DR. FORMAN is associate professor pediatrics and community and preventive medicine at the Mount Sinai School of Medicine in New York. The author has nothing to disclose in regard to affiliations with, or financial interests in, any organization that may h

Joel A. Forman, MD

Rising rates of asthma and obesity, more reports of developmental disabilities and early puberty, concerns about increasing incidence of childhood cancer... parents, scientists, and pediatricians alike worry about how these health conditions relate to the environment our children live in. Indeed, children are often more vulnerable than adults to the effects of environmental hazards 

, causing their parents to be concerned about the pollutants in the natural environment, i.e., physical, chemical, and biological contaminants in air, water, food, and soil. There is also increasing attention to the man-made or "built" environment comprising the network of roads, public transportation, and physical structures where children live, play, and work.

Fortunately, our knowledge about environmental health-the field of science that concerns how the environment influences human health and disease-has expanded greatly in the past decade.

 Research has shed light on the relationship of children's health and developmental conditions to toxicants (a "toxicant" refers to a chemical agent; "toxin" is often used for a biological agent) in the air they breathe, the water they drink, and the food they eat. Many questions about these relationships, however, remain unanswered. 

Science is increasingly recognizing that gene-environment interactions can shift the balance between health and disease. Olden's line is often quoted, "Genetics loads the gun, but environment pulls the trigger."

 Our children's health is influenced by the interaction of genetic susceptibility and environmental exposures-and these gene–environment interactions are influenced by behavior, gender, age, and developmental stage.

Pediatricians are well positioned to identify children's environmental exposures, counsel on ways to help prevent exposures, and where the evidence supports it, give abatement advice. As trusted family advisors, we can also answer questions about what is known and not known about environmental exposures and health. 

The first step in evaluating a child's environment is taking an environmental history. During much of the last century, when it was common for doctors to make house calls, doctors could observe a child's environment. Since house calls are no longer standard practice, asking about surroundings is the necessary starting point. For some areas of environmental health-counseling smokers to stop smoking, and certain aspects of sun safety-scientific evidence supports the importance of taking a history and giving advice in promoting behavior change. 

In this article, we will review important areas of the environmental history to cover on well-child and well-adolescent visits. We will give you a list of questions for each area, discuss why each question is important, and then suggest interventions if you find a situation needing change. We will touch upon community, school, and advocacy issues relevant to environmental health. (A more extensive article focusing on environmental health issues in communities and schools will follow in a future issue.) We will then briefly discuss taking an exposure history when an illness or symptom raises concern about a possible environmental etiology, and list several resources. Although the "environment" can be broadly defined as mentioned above, we will concentrate on chemical and certain physical hazards (such as ultraviolet radiation) that can affect children's health.

Questionnaires and forms from the National Environmental Education & Training Foundation's (NEETF) 

 may be used to facilitate taking the history.

 gives suggestions about when to introduce environmental health questions, while 

 summarizes the suggested questions for a complete environmental history.

Young children spend 80%–90% of their time indoors. This includes the primary residence, but may also include relatives' and care-givers' homes, and daycare facilities. 

What type of home does your child live in or spend time in? Single-family home, apartment, mobile home, or temporary shelter?

What are the age and condition of your home? Is there lead, mold, or asbestos?

 The US has made great strides towards eliminating lead poisoning. Yet many children-particularly impoverished children-have elevated blood lead levels. Although the prevalence of lead poisoning in the US has decreased to near 1%, the risk of having a blood lead level greater than or equal to 10 μg/dL is highest for poor children, and those living in deteriorated housing. 

Lead paint was used in home construction until the late 1970s, but due to the concentration of lead paint used, houses built before 1950 pose the greatest risk. 

Lead paint may chalk or dust from walls, and may be released with the opening and closing of windows or during room renovation (common in preparation for the birth of a baby, or soon thereafter), potentially affecting young children's neurological development.

 Depending on the child's age, housing situation, and other risk factors, check the child with a blood lead test. Federal law requires testing these levels on children receiving Medicaid at ages 1 and 2 years.

 Water damage and damp conditions may result in mold growth, causing allergy and asthma symptoms. Exposure to the mold 

) has been associated with the development of acute idiopathic pulmonary hemorrhage (AIPH) in young infants. This association is based upon only a few studies, however, and a causative link has not been demonstrated. In a recent report, the AAP concluded that there is some evidence of biological plausibility for this association.

Epidemiologic studies suggest that exposure to SHS may be an additional risk factor for AIPH.

 Ongoing work in toxicology and epidemiology is needed to provide more information. 

 Advise parents to fix water leaks. Any areas of visible mold measuring less than or equal to nine sq. ft can be removed using a dilute solution of chlorine bleach (1 part chlorine to 10 parts water); professional removal is recommended for moldy areas larger than nine sq. ft.

 Given the known adverse effects of mold exposure and the concern about AIPH in infants, it is prudent to advise that children, particularly young infants, avoid exposure to moldy environments.

 Friable (crumbly) asbestos may be present in older homes as insulation around boilers and pipes, in ceiling and floor tiles, and in other areas. Asbestos may be released into the air during renovation or other work. When airborne, asbestos may be inhaled into the lung, possibly resulting in mesothelioma or lung cancer years after exposure. 

 It is best to leave undamaged asbestos alone if it is not likely to be disturbed. If it must be replaced, have it identified by contacting the manufacturer, or by calling an inspector or certified lab. If asbestos is in poor condition (more than a very small amount), a certified contractor should perform the removal.

Unintentional carbon monoxide (CO) poisoning causes hundreds of deaths in the US each year. Infants and children have increased susceptibility to CO poisoning because of their increased metabolic rates. Sources of CO include unvented kerosene and propane gas space heaters, leaking chimneys and furnaces, woodstoves, fireplaces, and gas appliances. Gasoline-powered portable generators, misplaced close to homes, were implicated in CO deaths following recent hurricanes in 2004 and 2005.

 Several states and municipalities, including New York City, have enacted mandatory CO detector laws for dwellings with multiple occupants.

 Chimneys should be inspected and cleaned annually. Make sure that combustion appliances are properly installed, maintained, and vented according to the manufacturers' instructions. Urge parents to install CO detectors that meet Underwriters Laboratories (UL) most recent standards in every sleeping area. Never ignore an alarming CO detector.

Is your child exposed to toxic chemicals? Where and how do you store chemicals and pesticides?

Pesticides and other chemicals ingested, inhaled, or absorbed through the skin can cause acute poisoning and death, as well as subacute and chronic poisoning. 

 Encourage parents to use the least toxic option for pest control. Have them place toxic chemicals out of reach. Never store chemicals in something other than the original container, because the child may be attracted to taste contents in soda bottles, juice bottles, or other containers. 

What type of heating/air system does your home have? 

Byproducts of heating systems, such as nitrogen dioxide (NO

), respirable particulates, and polycyclic aromatic hydrocarbons released from wood-burning stoves or fireplaces may precipitate or worsen respiratory symptoms. 

 Find out how the family heats the home, especially if there is a respiratory problem. Advise parents to properly maintain and clean heating systems.

Do you use chemicals in the garden or spray the lawn with pesticides?

Young children may be harmed if they play on lawns and in gardens freshly sprayed with pesticides or herbicides. Hand-to-mouth activities, and eating without washing hands after playing, contribute to exposure. Herbicides in general have less acute toxicity than insecticides, although this can vary from chemical to chemical. 

 There is no clearly established length of time that parents must prohibit children from playing in freshly sprayed lawns and gardens. Pediatricians should advocate for primary prevention by advising that pesticides not be applied to home or garden for ornamental purposes. If a parent has applied an herbicide, prudence dictates a minimum of 24-48 hours before having contact with the lawn. Since insecticides are generally more toxic to animals than compounds designed to kill plants, it is reasonable to avoid contact for a longer time period, such as 48-72 hours, after pesticide application.

Radon is a leading-and preventable-cause of lung cancer in the US. Ten percent of lung cancers are attributable to radon. 

 The Environmental Protection Agency (EPA) and the Surgeon General recommend testing homes below the third floor for radon.

 The EPA also recommends that radon testing be done before buying or selling a home.

 In terms of costs, radon testing and remediation are generally affordable. 

Do you think there is lead in your soil? 

Lead can contaminate soil when paint chips from old buildings mix with the soil. Lead was present in gasoline in the US until the 1970s. Because lead moves very little once deposited, lead that originated from auto emissions can remain present in soil. Indeed, studies conducted in urban areas have shown that soil lead levels are highest around building foundations, and within a few feet of busy streets. 

If high levels of lead in soil are suspected and there are young children who play there, parents may want to have the soil tested. Ways to remediate high-lead soil levels are by raising soil pH and adding organic material followed by planting of sod, by mixing or covering the high-lead soil with low-lead soil, or by physically removing the soil.

Do your children play on a wooden playset?

Outdoor playsets may have been treated with chromated copper arsenate (CCA), a preservative that protects wood from decay, from insects, and microbial agents. Normal hand-mouth and hand-object behavior may result in exposure to the arsenic leaching from CCA. Exposure to arsenic, a known human carcinogen, may increase the possibility of children developing lung or bladder cancers over their lifetimes. Manufacturers of CCA reached a voluntary agreement with the EPA to end the manufacture of CCA-treated wood for most consumer applications as of December 31, 2003. Some stocks of wood treated with CCA before then were expected to be found on shelves until mid-2004. More importantly, hundreds of thousands of play structures and decks were built before the ban, and are still in children's yards.

If there is a playset manufactured before 2003, parents can call the manufacturer to determine whether it contains CCA. If there is CCA in the deck or play structure, it should be treated with a clear sealant every six months to one year to decrease the amount of arsenic leaching out of the wood. Alternatively, parents can choose to have the set safely dismantled. They should never burn or saw CCA-treated wood, as this will increase the amount of arsenic released. If parents keep the playset, they should wash children's hands with soap and water immediately after outdoor play, and especially before eating. Children should not eat while playing on CCA-treated playground equipment. 

Between 12%–34% of children are exposed to secondhand smoke (SHS, also known as environmental tobacco smoke [ETS]) from parental smoking, making these children 

. Passive smoking has a tremendous impact on children's health, including asthma (over 200,000 episodes/yr attributable to SHS exposure including new onset and exacerbations), lower respiratory infections, otitis media (almost 800,000 episodes/yr), and Sudden Infant Death Syndrome (SIDS; 430 deaths/yr, out of a total of ~2500 cases of SIDS, are attributable to SHS).

Even a brief doctor-delivered quit-smoking message has an effect on quit-smoking rates.

 The US Public Health Service recommends that clinicians ask about smoking at every visit, and offer smokers at least a brief intervention-one to three minutes-at each visit. Asking parents if they smoke and advising them to quit is part of the 

 model of the National Cancer Institute (

Ask, Advise, Assess, Assist, and Arrange follow-up

 about smoking at all visits; asking is the first "A." Next, strongly 

 parents to quit (the second "A"): "As your child's pediatrician, I think the best thing you can do for your health and your child's health is to quit smoking. My staff and I can help you."

-determining whether smokers are interested in quitting soon (within the next 2–4 weeks). If so, provide practical cessation advice if you have the time and knowledge (the fourth "A"-

). Progress with quitting can also be addressed at subsequent visits (

-the fifth "A"). Otherwise, refer the smoker to a trained cessation counselor or suggest that the smoker contact their state's Quitline. If there is no Quitline in your state, suggest that parents contact the nationwide network of Quitlines through 1-800-QUIT-NOW. 

Drinking water comes from municipal water suppliers or private wells. It can be consumed straight from the tap, used to reconstitute infant formula and juice, or in cooking. The federal Safe Drinking Water Act of 1974 regulates standards for community water supplies serving 25 or more customers; states may have standards for smaller suppliers. Most states have rules for private wells, but since these rules may not completely protect a private well, it becomes the responsibility of a private well owner to ensure that the water is safe.

Water contaminants of particular concern for US infants and children are lead and nitrates. Most large municipal water supplies keep lead levels at or below the EPA standard of 15 ppb (parts per billion). Even though most systems have acceptable lead levels, some cities, including New York, Boston, and Chicago, still have lead piping to connect water mains to homes. 

Well water may contain nitrates that enter the water supply from runoff of agricultural fertilizers, and may also be produced by the action of bacteria on animal waste runoff. Nitrates ingested by small infants may be converted to nitrites, which may in turn cause fatal methemoglobinemia.

What is the source of your drinking water?

 Test tap water for lead if it is consumed by infants and young children. If water contains lead, it should be run for at least two minutes if it has been standing overnight in pipes, or until cold. Alternatively, bottled water can be used. Private wells should be tested initially (upon construction or upon purchasing a home) for total dissolved solids, nitrates, coliforms, inorganic compounds (iron, magnesium, calcium, chloride) and lead. Repeat testing for nitrates and coliforms should be performed annually. Consider repeat testing for other contaminants if a new source of contamination becomes known (for example, if a neighbor discovers a new containment in their well). Local health or environmental departments can advise regarding testing.

 Water high in nitrates should not be given to infants!

If parents choose to boil drinking water, one minute of a rolling boil is sufficient to kill microorganisms. They should also avoid over-boiling water, since this may concentrate any contaminants.

Fish is an excellent source of protein and can be high in omega-3 fatty acids. However, mercury and persistent organic compounds such as polychlorinated biphenyls (PCBs) in water can contaminate fish and subsequently, people who ingest the fish. Mercury from natural and combustion sources enters the air and then falls into bodies of water, where it is methylated by aquatic organisms into organic methylmercury. It is then taken up by fish, where it accumulates in their muscle tissue. Large predator fish that feed on smaller fish, such as swordfish and tuna, accumulate the most mercury. 

Fetuses and young children are most susceptible to the neurotoxic effects of mercury. In 2000, the National Research Council estimated that 60,000 American children born each year may suffer from learning disabilities due to prenatal mercury exposure.

Do you eat fish? Does your child eat fish? What kinds and how often?

Recommendations: For parents eating commercially caught fish, advise them to choose fish low in mercury and persistent organic pollutants, and higher in omega-3 fatty acids. Pregnant women, women of childbearing age, nursing mothers, and young children should completely avoid shark, tilefish, swordfish, and king mackerel because they contain high levels of methylmercury, and should limit consumption of other mercury-containing fish.

 A recent literature review suggests that for major adult health outcomes, the benefits of fish intake outweigh the potential risks.

 In this same review, the weight of evidence suggested that modest fish intake for women of childbearing age, except for the species listed above, also outweigh the risk. Several Web sites, including the Oceans Alive campaign of Environmental Defense, list best and worst fish alternatives.

Out of economic necessity or as a recreational pursuit, families may catch and eat fish from lakes and streams. These fish may be exceptionally high in contaminants. 

 Most states publish and post fish advisories regarding which fish should be limited or avoided. 

Exposure to ultraviolet (UV) light through natural and artificial sources is linked to the development of skin cancer (basal cell carcinoma [BCC], squamous cell carcinoma [SCC], and melanoma) later in life. Although melanoma comprises only 3% of all skin cancers, it causes 80% of skin cancer fatalities. The American Cancer Society predicts that in 2007, there will be 59,940 new melanoma cases with 8,110 deaths.

 People at highest risk have light skin and eyes, and sunburn easily. Although melanoma primarily affects older white men, it can also occur in teenagers and young adults. 

When detected early, melanoma has an excellent prognosis. Metastatic melanoma has a grave prognosis, with few if any successful treatment options. Our efforts must therefore focus on prevention and early detection. Intense (or "brutal") sun exposure in childhood and adolescence, enough to cause blistering sunburn, is linked with an increased risk of melanoma later in life. 

There is accumulating evidence that artificial sources of UV light-those emanating from tanning lamps and beds-are also carcinogenic. In the US in 2003, 26% of people under 25 visited a tanning parlor, compared to 8% in 1996. Between 32%–55% of college students used tanning parlors; 6%–44% of high school boys and 30%–70% of high school girls used tanning parlors. In 2001, the indoor tanning industry generated $4 billion in revenues.

The International Agency for Research on Cancer (IARC) recently convened an International Working Group to assess the evidence on the health effects (positive and detrimental) of artificial UV radiation. The IARC, part of the World Health Organization, coordinates and conducts research on the causes of cancer and the mechanisms of carcinogenesis, and develops scientific strategies for cancer control.

The 2006 IARC literature review concluded that there is a 75% increase in risk of melanoma for users of sunbeds in their teens and twenties. An increased risk of developing SCC was also associated with sunbed use during the teen years. The data suggested detrimental effects on the skin's immune response and possibly on the eyes (ocular melanoma). No positive effects were observed: artificial tanning conferred little, if any, protection against solar damage to the skin, nor did using indoor tanning facilities provide protection against vitamin D deficiency. The IARC concluded that "effective action to restrict access to artificial tanning facilities (solariums, tanning salons, tanning parlors) to minors and young adults should be strongly considered."

 Sun protection messages are best delivered in the context of promoting outdoor physical activity-in a sun-safe manner. Advise parents not to allow their child to sunburn. Children and teens should wear protective clothing, brimmed hats and sunglasses when feasible, seek shade when possible, and use extra caution near water, snow, and sand since these surfaces reflect sunlight.

 Pediatricians can work with schools, child-care settings, and communities to promote the adoption of shaded playgrounds and play areas. To prevent sunburns when sun exposure is anticipated, parents and teens should generously apply a broad-spectrum (UVA and UVB protection) sunscreen with a sun protection factor (SPF) of at least 15 before going outside, and to reapply often, especially after swimming or sweating.

The SPF, a scale for rating the level of sunburn protection in sunscreen products, applies only to UVB protection. Sunscreens with an SPF value of 2 through 11 give minimal protection against sunburns. Sunscreens with an SPF of 12 through 29 give moderate protection. Those with an SPF of 30 or higher give the most protection against sunburn.

 Although sunscreen has been shown to protect against SCC, there is no data showing that sunscreen prevents melanoma.

 The American Academy of Pediatrics advises that an SPF of 15 should be adequate in most cases.

 It is important to use enough sunscreen (1 oz per sitting is recommended for young adults; proportional amounts should be used for infants and children). Reapplying often is key-every 2 hours even on cloudy days-especially after swimming or sweating.

 Using sunscreen should not be seen as a reason to extend time spent in the sun.

 Strongly discourage teens and their parents from visiting tanning parlors. If they feel that tanned skin looks healthier or more beautiful, suggest that they may use a sunless self-tanning product-but they must continue to use sunscreen with it. It should also be noted that there is no evidence that a "pre-vacation tan" protects against solar damage. 

Parents may present with any number of concerns about known or unknown environmental exposures. Common situations include families searching for environmental causes for cryptic constellations of symptoms in their children, families searching for an environmental cause of a known disorder such as autism, or community concerns about an apparent or real cancer cluster. Pediatricians are sometimes called upon to give advice and guidance in these areas, but they may not feel knowledgeable or comfortable giving information. Resources are available. 

Experts from Pediatric Environmental Health Specialty Units (PEHSUs), developed as a joint effort of the EPA, the Agency for Toxic Substances and Disease Registry (ATSDR, a part of the CDC), and the Association of Environmental and Occupational Clinics (AEOC), are available to answer questions and provide advice. PEHSU staff includes pediatricians trained in environmental health and occupational medicine physicians. 

A comprehensive list of PEHSU locations is available at 

Toxicants encountered in parents' occupations can be brought home on clothes and shoes, contaminating the home and exposing children ("fouling one's own nest" or "para-occupational exposure"). Exposures include pesticides used in agriculture that may be tracked indoors, and lead brought home on clothes of house painters and construction workers. Parents working inside the home with lead used in stained glassmaking, soldering, or pottery making may inadvertently expose young children. Parents who refinish boats also carry the potential to bring lead into the home. 

Teen job sites may also be an area of interest. More than 80% of high school students work at some time during the year. These teens may be exposed to inappropriate situations, including the use of dangerous machinery and hazardous chemicals. Indeed, each year work-related injuries kill about 70 adolescents and children; about 70,000 more are seen in emergency departments for work-related injuries.

What are the occupations and hobbies of the adults in the household?

 Parents employed in hazardous occupations should shower at work and change clothing and shoes before driving home. If toxic substances are used inside the home during work or hobby activities, make sure that the areas are properly ventilated, cleaned regularly, and inaccessible to small children. 

Pediatricians can find out about the nature of the teen's work during health maintenance visits, sports physicals, visits for "working papers," and if there is a work-related injury. A teen's employment should be considered when diagnosing an illness, and in the medical management of illness (e.g., asthma may flare up when the teen works with certain chemicals or is exposed to SHS on the job). Pediatricians need to know their state's child labor laws.

Children's environments include hazards in the broader community. These include diesel bus terminals, loading docks, industrial sites, hazardous waste sites, landfills, and agricultural areas sprayed with pesticides or fertilized with nitrate-containing fertilizers. Poor communities are more likely to be faced with these exposures; this is referred to as "environmental disparity" or "environmental injustice." Moreover, we have come to appreciate the importance of asking about other aspects of "community" that may impact health-e.g., are there safe places to walk and exercise? Does the way the community was planned and built allow for walking to school or work? 

Any examination of a child's environmental exposures would also be incomplete without a look at the schools that house them. Each day more than 53 million school children enter the nation's 120,000 school buildings that are often "unhealthy," poorly maintained, or overcrowded. Schools are sometimes situated in less desirable areas next to roads, highways, industrial plants, or abandoned landfills. According to the EPA, half of our nation's schools have problems linked to indoor air quality.

Most clinicians don't have time to visit community schools. We can, however, use the pre-school office visit to suggest to parents that they visit the school with the purpose of conducting an "environmental audit" before their child enters. Parents can look for mold or water damage and for pets in the classroom, and determine whether they can detect the smell of harsh or hazardous cleaning products. They can check to see if newly renovated areas are cleaned up or aired out. Parents may not be able to detect more hidden hazards such as lead paint (unless there is chipped paint), PCBs, CO, mercury spills, or asbestos-but they can ask for any written statements about the known presence of such substances, such as asbestos. 

 Parents can be encouraged to be advocates for their child. It may be necessary for parents to meet with the principal or school district officials. There may be an intermediary role for pediatricians or local health department officials in situations where school officials are not fully responsive. There may also be a role for the regional Pediatric Environmental Health Specialty Unit. 

Making the connection between a child's disease and the environment requires a high index of suspicion. Illnesses caused by environmental agents may present as common medical problems. Most clinicians will think about SHS exposure when a child has asthma or recurrent ear infections. Lead poisoning is in the differential diagnosis of coma, seizures, developmental delay, irritability, and constipation. Poisoning from certain types of pesticides may present with headache, dizziness, and diarrhea. It is critical (and even life-saving) to consider CO poisoning when there is fatigue, headache, dizziness, weakness, nausea, or vomiting, especially when there is more than one family member with these symptoms. 

Articles

There is increasing evidence that environmental toxicants affect kids' health. Given this reality, pediatricians need to know the most important environmental health questions to ask, and what resources to draw from.

Safeguarding kids from environmental hazards-CME

DR. BALK is professor of clinical pediatrics at the Albert Einstein College of Medicine in the Bronx, New York. 

DR. FORMAN is associate professor of pediatrics and community and preventive medicine at the Mount Sinai School of Medicine in New York. 

DR. JOHNSON* is a Commander in the United States Navy's Medical Corps at the Naval Medical Center, San Diego. 

*The opinions or assertions contained herein are the private ones of the authors, and are not to be construed as official or reflecting the views of the Naval Medical Center, San Diego, the Department of Defense, or the United States Navy.

  Research has shed light on the relationship of children's health and developmental conditions to toxicants (a "toxicant" refers to a chemical agent; "toxin" is often used for a biological agent) in the air they breathe, the water they drink, and the food they eat. Many questions about these relationships, however, remain unanswered.  

  Our children's health is influenced by the interaction of genetic susceptibility and environmental exposures-and these gene–environment interactions are influenced by behavior, gender, age, and developmental stage. 

Pediatricians are well positioned to identify children's environmental exposures, counsel on ways to help prevent exposures, and where the evidence supports it, give abatement advice. As trusted family advisors, we can also answer questions about what is known and not known about environmental exposures and health.  

The first step in evaluating a child's environment is taking an environmental history. During much of the last century, when it was common for doctors to make house calls, doctors could observe a child's environment. Since house calls are no longer standard practice, asking about surroundings is the necessary starting point. For some areas of environmental health-counseling smokers to stop smoking, and certain aspects of sun safety-scientific evidence supports the importance of taking a history and giving advice in promoting behavior change.  