Particulate matter (PM) is a mixture of solid particles and liquid droplets found in the air. PM can include a mixture of dust, pollen, soot, smoke, and liquid droplets according to the United States Environmental Protection Agency (EPA).
Why do we care about these small particles in the atmosphere? Depending on the size of PM, it can be harmful to human health. PM with a diameter of more than 10 microns are the larger particles of PM. These include particles like dust, pollen mold, etc. These are the least harmful because these particles are inhalable. Particles that are less than 10 microns in diameter pose a greater threat to human health says the EPA. Fine particles, or particles that are less than 2.5 microns in diameter are the most harmful to human health. These particles include combustion particles, organic compounds, and various metals. According to the NYS Department of Health, these fine particles can come from vehicle exhausts, burning of fossil fuels such as wood, heating oil or coal, and natural sources such as forest and grass fires. Another source are reactions of gases or droplets in the atmosphere from power plants.
Fine particles with a diameter of less than 2.5 microns can be traveled at further distances by the wind than larger particles. This is because these particles are lighter and are carried easier by the wind.
In general, we can try to forecast where PM particles are going based on winds. The trade winds and the westerly jet streams spread PM particles around the globe. An image created by NOAA shows all the different types of particles being spread at a specific time below. In the image, the orange represents dust particles, blue represents sea spray particles, white represents smoke or pollutants, and green represents smoke being released from the burning of natural things such as trees.
It is also important to know how harmful fine particles can affect human health. The NYS Department of Health states that “exposure to fine particles can cause short-term health effects such as eye, nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath. Exposure to fine particles can also affect lung function and worsen medical conditions such as asthma and heart disease.”
It is important to keep track of PM in our atmosphere. No need to worry, not all PM is harmful and there are air quality regulations set by the EPA. This ensures that there is only a certain amount of PM allowed to be released into the air by human activities (such as the burning of fossil fuels) to keep the environment safe for us.
Credit: (United States Environmental Protection Agency (EPA), NYS Department of Health, NOAA)
©2019 Weather Forecaster Brittany Connelly
DISCUSSION: When it comes to dealing with various global issues connecting weather events and general health issues, there are several different things which come to mind. One such issue which millions of people around the world deal with on a regular basis is an atmospheric chemistry-based phenomenon known as smog. Since the onset of the industrial revolution, there has been a marketable increase in the overall global demand for fossil fuel resource consumption. In that light, one of the premiere issues when it comes to the increased demand for fossil fuel resources are the atmospheric emissions and airborne chemical by-products which result.
More specifically, when planes, trains, and/or cars around the world burn fossil fuel resources such as (but certainly not limited to) gasoline and/or diesel fuel, there are various types of carbon emissions which are immediately released into the surrounding environment. If such emissions are released into a region where there happens to be a substantial amount of lower level atmospheric water vapor in place (i.e., locally high levels of atmospheric moisture), this can often lead to such emissions becoming “trapped”. To explain a bit further, under typical conditions with relatively clear skies and light winds, most densely populated cities around the world which produce the greatest fossil fuel emissions will often have scenarios where most of the regional emissions will be dispersed and/or deposited over time in varying capacities.
However, when such fossil fuel emissions enter a low-level environment which is predominantly “wet” from greater levels of atmospheric water vapor being in place, such emissions can get trapped in the lowest portion of the atmosphere. As a result of such a scenario, the corresponding fossil fuel emissions can sometimes interact and effectively combine with low-level moisture in place from an ongoing ground fog and/or advection fog event to form a more dangerous health hazard known as smog. When smog forms and persists in more densely populated metropolitan city centers such as Los Angeles, California, Hong Kong, China, and Beijing, China, this can lead to an increased prevalence of health concerns for people with respiratory illnesses such as asthma. Therefore, there are most certainly things which can be done in the hopes of mitigating the future likelihood of smog events in more densely populated regions spread around the world. For example, in the hopes of lowering our collective carbon footprint, anyone around the world can aid in this goal by doing simple things such as making even more consistent use of public transportation as well as doing things like riding a bike or walking to work. It just goes to show that even when there are ominous issues which are faced by millions of people around the world on a routine basis, there are things which can be done to help resolve such issues.
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©2019 Meteorologist Jordan Rabinowitz