School buildings are often common places for asthma and allergy triggers. Children are particularly vulnerable to these harmful pollutants.

Improving indoor air quality in schools is an important measure for preventing asthma and allergy flare-ups among students. According to recommendations published in Health Promotion Perspectives, when schools actively filter PM2.5, or fine particle pollution, they can reduce the incidence of asthma from 16 percent to 13 percent (1).

The “September Asthma Epidemic” or “Asthma Peak Week” is a trend that lands more people – especially children – in the hospital for asthma attacks in September than any other month (2). During that time, mould counts are higher as fallen leaves are gathered. Children return to school and are exposed to more respiratory illnesses and asthma triggers.

Sources of poor indoor air quality in schools

There are several sources of air pollution in schools. These sources can differ depending on the age of the school building.

Newer school buildings may be tightly sealed and lack sufficient ventilation. Using synthetic building materials and furniture that off-gas chemicals, such as formaldehyde, can also be a problem.

Many schools are located dangerously close to heavily-trafficked roads and freeways. Air pollution near schools can include particulate matter from vehicles. PM2.5,PM10, and PM1 orultrafine particulates can all pose a threat to children's health.

Airborne pollutant sources in schools include (3):

• mold
• dust
• volatile organic compounds (VOCs)
• radon
• lead
• asbestos
• PCBs
• pesticides
• smoke

Animal-free doesn’t mean animal allergen-free

Animal allergens can be present in environments where there are no animals.

In a 2008 study published in the Annals of Allergy, Asthma & Immunology, researchers found that cat and dog allergens were present in virtually every U.S. home surveyed (4). Pet allergens were found to be transported by clothing. This is particularly problematic for sensitized children who do not have pets at home.

A 2005 study published in Allergy also found that human hair can transport pet allergens among schoolchildren (5).

Dust mite allergens in schools

Dust mites are close relatives of ticks and spiders. They thrive on soft surfaces in households, such as:

• mattresses
• bedding
• upholstered furniture
• carpets
• drapes and curtains

Dust mite droppings and their decomposing bodies are a major allergen affecting people with allergies and asthma.

A 2009 study in the Journal of Allergy and Clinical Immunology found that dust mite allergens are present in many schools and daycare facilities (6). Reported levels are often similar or slightly lower than in corresponding local homes.

Carpeting and upholstered furnishings are important reservoirs and sources of exposure in schools and daycare centers, particularly in humid regions.

Cockroach and rodent allergens in schools

Cockroach and rodent allergens are commonly detected in inner-city and rural schools. A 1996 study published in Clinical & Experimental Allergy found that detectable levels of cockroach allergen were found in 65 percent of vacuumed dust samples from classrooms (7).

A 2017 study published in JAMA Pediatrics found mice allergens in 99.5 percent of school samples (8).Children exposed to mouse allergens in schools experienced more asthma symptoms and lower lung function after adjusting for variation in exposures at home.

Airborne cockroach and mouse allergens are also found in airborne samples. Not surprisingly, the highest levels of these allergens are usually where there is food (9).

Dustless chalk can trigger milk allergies

Chalk dust is a common classroom allergen and asthma trigger. Many school teachers are now opting for dustless chalk.

Casein is a milk protein often used in low-powder chalk. Milk-allergic children who inhale low-powder chalk particles with casein can suffer asthma attacks and other respiratory (10).

Traffic-related air pollution

In the U.S. alone, almost 8,000 public schools are within 500 feet of highways, truck routes and other traffic-heavy roads (11).In the United Kingdom, there were 2,200 schools and nurseries near heavily-polluted roads in 2017. In Montreal, Canada, 127 elementary and secondary schools were within 150 meters of busy roads as of 2019 (12)(13).

Vehicle exhaust is the largest source of traffic-related air pollution. Other sources include dust from brakes, tires, and the road surface.

The most common traffic pollutants include:

• particulate matter
• nitrogen oxides
• carbon monoxide
• volatile organic compounds (VOCs)

Carcinogenic VOCs in traffic-related air pollution include formaldehyde, acetaldehyde, and benzene.

How parents can help at school

Questions parents can ask their school administrators include:

• Are the HVAC systems being properly inspected and maintained?
• Are there regular moisture and mold inspections?
• Is dust being removed daily with a damp cloth?
• Is the school being vacuumed using a HEPA filter daily?
• Are the cleaning products used safe?
• Are the building materials and furniture releasing harmful chemicals?
• Is food being properly stored?
• Is an optimal humidity level (between 30 and 50 percent) being maintained?

Parents should visit their child's school to find out what trigger sources are present. Parents can also talk to the school about what they can do to limit allergens, such as keeping windows shut on high pollen days or limiting carpets in the classroom.

Parents can also suggest a classroom project to identify trigger sources and get students involved in recognizing what contributes to good indoor air quality.

Other steps parents can take

• Before school starts, schedule an appointment with your child’s physician or board-certified allergist.
• Have a fully documented asthma plan: Develop your child’s plan with the physician or board-certified allergist. Each plan is specific to each child.
• Never rely on home remedies for allergies and asthma, unless your doctor says it’s okay.
• If your child’s asthma is severe, ensure there’s a peak flow meter available. Be sure your child and the school staff are comfortable using it.
• Ensure there’s an up-to-date rescue albuterol inhaler at the school.
• If your child has exercise-induced bronchoconstriction (EIB), let the school know they need to use their albuterol inhaler before exercise.
• Download an air quality app and track local air quality.
• Consider getting an air quality monitor for your child’s classroom. Connect it to the school’s Wi-Fi and check the air quality from your phone or desktop.

The takeaway

Although you can’t completely control allergens and asthma triggers outside your home, you can take steps to keep your child as safe as possible. By actively monitoring air quality and asking school administrators to take proactive actions, parents can help minimize asthma and allergy flare-ups for their children.