A University of Maryland economics professor was a commissioner and co-author of a report that linked pollution to nine million — or 1 in 6 — premature deaths worldwide in 2015.

The report — published in the medical journal The Lancet — also found that exposure to various types of pollutants, such as air pollution and unsafe water sources, is one of the largest risk factors for premature death, said Maureen Cropper, the report commissioner and the chairwoman of this university's economics department.

In 2015, about 6.5 million deaths were due to air pollution, which includes household air pollution and outdoor air pollution, according to the report. Water pollution caused about 1.8 million deaths and workplace-related pollution, which includes exposure to asbestos and other types of carcinogens, caused 800,000 deaths.

Logan Kline, a junior environmental science and policy major, said she was not surprised by the findings of the report.

"Pollution is such a big problem and it seems like it would be easy to solve, but if you are thinking of all of the pollution emitted throughout the world it's not being addressed fully at all," said Kline, a member of the University Sustainability Council.

Ninety-two percent of pollution-related deaths occurred in low and middle income countries, the researchers found. The countries impacted the most are the ones going through massive development. India and China had the highest deaths due to pollution in 2015, with 2.5 million deaths, and 1.8 million deaths, respectively.

"In the U.S. and Europe there have been huge strides in controlling outdoor air pollution over the years, but in other lower income counties that's not the case," Cropper said. "Failure to control emissions, such as coal burning in India and China, cause significant heath problems like lung cancer."

More than 10 organizations sponsored the report, which had $550,000 in direct funding, said Elena Rahona, who works at Pure Earth, one of the sponsors. Other sponsors include the European Union, the UN Industrial Development Organization and the Swedish Ministry of Environment and Energy.

The report, which more than 40 individuals researched for two years, also highlighted the economic effects of these premature deaths.

"If someone dies prematurely, the output they would have produced for that country's gross national product is then not produced," Cropper said. "We tried to calculate the effects of that."

The gross domestic product for low-income countries lost due to premature deaths is between 1.3 percent and 1.9 percent in output, according to the report. It also mentioned healthcare spending on pollution-related diseases disproportionately affects lower income countries. In Sri Lanka, air pollution-related diseases alone accounted for an estimated 7.4 percent of health spending.

Researchers also calculated what actions people in 2015 would take to reduce their chances of premature death from pollution. Some examples of this include working safer jobs or purchasing medicine to stop the health effects of pollution, according to Cropper. The total amount calculated was $4.6 trillion.

Cropper said there are ways to potentially lower the number of pollution related deaths in the future. She said the first step is to limit pollution from large stationary sources, such as power plants and factories, and for transportation as well. Cropper also suggested low and middle-income countries should use methods that have already been developed and tested by high-income countries, since they have proven to be effective.

"I think as a university we are definitely taking the right steps to lower our pollution output," Kline said. "Back in 2005, the university decided to lower its emissions by 50 percent before 2020 and have zero emissions by 2050 — we have gone down about 28 percent since then."

Limiting pollution can also have an economic benefit on countries as well: Every dollar invested to control ambient air pollution in the U.S. not only improves health, but also yields an estimated $30 in benefits, according to the report.

"I have worked in environmental heath for decades, so these findings don't surprise me," Cropper said. "They are things people in the environmental health field have known about for years, but bringing this to the attention of the broader public health community is very important and I believe this research has done exactly that."