Sights of smoggy streets and dirty air are typical in India, where pollution levels remain among the worst in the world.
Poor infrastructure, rapid industry growth and crop burning are widely recognized by environmental experts as contributors to the problem. But what was recently discovered in an Associated Press investigation is that U.S. oil refineries could also be key players in contributing to poor air quality overseas.
Petroleum, commonly known as petcoke, is the byproduct of Canadian oil sands. Typically found at the bottom of oil barrels, petcoke is often used as a cheap alternative to coal. Since it contains much more sulfur and carbon than coal, U.S. companies largely abandoned the use of the waste product when cleaner natural gas made its debut.
Unable to sell the dirty fuel domestically, US.. companies such as Oxbow Energy Solutions and Koch Carbon are finding markets for the product thousands of miles away -- in places like India.
"When petcoke leaves refineries and eventually makes its way to third world countries, it is burned as a coal substitute. It actually makes dirty coal plants dirty."
Because of its pollutant-ridden composition, petcoke doesn't have the best reputation in the U.S. Some scientists even say it could be jeopardizing the planet in addition to people's health. The Environmental Protection Agency warned that the inhalation of petcoke particles could affect the heart and lungs "and cause serious health effects."
According to the investigation, the U.S. sent more than 8 million metric tons of petcoke to India in 2016. For some perspective, that could fill the Empire State Building eight times.
Lab tests on imported petcoke used near New Delhi discovered that it contained 17 times more sulfur than the limit set for coal, and a staggering 1,380 times more than for diesel, according to India's court-appointed Environmental Pollution Control Authority.
"We should not become the dustbin of the rest of the world. We certainly can't afford it. We're choking to death already," said Sunita Narain, director of the Delhi-based Center for Science and the Environment.
Pollution-related health issues have become somewhat widespread in India, particularly among the younger generations. Dr. Sai Kiran Chaudhuri, the head of the pulmonary department at Delhi Heart and Lung Institute, explained that about 50 percent of children in the area exhibit abnormalities in lung functions.
But trading companies see the petcoke very differently -- as a valuable resource that would have otherwise gone to the waste side. The American Fuel and Petrochemcial Manufacturers, a petroleum industry trade group, described just that in a released statement, saying that the U.S. "export[s] petroleum coke to more than 30 countries to meet growing market demand."
In many ways, overseas demand for petcoke helped revive the industry. The demand for petcoke, which was traditionally used to make aluminum and steel, declined after mills began to close. The changing landscape was compounded when other industries began to make the transition to natural gas, instead of investing in costly upgrades to control petcoke's pollutant emissions.
According to Global Market Insights, Inc., the global demand for petcoke is expected to surpass $25 billion by 2024.
"You have, rightly so, strict guidelines of the use of petcoke in the United States because you're worried about pollution, as you must be," Narain said. "But that doesn't mean that India should import all the dirt and the garbage of the rest of the world."
India's government denies that petcoke threatens public health, but the country's Supreme Court banned its use by some industries in areas surrounding New Delhi.
The Associated Press contributed to this report.
Check out these other Circa stories:
Christmas markets across the globe continue to thrive despite ISIS terror threats
The Karni Mata Temple in India is known for one thing: rats
This artist received a heart from a drug overdose victim. Now she's painting Michelle Obama’s portrait.