Nov. 19 (UPI) -- Pollution in China is reaching such critically high levels in places like Hebei Province the Air Quality Index can no longer be used to measure the impact of smog and harmful particles in the atmosphere, according to a South Korean press report.
Television network JTBC reported Monday in Jiuzhou, Hebei Province, the AQI indicated pollution had reached 999, after which measurement is no longer possible.
The AQI is a number used by government agencies to inform the public about air quality.
In China the AQI runs from a scale of 0 to 999. Any measurement greater than 300 indicates a "severely polluted" atmosphere, which can trigger illness even among healthy people.
In China's northeastern Liaoning Province, where many factories are in operation, the AQI reached the 800s, according to JTBC.
Last week 25 Chinese regions were were hit with pollution warnings because ultrafine dust was expected to reach 200 micrograms per cubic meter.
China's meteorological bureau said air quality was deteriorating because the pollution from residential heating was overlapping with deep fog.
China's smog spreads across the region, and affects air quality in South Korea.
The ongoing problem between the two countries was raised during a meeting in Seoul on Monday, Yonhap reported.
South Korean Prime Minister Lee Nak-yeon told Wang Yong, a visiting Chinese politician and state councilor in Beijing, the two countries should cooperate on the issue of fine dust.
Wang was in Seoul to attend the Seoul conference of the 2018 Boao Forum for Asia, a high-level forum for government leaders, business executives and academics held in China earlier this year.