That’s the most serious warning signaling three consecutive days of severe smog.

严重的雾霾持续了三天，红色是最为严重的警告信号。

A U.S. government source - speaking off the record – said the ICAO report would probably cause the Federal Aviation Administration to review Thailand's flight safety practices. He said the ICAO review results were a serious warning signal for the FAA.

一位美国政府消息人士 - 私下发言 - 表示国际民航组织的报告可能会导致联邦航空管理局审查泰国的飞行安全做法。他说，国际民航组织的审查结果对美国联邦航空局来说是一个严重的警告信号。