Making an 

Impact Fact 

by Fact

Promoting Good Prenatal Health: 

Air Pollution and Pregnancy

Information for Prenatal 

Health Care Providers

With tips for patients on preventing and reducing 

exposure to air pollution

Recent literature suggests that exposure to air pollution during pregnancy can 

cause adverse birth outcomes and health problems for the mother and child.

Some pollutants of concern are secondhand smoke, 

carbon monoxide, fumes from paint and household 

cleaners, particulate matter, and ozone.1, 2, 3, 4, 5, 6

Women of child-bearing age, pregnant women, new 

mothers, families, and their health care providers 

should be aware of the potential hazards of outdoor 

and indoor air pollution to developing fetuses and 

small children. Research shows that prenatal exposure 

to pollutants can increase the risk of preterm delivery 

and low birth weight (LBW; less than 2,500 grams, 

or 5.5 pounds), which are public health challenges in 

the United States, as they contribute significantly to 

infant mortality and developmental disabilities.7, 8, 9 This 

fact sheet identifies some common environmental 

exposures and provides simple steps that health care 

providers can recommend to pregnant women and 

new mothers to avoid exposure.
Healthier Environments, Healthier 

2

Sources

Of Air Pollution and Risks Associated with Exposure

Tips for Preventing 

Exposure to Tobacco Smoke

• Pregnant women should not smoke. 

• Pregnant women should avoid public 

places where smoking is allowed.

• Pregnant women should make their 

homes and cars smoke-free.

Tobacco Smoke

It is well documented that maternal smoking during 

pregnancy is associated with poor fetal development.10, 11, 12, 13

However, exposure to secondhand smoke during pregnancy 

might also result in a higher risk of poor fetal development 

(i.e., reduced birth weight and birth length), reduced lung 

function, respiratory illnesses (e.g., asthma), and cognitive 

deficits (e.g., impaired speech, language skills, and 

intelligence).2, 3, 14, 15

Secondhand smoke, also known as environmental tobacco 

smoke (ETS), contains more than 4,000 compounds, of 

which at least 250 have been found to be toxic to human 

health.16 Some of these chemicals can cross the placenta to 

the developing fetus and increase the risk of adverse birth 

outcomes.14 Children exposed to secondhand smoke after 

birth are more likely to suffer serious health problems such 

as asthma, lower respiratory tract infections, ear infections or 

Sudden Infant Death Syndrome (SIDS).2, 3, 14, 15
 Babies, Healthier World.

3

Carbon Monoxide

Carbon monoxide (CO) is often referred to as a silent killer. CO 

is a toxic gas that is difficult to detect because it is colorless, 

odorless, tasteless, and does not irritate the skin.17

Malfunctioning or improperly used fuel-burning appliances 

and idling automobiles in enclosed spaces are responsible 

for hundreds of unintentional CO-related deaths every year.18 

Indoor sources of CO include back-drafting from woodstoves 

and gas water heaters, gas stoves, the improper use of 

generators in enclosed spaces such as homes, cigarette 

smoke, and unvented gas and kerosene space heaters.17 CO 

reduces the capacity of a mother’s blood to carry oxygen 

(O2), complicating delivery of O2 to the developing fetus.19, 20

Epidemiological and animal toxicological studies suggest that 

long-term exposure to ambient CO, especially during the first 

trimester, may increase risk for preterm birth, reduced fetal 

growth, and certain birth defects such as cardiac birth defects 

and otoacoustic deficits.19, 21, 22 The severity of CO poisoning for 

the fetus depends on the amount and length of exposure, as 

well as gestational age at the time of exposure.23

In situations of suspected CO poisoning, if a pregnant woman 

experiences very mild symptoms, or no symptoms at all, 

generally it is unlikely her fetus is at significant risk. However, 

detecting CO poisoning in pregnant women can be more 

difficult because symptoms mirror conditions that normally 

appear in pregnancy (nausea, vomiting, and tiredness).23

Symptoms of high exposure to CO are serious and potentially 

life-threatening, and include mental confusion, lack of muscular 

coordination, and loss of consciousness. 

**Anyone who exhibits symptoms that could be related to CO 

exposure should be taken to an emergency room immediately. The 

source of the CO should be identified and the problem corrected to 

prevent further exposure.18

Tips for Preventing 

CO Exposure

• Install carbon monoxide alarms that 

are Nationally Recognized Testing 

Laboratory (NRTL) approved (such as 

Underwriters Laboratories Inc.) outside 

all sleeping rooms.

• Have fuel-burning appliances, furnace 

flues, and chimneys checked at the 

beginning of every heating season by 

a trained professional to ensure proper 

working order.

• Don’t use gas ovens or burners to heat a 

home, not even for a short time.

• Don’t use charcoal grills indoors, even in 

a fireplace.

• Don’t use any gasoline-powered engines 

(mowers, weed trimmers, snow 

blowers, chain saws, small engines, or 

generators) in enclosed spaces.

• Don’t idle cars in the garage.

• Don’t ignore symptoms (nausea, 

vomiting, and tiredness) when around a 

CO source, especially if more than one 

person is feeling them. You could lose 

consciousness and even die if you do 

nothing.

• Go to the emergency room if 

CO poisoning is suspected.
Healthier Environments, Healthier 

4

Tips for Reducing 

Exposure to Particle 

Pollution and Ozone

• Check local news media for air quality 

forecasts and plan outdoor activities for 

days when particle and ozone levels are 

lower. EPA’s Air Quality Index (AQI) is a 

tool that state and local agencies use to 

issue public reports of actual levels of 

particles, ground-level ozone, and other 

common air pollutants.

• When the AQI indicates poor air quality, 

reduce activity time or substitute another 

activity that requires less energy. For 

example, walk rather than jog.

• Don’t exercise near high-traffic roads, 

where particle levels are generally 

higher.

• Protect yourself from exposure to 

particulate matter in wood smoke.

– Burn only clean, seasoned wood, not 

trash or plastics.

– If you have a woodstove purchased 

before 1992, upgrade to either an 

EPA-certified wood or pellet stove, or 

other cleaner burning heater.

– Maintain your stove annually.

– Consider upgrading your outdoor 

wood-fired boiler to a new 

EPA-qualified model.

Particle Pollution

Particle pollution, also known as particulate matter or PM, 

is the generic term for a broad class of chemically and 

physically diverse substances that exist as discrete particles 

(liquid droplets or solids) over a wide range of sizes. Particles 

originate from a variety of anthropogenic stationary and 

mobile sources as well as from natural sources. Particles 

may be emitted directly, or formed in the atmosphere by 

transformations of gaseous emissions such as sulfur oxides 

(SOX), nitrogen oxides (NOX ), and volatile organic compounds 

(VOCs). The chemical and physical properties of PM vary 

greatly with time, region, meteorology, and source category, 

thus complicating the assessment of health and welfare 

effects.24, 25 Size directly determines a particle’s potential 

for causing health problems, with the smaller particles, 

those 10 micrometers in diameter or less (PM10 and PM2.5), 

being more dangerous. These small particles can enter the 

respiratory system and penetrate deep into the lungs, with 

possible serious health effects.24, 25

Research suggests that exposure to ambient levels of particle 

pollution may increase the risk for adverse cardiovascular 

and/or respiratory health effects.25 Some research has linked 

particle exposure to a greater risk of low birth weight (LBW) 

and infant mortality, especially due to respiratory causes 

during the postnatal period. However, outcomes are highly 

variable based on the size of particles, duration of exposure, 

and time during pregnancy when the mother is exposed.25

The risk of being affected by particle pollution and ground-level 

ozone increases with the difficulty and duration of outdoor 

activities, and with increased pollution levels in the area.

Ozone

Ozone is a gas composed of three oxygen atoms (O3). 

“Good” ozone is a naturally formed layer in the stratosphere 

that helps protect life on Earth from the sun’s rays. “Bad” 

ozone exists at ground level and can be harmful to health. 
 Babies, Healthier World.

5

Ground-level ozone is created by chemical reactions of tailpipe 

exhaust, gasoline vapors, industrial emissions, chemical 

solvents, and natural sources. Joined with particulate matter 

and acted on by sunlight and heat, ozone creates “smog.”26 

Ozone can be present in indoor air as well. Ozone generators, 

personal air purifiers, “pure-air” generators and “super 

oxygen” purifiers are devices that emit ozone gas into the 

indoor air at levels that can irritate airways and exacerbate 

existing respiratory conditions. Evidence shows that at 

concentrations that do not exceed public health standards, 

ozone is ineffective at removing indoor air contaminants or 

biological pollutants such as mold from the air.27

Exposure to ozone has been linked to LBW babies. 

Researchers at the University of Southern California found 

that women who breathe air heavily polluted with ozone are 

at particular risk for having babies afflicted with intrauterine 

growth retardation (IUGR), meaning they fall below the 

15th percentile of expected size. The association was even 

stronger for ozone exposure over the second and third 

trimesters.6

Animal studies contribute to the understanding of the role 

of ozone in LBW. Pregnant rats were found particularly 

vulnerable to lung inflammation from ozone. Researchers 

suspect that lung inflammation initiates a biochemical 

response that may harm the placenta. 25, 28, 29

Paint Fumes 

When preparing the house for the new baby, be aware that 

exposure to paint fumes can be hazardous to the health of 

the mother and developing fetus. There are two general types 

of household paints, oil-based and water-based. Oil-based 

(alkyd) paint is often used on the exterior of houses because 

it dries very hard and withstands harsh weather for a long 

time. Water-based (latex) paint generally emits fewer chemical 

Tips for Preventing 

Exposure to Paint Fumes

• Pregnant women and children should 

avoid exposure to paint fumes and limit 

their time in freshly painted rooms. 

• Creating a nursery can involve exposure 

to hazardous substances. Before using 

any product, always read the label first 

for instructions and safety information.

• Open the windows and doors fully in 

any room that is being painted or has 

recently been painted. 

– Put a box fan in the window directing 

the air and fumes outdoors. Keep the 

fan on while painting and for about 

48 hours afterward. 

– If the room does not have a window, 

use a fan to circulate and exhaust air 

away from the work area. Keep 

doors open.

• Do not paint indoors with paint labeled 

“for exterior use only.”

• Ask a local paint dealer whether they 

carry low-VOC or zero-VOC paint. 

Due to environmental regulations and 

consumer demand, there are now 

several low-VOC and zero-VOC paints on 

the market. Currently, low- and zeroVOC paints as marketed may still emit 

VOCs of concern, and efforts should be 

taken to properly ventilate the room, 

and keep exposures to a minimum.
6

Healthier Environments, Healthier 

Tips for Reducing 

Exposure to Cleaning 

Products

• Never mix cleaning products, as the 

fumes can be hazardous or deadly! For 

example, mixing chlorine bleach and 

ammonia can generate very harmful 

chloramine gas. 

• Pregnant women should only use 

cleaning products in well-ventilated 

areas, wearing protective gloves.

• Consider using alternative cleaners. 

Baking soda can be used to scrub 

greasy pots, pans and ovens; and 

vinegar and water to clean countertops 

and other surfaces.

• Look for the Design for the Environment 

(DfE) logo on safer cleaning products.

– The DfE logo on a product means 

that EPA scientists have screened 

each ingredient for potential human 

health and environmental effects, 

and that based on currently available 

information, the product contains 

only those ingredients that pose the 

least concern among chemicals in 

their class.

vapors, often called volatile organic compounds (VOCs), than 

alkyd paint, but may still contain some hazardous chemicals 

such as ethylene glycol ethers and biocides (e.g., mercury 

or formaldehyde). VOCs are emitted as a gas from various 

solids or liquids, including most paints, and can cause adverse 

health effects, especially with extended duration or frequency 

of exposure to fumes.4, 30, 31

Short-term exposure to solvents from alkyd paints can be 

significantly higher than from latex paints.4 Headaches, 

nausea, dizziness, and fatigue are typical symptoms of paint 

fume inhalation and can be worse with acute, higher level 

exposure.4, 31 Pregnant women should avoid alkyd paint, and 

limit the use of latex paint in order to reduce exposure to 

potentially harmful vapors in both home and occupational 

settings.

Cleaning Products 

Exposure to fumes from some cleaning products during 

pregnancy can pose risks when used in the home and in the 

workplace. 

Common cleaning products contain a range of ingredients 

including solvents, strong acids and bases, and fragrances. 

Some of these ingredients pose health concerns, others can 

be bad for the environment, and some of them can release 

toxic fumes either individually, or if mixed together.5, 32, 33

Phthalates can be carriers for fragrance in glass cleaners, 

deodorizers, laundry detergents, and fabric softeners. Some 

phthalate compounds can be associated with potential 

adverse effects in male children, reduced sperm count in 

adult men, and increased allergic symptoms and asthma in 

children.34
 Babies, Healthier World.

7

Additional Resources

Environmental Protection Agency

• Office of Children’s Health Protection www.epa.gov/children

• Air Quality Index: www.airnow.gov

• Indoor air quality: www.epa.gov/iaq – Burn Wise Program: www.epa.gov/burnwise

• National Ambient Air Quality Standards (NAAQS): www.epa.gov/air/criteria.html

• Particle pollution and your health: www.epa.gov/oar/particlepollution/pdfs/pm-color.pdf 

• Protect your family and yourself from CO poisoning: www.epa.gov/iaq/pubs/coftsht.html 

• Six common air pollutants: www.epa.gov/air/urbanair/6poll.html 

• Consumer Product Safety Commission: www.cpsc.gov

• Learn about chemicals around your house: www.epa.gov/kidshometour 

• Find safer products that bear EPA’s DfE logo: www.epa.gov/dfe

• Smoke-free homes: www.epa.gov/smokefree

Pediatric Environmental Health Specialty Units (PEHSU)

• Children’s environmental health experts: www.pehsu.net

Centers for Disease Control and Prevention

• CO poisoning: www.cdc.gov/co/faqs.htm

• Indoor air quality information: www.cdc.gov/nceh/airpollution/indoor_air.htm 

U.S. Department of Health and Human Services

• Office on Women’s Health www.womenshealth.gov/owh
8

References

1 Sram, R.J., Binkova, B., Dejmek, J., et al. (2005). Ambient air pollution 

and pregnancy outcomes: a review of literature. Environmental Health 

Perspectives, 113 (4): 378-382. Retrieved from: www.ehponline.org/

members/2005/6362/6362.pdf on May 28, 2009.

2 Miller, R.L., Garfinkel, R., Horton, M., et al. (2004). Polycyclic aromatic 

hydrocarbons, environmental tobacco smoke, and respiratory symptoms 

in an inner-city birth cohort. Chest, 126: 1071-1078. Retrieved from: www.

chestjournal.org/content/126/4/1071.full.pdf+html on May 28, 2009.

3 Rauh, V.A., Whyatt, R.M., Garfinkel, R., et al. (2004). Developmental effects 

of exposure to environmental tobacco smoke and material hardship among 

inner-city children. Neurotoxicology and Teratology, 26(3): 373-85.

4 U.S. Environmental Protection Agency (EPA). (2000). Healthy Indoor Painting 

Practices. EPA 744-F-00-011. Retrieved from: 

www.epa.gov/oppt/exposure/pubs/inpaint5.pdf on April 27, 2009.

5 EPA. (2007). Learn About Chemicals Around Your House: Kitchen and 

Bathroom. Retrieved from: www.epa.gov/kidshometour/tour.

htm#view on December 31, 2008.

6 Salam, M.T., Millstein, J., Li ,Y., et al. (2005). Birth outcomes and prenatal 

exposure to ozone, carbon monoxide, and particulate matter: results 

from the children’s health study. Environmental Health Perspectives,

113(11):1638-1644. 

7 Lacasana, M., Esplugues, A. and F. Ballester. (2005). Exposure to ambient 

air pollution and prenatal and early childhood health effects. European Journal 

of Epidemiology, 20:183–99. 

8 U.S. Department of Health and Human Services, Centers for Disease 

Control and Prevention (CDC). (2002). Infant mortality and low birth weight 

among black and white infants—United States, 1980–2000. Morbidity and 

Mortality Weekly Report, 51(27):589-592. Retrieved from: www.cdc.gov/

mmwr/preview/mmwrhtml/mm5127a1.htm on June 12, 2008.

9 Paneth, N.S. (1995). The problem of low birth weight. Future Child, 5(1): 

19-34. Retrieved from: http://futureofchildren.org/futureofchildren/

publications/journals/article/index.xml?journalid=60&articleid=370

§ionid=2478 on June 12, 2008.

10 Jaakkola, J.J., Kosheleva, A.A., Katsnelson, B.A., et al. (2006). Prenatal and 

postnatal tobacco smoke exposure and respiratory health in Russian children. 

Respiratory Research, 7(1): 48. Retrieved from: www.princeton.edu/

futureofchildren/publications/journals/article/index.xml?journalid=

60&articleid=370§ionid=2477&submit on June 12, 2008.

11 Werler, M. (1997). Teratogen update: smoking and reproductive 

outcomes. Teratology, 55:382-88. Retrieved from: http://teratology.org/

updates/55pg382.pdf on June 12, 2008.

12 Bardy, A.H., Seppala. T., Lillsunde, P., et al. (1993). Objectively measured 

tobacco exposure during pregnancy: neonatal effects and relation to maternal 

smoking. British Journal of Obstetrics and Gynecology, 100(8):721-6.

13 Jaakkola, J.J. and M. Gissler. (2004). Maternal smoking in pregnancy, fetal 

development, and childhood asthma. American Journal of Public Health,

94(1): 136-40. Retrieved from: www.ajph.org/cgi/reprint/94/1/136 on 

May 28, 2009.

14 CDC, National Center for Chronic Disease Prevention and Health 

Promotion, Office on Smoking and Health. (2006). The health consequences 

of involuntary exposure to tobacco smoke: a report of the surgeon general. 

Retrieved from: www.surgeongeneral.gov/library/secondhandsmoke

on June 12, 2008. 

15 Herrmann, M., King, K. and M. Weitzman. (2008). Prenatal tobacco smoke 

and postnatal secondhand smoke exposure and child neurodevelopment. 

Current Opinion in Pediatrics, 20(2):184-90.

16 EPA. (2008). Health Effects of Exposure to Secondhand Smoke. Retrieved 

from: www.epa.gov/smokefree/healtheffects.html on May 14, 2009.

17 EPA. (2006). Sources of indoor air pollution—carbon monoxide. Retrieved 

from: www.epa.gov/iaq/co.html#Definition on May 19, 2009.

18 EPA. (2006). Protect your family and yourself from carbon monoxide 

poisoning. Retrieved from: www.epa.gov/iaq/pubs/coftsht.html on 

May 19, 2009. 

19 EPA. (2009). Integrated Science Assessment for Carbon Monoxide (First 

External Review Draft). EPA-600-R-09-019. Retrieved from: http://oaspub.

epa.gov/eims/eimscomm.getfile?p_download_id=487236 on 

May 18, 2009.

20 Di Cera, E., Doyle, M.L., et al. (1989). Carbon monoxide and oxygen binding 

to human hemoglobin F0. Biochemistry, 28(6): 2631-2638. 

21 Wilhelm, M. and B. Ritz. (2005). Local variations in CO and particulate air 

pollution and adverse birth outcomes in Los Angeles County, California, USA. 

Environmental Health Perspectives, 113(9):1212-1221. Retrieved from: www.

ehponline.org/members/2005/7751/7751.pdf on May 28, 2009.

22 Bell, M.L., Ebisu, K., and K. Belanger. (2007). Ambient Air Pollution and 

Low Birth Weight in Connecticut and Massachusetts. Environmental Health 

Perspectives, 115:1118-1125.

23 CDC. (2005). Hurricanes—special population. Effects on pregnant 

women—carbon monoxide. Retrieved from: www.cdc.gov/ncbddd/

hurricanes/environmental.htm on May 19, 2009.

24 EPA. (2006). Particulate matter. Retrieved from: www.epa.gov/oar/

particlepollution on May 19, 2009. 

25 EPA. National Center for Environmental Assessment-RTP Division (2008). 

Integrated Science Assessment for Particulate Matter: First External Review 

Draft. Retrieved from: http://cfpub.epa.gov/ncea/cfm/recordisplay.

cfm?deid=201805 on January 27, 2009.

26 EPA. (2003). Ozone: Good Up High, Bad Nearby. EPA-451/K-03-001. 

Retrieved from: www.epa.gov/oar/oaqps/gooduphigh/ozone.pdf on 

April 9, 2009.

27 EPA. (2009). Ozone Generators that are sold as air cleaners. Retrieved 

from: www.epa.gov/iaq/pubs/ozonegen.html on May 20, 2009. 

28 Acevedo, S., Bizarro, P., Fortoul, T., Lopez, I., Sanchez, I., and M. Ustarroz. 

(2008). Ultrastructural alterations during embryonic rats’ lung development 

caused by ozone. Journal of Electron Microscopy, 57(1):19-23.

29 Gunnison, AF, Sobo, M., and P.A. Weideman. (1992). Enhanced 

inflammatory response to acute ozone exposure in rats during pregnancy and 

lactation. Fundamental and Applied Toxicology, 19(4):607-12.

30 EPA. (2009). An Introduction to Indoor Air Quality: Volatile Organic 

Compounds (VOCs). Retrieved from: www.epa.gov/iaq/voc.html on 

December 10, 2009.

31 American Pregnancy Association. Pregnancy and Paint Exposure. 

Retrieved from: www.americanpregnancy.org/pregnancyhealth/

paintexposure.html on December 31, 2008.

32 EPA. (2000). Read the Label First! Protect Your Household brochure. EPA 

740-F-00-004. Retrieved from: www.epa.gov/pesticides/regulating/

labels/pdf/home.pdf on December 10, 2009.

33 National Institutes of Health. U.S. National Library of Medicine. (2009). 

Medline Plus: Household Products. Retrieved from: www.nlm.nih.gov/

medlineplus/householdproducts.html#cat7 on December 10, 2009. 

34 Hauser, R. and A.M. Calafat. (2005). Phthalates and Human Health. 

Occupational and Environmental Medicine, 62: 806-818. Retrieved from: 

http://oem.bmj.com/cgi/reprint/62/11/806 on January 9, 2009.

Office of Children’s Health Protection and Environmental Education 

Child and Aging Health Protection Division (1107A)

EPA-100-F-09-020

www.epa.gov

January 2010

Printed on 100% recycled/recyclable paper with a minimum 

50% post-consumer waste using vegetable-based inks.