What is PM2.5 and how dangerous can it be?

2023-10-21 12:02:00, Shëndeti CNA

What is PM2.5 and how dangerous can it be?

Illustrative photo

Particulate matter (PM) is not a single pollutant, but rather a mixture of many chemical species. It is a complex mixture of solids and aerosols consisting of small liquid droplets, dry solid fragments, and liquid-coated solid cores.

Particles vary greatly in size, shape and chemical composition and may contain inorganic ions, metallic compounds, elemental carbon, organic compounds and compounds from the earth's crust.

Particles are defined by their diameter for air quality regulatory purposes. Those with a diameter of 10 microns or less (PM10) can be inhaled into the lungs and can cause adverse health effects. Fine particles are defined as particles 2.5 microns or less in diameter (PM2.5). Therefore, PM2.5 includes a part of PM10.

What kind of harmful effects can particles cause?

A number of negative health impacts have been associated with exposure to PM2.5 and PM10. For PM2.5, short-term exposures (up to 24 hours) have been associated with premature mortality, increased hospitalizations for heart or lung causes, acute and chronic bronchitis, asthma attacks, emergency room visits, respiratory symptoms, and limited. activity days.

These adverse health effects have been reported mainly in infants, children and the elderly with pre-existing heart or lung disease. Furthermore, of all common air pollutants, PM2.5 is associated with the largest proportion of adverse health effects associated with air pollution, both in the United States and worldwide based on the Global Burden of Air Pollution Project. Diseases of the World Health Organization.

Short-term exposures to PM10 have been associated primarily with exacerbations of respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD), leading to hospitalization and emergency department visits.

Long-term exposure (months to years) to PM2.5 has been linked to premature death, especially in people who have chronic heart or lung disease, and decreased growth of lung function in children.

The effects of long-term exposure to PM10 are less clear, although some studies suggest a link between long-term exposure to PM10 and respiratory mortality.

The International Agency for Research on Cancer (IARC) published a review in 2015 that concluded that particles in outdoor air pollution cause lung cancer.

Who is most at risk from exposure to particulate matter?

Research points to the elderly with chronic heart or lung disease, children and asthmatics as the groups most likely to experience adverse health effects from exposure to PM10 and PM2.5.

Also, children and infants are susceptible to harm from inhaling pollutants such as PM because they inhale more air per kilogram of body weight than adults—they breathe faster, spend more time outdoors, and are larger. small body parts.

In addition, children's immature immune systems may make them more susceptible to PM than healthy adults.

Research from the CARB-initiated Child Health Study found that children living in communities with high levels of PM2.5 had slower lung growth and had smaller lungs at age 18 compared to children living in communities with low levels of PM2.5.

CARB used the US EPA's risk assessment methodology to conduct an estimate of premature mortality associated with exposure to PM2.5 (California Air Resources Board 2010).

An update of this analysis using ambient air quality data from 2014-2016 showed that exposure to PM2.5 contributes to 5,400 (uncertainty range of 4,200 – 6,700) premature deaths from cardiopulmonary causes per year in California.

In addition, PM2.5 contributes to about 2,800 hospitalizations for cardiovascular and respiratory disease (uncertainty range 350 – 5,100), and about 6,700 emergency room visits for asthma (uncertainty range 4,200 – 9,300) each year in California.

How do particles affect the environment?

Particulate matter has been shown in many scientific studies to reduce visibility and also negatively affect climate, ecosystems and materials. PM, mainly PM2.5, affects visibility by changing the way light is absorbed and scattered in the atmosphere.

With reference to climate change, some components of the ambient PM mix promote climate warming (e.g., black carbon), while others have a cooling effect (e.g., nitrate and sulfate), and thus Ambient PM has climate warming and cooling properties.

PM can negatively affect ecosystems, including plants, soil and water through deposition of PM and its subsequent uptake by plants or its deposition in water where it can affect water quality and clarity.

Metals and organic compounds in PM have the greatest potential to alter plant growth and yield. The deposition of PM on the surface leads to contamination of materials./ CNA