Concentrations of PM that measure near or above the National Ambient Air Quality Standards can have adverse effects on human health and our environment.
PM can have significant impacts on the health of sensitive groups. High PM levels particularly affect children, people with lung disease, and people who are active outdoors. These pollutants are small enough to invade our respiratory system as we breathe in polluted air. They can damage lung tissues when they reach the alveoli, which are the tiny air sacs where we take in oxygen and unload carbon dioxide (see image below). This reduces lung capacity.
Particles 10 micrometers in diameter and smaller (also called PM10) pose the greatest problems, because they can get deep into the lungs, and some may even get into the bloodstream. Among these particles are "fine particles," which are 2.5 micrometers in diameter and smaller (also called PM2.5). These fine particles can affect both the lungs and the heart.
Children are at risk because their lungs are still developing and because they spend more time outdoors, and the elderly are also sensitive to the harmful effects of PM pollution. However, there is some risk for all of us.
Scientific studies have linked breathing PM to serious health problems, including:
Both short and long term exposure to PM, primarily PM2.5, can lead to these health problems. Short term exposure is measured on a daily basis. Effects such as nonfatal heart attacks and premature death are the result of repeated short term exposures, rather than a single instance of exposure to high PM levels. Long term exposure is measured on an annual basis.
For more information on the health effects of wildfire smoke, see DHEC's wildfires webpage.
PM pollution can reduce visibility (haze) and build up in the atmosphere, soils, plants, and animals.
PM pollution is the major cause of reduced visibility (haze) in parts of the United States, including many of our treasured national parks and wilderness areas.
The U.S. Environmental Protection Agency Regional Haze program addresses visibility.
Pictured to the right is Cape Romain National Wildlife Refuge; hover your cursor over the image to compare visibility on a clear day versus a hazy one.
(Images provided courtesy of the U.S. Fish and Wildlife and National Park Service Visibility Programs.)
Particles can be blown by wind over long distances where they then settle on the ground or in water. This settling action is called called deposition. Effects of PM deposition include:
Over time, some particulate matter can stain and damage stone and other materials through deposition. This includes culturally important objects like monuments and statues. Aesthetic damage can also be caused by acid rain.