Center for Asbestos Safety

Particulate air pollution

Particulate air pollution

Particulate pollution (also called fine particles or particulates) refers to microscopically small fragments of solid or liquid which can be found in a suspended state in gases or other liquids. For example, a coal plant’s smokestack expels coal smoke into the atmosphere. These smoke particles can get trapped inside water vapor droplets present in clouds, something that can result in acid rain.

How to measure particulate air pollution?

It is difficult to measure the potential damage that microscopic air pollution agents can cause since they differ in shape, size and chemical properties. Majority of agencies associated with pollution research and prevention categorize these particles according to their size: fine particles are those that are 2.5 microns across and inhalable coarse particles range from 2.5 to 10 microns across. In comparison to the size of these particles, a human hair is usually around 70-100 microns whereas red blood cells are about 7 microns across. Of special concern are carcinogenic particulates. Indeed, asbestos fibers are known to cause malignant mesothelioma.

What other sources can lead to particulate air pollution?

According to a research study conducted by the US Environmental Protection Agency (EPA), one of the major sources of fine particulate air pollution also happens to be the oldest: fires. As per EPA estimates for 2002, the amount of fine particulate air pollution generated by fires was more than one million tons. Voluminous amounts of untreated, unfiltered smoke has been continuously released in the air since the time humans developed the knowledge of creating a spark and lighting up fires for comfort and warmth. Concerns regarding particulate air pollution may have been raised only recently, but both the issue and the sources are as old as civilization, irrespective of what the source might be, a small campfire or an uncontrolled forest blaze.

The research study also estimates that road dust contributed more than eight hundred thousand tons to fine particulate air pollution and electricity generation around five hundred thousand tons. Amazingly, fine particulate air pollution generated through the use of fossil fuels (gasoline, oil, kerosene, coal) along with automobile usage contributed less than four hundred thousand tones, which is a third of the total generated through fires.

However, outdoor sources are not the only contributors to air pollution. Certain indoor sources can also lead to air pollution. Sheet rock particles, cigarette smoke, dirty ventilation systems, and dust can generate fine particles that can raise indoor particulate air pollution levels.

What are the potential effects of exposure to fine particulate air pollution?

Results of varied studies compiled by the United Nations World Health Organization (WHO) indicate that prolonged exposure to current ambient (fine particulate air pollution levels) can reduce life expectancy. The primary reasons for reduced life expectancy include lung cancer and cardio-pulmonary mortality.

Continued exposure to fine particulate air pollution can prove to be extremely hazardous to human health. These fine particles can settle and accumulate inside the lungs, resulting in irregular breathing. Prolonged exposure can result in the damage of small sacs in the lungs known as “alveoli” that control the exchange of oxygen and carbon-dioxide. Such exposures can lead to a variety of respiratory diseases such as chronic obstructive pulmonary disease (COPD). They can also worsen existing medical conditions such as bronchitis, asthma and heart disease.

Since most of the fine particles are smaller in size in comparison to red blood cells, fine particulate air pollution can lead to the damage of these healthy cells. When these fine particles start affecting healthy red blood cells, it can result in poor circulation, high blood pressure and fatigue. In more extreme cases, prolonged exposure can induce blood clots that can act as primary causes of strokes and deep vein thrombosis (DVT).

How to reduce particulate air pollution and minimize its effects?

Several agencies including both privately owned and government-run organizations are implementing steps to curtail the problem of fine particulate air pollution. Emission norms for facilities, as imposed by the US EPA, limit the allowed quantity of inhaled coarse materials to 150 micrograms for every cubic meter of air per day. For fine particles, the limit is 35 micrograms for every cubic meter of air per day.

Individuals can also help reduce fine particulates in the air and minimize adverse effects associated with exposure to these agents. Existing fire safety and energy conservation measures can help curb the growing menace of particulate air pollution. Moreover, individuals with respiratory conditions such as COPD or asthma should avoid rigorous outdoor activities on days when the local forecast may have expressed concerns over air quality.


Center for Asbestos
Safety in the Workplace