Pollutant Fact Sheets

Particulate Matter


Airborne particulate matter, also known as PM or particle pollution, is a mixture of extremely small particles and liquid droplets that can include acids, organic chemicals, metals, soil and dust particles, and biological matter such as fungal spores. Smaller particles pose a health concern because they can be inhaled into and accumulate in the lungs. Particles less than 2.5 micrometers in diameter, called PM2.5 or “fine” particulate matter, pose the greatest health risks. Because of their small size (about 1/30th the width of a human hair), these tiny particles penetrate deeply into the lungs.1,2


PM comes from many sources and is often too small to see directly with the human eye. Sometimes you can see a “haze” in the atmosphere that results from PM (and not humidity).  Outdoors, important sources include cars, trucks, trains, construction equipment, power plants, incinerators, fireplaces, burning leaves and brush, and some industrial processes.  “Coarse fraction” particulate matter, with a diameter between 2.5 and 10 micrometers, is due to crushing and grinding operations, as well as windblown dust from roads and fields.1 PM also results from chemical reactions involving combustion gases, organic vapors, ammonia and ozone.  Indoors, PM can come from cigarette smoking and cooking (especially frying), woodstoves, candles, or from outdoor air that comes into houses or buildings. 2

PM25 Pie Chart

Figure 1: Emissions of PM2.5 from major sources in Wayne County.  National Emissions Inventory data, 2011.


Exposure to PM, particularly PM2.5, can cause or worsen a number of diseases and can cause death.  PM2.5 can increase your risk of the following:3, 4, 5

  • Lung irritation, coughing, and difficulty breathing
  • Asthma attacks and hospitalizations– especially children
  • Adverse birth outcomes, including premature births and low birth weight babies
  • Decreased lung function and impaired lung growth in children and teenagers
  • Increased blood pressure
  • Heart attacks and irregular heartbeat
  • Cancer
  • Death


PM levels across Detroit have declined in recent years and now meet the US Environmental Protection Agency standards.3 However, even at their current levels, there are effects of PM on health, including blood pressure, asthma, and birth outcomes.  In addition, some areas of Detroit have higher PM levels, including areas near major highways and large industrial emitters.

The top industrial emitters of PM2.5 in Wayne County include a large coal-fired power plant, two steel mills, an oil refinery, and a large cement producer.6  Portions of Detroit downwind from such sources may experience higher PM levels.7


About one out of every three people in the USA is at risk of experiencing PM2.5 related health effects.  Some people are more likely to be exposed to unhealthy levels of PM, and to suffer negative health effects.2 People at risk of higher exposure levels include those who work or are active outdoors and those who live near major sources, including large industry and major roadways. 3

Some populations are more likely to have adverse health effects of PM. Individuals at risk include: infants, children-especially if very active during high pollution periods, people over 65 years of age, people with lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), chronic bronchitis and emphysema, people with heart disease or diabetes, and those with lower incomes . 3



  • Avoid smoking and avoid breathing second-hand smoke.
  • Minimize open fires, the use of fireplaces, and replace wood-burning stoves with gas-powered versions.
  • Install particulate filters to reduce PM levels in your home, office, or school.8
  • Support regulations that require installation of the best available technology at local steel mills and other PM-producing industries to help keep PM and many other harmful pollutants out of our air.
  • Reduce the number of polluting vehicles, by upgrading the diesel truck, bus and rail fleet, or retrofitting vehicles with diesel particulate traps.
  • Assure that industries and transport stations are not located near schools and residential areas.
  • Enforce diesel truck idling ordinances to reduce PM levels on roads and parking areas.9


  1. EPA (Environmental Protection Agency). 2014. Particulate Matter. http://www.epa.gov/pm/ [accessed 3/8/14.]
  2. EPA (Environmental Protection Agency). 2014. Frequent questions- fine particle designations. http://www.epa.gov/airquality/particlepollution/designations/2012standards/faq.htm [accessed 9/8/14]
  3. EPA (Environmental Protection Agency). 2014. Integrated science assessment for particulate matter, health criteria, final report. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546#Download [accessed 8/12/14]
  4. American Lung Association. 2014. Health effects of ozone and particle pollution. State of the Air 2014: 34. http://www.stateoftheair.org/2014/assets/ALA-SOTA-2014-Full.pdf [accessed 12/18/14.]
  5. Dvonch, J. T., et al. 2009. Acute Effects of Ambient Particulate Matter on Blood Pressure: Differential Effects across Urban Communities. Hypertension53(5), 853–859.
  6.  National Emissions Inventory. 2011. Wayne county, MI particulate matter (2.5) emissions. https://www.google.com/fusiontables/DataSource?docid=1dn790Dk55RsU0trA48nAtiAMa0sR1nvnpU4JW2Q#rows:id=1 [accessed 9/5/14]
  7. MDEQ (Michigan Department of Environmental Quality). 2014. Particulates. http://www.michigan.gov/deq/0,4561,7-135-3310_30151_31129_50581—,00.html [accessed 12/18/14]
  8. Batterman, Stuart. 2012. Particulate matter concentrations in residences: an intervention study evaluating stand-alone filters and air conditioners. Indoor Air 22, no. 3 (2012): 235-52. http://www.ncbi.nlm.nih.gov/pubmed/22145709 [accessed 12/18/14]
  9. Morishita, M., et al. 2014. Exploration of the composition and sources of urban fine particulate matter associated with same-day cardiovascular health effects in Dearborn, Michigan. Journal of Exposure Science and Environmental Exposure. (2014) Epub ahead of print. http://www.ncbi.nlm.nih.gov/pubmed/24866265 [accesses 12/18/2014]