Every person, rich or poor, has to breathe the air, and in New York City this cocktail has long been known to be polluted enough to cause premature death.
Two studies published in the Lancet last month reiterate this unfortunate truth by analyzing the past two decades worth of satellite photos of air pollution caused by burning fossil fuels over 13,000 cities worldwide — and the corresponding local health data.
New York City and some other metropolitan areas have significantly lowered their emissions through more stringent air quality regulations, but it isn’t low enough, experts said, to prevent severe health consequences such as asthma, especially for city kids.
“Just to reiterate, these are preventable cases of asthma,” said Susan Anenberg, an associate professor of environmental and occupational health at George Washington University who co-authored both air pollution studies. “So these are cases of asthma among children that will affect them through the course of their lives and their parents, and they are preventable by reducing transportation-related air pollution.”
The first study focused on the most dangerous of these pollutants, according to Anenberg: particulate matter that’s smaller than 2.5 millionths of a meter, known as PM2.5. The designation is a catch-all for solid or liquid particles of this size that are released in the air, which happens anytime fuel is burned. They are so small, they can only be seen with a microscope. It’s mostly made up of sulfate, nitrates, ammonia and black carbon, all of which negatively affect human health – from causing burning eyes to exacerbating blindness and cancer.
The biggest urban source for this pollutant is traffic, especially big diesel trucks and buses. People who live near New York City airports are often exposed to high levels of PM2.5 due to cars moving around travelers as well as emissions from planes.
This particulate matter causes the greatest disease burden – cancer, stroke and heart disease. These particles can penetrate the lungs and enter the bloodstream. PM2.5 exposure was found to decrease life expectancy by one year in the European Union and by nearly two years in Asia and Africa, where air pollution is worse. If countries met the World Health Organization’s air quality guidelines, life expectancy could increase by up to one year.
“We even have increasing evidence for associations with early birth, preterm birth and low birth weight, as well as cognitive decline,” Anenberg said. “It’s a pollutant that affects every organ, and I think we’re probably only scratching the surface with the health outcomes that we considered.”
The New York City metropolitan-area has cut its PM2.5 pollution by 40% over the last 20 years with stringent regulations and enforcement from the state’s aggressive air pollution control program, which regulates permitting and imposes emissions limits. Federal law requires states to submit plans and prove that they are lowering emissions to meet the National Ambient Air Quality Standard. The metropolitan area is now well below the national average, but its levels are still nearly double the World Health Organization’s limits for a safe environment.
Children are most at risk, according to Illias Kavouras, an environmental health sciences professor at the City University of New York School of Public Health, who wasn’t involved with the studies.
“There is no safe threshold,” Kavouras said. “Government policies and regulations have brought down the levels of PM2.5 pollution, but they are still at levels where they can cause significant damage, particularly in children because they are still developing their respiratory systems.”
Found alongside PM2.5, nitrogen dioxide is a dangerous pollutant ubiquitous in city life, and the focus of the second study. Anenberg said that it not only exacerbates pediatric asthma but has been found to cause it. Kavouras said early and prolonged exposure physically alters the structure of a child’s lungs as they develop.
This highly reactive gas is emitted from power plants and burning fuel in cars. When it interacts with water and oxygen, acid rain can form, which can harm the ecosystems of waterways and forests.
New York City cut its nitrogen dioxide emissions by more than half, still slightly above WHO’s acceptable levels. But the unsettling dangers of nitrogen dioxide for Kouvaras is that it stimulates ozone production, the smog that often surrounds cities and makes it difficult to see.
Hot sunny days in the city, such as one of the 17 days last summer when temperatures hit 90 degrees or higher, coupled with traffic and power plant emissions make ripe conditions for ozone. From June to August 2021, one-third of the recorded outdoor concentrations of ozone published by the New York State Department of Environmental Conservation for Manhattan were above the EPA’s National Ambient Air Quality Standard of 0.07 parts per million.
Inhaling ozone can damage lungs, and even low levels can cause chest pains, coughing and shortness of breath that affect healthy people, too. Those who exercise while exposed to ozone can increase the amount inhaled. The American Lung Association, an advocacy group that promotes lung health through research and education, gave New York City an F grade for ozone pollution, based on the number of days of elevated levels.
With a failing grade, New York City fares better than most cities. Worldwide, nine out of 10 people live in places where the air is polluted beyond WHO standards. Lowering these air pollutants is the only way to combat their associated health and environmental impacts, said Anenberg. She hopes the studies can provide information relevant to policymakers to make more informed decisions about stronger air pollution controls and designing cities better to move people around within them.
“The more fuel we burn, the more air pollution we have, the more greenhouse gases we have, the more heat we have,” Anenberg said. She added that by increasing public transportation and recreational trails for walking and cycling instead of roadways for our vehicles, not only would we reduce air pollution we would make our cities a more pleasant place to live.