Introduction

For the sick child, the pediatrician should consider an environmental agent as potentially related to a child’s current illness. This is particularly true when the illness does not follow a usual pattern or when more than one family member or a schoolmate is affected.

General Exposure-Related Questions

The first step in evaluating whether an illness is related to an environmental exposure is to elicit a connection between exposure(s) to an environmental hazard and specific symptoms. This can be accomplished by asking the patient or parent the following questions:

• Location - Do symptoms subside or worsen in a particular location (e.g., home, school, day care, playground, or neighborhood)?
• Temporal relationship - Do symptoms remit or worsen during a particular period of time? At a particular time of day? On weekdays or on weekends? During a particular week or season of the year?
• Activity - Do symptoms worsen during a particular activity, such as playing outdoors, being at school, or engaging in a hobby?
• Are others affected? - Do adults, siblings, or children with whom your child spends time have the same symptoms as your child? [AAP, 2003]

Follow-up Questions Regarding Location

Questions to help gather further details from the patient or parent about the physical setting where a child may be exposed are the following:

• Do you think that you or a family member may have a health problem caused by the home? If yes, then continue with the following questions.
• What type of building do you live in (e.g., single family dwelling, condominium, apartment, mobile home, multi-family dwelling)?
• Is it a one- or two-story home? Are cars parked in an attached garage?
• What is on the lowest level of the home?
• In what year was the home built?
• Where is it located?
• Have you renovated or added on to your home recently?
• How do you heat your home? Oil, wood, coal, solar, heat pump, natural gas?
• Do you have a secondary heat source in the home?
• Do you have a wood stove or fireplace? If so, how often do you use it/them?
• Do you or a family member run a hobby or home business that might involve hazardous exposures?
• Is any part of your home damp or have you had a major leak or flood in your home recently?
• Do you use pesticides or herbicides in or around the home?
• Has your home been tested for lead paint and/or radon?
• What is the source of your water supply?
• Are there any family members who could bring home contamination from work on clothing or shoes?
• Is your child in day care? A relative’s or a friend’s house?
• Is your child in school?
• Is your home located near industrial facilities, commercial orchards or farms, hazardous waste sites, municipal landfills, or underground storage tanks?
• Does your child spend time outdoors [Children’s Environmental Health Network 1999]?

Temporal Relationship

Timing and duration of exposure can be important in determining whether an illness results. If the exposure is known, it is important to ask how long someone was exposed to a toxic substance and how often the child was exposed (daily, weekly, monthly, etc.).

In order to establish that environmental exposure is the cause of the illness, it is necessary to ask if the exposure to the substance of concern occurred before the onset of the health condition. To complicate matters, for many toxic substances, there is a latent period between time of exposure and the appearance of a health effect. It is therefore not enough to ask if the exposure occurred before the health effect, but rather to determine if the exposure occurred within the latent period for that substance’s health effect(s). For example, exposure to asbestos may result in asbestosis, lung cancer, or mesothelioma (a cancer of the pleura), but not until a latent period of 20–40 years has passed (this form of cancer occurs mainly in occupationally exposed adults and is not generally seen in children).

Are Others Affected?

Others similarly affected can point to a possible environmental exposure-related cause at home, at child care, at school, or the workplace. For public health reporting purposes, the appropriate authorities must be notified if an illness is found to be related to an environmental exposure.

Final Follow-up Questions

After completing the screening exposure history and asking more specific exposure-related questions, the pediatrician should then answer these questions to ascertain whether the illness might be exposure-related.

• What is the child’s specific health condition?
• Is the substance(s) that the child was exposed to known to cause this type of health problem?
• If so, what is the weight of scientific evidence linking that health condition to a particular substance?
• Did any other exposures occur that might be related to the identified signs and symptoms?

If the answers to these questions and the physical findings point to a link between an illness and an exposure, the pediatrician should consult with a specialist in pediatric environmental medicine (one source of consultation is http://aoec.org/PEHSU/). The pediatrician should then move ahead with ordering laboratory testing

• for possible markers of exposure (if they exist for that substance),
• for possible toxicant-related biological effects, and
• of the child’s environment for the exposure source.

Progress Check