1. Ground-level Ozone Basics | US EPA
Health Effects of Ozone Pollution · What are ozone standards? · Ecosystem Effects
Learn the difference between good (stratospheric) and bad (tropospheric) ozone, how bad ozone affects our air quality, health, and environment, and what EPA is doing about it through regulations and standards.

2. Ground-level Ozone Pollution | US EPA
Known as tropospheric or "ground-level" ozone, this gas is harmful to human heath and the environment. Since it forms from emissions of volatile organic ...
Known as tropospheric or "ground-level" ozone, this gas is harmful to human heath and the environment. Since it forms from emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx), these pollutants are regulated under air quality standards.

3. Ground-Level Ozone (O3) Pollution - ADEQ
Ground-level ozone (O 3 ) is regulated by EPA. Ground-level ozone comes from pollution emitted from cars, power plants, industrial boilers, refineries, and ...
There are two kinds of ozone:
4. What is Ground-Level Ozone? - Air Central Texas - English
Ground-level ozone forms just above the earth's surface (up to about 2 miles above ground) and impacts human, animal, and plant respiration. Although ground- ...
Of all of the air pollutants that are measured in Central Texas, ground-level ozone is the one that the region has the most trouble with. Learn more about ground-ozone here

5. Ozone | American Lung Association
Apr 17, 2023 · Ozone aggressively attacks lung tissue by reacting chemically with it. When ozone is present, there are other harmful pollutants created by the ...
It may be hard to imagine that pollution could be invisible, but ozone is. The most widespread pollutant in the U.S. is also one of the most dangerous.
6. Ground-level ozone - Washington State Department of Ecology
No information is available for this page. · Learn why
Ozone damages trees and plants. It impairs plant growth, and makes them more easily harmed by insects and disease.
7. Tropospheric ozone | Climate & Clean Air Coalition
Tropospheric (or ground-level) ozone is a short-lived climate pollutant that remains in the atmosphere for only hours to weeks.
WHAT IS Tropospheric Ozone? Ozone (O3) is a reactive gas that exists in two layers of the atmosphere: the stratosphere (upper layer) and the troposphere (at ground level and up to 15km). In the stratosphere, ozone protects life on Earth from the sun’s ultraviolet radiation. In contrast, at lower levels, it is an important greenhouse gas and air pollutant, which is harmful to human and ecosystem health. It is also a major component of urban smog. Tropospheric ozone is a short-lived climate pollutant with an atmospheric lifetime of hours to weeks. It does not have any direct emissions sources, rather it is a secondary gas formed by the interaction of sunlight with hydrocarbons – including methane – and nitrogen oxides, which are emitted by vehicles, fossil fuel power plants, and other man-made sources. Strategies to prevent the formation of tropospheric ozone are primarily based on methane reductions and cutting the levels of atmospheric pollution arising from man-made sources, such as agriculture and fossil fuel production and distribution. Key figures Hours-weeks 79–121 million 1 million Tropospheric ozone has an atmospheric lifetime ranging from a few hours to a few weeks in polluted urban regions Estimated global crop production losses owing to ozone total 79–121 million tonnes, worth USD 11–18 billion annually Long-term exposure to ozone air pollution is linked to 1 million premature deaths per year due to respiratory diseases PRIMARY SOURCES OF Tropospheric Ozone In the troposphere, ozone is the product of the atmospheric reaction of a number of precursor pollutants, which have both natural and man-made sources. Precursor pollutants created by human activities include hydrocarbons and nitrogen oxides, which are largely emitted by cars and other vehicles, fossil fuel power plants, oil refineries, the agriculture sector and a number of other industries. Tropospheric Ozone IMPACTS CLIMATE IMPACTS Ozone absorbs radiation and consequently acts as a strong greenhouse gas. Tropospheric ozone affects the climate beyond increased warming, having impacts on evaporation rates, cloud formation, precipitation levels, and atmospheric circulation. These impacts mainly occur within the regions where tropospheric ozone precursors are emitted, and so disproportionally affect the Northern Hemisphere. HEALTH IMPACTS Tropospheric ozone is a major component of smog, which can worsen bronchitis and emphysema, trigger asthma, and permanently damage lung tissue. Tropospheric ozone exposure is responsible for an estimated one million premature deaths each year. Children, the elderly, and people with lung or cardiovascular diseases are particularly at risk of the adverse health impacts of ozone. AGRICULTURE AND ECOSYSTEM IMPACTS Tropospheric ozone is a highly reactive oxidant that significantly reduces crop productivity as well as the uptake of atmospheric carbon by vegetation. Its effects on plants include impeded growth and seed production, reduced functional leaf area and accelerated ageing. Studies have shown that many species of plants are sensitive to ozone, including agricultural crops, grassland species and tree species. These effects impact on the important ecosystem services provided by plants, including food security, carbon sequestration, timber production, and protection against soil erosion, avalanches and flooding. SOLUTIONS Strategies to prevent the formation of tropospheric ozone are primarily based on methane reductions. The relatively short atmospheric lifetime of methane, combined with its strong warming potential, means that targeted strategies to reduce emissions can provide climate and health benefits within a few decades. The Coalition supports implementation of control measures that, if globally implemented by 2030, could reduce global methane emissions by as much as 40%. Several of these emission reductions could be achieved with net savings, providing quick benefits for the climate as well as public health and agricultural yields. METHANE - 40% emissions reduction potential globally by 2030 AGRICULTURE Improve manure management and animal feed quality Apply intermittent aeration of continuously flooded rice paddies Improve animal health and husbandry by combining herd and health management, nutrition and feeding management strategies Introduce selective breeding to reduce emission intensity and increase production Promote farm-scale anaerobic digestion to control methane emissions from livestock Adopt guidelines on healthy dietary choices FOSSIL FUELS Carry out pre-mining degasification and recovery and oxidation of methane from ventilation air from coal mines Reduce leakage from long-distance gas transmission and distribution pipelines Extend recovery and utilization from gas and oil production Recover and use gas and fugitive emissions during oil and natural gas production WASTE MANAGEMENT Separate and treat biodegradable municipal waste, and turn it into compost or bioenergy Upgrade wastewater treatment with gas recovery and overflow control Improve anaerobic digestion of solid and liquid waste by food industry Upgrade primary waste water treatment Divert organic waste Collect, capture and use landfill gas More control measures

8. Ozone - Air Pollution Information System
Ground-level ozone (O3) is not emitted directly from anthropogenic sources. It is a “secondary” pollutant formed by a complicated series of chemical reactions ...
Ozone (O3) is present throughout the atmosphere although there are concentration peaks at two levels, the stratosphere (15 - 50 km) and troposphere (0-15 km), with the largest fraction and concentrations being in the stratospheric O3 layer ( Royal Society, 2008). Stratospheric O3 is important as it regulates the transmittance of ultraviolet light to the surface of the earth. Hence reductions in stratospheric O3 in polar regions, particularly the Antarctic "ozone hole", are of concern regarding the health effects of exposure to increased levels of UV-B.
9. Ozone & Health - California Air Resources Board
The ozone that CARB regulates as an air pollutant is produced close to the ground level, where people live, exercise and breathe. A layer of ozone high up in ...
What is ozone (O3)? Ozone, an important component of smog, is a highly reactive and unstable gas capable of damaging living cells, such as those present in the linings of the human lungs. This pollutant forms in the atmosphere through complex reactions between chemicals directly emitted from vehicles, industrial plants, consumer products and many other sources. Ozone is a powerful oxidant – its actions can be compared to household bleach, which can kill living cells (such as germs or human skin cells) upon contact.
10. Why are ozone concentrations higher in rural areas than in cities?
Ozone is a secondary pollutant, which means it is not directly emitted by traffic, industry,.. but it is formed on warm summer days by the influence of ...
Ozone is a secondary pollutant, which means it is not directly emitted by traffic, industry,.. but it is formed on warm summer days by the influence of solar radiation on a cocktail of airborne pollutants. These ozone precursors are nitrogen oxides (NOx) and volatile organic compounds (VOC). Traffic is the main source (>50%) of ozone precursors.
11. Ozone - New York State Department of Health
Ground-level ozone (ozone) is the main ingredient in smog. Breathing in unhealthy levels of ozone can increase the risk of health problems like coughing, ...
Ozone Fact Sheet
12. Ozone Pollution: A Major Health Hazard Worldwide - Frontiers
Oct 9, 2019 · The current WHO Air Quality Guidelines for ambient (outdoor) ozone is 100 μg/m3 (~50 ppb) measured as 8-h maximum moving average within a day.
Oxides of nitrogen (NOx) and volatile organic compounds (VOCs) released into the atmosphere can react in the presence of solar irradiation, leading to ozone formation in the troposphere. Historically, before clean air regulations were implemented to control NOx and VOCs, ozone concentrations were high enough to exert acute effects such as eye and nose irritation, respiratory disease emergencies, and lung function impairment. At or above current regulatory standards, day-to-day variations in ozone concentrations have been positively associated with asthma incidence and daily non-accidental mortality rate. Emerging evidence has shown that both short-term and long-term exposures to ozone, at concentrations below the current regulatory standards, were associated with increased mortality due to respiratory and cardiovascular diseases. The pathophysiology to support the epidemiologic associations between mortality and morbidity and ozone centers at the chemical and toxicological property of ozone as a strong oxidant, being able to induce oxidative damages to cells and the lining fluids of the airways, and immune-inflammatory responses within and beyond the lung. These new findings add substantially to the existing challenges in controlling ozone pollution. For example, in the United States in 2016, 90% of non-compliance to the national ambient air quality standards was due to ozone whereas only 10% was due to particulate matter and other regulated pollutants. Climate change, thr...

13. About Ozone - SCDHEC
Ozone is a highly reactive, colorless gas pollutant that is not typically emitted directly into the air by any one source. Instead, ozone is considered a ...
Ozone is a highly reactive, colorless gas pollutant that is not typically emitted directly into the air by any one source. Instead, ozone is considered a secondary pollutant, which means that it is formed through complex chemical reactions of molecules in the air. Specifically, ground level ozone is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) chemically react in the presence of sunlight. While ozone high up in the atmosphere protects us from harmful ultraviolet rays, exposure to high concentrations of ground level ozone can be quite harmful to our health and environment. That is why we say ozone is “good up high, but bad nearby”.
FAQs
Ozone At Ground Level Is Considered To Be A Pollutant? ›
Ozone at ground level is a harmful
They are particulate matter (often referred to as particle pollution), ground-level ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead. These pollutants can harm human health, harm the environment, and cause property damage.
Ground-level ozone is a colorless and highly irritating gas that forms just above the earth's surface. It is called a "secondary" pollutant because it is produced when two primary pollutants react in sunlight and stagnant air.
Why is ozone considered pollution when it is at ground level? ›Ozone damages vegetation and ecosystems by inhibiting the ability of plants to open the microscopic pores on their leaves to breathe. It interferes with the photosynthesis process by reducing the amount of carbon dioxide the plants can process and release as oxygen.
Is ozone at ground level a harmful air pollutant and it is the main ingredient in smog? ›Ground-level ozone (ozone) is the main ingredient in smog. Breathing in unhealthy levels of ozone can increase the risk of health problems like coughing, breathing difficulty, and lung damage. Unhealthy levels can also reduce visibility and cause the air to appear hazy.
What ozone level is ground level? ›Ground-level ozone (O3), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas.
Is ozone a type of pollutant? ›Ozone, an important component of smog, is a highly reactive and unstable gas capable of damaging living cells, such as those in human lungs. This pollutant forms in the atmosphere through complex reactions between chemicals directly emitted from vehicles, industrial plants, consumer products and many other sources.
Is ground-level ozone a criteria pollutant under the Clean Air Act? ›The Clean Air Act requires EPA to set National Ambient Air Quality Standards (NAAQS) NAAQS are currently set for carbon monoxide, lead, ground-level ozone, nitrogen dioxide, particulate matter, and sulfur dioxide. for six common air pollutants (also known as " criteria air pollutants.
Is ozone a toxic pollutant? ›Ozone (O3) is a gas molecule composed of three oxygen atoms. Often called photochemical "smog," ozone is harmful to breathe. Ozone aggressively attacks lung tissue by reacting chemically with it. When ozone is present, there are other harmful pollutants created by the same processes that make ozone.
Which pollutants are most responsible for smog or ground ozone? ›Ground-level ozone (O3) is a major component of smog. It is formed from photochemical reactions with pollutants such volatile organic compounds, carbon monoxide and nitrogen oxides (NOx) emitted from vehicles, and industry.
What pollutants damage the ozone layer? ›- chlorofluorocarbons (CFCs)
- halon.
- carbon tetrachloride (CCl4)
- methyl chloroform (CH3CCl3)
- hydrobromofluorocarbons (HBFCs)
- hydrochlorofluorocarbons (HCFCs)
- methyl bromide (CH3Br)
- bromochloromethane (CH2BrCl)
What is the difference between ground-level ozone and ozone? ›
Unlike stratospheric ozone, which forms naturally in the upper atmosphere and protects us from the sun's harmful ultraviolet rays, ground-level (or tropospheric) ozone is created through the interactions of man-made (and natural) emissions of volatile organic compounds and nitrogen oxides in the presence of heat and ...
Is ground-level ozone increasing? ›Climate connection
Studies suggest that ozone levels today are 30–70% higher than they were 100 years ago. This increase reflects two trends, both of which are connected to climate change. The first trend is a rise in emissions of the chemicals that form ozone.
These six pollutants are carbon monoxide, lead, nitrogen oxides, ground-level ozone, particle pollution (often referred to as particulate matter), and sulfur oxides.
Is ozone a greenhouse gas at ground level? ›Ozone is technically a greenhouse gas, but ozone is helpful or harmful depending on where it is found in the earth's atmosphere.