Rail traffic is a major contributor to global pollution, according to a new study.
The report from the Stockholm Environment Institute and the University of California, Berkeley found that the train industry accounts for about 10 percent of global air pollution, with a staggering 70 percent of it being from trains.
That makes the train the second-leading contributor to air pollution in the world, behind coal-fired power plants.
The study, “The Rail Industry and Global Air Pollution,” was released Wednesday, and was based on data from air quality monitoring stations in the United States and China.
The study found that between 2010 and 2020, there were 3,400 air quality incidents, an increase of nearly 5 percent.
This trend is not expected to continue, the report said.
In a report released in November, the World Health Organization said the U.S. is the second most polluted country in the World.
China, which has the world’s largest railway network, is the fourth-most polluted country, behind Russia, Japan and the U., according to the World Bank.
The Institute also released a report this month that found that China has surpassed the U, as the country has more than doubled its annual emissions of carbon dioxide.
The institute found that trains account for about 40 percent of all emissions of CO2 from vehicles in the U (or 3.2 billion metric tons).
That is the highest of any country.
According to the report, the U has increased its coal-to-gas emissions by 10 percent over the past five years.
The rail industry is also responsible for the majority of global CO2 emissions, but its emissions have dropped slightly since 2010.
China, for instance, has reduced its coal emissions by almost 20 percent since 2010, according the report.
The trains, however, are responsible for nearly 50 percent of the global air quality pollution.
The transportation sector, which includes all freight and passenger transportation, accounts for 60 percent of emissions of nitrogen oxide (NOx), a pollutant that is linked to lung cancer, heart disease, and other health effects.