False-color image of ozone concentrations above Antarctica on Oct. 2, 2015.
NASA/Goddard Space Flight Center
Earth's ozone layer shields us from harmful ultraviolet radiation. Nations have been working to reduce ozone-depleting chemicals since the 1980s, but recent studies show that there is still work to do.
Rush hour on the Hollywood Freeway, Los Angeles, September 9, 2016.
AP Photo/Richard Vogel
Air pollution could be the next battleground between California and the Trump administration, which is reviewing the Golden State's special legal authority to regulate tailpipe emissions.
When present in the lowest atmospheric layer – the troposphere, 8-14 kilometers above earth – ozone becomes a concern for human and plant health.
When present in the lowest atmospheric layer, ozone becomes a concern for human and plant health.
What if air quality standards were decided not by governments but by a dedicated federal body?
AAP Image/Dan Peled
Environmental and health groups have called for the creation of a non-political federal agency with the power to rule on pollution levels - much like the Reserve Bank does for interest rates.
A woman walks past a Mahindra e2o electric car during a media preview in Bengaluru.
There is a rapid shift in production of electric cars all over the world. But how will it benefit ordinary people?
A trash truck discharges solid waste at the South East Reserve Recovery Facility’s refuse storage pit in Long Beach, California, August 24, 2010.
AP Photo/Damian Dovarganes
Most Americans don't want incinerators in their neighborhoods, so waste management companies are burning trash in other facilities such as cement kilns. Is this a sustainable way to deal with garbage?
Free public transport could be one way to get more people to ditch the car.
We need to measure the volatile compounds that waft off the products in our homes and offices.
A surprising study published in Science found that as fuel emissions drop, consumer products are playing a larger role in air pollution.
Because of Hurricane Harvey, refineries and other facilities released 2,000 tons of pollutants.
AP Photo/LM Otero
An analysis of air pollutants from Texas shows how significant – and largely underregulated – the category of 'excess' emissions is across the US.
Times Square traffic jam.
New York soon may charge a fee to drive into central Manhattan as a way of reducing traffic and raising funds for public transit. An urban scholar says this step is overdue in the United States.
Artists impression of the purification tower.
SCMP / handout
China has built a skyscraper-sized purification tower. But it will only clean perhaps 0.01% of the air in the 'atmospheric box' sat over a city.
When a house is better sealed, the quality of ventilation becomes more critical.
Our health depends on the quality of air indoors, where most of us spend 90% of our time. The easiest solution is to open a window, but what if that's not an option?
If you’re taking a walk, go to the park instead of walking near cars.
The beneficial effects of walking are reduced by the detrimental effects of inhaling polluted air.
A pall of inaction and apathy hangs over Delhi’s reaction to its air pollution crisis.
While India struggles for answers to its urban air pollution crisis, Beijing is moving forward with strong resolve and effective policy.
Gates of the Arctic National Park, Alaska. Plants on the Arctic tundra absorb mercury from the air, then transfer it to soil when they die.
How do mercury emissions from industrialized countries reach the remote Arctic? Recent research shows that plants on the tundra absorb mercury vapor through their leaves, then pass it into soil.
Rajat Gupta / EPA
Winter has once again brought severe air pollution to the Indian capital.
Flames and smoke shroud State Route 33 as a wildfire burns in Ventura, California, Dec. 5, 2017.
Daniel Dreifuss via AP
Intense wildfires in southern California are triggering air quality alerts. Health experts know surprisingly little about how inhaling smoke affects human health, especially over the long term.
Pacific seabirds, such as this Great Blue Heron, can accumulate mercury in their bodies from the fish they eat.
Mercury levels in seabirds living off the coast of British Columbia have been stable in recent years. New research suggests that this may be due to changes in their diet, not pollution control.
Widnes, England, during the late 19th century.
Researchers have found a way to measure the impact of air pollution during 19th-century England on the public's health.
Fracking has led to an increase in truck traffic, one of the reasons for worsening trends on air quality in areas with oil and gas drilling.
AP Photo/Charles Rex Arbogast
The fracking boom has led to a large increase of hydrocarbon emissions in rural areas, reversing some regional air toxics trends.