic conditions, passive 

smoking, sleep habits, school 

problems, developmental problems, 

and use of health care services. 

For each family interviewed in 

NHIS during 1988, one child 17 years 

of age and under was selected to 

receive the child health questionnaire 

according to a probability determined 

by birth order. About 20,000 children 

from birth through 17 years of age 

were represented. The overall 

response rate for NHIS-CH was 

about 91 percent. 

The questions about children’s 

potential exposure to cigarette smoke 

were asked only for sample children 

5 years of age and under, This age 

limit was selected to limit recall 

problems and confounding from 

multiple exposures. Because some of 

the information being obtained 

referred to the mother’s smoking 

practices during pregnancy, the 

accuracy of reporting was expected to 
Advance Data No. 202 � June 18, 1991 3 

Table 1. Number of children 5 yeara of age and under and percent distribution by exposure to smoke before and after birth, according to 

selected characteristics: United States, 1988 

Number of All exposures to smoke 

children Never Total Both 

in exposed ever prenatal Prenata/ Postnatal Continuous 

Characterlstlc thousands’ Total to smoke exposed 2 and postnatal only only exposure 

Percent distribution 

Allchlldren3 . . . . . . . . . . . . . . . . . 19,008 100.0 49.9 (0.9) 50.1 (0.9) 27.6 (0.9) 1.2 (0.2) 21.2 (0.7) 16.4 (0.6) 

Race 

White . . . . . . . . . . . . . . . . . . . . . 15,564 100.0 50.7 (1.0) 49.3 (1.0) 28.1 (1.0) 1.2 (0.2) 19.8 (0.7) 16.7 (0.8) 

Black, . . . . . . . . . . . . . . . . . . . . 2,759 100.0 40.3 (2.4) 59.7 (2.4) 28.8 (1.9) 1.2 (0.5) 29.7 (2.3) 17.8 (1.6) 

Hispanic origin 

Non-Hlspanlc . . . . . . . . . . . . . . . . 16,912 100.0 49.2(1,0) 50.6 (1.0) 28.5 (0.9) 1.2 (0.2) 20.9 (0.8) 17.2 (0.8) 

Hlspanlc, . . . . . . . . . . . . . . . . . . 2,096 100.0 55.7 (2.4) 44.3 (2.4) 19.9 (1.9) 0.7 (0.3) 23.5 (2.1) 10.1 (1.4) 

Mexican-American . . . . . . . . . . . 1,006 100,0 60.2 (4.1 ) 39.8 (4.1 ) 15.1 (2.7) 0.4 (0.3) 24.3 (3.3) 7.7(1.8) 

Famllylncome 

Lessthan$lO,OOO . . . . . . . . . . . . 2,663 100.0 32.3 (2.1 ) 67.7 (2.1) 42.2 (2.1) 1.1 (0.4) 24.2 (2.0) 27.0 (1.9) 

$10,000-$24,999 . . . . . . . . . . . . . 5,434 100.0 4s.4 (1.5) 56.6 (1.5) 30.9 (1.4) 0.9 (0.3) 24.6 (1.3) 19.2 (1.3) 

$25,00&$39,999 . . . . . . . . . . . . . 4,869 100.0 54.9 (1.7) 45.1 (1.7) 25.4 (1.4) 1.0 (0.3) 16.5 (1.2) 14.1 (1.2) 

$40,0000rmore . . . . . . . . . . . . . . 4,144 100.0 64.0 (1.8) 36.0 (1.8) 17.9 (1.4) 1.6 (0.4) 16.5 (1,3) 9.3 (1.1) 

Poverty status 

Inpoverly. . . . . . . . . . . . . . . . . . 3,374 100.0 35.3 (2.1) 64.7 (2.1) 36.7 (1.9) 1.1 (0.5) 26.8 (2.0) 23.5 (1.7) 

Notln poverty . . . . . . . . . . . . . . . 14,573 100.0 53.5 (1.0) 46.5 (1.0) 25.4 (0.9) 1.2 (0.2) 19.7 (0.8) 14.7 (0.8) 

Mother’s education 

Lessthan 12years . . . . . . . . . . . . 3,279 100.0 32.9 (2.2) 67.1 (2.2) 43.0 (2.5) 0.4 (0.2) 23.4 (2.0) 30.0 (2.4) 

.3) 56.6 (1.3) 32.5 (1.3) 1.3 (0.3) 22.9 (1.1) 19.5 (1.2) 

Morethan 12years . . . . . . . . . . . . 7,496 100.0 65.0 (1.2) 35.0 (1.2) 15.2 (0.8) 1.3 (0.2) 18.3 (1.0) 7.1 (0.6) 

Place of residence 

MA. . . . . . . . . . . . . . . . . . . . . 14,544 100.0 50.3 (1.0) 49.7 (1.0) 27.5 (1.0) 1.2 (0.2) 20.8 (0.9) 16.4 (0.9) 

Crmtralcity . . . . . . . . . . . . . . . . 5,991 100.0 46.0 (1 ,3) 52.0 (1.3) 27.4 (1.5) 1.4 (0.4) 23.1 (1.3) 16.5 (1.3) 

Notcentralclly . . . . . . . . . . . . . 8,554 100.0 51.9 (1.4) 48.1 (1.4) 27.7 (1.2) 1.0 (0.2) 19.3 (1.1) 16.3 (1.1) 

NotMSA . . . . . . . . . . . . . . . . . . 4,464 100.0 48.5 (2.0) 51.5 (2.0) 27.7 (1.7) 1.1 (0.4) 22.5 (1.1) 16.5 (1.5) 

Assessed health status 

Excellent, verygood,orgood . . . . . 16,193 100.0 50.3 (0.9) 49.7 (0.9) 27.4 (0.6) 1.2 (0.2) 21.0 (0.7) 16.4 (0.7) 

Falrorpoor . . . . . . . . . . . . . . . . . 594 100.0 37.1 (5.1) 62.9 (5.1) 33.7 (4.0) 0.0 (0.0) 29.1 (5.5) 17.5 (3.1) 

1~x~lude~ ~hl[dren whose total axposure to smoke Is unknown. 

?[n~[”de~ e~~~~ed children whose period of exposura ia unknown. 

+n~[uda~ ~11Qthar racaa, unknown family Incomer unknown poveriy status, unknown education of mother, and Unknownassessed health status 

12years . . . . . . . . . . . . . . . . . . . 6,012 100.0 43.2 (1 

NOTES I%vettv status Is determined in ihe Natlonel Health Interview Survey by femily size, number of children, and family income using 19e7 Poverty Ievsls defined by the U.S. Bureau of the 

Census. MSA ii metrogmlitan sta!lsticel aree. Figures In parentheses ere starida~d errors of estimates. 

ckcrease as the interval between the 

pregnancy and the time ofintewiew 

increased, Obtaining data on the 

older child presents the problemof 

documenting increasing outside 

exTosure to the child compounded 

with the concern that children 

themselves may actually begin to 

smoke in the elementary school years. 

The questions about mothers’ 

smoking behavior during pregnancy 

were w&edonlyof biological mothers 

who were still living in the household 

and available to respond at the time 

of the interview. Data presented in 

this report are limited to those 

children for whom prenatal maternal 

smoking information was available. 

I About ll,5 tmcentof 

A otherwise 

eligible sample children 5 years of age


and under are excluded from this


analysis because the biological mother


was not available for interview. Also


excluded from this analysis are an


additional 2 percent of eligible


sample children for whom no smoking


exposure information was available on


the NHIS-CH questionnaire. For this


report, the final NHIS–CH passive


smoking sample includes 5,356 sample


children representing 86 percent of


U.S. children 5 years of age and


under. Comparison of sample


children by the demographic and


socioeconomic descriptors used in this


report shows no differences indicating


response bias as a result of these


exclusions,


The estimates presented in this 

report are weighted to produce 

representative national estimates of 

U.S. noninstitutionalized children 

5 years of age and under, less the 

sample exclusions just described. This 

weighted national estimate represents 

about 19 million children. U.S. 

population totals for all 

noninstitutionalized children these 

ages are provided in table 5 for data 

users interested in approximating 

total U.S. estimates. 

Initially, mothers were asked 

whether they smoked at all during the 

year before the child’s birth. 

Subsequent questions included 

whether they continued to smoke 

during the entire pregnancy or 
4 Advance Data No. 202. June 18, 1991 

Table 2. Number of children 5 years of age and under and percent distribution by whether exposed to smoke before birth, according to 

selected characteristics: United States, 1988 

Exposed before birth 

Number of Not 

children exposed Mother 

in before Mother and others Pofen!/a/ 

Characteristic thousands’ Total birth smoked smoked exposure 

Percent distribution 

Alichildren2 . . . . . . . . . . . . . . . . . . . . . . . . 18,849 100.0 49,4 (0.9) 26,8 (0.9) 20.8 (0.8) 21.6 (0.6) 

Race 

White . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15,448 100.0 49.9 (1.0) 29.3 (1.0) 21.7 (0,9) 20.7 (0.8) 

Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,728 100.0 41.5 (2.4) 30.0 (1.9) 18.6 (1.7) 28.4 (2.3) 

Hispanic origin 

Non-Hispanic . . . . . . . . . . . . . . . . . . . . . . . 16,799 100.0 48.6 (1.0) 29.8 (0.9) 21.6 (0.9) 21.5 (0.8) 

Hispanic . . . . . . . . . . . . . . . . . . . . . . . . . . 2,050 100.0 56.5 (2.3) 20.6 (1.8) 13.8 (1 .9) 22.5 (2.4) 

Mexican-American . . . . . . . . . . . . . . . . . . 987 100.0 59.5 (3.7) 15.4 (2.7) 9.9 (2.6) 24.7 (3.4) 

Family Income 

Lessthan $10,000 . . . . . . . . . . . . . . . . . . . . 2,679 100.0 32.1 (2.1) 43.3 (2.0) 31.5 (1.9) 24,5 (1.8) 

$10,000-$24,999 . . . . . . . . . . . . . . . . . . . . 5,372 100.0 44.1 (1.6) 31.8 (1.4) 23.3 (1.3) 23.8 (1.4) 

$25,000-$39,999 . . . . . . . . . . . . . . . . . . . . 4,833 100.0 53.3 (1.6) 26.5 (1.5) 19.6 (1.3) 20.1 (1.3) 

$40,0000rmore . . . . . . . . . . . . . . . . . . . . . 4,109 100.0 62.9 (1.7) 19.5 (1.4) 12.7 (1.2) 17,4 (1.3) 

Poverly status 

In povetty . . . . . . . . . . . . . . . . . . . . . . . . . 3,344 100.0 35.9 (2.1) 37.8 (1.9) 27.9 (1.7) 26.0 (1 .6) 

Notin poverty, . . . . . . . . . . . . . . . . . . . . . 14,456 100.0 53.0 (1.0) 26.6 (0.9) 18.9 (0.8) 20.2 (0.8) 

Mother’s education 

Lesathan 12years . . . . . . . . . . . . . . . . . . . 3,249 100.0 33.0 (2.1) 43.5 (2.6) 34.6 (2.3) 23.2 (1.9) 

12years . . . . . . . . . . . . . . . . . . . . . . . . . . 7,964 100.0 41.7 (1.4) 33.8 (1 .3) 24.4 (1.2) 24.3 (1.2) 

Morethan 12years . . . . . . . . . . . . . . . . . . . 7,416 100.0 65,3 (1,2) 16.5 (0.6) 10.4 (0.6) 18.0 (0.9) 

Place of residence 

MA. . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,406 100.0 50.3 (1.0) 28.7 (1.0) 20.8 (1.0) 20.7 (0.9) 

Centralcify . . . . . . . . . . . . . . . . . . . . . . . 5,920 100.0 48.6 (1.5) 28.8 (1.5) 20.7 (1.3) 22.2 (1,5) 

Notcentralcity . . . . . . . . . . . . . . . . . . . . 8,487 100.0 51.4 (1.4) 28.7 (1.2) 20.9 (1.1) 19.7(1 ,2) 

NotMSA . . . . . . . . . . . . . . . . . . . . . . . . . . 4,443 100.0 46.5 (2.1) 26.8 (1.8) 20.8 (1.5) 24,5 (1.1) 

Assessed health status 

Excellent, verygood,orgood. . . . . . . . . . . . . 18,054 100.0 50.1 (0.9) 26.6 (0.8) 20.7 (0.8) 21.1 (0.7) 

Fairorpoor . . . . . . . . . . . . . . . . . . . . . . . . 574 100.0 33.0 (4.6) 33.6 (4.0) 26.3 (3.8) 32.4 (5.6) 

1Excludes children whose exposure to smoke before birth Is unknown.


zln~lud~~sll other ,SceS,unknown family income, unknown poveriy status, unknown education of mother, and unknown sssessed hesllh status.


NOTES:Exposure before birth includes children exposed by mo!hers’ dfrect smokfng ss well ss possible exposure from mothsrs’ contscts who smoked. Poverlyslatua Is determined in the Nstionsl


Health Intetview Sutvev bv familv size, number of children, and family income using 1987 poverty levels defined by the U.S. Bursau of the Census. MSAIs metropolitan statisticalaree. Figures In


parentheses are stand&d’errors”of estlmatea. 

stopped during the first 3 monthsor 

later and the average daily number of 

cigarettes smoked. An additional 

question about potential exposure 

involved the frequency with which the 

mother was in contact with friends, 

coworkers, or family members who 

smoked during the pregnancy. 

To assess a child’s exposure to 

cigarette smoke afterbirth, the 

mother’s current smoking status was 

determined, Ifshe wasnot acurrent 

smoker, the interval since she had last 

smoked was ascertained. Other 

questions were used to determine 

whether any household member had 

smoked regularly since thechild’s 

birth. If so, determinations were 

made as to (a) whether any 

household member currently smoked 

and (b) whether it had been more or 

Iess than 12months since anyone in 

the household had smoked. A 

facsimile of the NHIS-CH 

questionnaire items is provided in 

Current Estimates from the National 

Health Interview Survey, 19S8 (28). 

Results 

Exposure status 

Figure lshowsthe distribution of 

U.S. children 5 years of age and 

undcrbywhethe rtheywere ever 

exposed to cigarette smoke and the 

proportion exposed before and after 

bir~h. About one-half of U.S. children 

5 years of age and under have ever 

been exposed to cigarette smoke, For 

this report, the estimates of children 

ever exposed include children whose 

mother smoked at any time during 

the pregnancy or afterward and 

children who lived in a household 

where someone ever smoked regularly 

since their birth. More than 

one-fourth of all young children, on 

the average, were exposed to passive 

smoke both before and after birth, 

A higher proportion of black 

children (60 percent) than white 

children (49 percent) were ever 

exposed, with most of the difference 
Advance Data No. 202. June 18, 1991 5 

Table 3. Numbar of children 5 yeara of age and under and percent distribution by whether exposed to household smoke since birth, 

according to selected characteristics: United States, 1988 

Number of Not 

Exposed since birth 

chi/drerr exposed Current Former 

in since smoker in smoker In 

Characteristic thousands~ Total birth Total 2 household household 

Percent distribution 

Allchildren3, .,, , . . . . . . . . . . . . . . . . . . . 19,019 100.0 51.1 (0.9) 48.9 (0.9) 42.4 (0.9) 6.1 (0.4) 

Race 

White . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15,575 100.0 51.9 (1.0) 46.1 (1.0) 41.6 (1.0) 6.1 (0.4) 

Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,759 100.0 41.5 (2.4) 58.5 (2.4) 51.3 (2.4) 6.7 (1.2) 

Hispanic origin 

Non.Hlspanlc, . .,, . . . . . . . . . . . . . . . . . . 16,923 100.0 50.4 (1.0) 49.6 (1.0) 43.2 (1.0) 6.0 (0.4) 

Hlspanlc . . . . . . . . . . . . . . . . . . . . . . . . . . 2,096 100.0 56.4 (2.6) 43.6 (2.6) 35.8 (2.5) 6.9 (1.2) 

Mexican-American, ..,,,.,,.. . . . . . . . 1,006 100.0 60.7 (4.1) 39.3 (4.1) 31.8 (3.8) 6.5 (1.6) 

Famllylncome 

Lessthan$lO,OOO, .,, ,., .,... . . . . . . . . 2,685 100.0 33.4 (2.1) 66.6 (2.1) 57.7 (2.3) 8.7(1.1) 

$10,000-$24,999 . . . . . . . . . . . . . . . . . . . . 5,436 100.0 44.3 (1 .5) 55.7 (1 .5) 48.8 (1.6) 6.3 (0.7) 

$25,000-$39,999 . . . . . . . . . . . . . . . . . . . . 4,671 100.0 55.9 (1.7) 44.1 (1.7) 38.3 (1.6) 5.4 (0.7) 

$40,0000rmore . . . . . . . . . . . . . . . . . . . . . 4,149 100.0 65.7 (1.8) 34.3 (1

Poverty status 

In poverty . . . . . . . . . . . . . . . . . . . . . . . . . 3,376 100.0 36.4 (2.1 ) 63.6(2.1) 55.7 (2.3) 7.6 (1.0) 

Notlnpoverty, , . . . . . . . . . . . . . . . . . . . . 14,562 100.0 54.8 (1.0) 45.2 (1.0) 39.2 (1.0) 5.6 (0.4) 

.8) 29.5 (1.5) 4.6 (0.9) 

Mother’s education 

Lessthan 12years . . . . . . . . . . . . . . . . . . . 3,279 100.0 33.3 (2.2) 66.7 (2.2) 61.2 (2.1) 5.1 (0.8) 

.4) 47.9 (1.4) 7.3 (0.6) 

Morethan 12years . . . . . . . . . . . . . . . . . . . 7,505 100.0 66.3 (1.2) 33.7 (1.2) 27.6(1.1) 5.4 (0.6) 

Place of residence 

MA. . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,550 100.0 51.5 (1.0) 48.5 (1.0) 42.2 (1.1) 5.9 (0.4) 

Centralcity. . . . . . . . . . . . . . . . . . . . . . . 5,994 100.0 49,4 (1.4) 50.6 (1.4) 43.8 (1.5) 6.3 (0.6) 

Notcentralclty, , .,....,.,.. . . . . . . . 6,556 100.0 52.9 (1.4) 47.1 (1.4) 41.1 (1.4) 5.6 (0.6) 

NotMSA, . . . . . . . . . . . . . . . . . . . . . . . . . 4,469 100.0 49.7 (1.9) 50.3 (1.9) 43.1 (1.7) 6.8 (0.8) 

Assessed health status 

Excellent,verygood, Osgood. .,...... . . . . 16,204 100.0 51.5 (0.9) 48.5 (0.9) 42.0 (0.9) 6.0 (0.4) 

Fairorpoor. . . . . . . . . . . . . . . . . . . . . . . . 594 100.0 37.1 (5.1) 62.9 (5.1) 55.7 (5.3) 6.7 (2.4) 

12years . . . . . . . . . . . . . . . . . . . . . . . . . . 8,014 100.0 44.5 (1.4) 55.5 (1 

1Excludeschildrenwhoseexposureto smokeIn ths home after birth is unknown. 

‘ln~l”des ~h[ldren exposed since birth whose period Of eXPOWre Is unknown. 

%cludes 811other races, unknown family Income, unknown poverty status, unknown education of mother, and unknown assessed health status. 

NOTES: Pove~status lsdetermlned lnthe Natlonsl Health lntewlew Suweyby famllyslze, number ofchifdren, and family income using 1987 poverly fevelsdefined bythe U.S. LIureau of the 

Census.M8AIe metropolitanstatisticalarea.FiguresIn parentheses are standard errors of estimates. 

occurring in the postnatal period more, almost a twofold risk. Similarly, whether the child’s overall health is


(table 1). Children of Hispanic origin the overall rate of exposure to passive considered excellent, very good, good,


were less likely ever to be exposed to smoke declined as level ofmother’s fair, or poor.


smoke than were non-Hispanic education increased, from67 percent A higher percent of children in


children (44and51 percent, of children whose mother did not fair or poor health than other


respectively). Mexican-American complete high school to 35 percent of children were ever exposed to smoke;


children werethe Ieastlikely tobe those whose mother had Iyearor almost two-thirdsof all children


exposed prenatally, but their more of college. Differences were reported to be in fair or poor health


“postnatal only” exposure was similar significant atthe O.05 level between were exposed to cigarette smoke


to that of children of other origins. each level of income, poverty, and either before orafter their birth,


Differentials in exposure levels maternal education. compared with about one-halfof all 

were also found among children by Table lalso contains exposure children whose overall health was 

come categories and estimates according toone NHIS reported to be excellent, very good, 

according tomother’s education. health status measure: Respondent- or good. 

About two-thirds ofyoung children in assessed health status. Respondent- Although questions detailing the 

families with incomes of less than assessed health status for children is entire duration of smoking exposure 

$10,000 were ever exposed to smoke, reported by the household respondent before and after birth were not 

compared with36 percent of children for NHIS, usually a parent. The included as part of this survey, some 

whose family income was$40,0000r question is used to determine approximation is possible to estimate 

wwicrusin 
6 Advance Data No. 202. June 18, 1991 

Table 4. Percent of children 5 years of age and under assessed in fair or poor health, by exposure to smoke and eelected 

characteristics United States, 1988 

Ever exposed 

Mother 

smoked Current Former 

All Never durkrg smoker in smoker in 

Characteristic children’ exposed Total pregnancy household household 

Percent of children 

Allchildren2 . . . . . . . . . . . . . . . . . . . . . . . . 3.2 (0.33) 2.4 (0.34) 4.0 (0.57) 3.7 (0.50) 4.1 (0.64) 3.5 (1.25) 

Race 

White . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 (0.36) 2.2 (0.38) 3.7 (0.63) 3.3 (0.49) 4.0 (0.72) 3.1 (1.16) 

Black . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 (0.95) 3.1 (1.08) 5.1 (1.37) 6.1 (2.06) 5.0 (1.42) 6.4 (4.91) 

Hispanic origin 

Non-Hispanic . . . . . . . . . . . . . . . . . . . . . . . 3.0 (0.35) 2.1 (0.34) 3.6 (0.61) 3.6 (0.53) 4.0 (0.69) 3.3 (1.34) 

Hispanic . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 (1 ,07) 4.1 (1.42) 5.0 (1.59) 5.2 (2.24) 5.3 (1.88) 5.2 (3.34) 

Mexican-American . . . . . . . . . . . . . . . . . . 5.3 (1.72) 5.5 (2.32) 4,3 (2.31) 2.4 (2.14) 5.4 (2.84) 0.0 (0{00) 

Famllylncome 

Lessthan$lO,OOO . . . . . . . . . . . . . . . . . . . . 7.0 (1.52) 4.5 (1.55) 8.1 (2.20) 7.5(1.63) 8.0 (2.52) 10.7 (4.76) 

$10,000-$24,999 . . . . . . . . . . . . . . . . . . . . 3.6 (0.56) 2.7 (0.73) 4.4 (0.85) 3.5 (0.95) 4.6 (0.92) 3.4 (2.1 o) 

$25,000-$39,999 . . . . . . . . . . . . . . . . . . . . 2.7 (0.54) 2.4 (0.77) 2.9 (0,70) 3.2 (0.91) 3,3 (0.80) 0.0 (0.00) 

$40,0000rmore. .. c . . . . . . . . . . . . . . . . . 1.4 (0.37) 1.1 (0.37) 1.9 (0.61) 1.3 (0.94) 2.0 (0.94) 2.1 (2.05) 

Poverty status 

In poverty . . . . . . . . . ...<... . . . . . . . . . 8.5 (1.30) 3.5 (1.1 2) 8.1 (1.85) 7.8 (1 .84) 8.0 (2.19) 9.8 (4.44) 

Notin poverty . . . . . . . . . . . . . . . . . . . . . . 2.4 (0,27) 2.0 (0.34) 2.9 (0.41) 2.7 (0.49) 3.2 (0.45) 1.9 (1.01) 

Mother’s education 

Lessthan 12years . . . . . . . . . . . . . . . . . . . 6.0 (1.28) 3.3 (1.19) 7.3 (1.62) 5.6 (1.23) 7.3 (1.96) 10.6 (6.12) 

12years, . . . . . . . . . . . . . . . . . . . . . . . . . 

Morethan 12years . . . . . . . . . . . . . . . . . . . 

3.0 (0.47) 1.9 (0.28) 

2.7 (0.73) 1.8 (0.33) 3.3 (0.57) 2.0 (0.52) 3.7 (0.75) 1.6 (0.76) 3.6 (0.65) 1.9 (0.53) 2.3 (1.16) 2.5 (1.77) 

Place of residence 

MA. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9 (0.36) 1.9 (0.36) 3.9 (0.68) 3.9 (0.59) 4.1 (0.77) 3.5 (1.44) 

Central ity. . . . . . . . . . . . . . . . . . . . . . . 2.9 (0.46) 1.4 (0,46) 4,3 (0.82) 4.9 (1.14) 3.9 (0.86) 7.5 (3.21) 

Noncentral city . . . . . . . . . . . . . . . . . . . . 2.9 (0.56) 2.2 (0,53) 3.6 (1.04) 3.2 (0.66) 4.2 (1.21) 0.4 (0.37) 

NotMSA . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 (0.66) 4.0 (0.85) 4.1 (0.95) 3.1 (0.86) 4.4(1.04) 3.6 (2.55) 

1~clude~ ~~ldren whose total exposure to smoke is unknown. 

21ncludes ell other races, unknown family Income, unknown poverty status, and unknown education of mother. 

NOTES Pove~ ststus is determined In the National Health Interview Survey by family size, numbsr of children, and family income using 1987 poveriy Ievsls defined by the U.S. Bureau of the 

Census. MSA Is metropolitan atatiatlcal araa. Figures In parentheses are standard errors of estimatas. 

the proportionof children at highest 

risk, that is, those continuously 

exposed from the prenatal period to 

the time ofinterview, For this report 

children were classified as being 

“continuously” exposedto cigarette 

smoke if either(a) their mother 

smoked during the entire pregnancy 

and currently smokesor (b) their 

mother smoked during the entire 

pregnancy, a household member 

smoked regularly since their birth, 

and a household member currently 

smokes. 

Using this operational definition, 

about16 percent ofU.S. 

children—one in six—have been 

exposed continuously, that is, 

prenatally to tobacco smoke 

constituents and postnatallyto 

sidestream smoke in the household. 

About the same proportion of black 

and white children experienced 

continuous exposure to smoke, but 

more non-Hispanic than Hispanic 

children were exposed continuously 

(17 percent and 10 percent, 

respectively). Children in families 

with incomes of less than $10,000 

were three times as likely to be 

exposed from conception to the 

current time as were those with 

family incomes of $40,000 or more 

(27 and 9 percent). Children whose 

mother had not completed high 

school were four times as likely to be 

exposed asthose whose mother 

continued her education beyond high 

school (30and7 percent). 

Prenatal exposure 

In table 2estimates ofchildren’s 

exposure to smoke before birth are 

expanded. The criteria for classifying 

children’s exposure to cigarette smoke 

used for this table also differ from 

those used for figure Iand table 1, 

For most of the exposure status categories shown in table 2, the data 

incorporate estimates for children 

whose mother was often in contact 

with a smoker (such as friends, 

coworkers, or family members who 

smoked). 

Some of the four categories 

shown in table 2 are not mutually 

exclusive. They are defined in the 

following way: 

� “Not exposed before birth” 

includes children whose mother 

did not smoke at all during 

pregnancy and did not often 

come in contact with persons who 

smoked. 

� “Mother smoked” includes all 

children whose mother reported 
� 

� 

Table 5, Number of children 5 years of age 

and under, by selected sociodemographic 

characteristics and assessed health status: 

United States, 1988 

Number /n 

Characteristic thousands 

Totcdi ..,....,..,,,,.,,. 22,107 

RacEI 

Whlto . . . . . . . . . . . . . . . . . . 17,82S 

Black .,,.,....,.,..,,,, 3,336 

Hlspanlc orlgln 

Ncm-Hlspanlc, . . . . . . . . . . . . 19,570 

Hlspanlc, . . . . . . . . . . . . . . . 2,537 

Mcxlcan-Amcrlcan. . . . . . . . . 1,229 

R3mlly Income 

Undex$lO,OOO . . . . . . . . . . . . 3,046 

$10,000-$24,999 . . . . . . . . . . . 6,279 

$25,000-$39,999 ... . . . . . . . . 5,550 

$40,0000 r more . . . . . . . . . . . 4,905 

Poverty status 

In poverty . . . . . . . . . . . . . . . 3,878 

Notln poverty . . . . . . . . . . . . . 16,906 

Mother’s education 

Less than 12years. . . . . . . . . . 3,959 

12years ., ., ., . .,..,,.., 9,071 

Morethan12 years . . . . . . . . . 8,604 

Place of residence 

MA.. . . . . . . . . . . . . . . . . . 16,924 

Central city . . . . . . . . . . . . . 7,038 

Noncentral cky. . . . . . . . . . . 9,886 

Not MSA . . . . . . . . . . . . . . . . 5,183 

Assessed health status 

Excellent, verygood, orgood. . . 21,196 

Falrorpoor . . . . . . . . . . . . . . 664 

11ndUde8 all other races, unknown family Income, unknown 

poverty status, unknown educatlonof mother, and unknown 

nmosscd hocillh status. 

NOTES: Povorfystcius Is determined In the National Health 

Intorvlew Survey by family size, number of children, and family 

Income using 19 S7poverty levels defined bythe U. S. Bureau 

of !ho Consu% MSA Is metropolitan statistical area. 

FmrlStel Onfy 

1.2% 

Figure 1. Percent distribution of children 5 years of age and under by exposure to smoke 

b[fore and after birth: United States, 1988 ­

smo~ingat all during the 

pregnancy, 

“hlother and others smoked” 

refers to children whose mother


smoked at all during the


pregnancy and also often came in


contact with someone who


smoked. This category is a subset


of the preceding category (mother


smoked), which includes these


children as well as children of


mothers who smoked but did not


come in contact frequently with


other smokers.


“Potential exposure” includes


children whose mother did not


smoke at all during pregnancy but


was often in contact with persons,


such as friends, coworkers, or


family members, who smoked. 

Children in this category, by 

definition, are not included in any 

of the preceding categories. 

About 29 percent of all children, 

regardless of race, were exposed 

prenatally to smoke as a direct result 

of their mother’s smoking, The 

percent of children of Hispanic origin 

exposed before birth as a 

consequence of their mother’s 

smoking was somewhat lower, about 

20 percent. Proportionately about 

twice as many youngsters from the 

lowest family income category were 

exposed from their mother’s smoke 

(43 percent) as were children whose 

family’s total earnings were $40,000 

or more (20 percent). The risk of 

exposure prior to birth from mothers’ 

smoke was more than 21Atimes as 

great for children of mothers with 

less than a high school education 

(44 percent) as for those whose 

mother had 1 year or more of college 

(17 percent). 

On the average, more than 

one-fourth of the Nation’s children 

were exposed to maternal smoke. 

However, this estimate rises to 

50 percent when children whose 

nonsmoking mothers were exposed to 

sidestream smoke during pregnancy 

are also considered potentially at risk. 

Overall, about 22 percent of children 

were reported to have mothers 

exposed frequently to cigarette 

smoke, even though they were not 

smokers themselves. This estimate 

was somewhat higher for black 

children (28 percent, compared with 

21 percent of white children). 

Proportionately there were more 

children with nonsmoking mothers 

exposed to smoke among families 

comprising the lowest income and 

maternal education categories than 

among families with incomes of 

$40,000 or more and mothers with 

more than 12 years of education. 

The proportions of children with 

potential exposure, shown in table 2, 

are very similar to those of children 

exposed postnatally only by household 

members, shown in table 1, 

suggesting that household exposure 

may be the main potential source for 

pregnant nonsmoking mothers. 

Postnatal exposure 

Forty-two percent of all U.S. 

children 5 years of age and under 
8 Advance Data No. 202. June 18, 1991 

were currently living in a household


with a smoker (table 3). This


estimate was highest among black


children: On the average, one out of


two black children lived with someone


who smoked. Only 6 percent of U.S. 

children lived in households where 

smoking had ceased since the child 

was born. Proportionately fewer 

Hispanic children than others were 

currently exposed in the home 

(36 percent). 

As with the estimates of children 

exposed to cigarette smoke prenatally, 

a disproportionately high number of 

children comprising the lower income 

and education categories were 

currently exposed to smoke in the 

home. Fifty-eight percent of those 

whose family income was less than 

$10,000 were living with a smoker, 

compared with 30 percent of children 

in families with incomes of $40,000 or 

more, a twofold risk, More than twice 

as many children having mothers with 

less than 12 years of education were 

currently exposed to household smoke 

(61 percent) as were children whose 

mothers reported completing 1 year 

or more of college (28 percent). 

A higher proportion of children 

in fair or poor health were reported 

to be living in households with a 

current smoker: 56 percent versus 

42 percent of those whose overall 

health was said to be good to 

excellent, 

The percent of children living 

with a household member who had 

quit smoking appears to be higher 

among those with incomes less than 

$10,000 or in poverty (9 and 

8 percent, respectively) than the 

overall average of 6 percent, These 

differences may be due to sampling 

variation. However, the level of 

current smokers is still highest in 

these categories. 

Exposure and assessed health 

status 

As previously mentioned, parents 

are asked to assess their children’s 

overall health as part of the basic 

NHIS interview, Accordingly, about 

3 percent of all U.S. children 5 years 

of age and under are said to be in 

fair or poor health (table 4). The 

relative risk of fair or poor health was 

almost twice as great for children who 

lived in households with current 

smokers as it was for children who 

were never exposed – 4.1 and 

2,4 percent, respectively. This 

approximate ratio. also is observed 

between the estimates for most of the 

smoking categories shown in table 4. 

However, the differences seen are not 

statistically significant at the 0,05 

level when the standard errors 

associated with these estimates are 

considered. 

Nevertheless, the estimates in 

table 4 are included in this report to 

show an apparent pattern suggesting 

that, for most children, fair or poor 

health appears to be associated with 

various exposures to cigarette smoke, 

Children currently exposed appear to 

be at somewhat greater risk than 

those formerly exposed, whether at 

home or prenatally. The children at 

least risk appear to be those who 

have never been exposed to cigarette 

smoke at all, The estimates presented 

in this table should be interpreted 

with caution, however, because 

sampling variability may account for 

the differences that are observed and 

other determinants of perceived 

health status have not been taken 

into account. 

Summary 

In this report, the differences 

found in exposure by family income, 

poverty, and total years of maternal 

education follow what is known about 

overall smoking rates in the U.S. 

population (l–6), Overall, about 

one-half of all US. children 5 years 

of age and under have been exposed 

to environmental cigarette smoke 

from prenatal maternal smoking 

and/or sidestream smoke from 

household members after their birth. 

Twenty-one percent were exposed 

only after they were born, and 

28 percent were exposed both from 

prenatal maternal smoking and 

subsequent household exposure. 

Sixteen percent were continuously 

exposed, 

The findings show that a large 

proportion of children at 

disadvantage from low income and 

educational levels in the household 

are also at increased risk of exposure 

to maternal and sidestream smoke, 

potentially adding to differentials in 

their health risks. The differences in 

exposure by family income, poverty 

status, and total years of maternal 

education are consistent with current 

smoking patterns of the U.S. 

population during the childbearing 

years. Children 5 years of age and 

under in families with the lowest 

income levels were almost twice as 

likely to have ever been exposed as 

those with the highest incomes 

(68 percent compared with 

36 percent). Almost twice as many 

children living in households where 

the mother had not completed high 

school as in those where the mother 

had completed 1 or more years of 

college had ever been exposed 

(67 percent compared with 

35 percent). 

Black children were more likely 

to have ever been exposed than white 

children (60 and 49 percent, 

respectively). Non-Hispanic children 

were more likely to have been 

exposed than Hispanic children (51 

and 44 percent, respectively), with 

Mexican-American children the least 

likely to have been exposed 

(40 percent). 

The children least likely to h:ive 

been continuously exposed since 

conception had mothers with more 

than 12 years of education 

(7 percent) or lived in households 

with family incomes of $40,000 or 

more (9 percent). Hispanic children 

were also less likely to be exposed 

continuously. Mexican-American 

children had one-half the risk of 

continuous exposure (8 percent) th? 

non-Hispanic children had 

(17 percent), because MexicanAmerican mothers were one-half as 

likely as others to smoke while 

pregnant (16 percent compared wit 

30 percent). 

Patterns are similar for childre] 

currently living with smokers. Abou 

twice as many children living in 

families with the least income as in 

families with an income of $40,0[J0 

more were exposed (5S percent 

versus 30 percent). Children living 
Advance Data No. 202 � June 18, 1991 

with mothers with less than 12 years


of education were more than twice as


likely to be living with a current 9.


smoker (61 percent) as those with


the most educated mothers


(28 percent). However, 32 percent of


Mexican-American children currently


lived with a smoker, compared with 10.


43 percent of non-Hispanic children.


The differences found among 

educational, racial, and ethnic groups 

reinforce the concern about 

advertising targeted to the most 11. 

vulnerable populations (2,6,8,29), The


focus of appropriately specific


intervention should be intensified for


the highest risk groups of parents and 12.
 parents-to-be.


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13. 

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Bland M, Bewley BR, Pollard V,


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Coney JRT, Holand WW, Corkhill


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Neuspiel DR, Rush D, Butler NR, et


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wheezing in children: A prospective 

cohort study. Am J Public Health 

79:168-71.1989. 

Bonham GS, Wilson RW. Children’s 

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Weiss ST, Tager IB, Speizer FE,


Rosner B. Persistent wheeze: Its


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Weitzman M, Gortmaker S, Sabol A.


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Cassano PA, Koepsell TD, Fanvell


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10 Advance Data No. 202. June 18, 1991 

the estimates have been included in


the tables. The standard errors for


this report were calculated using


SESUDAAN, a SAS-based software


package designed to produce


standard errors for estimates based


on complex, multistage sample


designs (30). Standard errors based


on such survey designs are typically


about 20 percent larger than those


that would be obtained with a simple


random sample of the same size. 

In this report, persons whose 

Technical notes 

Methods 

The estimates presented in this 

report are based on data from the 

National Health Interview Survey 

(NHIS), an ongoing survey of U.S. 

households conducted by the National 

Center for Health Statistics. Each 

week, a probability sample of the 

civilian noninstitutionalized 

population of the United States is 

interviewed by personnel of the U.S. overall smoking exposure was 

Bureau of the Census, Interviewers unknown for certain items were 

obtain information about the health excluded from both the denominators 

and other characteristics of each and numerators of percents and 

member of the households included percent distributions. This exclusion 

in the NHIS sample. of unknowns implicitly assumes that 

NHIS consists of two parts: (a) a the response distribution for these 

basic health questionnaire that persons is the same as that for


remains the same each year and is persons for whom valid responses


completed for each household were provided.


member and (b) special topics All differences cited in this report


questionnaires that vary from year to are statistically significant at the 0.05


year and usually are asked of just one level. The t-test, with a critical value


person in each family. In 1988, the of 1.96, was used to test all pairwise


special topics included acquired comparisons. Lack of comment


immunodeficiency syndrome (AIDS) regarding the difference between any


knowledge and attitudes, medical two estimates does not mean that the


device implants, occupational health, difference was tested and found not


alcohol, and child health. These data to be statistically significant.


sets can be linked to provide The results presented in this


additional sources for analysis. report were derived from a corrected


The total sample interviewed for version of the 1988 NHIS-CH data 

1988 for the basic health tape. The original NHIS-CH public 

questionnaire consisted of 47,485 use tape, released in 1990, does not 

households containing 122,310 contain information about prenatal 

individuals. The total response rate exposure to smoke for about 

was 95 percent. For the National 10 percent of eligible sample children 

Health Interview Survey on Child because of an incorrect editing 

Health (NHIS-CH), one sample child procedure. Persons interested in 

17 years of age and under was purchasing a revised version of the 

selected from each family with public use tape should request the 

children in that age range. Interviews corrected copy by writing the Division 

were completed for 17,110 children of Health Inte~iew Statistics, 

17 years of age and under, 95 percent National Center for Health Statistics, 

of those identified as eligible on the 6525 Belcrest Road, Hyattsville, 

basis of the basic health Maryland 20782. 

questionnaire. The overall response 

rate for NHIS-CH was 91 percent, Definition of terms 

the product of the response rates for


the basic and child health


questionnaires. Children’s exposure to cigarette


Because the estimates presented smoke 

in this report are based on a sample Never exposed– Mother did not 

of the population, they are subject to smoke at all either during the 

sampling errors. Standard errors of pregnancy or after the child’s birth, 

and no household member has 

smoked regularly at any time since 

the child’s birth. 

Ever exposed-Mother smoked 

during some part of the pregnancy or 

after the child’s birth, or a household 

member has smoked regularly at any 

time since the child’s birth, 

Prenatal aposure only –Mother 

smoked during some part of the 

pregnancy but did not smoke after 

the child’s birth, and no household 

member has smoked regularly at any 

time since the child’s birth, 

Postnatal eqosure on&– Mother 

did not smoke at all during the 

pregnancy, and mother smoked after 

the child’s birth or a household 

member has smoked regularly at 

some time since the child’s birth. 

Prenatal and postnatal 

exposure –Mother smoked during 

some part of the pregnancy, and 

mother smoked after the child’s birth 

or a household member has smoked 

regularly at some time since the 

child’s birth. 

Continuous exposure – Mother 

smoked during the entire pregnancy, 

and mother reported smoking at time 

of interview or another household 

member smoked regularly since the 

child’s birth and reported smoking at 

time of interview, 

Prenatal e.tposure– Terms used 

only in table 2 

Not exposed before birth – Mother 

did not smoke at ail during the 

pregnancy and while pregnant 

was not often in contact with 

persons who did smoke, such as 

friends, coworkers, or family 

members. 

Exposed before birth (mother 

smoked) —Mother smoked during 

some part of the pregnancy. 

Exposed before birth (mother and 

others smoked) – Mother smoked


during some part of the


pregnancy and was often in


contact with other persons who L,


smoked, such as friends,


coworkers, or family members,


Exposed before birth (potential


exposure) – Mother did not smoke


at all during the pregnancy but

Advance Data No. 202 � June 18, 1991 11 

while pregnant was often in Administration in 1964 and revised by (child’s) health is excellent, very


contact with persons who did the Federal Interagency Committees good, good, fair, or poor?”


smoke, such as friends, in 1969 and 1980, The index, based


coworkers, or family members. on money income only, is derived


Exposed since bitlh – Mother or 

from the Department of Agriculture’s


another household member 1961 economy food plan and reflects


smoked since the child’s birth.	 the different consumption 

requirements of families according to 

Cument smoker in household – their size and composition. The 

Mother or another household poverty thresholds are updated 

member reported smoking at time annually to reflect changes in the 

of interview. Consumer Price Index. Because 

FoImer Srndier ill household – NHIS data on family income are 

Mother or another household collected by income-categories rather 

member smoked since the child’s than in specific amounts of money, 

birth, but no household member the NHIS estimates of persons living 

reported smoking at time of in poverty will vary slightly from the 

interview, Current Population Survey estimates. 

Mother’s education – The 

Not exposed since birth – Mother categories reflect the total number of 

did not smoke since the child’s years of regular school the child’s 

birth, and no other household mother completed. A regular school 

member smoked regularly at any is one that advances a person toward 

time since the child’s birth, an elementary or high school diploma 

or a college, university, or 

Demographic terms professional school degree. 

.Race-The population is divided Place of residence –A person’s 

into three groups according to race — residence is classified according to 

white, black, and all other races. whether it is inside a metropolitan 

Persons are classified according to statistical area (MSA) or outside an 

the respondents’ reported racial MSA. Generally speaking, an MSA 

identifications. In this report, those of consists of a county or group of 

iill other races, although not shown as counties containing at least one city 

il sup;wate category, are represented having a population of 50,000 or more 

in the estimates of “all children.” plus adjacent counties that are 

Hispanic origin –A person is metropolitan in character and are 

classified as Hispanic if the household economically and socially integrated


respondent reports one of the with the central city,


following groups as his or her Central city – The largest city in


national origin or ancestry: Puerto an MSA is always a central city. One


Ricun, Cuban, Mexican, Latin or two additional cities may be


American, or other Spanish. secondary central cities provided that


Non-Hispmic orikin – Persons not their population is one-third or more 

classified as-Hispani~ are non- of the largest city, with a minimum 

Hispanic. This catego~ includes population of 25,000, or that they 

persons whose Hispanic status is have at least 250,000 inhabitants. 

unknown. Not central cily – This includes all 

Fmni!s i]lcome –This includes the of the MSA that is not part of the 

total of all income for the past central city itself.


12 months received by members of Not in MS4 – This includes all


:+e child’s family. Income from all other places in the country.


wrces is included, for example,


\I::iges, soltiries, rents from property, Health measures


pensions, and help from relatives. 

Polvrp statm – Persons are Respondent-assessed health 

status – The categories related to this classified as being in poverty or not in health measure result from asking the 

poverty according to the poverty 

index originated at the Social Security NHIS respondent, “Would you say 

‘US. Government Printing Office 1991 — 312-0W40011 
12 Advance Data No. 202 � June 18, 1991 

Suggested citation 

Overpeck MD, Moss AJ. Children’s exposure 

to environmental cigarette smoke before and 

afterbirth: Health ofour Nation’s children, 

United States, 1988. Advance data from vital 

and health statistics; no 202. Hyattsville, 

Maryiand: Nationai Center for Health 

Statistics. 1991. 

US. DEPARTMENTOF HEALTH AND 

HUMAN SERVICES 

Public Health Service 

Centers for Disease Control 

National Center for Health Statistics 

6525 Belcrest Road 

Hyattsville, Maryland 20782 

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