4.5 billion — that’s how many people around the world today are exposed to levels of air pollution that are at least twice what the World Health Organization (WHO) considers safe. And until now, the impact of prolonged exposure to pollution on a single person’s life expectancy has remained largely unanswered.

Now, this information has become publicly available. And it might shock you.

In a new report published in the Proceedings of the National Academy of Sciences journal, researchers from around the world have created a map based on findings that show, depending on where you live, just how many years of life air pollution is stealing from you.

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“It suggests that particulates are the greatest current environmental risk to human health, with the impact on life expectancy in many parts of the world similar to the effects of every man, woman and child smoking cigarettes for several decades,” Michael Greenstone, an author of the paper and director of the Energy Policy Institute at the University of Chicago, explained in a statement.

Greenstone and his colleagues measured populations exposed to PM2.5, a hazardous particulate matter and global indicator for air pollution, and compared the data to mortality rates over the last couple of years.

As it turns out, in some countries pollution can shave quite a lot time off a person’s life. Here’s what the study found:

China — 3.5 Years Lost

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Some of you might be thinking: “no surprise there.” There have been numerous examples of heightened air pollution in China, including the horrible 33-car pileup in 2015 caused by thick pollution.

But what startled researchers is that compared to the country’s southern region, the concentration of pollution in northern areas, which includes the capital of Beijing, is around 50% higher. The findings concluded that life expectancy is about 5.5 years lower in those northern cities.

The disparity comes down to the well-intentioned, but ultimately, it appears, deadly, Huai River Policy, instated between 1950 and 1980, under which the government provided free coal during the winter season for indoor heating in households north of the Huai River.

Since then, the policy has caused 500 million residents of Northern China to lose more than 2.5 billion life years of life expectancy, according to a 2013 study.

China has been making moves toward cleaner air, investing heavily in renewable energy, switching out fossil fuels, subsidizing electric vehicles, and punishing firms that violate air pollution laws.

India — 4.01 Years Lost

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This may seem bad, but for someone living in the capital, New Delhi, things are even worse. In New Delhi, air pollution can cut a person’s life by nearly a decade, the study found.

While the dangerous particle, PM2.5, has stabilized in China over the past few years, in India, levels have sharply increased.

Between 1990 and 2015, India’s rapidly worsening air pollution has caused about 1.1 million people to die prematurely, officially surpassing China’s pollution as the world’s deadliest.

As India tries to industrialize, “the idea that policy making should be led by government is lacking,” Bhargav Krishna, manager for environmental health at the Public Health Foundation of India, a health policy research center in New Delhi, said in an interview.

As a matter of fact, the country of 1.3 billion people has yet to undertake sustained public policy initiatives to reduce pollution, according to Gopal Sankaranarayanan, an advocate of the Supreme Court of India. Weak environmental regulations in India, he explained, leave citizens with few alternatives other than to petition the courts to take action to protect public health.

Chile — 1.37 Years Lost

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Renown for its clouds of smog, Chile is one of the world’s most polluted countries, according to the country’s Environmental Ministry. Booming factories and growing city centers paired with the country’s geographic location are at fault here.

Santiago, for instance, is nestled in between two mountain ranges which creates a stale air pocket in the valley with minimal ventilation. In 1996, the city’s air quality was so bad that influenza spread rampantly, sending about 3,500 children to the hospital daily.

Conditions have continued to worsen and in 2015, the Environmental Ministry declared an environmental emergency, partially shutting down the city. More than 1,300 factories and 80% of the Santiago’s 1.7 million cars ceased operation, sending over 6 million underground to commute using the subway system.

Since then, transportation has been reduced by 40% in order to slash toxic emissions and improve the life expectancy of Chile’s population, which has lost nearly two years overall.

Democratic Republic of the Congo — 1.84 Years Lost

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The Democratic Republic of Congo (DRC), particularly rich in natural resources, has had a long history of extensive mining. That exploitation, coupled with traffic congestion, poor road maintenance, and inadequate infrastructure, is the reason millions across the country have lost nearly two years in their life expectancy rate.

Research released in 2016 by Centre for Research on Multinational Corporations revealed that serious environmental pollution, as well as human rights violation, were still occurring in 2016 as a result of cobalt mining, making water, “unfit for human consumption and agriculture.”

The country has the greatest extent of tropical forests in all of Africa and in 2005, the government received a $90 million grant from the World Bank to help it police and protect its forests. The DRC, however, still has a long way to go to develop sustainable environment plans.

The United States and other developed countries aren’t in the clear, either.

For cities like New York and Los Angeles, air pollution is also a problem. According to the Air Quality-Life Index, high levels of the pollutant, PM2.5, have shortened lifespans in New York by one month. In Los Angeles, that figure is eight.

Researchers argue that in the case of Los Angeles, people would live much longer if the city complied with the Clean Air Act.

“The Clean Air Act has made a vast difference in the quality of the air we breathe,” Greenstone said in a statement, “and in the length of our lives.”

Read More: Almost 1 in 7 Children Is Breathing Toxic Air Right Now

Similarly, in some European countries, strict environmental regulations have yet to be enforced.

Poland, which recently broke records in its southern city of Skala for surpassing Beijing’s level of pollution, has become the smog capital of Europe. In Italy, pollution-related deaths are on the rise, and reached a toll of 84,000 in 2012.

Both countries’ pollution levels, the report found, have reduced lifespans by about a year.

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“The histories of the United States, part of Europe, Japan and a handful of other countries teach us that air pollution can be reduced,” Greenstone added. “But it requires robust policy and enforcement.”

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