Many of these studies were discussed in EPA’s Particulate Matter Integrated Scientific Assessment (PM ISA). This rating was published in 2019 and is based on the previous PM ISA published in 2009. The 2019 report represents EPA’s latest assessment of the scientific literature it examines. Potential relationships between PM exposure and health and welfare effects. ISA is the scientific basis for EPA’s National Air Quality Standards (NAAQS) review of six criteria pollutants, including PM, as required by the Clean Air Act.
The PM ISA concluded as follows:Extensive scientific evidence that we breathe PM2.5 Over days to years, it can cause a variety of cardiovascular effects, from changes in heart function to more obvious effects such as atherosclerotic plaque progression and death. The PM ISA characterizes evidence of a relationship between exposure to fine particulate matter and many clinical cardiovascular outcomes. This is explained below.
Related Links:
Particulate matter (PM) pollution
2019 Comprehensive scientific evaluation final report for PM
clinical results
Extensive evidence across both experimental and epidemiological studies supports a biologically plausible route to breathing fine particulate matter (PM).2.5) may cause more obvious health effects, including cardiovascular clinical outcomes. These early effects, which can lead to a cascade of effects that lead to clinical cardiovascular outcomes, include:
- inflammation and oxidative stress
- Movement of particles out of the respiratory tract and into the blood
- Disturbance of autonomic nervous system
Short-term and long-term exposure to PM2.5 It can cause or worsen the following clinical cardiovascular outcomes:
Cardiovascular-related mortality: Inhaling particulate matter can cause changes in the function of the heart and blood vessels, which can lead to clinical outcomes that can be fatal, including heart attack, stroke, cardiac arrest, and congestive heart failure. Epidemiological studies conducted in different geographic locations, in diverse populations, and using a variety of study designs have reported increased cardiovascular mortality with both short- and long-term fine particulate matter exposure.
Ischemic heart disease and heart failure: Once inhaled, fine particulate matter can trigger a series of events that lead to vascular dysfunction (changes in blood vessels), resulting in the formation of blood clots, increased blood pressure, and decreased ability of the heart to pump blood. may occur. All of these can lead to worsening of ischemic heart disease and heart failure. Epidemiological studies examining short-term particulate exposure have reported evidence of increased emergency department visits and hospitalizations for ischemic heart disease and heart failure. Additionally, evidence across both animal toxicology and epidemiology studies indicates that long-term exposure to particulate matter reduces heart function and coronary artery wall thickness, which may contribute to heart failure. .
Heart attack (myocardial infarction): Breathing in particulate matter can impair vascular function (changes in blood vessels), including the development of atherosclerosis (clogged arteries) after long-term exposure and the development of blood clots after short-term exposure. may include the formation of These changes can reduce the supply of oxygen and nutrients to the heart, which can then lead to a heart attack.
stroke: There are multiple ways that inhaling particulate matter can cause a stroke. For example, once inhaled, particles can cause systemic inflammation and oxidative stress, leading to changes in blood vessel function and the formation of blood clots, which can ultimately block blood flow to the brain and cause a stroke.
Cardiac arrest: Among patients with advanced heart disease who wear internal defibrillators, inhaling particulate matter can affect the nervous system, resulting in disruption of the heart’s electrical function, which can be fatal in some people. It has been shown that it may cause abnormal heart rhythms (arrhythmia). ).
Vascular function: Once inhaled, particulate matter causes a series of events that lead to vascular dysfunction (changes in blood vessels), including constriction of blood vessels, progression of atherosclerosis (clogging of arteries), formation of blood clots, and calcification of coronary arteries. may cause. , which is a strong predictor of coronary heart disease. Changes in vascular function can contribute to a variety of cardiovascular diseases, including ischemic heart disease, heart failure, stroke, heart attack, and death.
blood pressure: Short-term exposure to fine particulate matter can cause increased blood pressure through multiple pathways, including: May cause impairment of vascular function and vasoconstriction. Increased blood pressure in response to short-term exposure is more consistently observed in older adults (i.e., individuals over 65 years of age) and people with underlying cardiovascular disease.
cholesterol: Elevated cholesterol levels are a common chronic disease among U.S. adults and an important risk factor for other serious health conditions associated with PM.2.5 Exposures such as cardiovascular disease and diabetes. Some studies have investigated differences in PM.2.5– Health effects related to dyslipidemia. This limited epidemiological study provides some evidence of increased risk from short- and long-term PM.2.5 The amount of exposure in people with high cholesterol compared to people with normal cholesterol.
Overall, there is insufficient evidence to conclude whether adults with high cholesterol are at increased risk for PM.2.5 -Related health effects.
Which populations are at increased risk for cardiovascular clinical outcomes in response to PM?2.5 exposure?
Overall, scientific evidence indicates that some populations may be at increased risk of PM.2.5– Associated health effects may include cardiovascular clinical outcomes. These populations include:
- People who are already at high risk after a myocardial infarction or stroke
- Those with rhythm disorder, heart failure, or end-stage renal disease
