No time of year brings more changes for children and teens than the start of a new school year. They return to different classrooms and often entirely new schools. Classrooms may have been remodeled, repainted, recarpeted, or treated with pesticides.

These changes can affect children regardless of grade level — pre-kindergarten, grade school, high school and college. Amid the back-to-school excitement, some students wind up feeling sick, listless or distracted, unlike last year. And parents wonder why, and what they can do. Sometimes the school environment is the cause.

Understanding why your child feels bad is especially challenging with children who cannot tell you what may be going on at school. What to do? How about visiting the school yourself?

I have a personal example: My son was returning to fifth grade and for the first time was struggling in math and other subjects. When I visited his school on parents’ night, I was struck by the strong odor of new rubber-backed carpet that had been glued down throughout the school. The classrooms formerly had wood floors and windows that opened to let in fresh air. The goal of the remodeling was to reduce noise. But my son and many other children and teachers became ill when they returned to school after summer break. The most subtle and common symptom was difficulty concentrating and remembering, but headaches, fatigue and worsening asthma also occurred — all as a result of well-intentioned remodeling over the summer!

How can parents detect the early signs of TILT, or Toxicant-induced Loss of Tolerance? TILT is a process that starts with a chemical exposure, such as in a “sick building,” after remodeling at school or home, or from cleaning chemicals or a pesticide exposure. It can cause susceptible individuals to lose their tolerance for everyday substances that never bothered them before, frequently including foods! Intolerances people develop are not usual “allergies.” See a detailed explanation of the differences.

Here’s a 7-point guide for recognizing the early signs of TILT:

1. Over long weekends or during vacations away from school does your son or daughter feel better? Do they feel better just being outdoors? Pay particular attention to symptoms that occur when your child returns to school after a vacation. Do headaches, migraines, irritability, or other symptoms such as tics or stomach problems diminish when they are away from the school? Do the symptoms return “with a vengeance” once they return to classes? This is a useful “experiment”: avoiding the school for a week or so while on vacation, and then returning, paying close attention to symptoms. Re-exposure can evoke a “sharp response,” making it clearer which symptoms are related to a particular environment. Sometimes the return to school after the summer provides the clearest evidence — keep a symptom log on a wall calendar.
2. Did your child’s health problem(s) begin with a flu-like illness and fatigue that did not go away?
3. Does your child, and do other children from the school, report symptoms involving multiple organ systems, with a predominance of neurological symptoms such as fatigue, memory and concentration difficulties, sudden overwhelming sleepiness, headaches, confusion, unsteadiness/clumsiness, irritability or depression? But also, digestive difficulties, skin rashes, muscle weakness, sinus and nasal symptoms, recurrent infections, breathing problems (e.g. asthma) etc., that have become more frequent since school began. School nurses often have a handle on this and can be helpful if approached in a non-confrontational way.
4. Since your child returned to school, has she had any adverse or unusual reactions to medications, such as antihistamine/decongestants, antibiotics, antidepressants, injections, or general or local anesthetics (for example, at the dentist’s office)? This is particularly significant if the drug was formerly well-tolerated. It is an example of “loss of tolerance” due to exposure.
5. Does your child report feeling ill after meals, or that she is unable to tolerate foods she formerly enjoyed? Does your child have intense food cravings or feel ill if she misses a meal. Must she eat “on time” and or does she feel ill if a meal is missed? Does your child raid the refrigerator at night, e.g., for ice cream or other foods, drink large quantities of milk or sodas (corn sugar), eat chocolate or other candy, cookies, bread, popcorn/corn chips, or other foods “addictively.” Does she feel terrible the next morning from her food addictants?
6. Does your child use caffeine? What happens if she doesn’t get her usual amount each day? Is she now using increased amounts of caffeine or, alternatively, avoiding caffeine because it bothers her? Overuse and avoidance can both be signs of caffeine intolerance. Avoidance leads to withdrawal symptoms. As with drugs, overuse may help postpone/overcome caffeine and food withdrawal.
7. Is your child hypersensitive to: 1) noise (crowds yelling at sports events, vacuum cleaner); 2) bright light (closes blinds, uses sunglasses indoors); 3) vibration/touch as when someone bumps into their bed; or 4) certain odors.

Be sure to notice when symptoms occur and whether any particular exposures/odors may have preceded them. For example, do felt-tip markers, engine exhaust, fragrances, odorous cleaning products such as bleach, nail polish/remover, hair spray, and phenolic disinfectants (those whose names end in “-sol”) now make your child feel ill or trigger symptoms? Use EPA’s “Tools for Schools” to work with your school district to choose the least toxic cleaning and pest control approaches, e.g., integrated pest management where least toxic approaches are used first. Another excellent resource is the Healthy Schools Network website.

My tip to parents: Record symptoms on a calendar, along with where your child was that day, foods they ate, and symptoms such as dark eye circles (so-called “raccoon eyes”), headaches, nasal stuffiness or runny nose, fatigue, stomach ache etc., rating symptom severity on a 0-10 scale, with “5″ being moderate symptoms and “10″ severe or disabling. Seizures would be “10.”

For more information and a validated, diagnostic questionnaire on TILT, see the Quick Environmental Exposure and Sensitivity Inventory, or QEESI, that can be downloaded without charge from my website. Fill it out, score it, and take it to your doctor along with your calendar/graph of symptoms over time.