Particulates and Air Quality
- What is a particulate?
- Where do particulates come from?
- What are the possible health effects if I am exposed to particulates?
- How does a person usually become exposed to airborne particulates?
- What detemines whether I may have health effects from particulate exposure?
- What can be done to reduce exposure to particulates?
- Where can I get more information?
What is a particulate?
“Particulate” is a general name given to a tiny solid or liquid particle or piece of matter. It usually refers to particles in the air (airborne particulates).
Where do particulates come from?
There are many sources for particulates in the air. Among them are soil, plants, fires, and road dust.
A major man-made type is fumes from combustion processes and products, like tobacco smoke, car exhaust, power plants, wood stoves, oil burners or other heating systems. Even burning candles or oil in lanterns can be sources of particulates.
A second major type is dust. This includes dust from mechanical processes like grinding or sweeping, and common household dust that may include mold, pollen, and small insect parts. Fibrous building material such as fiberglass may also be a source of particulates.
A third major type is mist, like that caused by spray painting.
In general, the smaller and lighter a particulate is, the longer it will stay in the air. A fairly dense particulate, such as lead dust, is likely to stay in the air for a shorter period of time than other particulates. Some particulates, like certain types of fibers or pollen, may stay in the air for very long periods of time, especially if there is air movement caused by occupants, pets, open windows, fans, office equipment, vacuum cleaners, etc.
What are the possible health effects if I am exposed to particulates?
The health effects can range from none at all to very serious.
For people with allergies, certain types and amounts of particulates, such as mold spores, pet dander, pollen, or dust mites, may cause allergic reactions. Some people can be allergic to material in tobacco smoke and other combustion byproducts. Asthmatic episodes can occur in some people. Examples of allergic symptoms and signs include nasal discharge, difficulty breathing, coughing, runny eyes, throat irritation, rashes and headaches. In severe allergic reactions, death can occur.
Some particulates such as silica, asbestos fibers, and coal dust can cause permanent lung damage, with symptoms and signs like coughing, chronic shortness of breath and fatigue. When inhaled in high enough doses, lead dust can be a major source of lead poisoning in adults who engage in certain activities such as painting and building renovation. It can cause high blood pressure, decreased hearing, reproductive problems, and even death. Tobacco smoke, which contains numerous toxic materials in particulate form, can cause chronic obstructive pulmonary disease (COPD) such as emphysema and lung cancer.
How does a person usually become exposed to airborne particulates?
In order for particulates to pose a health risk, a person must be exposed in such a way that the particulates are drawn into the body. Sometimes, as in childhood lead poisoning, this exposure is through hand-to-mouth behavior in which the lead dust is actually eaten. In most instances, however, exposure comes from inhaling airborne particulates.
The size of the particle often determines where in the body the particle may come to rest and possibly cause health effects. For example, if pollen enters into the breathing zone, it may be captured in the nose or upper airways. The mucous and tiny hairs that line those body airways can capture the pollen, preventing it from entry into the lungs. Smaller particles, such as silica, tobacco smoke, lead, some materials used in office equipment, and combustion by-products get past the nose and upper airways and are deposited in the lungs.
What detemines whether I may have health effects from particulate exposure?
Airborne particulates are likely to be found in some amounts everywhere—both indoors and outdoors. There are several factors that can help determine the extent of health effects. Among those factors are:
- Length of exposure (how long the person breathed in the particulates)
- Type and toxicity
- Concentration (amount of particulates in the breathing zone )
- Size of particulates (affects how deep within the respiratory system the matter can go and how long the dust will remain in the air)
- Activity level and breathing rate
- Age and overall health
Exposure to particulates and harmful health consequences are more likely to occur
- In industrial or semi-industrial settings, including vocational centers in schools (welding fumes, wood dust, etc.)
- In a poorly maintained, poorly cleaned indoor setting (dry sweeping of settled dust, etc.)
- In an area where certain materials are used for a hobby, craft, or science experiment without personal protection equipment.
- In a building in which a water-damaged area has not been maintained or repaired, in which the design or construction is inadequate, or in which high moisture is not controlled.
- In an area in which building remodeling, renovation or demolition is being done in an unsafe or improper way.
- In an area in which someone is operating inadequately maintained equipment that contains filters, such as vacuums, air cleaners and humidifiers.
- In a home or workplace in which smoking occurs, a wood or coal stove is operated, pets are allowed in carpeted areas, or mechanical work involving uncontained or unvented combustion occurs.
- In an indoor setting—even an office or school setting—where uncontained construction activity is occurring.
In all of these locations, relatively simple steps can be taken to minimize exposure. A high level of particulates may also be characteristic of larger environments where control is more difficult, such as urban areas with heavy traffic or rural areas with dusty roads or tall grass.
What can be done to reduce exposure to particulates?
Whether in an office, a factory setting, at home or at school, there are actions that can be taken to reduce exposure.
Reduce or eliminate the potential source or activity. Use products or methods that do not have the potential for releasing or stirring up high amounts of particulates. For example:
- In schools: use liquid paints rather than powdered.
- At home: use roll-on deodorant rather than a spray powder.
- Anywhere: do not smoke, and do not allow others to smoke around you.
- At work, or when engaged in hobbies or home improvement: use methods other than power sanding, dry scraping and dry sweeping.
- Control exposure at the source, before indoor air becomes polluted. By using a local exhaust, such as a range hood over a kitchen cookstove or an exhaust vent very close to a hobby or work activity, a person can decrease exposure to particulates. Also, equipment can be installed to filter the air so as not to add to outdoor pollution.
- Improve ventilation. Have the general air movement and introduction of fresh air be from areas of non-contamination and into areas of work activity. In this way, home or building occupants who are not directly involved with such activity can have cleaner air to breathe in their immediate area.
- Filter the air. Use equipment or appliances that can filter the air in an adequate way. Examples: vacuum cleaners, portable in-place air cleaners, dehumidifiers, humidifiers, air conditioners, large air-handling units that are part of a building, like a unit ventilator or a central air handling system, and respirators.
- Separate the areas of occupancy from the areas of particulate-producing activity. Block off, with use of physical barriers, areas of polluting activity from other areas occupied by people. This is very important if and when renovation and construction are occurring in an occupied building. In a setting such as a vocational school, particulates from spraypainting, for example, can be kept separate by having the activity occur in an appropriate place such as a mechanically vented booth.
- Relocate occupants until the polluting activity stops. Sometimes, due to a variety of reasons, it is helpful, prudent, or even necessary to relocate occupants for a short period of time. Relocation may be to another part of the building, or from one building to another.
- NOTE ON INDUSTRIAL SETTINGS: lf you are in an industrial setting, VOSHA (Vermont Occupational Safety and Health Administration) standards limit the allowable amount of total particulates and respirable-sized particulates in the air. Certain toxic particulates such as silica, lead and various other metals, and asbestos are strictly regulated. VOSHA also requires that a series of practical controls be put into effect to prevent reliance on respirators as the only source of protection for exposed workers.
Where can I get more information?
More information can be obtained from the makers of filters and equipment such as vacuums, respirators, air cleaners, dehumidifiers, and heating, ventilating and air conditioning (HVAC) sysems. Other resources include the internet and organizations and agencies listed in our Indoor Air Quality Resource Guide.