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MA EPHT - Indoor Air Quality

Indoor air quality plays a major role in our overall health because we spend most of our time indoors. Understanding the pollutants we breathe can help minimize and prevent respiratory issues and other long-term health problems.

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Indoor air quality refers to the condition of air in a building, with a focus on the characteristics that can affect the health and comfort of the building occupants. Good indoor air quality is the key component of maintaining a healthy indoor environment, where we spend about 90% of our time. Children tend to be more susceptible to the unwanted effects of indoor pollutants. Other vulnerable occupants may include the elderly or people with a compromised immune system. 

Indoor air quality is influenced by:

  • Pollution sources inside a building
  • Pollution sources outside of a building
  • Indoor activities
  • Building and ventilation design that affects how air and pollutants get inside, move through, and exit a building

What are sources of indoor pollutants?

Indoor air pollution has sources from both outside and inside the building. 

Outdoor air pollution can enter through open windows or cracks in the building. Common outdoor air pollutants that affect air quality indoors are:

  • Odors
  • Water/water vapor
  • Radon

More often, indoor air quality is affected by materials found inside a building. Typical sources within buildings include:

  • Cleaning and personal care items
  • Pesticides
  • Building materials
  • Furnishings, and chemicals released from furnishings
  • Gases (such as carbon monoxide) and vapors created from fuel-burning equipment
  • Moisture

Other building conditions like higher temperatures and humidity can also increase pollutants.

Levels of indoor air pollutants can be 2 to 5 times higher than levels typically found outdoors – and occasionally more than 100 times higher.

What are common indoor pollutants?

Some common indoor air pollutant concerns include the following:

Tobacco smoke/secondhand smoke

Tobacco smoke is produced from burning cigarettes, cigars, pipes, or hookah. Secondhand smoke is a mix of smoke breathed out by a person smoking tobacco and the smoke from the burning end of a tobacco product.

Health Concern

Tobacco and secondhand smoke can be detrimental to infants and children. It is associated with frequent and severe:

  • Asthma attacks
  • Respiratory infections
  • Ear infections
  • Sudden infant death syndrome (SIDS)

In adults, health conditions associated with tobacco smoke include:

  • Coronary heart disease
  • Stroke
  • Cancer

Tobacco and secondhand smoke are associated with 12 different types of cancer. These range from lung and bronchus cancer to bladder and pancreatic cancer.

What you can do

  • Create a smoke-free environment at home, school, and the workplace
  • Reduce personal and secondhand smoke exposure by stopping tobacco use
  • Contact the Massachusetts Tobacco Cessation and Prevention Program for help quitting smoking. You can call 1-800-QUIT-NOW (1-800-784-8669)

Radon

Radon is a naturally occurring gas. It is produced from the breakdown of uranium and radium in soil and rock found across Massachusetts. It moves up through the soil into a home or building through cracks and crevices in the foundation and gets trapped inside. Radon gas can build up over time within a home or building.

Health Concern

Breathing in high levels of radon gas over many years increases the risk of lung cancer.

Radon is the leading cause of lung cancer in people who don’t smoke. It is the second leading cause of lung cancer among smokers or people with a smoking history. For people who smoke, tobacco use and radon exposure work together to increase the risk of developing lung cancer - the risk is up to 10 times greater than for people who never smoked.

What you can do

Contaminants created when fuel is burned or combusted (e.g. carbon monoxide, nitrogen dioxide, fine particulate matter)

Combustion contaminants are released when burning fuels, such as oil, natural gas, kerosene, and wood. Common contaminants include carbon monoxide, nitrogen dioxide, and fine particulate matter. Indoor air quality can be affected when appliances are not working or vented properly. Improperly working gas stoves, kerosene or gas heaters, chimneys, furnaces, or generators can cause contaminants to build up. Automobile exhaust in an attached garage can also enter indoor living spaces. These and other contaminants can also enter a building from outdoors.

Health Concern

Carbon monoxide (CO) is a colorless, odorless gas produced any time a fossil fuel is burned. When breathed, it reduces the amount of oxygen carried in the blood. This can lead to sudden illness, including death. Symptoms include headache, dizziness, weakness, nausea, trouble thinking, and flu-like symptoms.

Nitrogen dioxide is a colorless, odorless gas. It causes irritation of the eyes, nose, and throat. Inhalation increases the risk of respiratory infections.

Fine particulate matter or PM2.5 are microscopic airborne particles. Due to their size, these particles can travel deep into the lungs. For many, exposure to PM2.5 can cause irritation of the eyes, nose, throat, and lungs. Other symptoms include coughing, sneezing, runny nose, and shortness of breath. PM2.5 can worsen medical conditions such as asthma and heart disease. It can lead to decreased lung function. 

What you can do

Volatile organic compounds

Volatile organic compounds (VOCs) are chemicals found in household and commercial products. They are also found in building materials. Common sources of VOCs include:

  • Cleaners
  • Deodorizers
  • Paints
  • Personal care products
  • Furniture polishes
  • Dry-cleaned goods

Common VOCs include benzene, formaldehyde, and toluene.

  • Benzene is a slightly sweet-smelling chemical. It is released into the air when glues, paints, furniture wax, and detergents are used or when tobacco is lit.
  • Formaldehyde is a colorless gas with a slight pungent smell. It is primarily released into the air from pressed wood products like particle board and laminate. It also gets into air from furniture, carpets, and permanent-press fabrics.
  • Toluene is a solvent that gets into the air when a person uses paint and paint thinners. It is also released from fingernail polish, lacquers, and adhesives.

Health Concern

Breathing benzene can cause drowsiness, dizziness, rapid heart rate, and unconsciousness. Long-term exposure to benzene has major effects on blood. Over time, benzene is harmful to bone marrow and can cause anemia and leukemia.

Formaldehyde can cause irritation of eyes and the respiratory system. Continued exposure can cause severe allergic reactions of the skin and eyes. It is also a cancer-causing agent (carcinogen).

At low levels, toluene affects the nervous system and may cause tiredness, confusion, memory loss, or nausea. Repeatedly breathing high levels of toluene can cause brain damage.

What you can do

  • Products containing VOCs should be used in a well-ventilated area. Open windows and exhaust ventilation can help dilute and remove these chemicals.
  • Limit the use of scented products, including candles, which contain fragrance chemicals
  • When not in use, VOC-containing products should be tightly covered. This will prevent evaporation into the air.
  • Consider cleaning products and furniture polishes that contain no/low VOCs. EPA maintains a list of Safer Choice products that have safer ingredients. These products are considered safer for people and the environment.
  • Wash permanent-press clothing and curtains before using them
  • Let new products release formaldehyde outside of your living space (e.g. patio or garage) before using or installing them indoors
  • The best way to reduce buildup of indoor air contaminants is by opening windows to let in fresh air. Testing for chemicals in the air of a home is not usually necessary. Testing has drawbacks including cost, test reliability, and interpretability. It can also be difficult to identify specific chemical sources since many products contain similar ingredients.

Contaminants disturbed during renovation, including lead and asbestos

Contaminants disturbed during renovations may include dusts and certain hazardous materials. These can become airborne when disturbed. Disturbances may occur during remodeling, renovation, weatherization, or energy efficiency projects. In older buildings, an additional concern is lead dust and asbestos fibers.

Prior to remodeling or renovating a home or property, determine:

  • The age of the property
  • History of renovations or changes made to the building
  • Whether relevant lead or asbestos reports exist

Lead-based paint was commonly used in buildings constructed before 1978. Although lead paint is no longer used, remodeling activities can disturb lead-containing paint previously sealed under other paint layers. Lead was also used in plumbing before 1986, so drinking water may also contain lead.

Asbestos is a naturally occurring fibrous particle. It is resistant to heat, fire, and many caustic chemicals. Its use as insulation and in many building materials peaked from World War II until the 1970s. Asbestos-containing materials (ACM) may include:

  • Decorative plasters
  • Fireproofing
  • Flooring tiles
  • Heating system insulation
  • Joint compound
  • Mastics
  • Roofing and siding
  • Vinyl sheet flooring
  • Some vermiculite-containing materials
  • Wallboard

Health Concern

Lead is harmful to the brain, kidneys, and nervous system. Lead exposure is most likely to cause harm during pregnancy, infancy, and early childhood before age 6. There is no safe level of lead. Even at low levels, lead can make it hard for children to learn, pay attention, and behave. Home repairs and renovations can create lead dust, which lands on the floor and elsewhere. Lead gets into children’s bodies when they touch lead dust and put their hands and toys in their mouths. Children can also breathe in lead dust. Because lead poisoning often occurs with no obvious symptoms, it often goes unrecognized.

Breathing asbestos can cause scarring of the lung and the lining of the lung. Exposure to asbestos can cause lung cancer and mesothelioma. ACM that are not damaged or disturbed are not likely to pose a health risk.

What you can do

If you suspect lead paint in your home, take action. Research your home in a database of residential lead inspections. This database is maintained by the DPH Childhood Lead Poisoning Prevention Program (CLPPP).

  • If you rent your home, ask the property owner if the home was inspected. If you have a child under 6, you can call your local health department or CLPPP at (800) 532-9571 and ask for an inspection.
  • If you own your home, contact a licensed lead inspector to test your home. Homeowners can also perform low-risk deleading.

Repair and removal of asbestos must be done in accordance with Massachusetts Department of Environmental Protection (MassDEP) regulations and Department of Labor Standards (DLS) regulations that involve asbestos. The MA Executive Office of Energy & Environmental Affairs (EEA) provides a searchable database of asbestos removal projects.

Schools are required to maintain ACM in good condition and in accordance with the Asbestos Hazard Emergency Response Act (AHERA). This includes identifying ACM, development of a management plan, re-inspections, performing response actions, and recordkeeping requirements. Contact the DLS Asbestos Safety Program at (617) 626-6960 for questions or more information.

Pesticides

Pesticides refer to chemicals used to kill and control pests. Pesticides are most often associated with insects and rodents but they also refer to products used against bacteria, viruses, and other microorganisms. Common household products that contain pesticides include:

  • Cleaning products
  • Insect repellents
  • Weed killers

Health Concern

Most pesticide exposures occur when the product is breathed in. However, pesticides can also be absorbed through the skin or accidentally ingested. Immediate symptoms from pesticide exposure typically include irritation to eye, nose, and throat. Long-term and consistent exposure can damage the central nervous system and kidneys and also increase the risk of cancer.

What you can do

Use principles of integrated pest management (IPM) to manage and reduce pests. IPM are practices that control pests in a building with as little pesticide as possible. The following are some IPM steps that can help control pests and reduce the need for pesticides:

  • Keep food containers and bags tightly sealed. Eliminate crumbs through frequent cleaning of counters, floors, food cupboards, and garbage areas.
  • Repair water leaks, prevent standing water in planters, and reduce humidity to avoid attracting pests. Also, replace water-damaged materials.
  • Seal cracks and crevices around pipes and gaps in doors to prevent pest entry. Holes as small as ¼ inch are enough space for rodents to enter a building.

The MA Department of Agricultural Resources (MDAR) Pesticide Program regulates pesticides in Massachusetts. The MA Childrens and Families Protection Act requires schools and child care programs to develop IPM plans and submit them to MDAR. IPM plans are available from MDAR and searchable by school.

If insecticide use cannot be avoided, consider using non-aerosol options. These include gels and solids rather than sprays or foggers. Look for safer pesticides, such as boric acid and pyrethrin. Pyrethrin is a type of pesticide made from chrysanthemum flowers. EPA maintains a list of Safer Choice products that have safer ingredients.

Moisture and mold

Dampness and humidity in a building is associated with biological pollutants. These include pests, dust mites, mold and bacterial growth. Dampness is also associated with the release of chemicals in furniture and building materials. Water damage in a building can be caused by floods, leaks, or humid air coming into the building from the outside. Common activities such as cooking, bathing, and washing clothes or dishes can also contribute to moisture indoors.

Mold grows after spores contact wet or water-damaged building materials or furnishings. Mold can grow on absorbent or porous materials. Common materials that may grow mold are insulation, carpets, and gypsum wallboards. Sometimes mold may also grow on the surface of hard or non-porous surfaces like plastic, metal, and glass.

Damp environments are attractive to pests, such as rodents and cockroaches. Similarly, high humidity conditions can allow dust mites to thrive in bedding, upholstered furniture, and carpets.

Health Concern

Biological pollutants are irritants. They also produce allergens or substances that can cause allergic reactions. Common irritant responses include runny nose, sneezing, skin irritation, and itchy or red eyes.

Exposure to biological pollutants can worsen pre-existing conditions, such as asthma or allergies. Infants, children, elderly people, and immunocompromised individuals are more likely to experience allergy symptoms and may have more severe reactions.

What you can do

Moisture control is the primary way of preventing mold growth in a building. Mold testing is not necessary, since there are no standards or limits for comparison. Some steps to control moisture include:

  • Fix leaks or water problems when they are discovered. People who rent should report leaks and water problems to their landlord or building manager.
  • Reduce indoor humidity by using kitchen and bathroom exhaust vents. Wet building materials and furnishings should be completely dried within 24-48 hours of damage. Paper-based or drywall may need to be removed if it cannot be dried completely.
  • Clean or scrub hard surfaces, such as plastic, metal, or tile after material is dry
  • Add insulation to exterior walls, pipes, and other areas where condensation can occur

To reduce dust and dust mites:

  • Use a HEPA-filtered vacuum on carpeted areas and upholstered items
  • Use a wet cloth on tables and other flat surfaces
  • Wash bed linens weekly in hot water
  • Wash pillows and stuffed animals on a regular basis

In addition to moisture control, follow steps for IPM to avoid attracting pests.

EPA offers resources for homeowners, health professionals, and school and commercial building managers.

Do you rent? Contact your landlord or building manager about leaks, dampness, or other sanitary code concerns. If a landlord does not respond to a tenant’s complaints about a Sanitary Code violation, you may request that the local board of health inspect the apartment .

What are strategies for improving indoor air quality?

A healthy indoor environment depends on the operations and activities in the building. Proper ventilation and the way the building is built and maintained will affect the indoor air quality.

The main ways you can improve indoor air quality are:

  1. Operating ventilation properly
  2. Controlling moisture
  3. Reducing sources of pollution and emissions

These 3 steps can help prevent symptoms associated with poor air quality. For more information, visit the MA EPHT webpages on ventilation, moisture, and irritant sources. 

What symptoms are associated with indoor air pollution?

Without ventilation and removal of stale air, indoor pollutants tend to build up. Short-term exposure to indoor air pollutants can cause respiratory symptoms. These include coughing, stuffy nose, itchy eyes, and sore throat. Short-term exposure may also cause headaches and fatigue. These symptoms can also be associated with other indoor environmental factors like noise, poor lighting, and temperature issues.

Dust and mold are more likely to affect people with chronic respiratory conditions like asthma. Controlling moisture is the key to preventing mold growth and potential health impacts. Students with asthma may also be affected if they go to a school with poor air quality. Chronic aggravation of asthma can lead to more days of missed school. Studies show poor ventilation may also result in decreased student learning and performance.

Long-term exposure to some indoor air pollutants can have serious health effects. Exposure may cause damage to the body’s systems and lead to respiratory disease, heart disease, and cancer. Tobacco smoke, radon, asbestos, and formaldehyde are all cancer-causing agents.

Lead dust from chipping, peeling, or loose lead-based paint or disturbed during renovations can also cause harm. Lead dust is known to cause damage to the brain, kidneys, and nervous system. It can also cause behavioral and learning problems, particularly in children. This is because children absorb lead more easily than adults. There is no safe level of lead. Even low levels of lead are harmful to the health of a child.

What should I do if I have an IAQ concern?

A few simple actions to improve indoor air quality include:

  • Opening windows to let in fresh air and/or using exhaust fans or window fans to draw air out of a room. The latter is recommended for those who experience allergies or asthma to reduce exposure to pollen. For people who live near highways, use a fan to draw air out of the room to reduce exposure to pollutants from vehicles.
  • Cleaning often to get rid of dust, pet fur, and other allergens
  • Wet wiping, damp mopping, or using vacuums equipped with a HEPA filter are better than sweeping or feather dusting
  • Using cleaning products that contain safer ingredients. EPA maintains a list of Safer Choice products. These products are considered safer for people and the environment.
  • Controlling moisture to prevent mold growth by using kitchen and bathroom ventilation to remove excess moisture. A dehumidifier can also be used to reduce humidity.
  • Using IPM to remove conditions that attract pests
  • Not smoking or allowing others to smoke indoors

Have a question about a specific indoor air pollutant? Refer to the What are common indoor pollutants? section above for contact information.

Many of the above actions can be taken by most people, however, people who rent homes may not have the same opportunities. Historical housing policies and redlining have created neighborhoods with poor indoor environmental conditions. For example, redlined areas tend to be more polluted, which can affect indoor air quality. These conditions can exacerbate asthma symptoms or lead to other health outcomes. This housing stock is disproportionately used by communities of color and low-resourced families. Renters can work with landlords to improve these conditions and by reporting their concerns to local health departments, if needed.

Rental Housing

A housing code exists to ensure the health, safety, and well-being of the tenants. The code is known as the State Sanitary Code (105 CMR 410). It is enforced by local boards of health and health departments. (Note: In Boston, it is enforced by the Housing Inspection Department). The DPH Regulatory and Compliance Unit also has guidance on understanding the housing code, legal remedies for renters, and bed bugs.

Public Schools and Buildings

Indoor air quality concerns commonly arise in public buildings, such as schools, town halls, and libraries. TheDPH Indoor Air Quality Outreach and Education Unitperforms indoor air quality assessments of public schools and buildings. During these evaluations, staff collect measurements and observations about:

Indoor air quality reports are available for many schools and buildings evaluated by the DPH IAQ Unit. Public schools interested in an assessment can contact the DPH IAQ Unit at (617) 624-5757.

The DPH IAQ Unit also develops guidance documents, such as:

Related links

Ventilation  Moisture  Irritant sources  DPH Indoor Air Quality Outreach and Education Unit  DPH Radon Unit  DPH Childhood Lead Poisoning Prevention Program 

Additional resources

Massachusetts

National

Contact

Online

MA EPHT Website 
Email Massachusetts Environmental Public Health Tracking (MA EPHT) at DPH-MA-EPHT@state.ma.us

Phone

Call Massachusetts Environmental Public Health Tracking (MA EPHT) at (617) 624-5757

Address

250 Washington Street, Boston, MA 02108
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