Air pollution

FILE - In this May 16, 2018, file photo, Environmental Protection Agency Administrator Scott Pruitt testifies before a Senate Appropriations subcommittee on the Interior, Environment, and Related Agencies on budget on Capitol Hill in Washington. (AP Photo/Andrew Harnik, File)

FILE - In this May 16, 2018, file photo, Environmental Protection Agency Administrator Scott Pruitt testifies before a Senate Appropriations subcommittee on the Interior, Environment, and Related Agencies on budget on Capitol Hill in Washington. (AP Photo/Andrew Harnik, File)

This May 22, 2018 photo from video from an unpiloted aircraft provided by the U.S. Geological Survey, shows flow from what scientists call fissure 22 as lava from Kilauea Volcano continues to flow into the ocean, top, near the town of Pahoa, Hawaii. (U.S. Geological Survey via AP)

FILE - In this May 16, 2018, file photo, Environmental Protection Agency Administrator Scott Pruitt testifies before a Senate Appropriations subcommittee on the Interior, Environment, and Related Agencies on budget on Capitol Hill in Washington. (AP Photo/Andrew Harnik, File)

In this May 24, 2018 photo from the Federal Emergency Management Agency, lava erupts from a fissure in the Leilani Estates neighborhood near Pahoa on the island of Hawaii. Three lava flows from eruptions of Kilauea volcano are now flowing into the ocean off Hawaii's Big Island. Hawaii County officials say the third flow started pouring into the sea Thursday. Lava is spewing from a fissure in a rural community that's feeding the two other flows that are reaching the waves. (Grace Simoneau/FEMA via AP)

In this May 24, 2018 photo from the Federal Emergency Management Agency, lava erupts from a fissure in the Leilani Estates neighborhood near Pahoa on the island of Hawaii. Three lava flows from eruptions of Kilauea volcano are now flowing into the ocean off Hawaii's Big Island. Hawaii County officials say the third flow started pouring into the sea Thursday. Lava is spewing from a fissure in a rural community that's feeding the two other flows that are reaching the waves. (Grace Simoneau/FEMA via AP)

FILE - The Sept. 29, 2015 photo shows the street sign of the Dieselstrasse (Diesel Street) in Wolfsburg, Germany. The northern German city of Hamburg is going to ban older Diesel cars from two streets to combat air pollution. (AP Photo/Markus Schreiber, file)

A photographer records lava erupting from a fissure in Kapoho, Hawaii Monday, May 21, 2018. The eruption of Kilauea volcano in Hawaii sparked new safety warnings about toxic gas on the Big Island's southern coastline after lava began flowing into the ocean and setting off a chemical reaction. (AP Photo/Jae C. Hong)

FILE - In this Dec. 16, 2009 file photo, steam and smoke rise from a coal burning power plant in Gelsenkirchen, Germany. The European Union is taking six member states to court for exposing their citizens to too much air pollution. The European Commission on Thursday, May 17, 2018 referred France, Germany, Hungary, Italy, Romania and Britain the EU's highest Court of Justice saying they failed to respect air quality limits and did not take appropriate action in time. (AP Photo/Martin Meissner, File)

FILE - This Tuesday, May 24, 2016 file photo shows the former Oakland Army Base pier with the Port of Oakland in the background in Oakland, Calif. A federal judge in California on Tuesday, May 15, 2018, struck down the city of Oakland's ban on coal shipments at a proposed cargo terminal, siding with a developer who wants to use the site to transport Utah coal to Asia. (AP Photo/Eric Risberg, File)