BEIJING, Dec. 16 (UPI) -- Beijing issued a five-day red alert as the year's most severe air pollution enveloped the city.
The alert for Beijing and neighboring Tianjin Municipality came Thursday after readings of over 500 on a globally recognized Air Quality Index were noted; the World Health Organization has said the maximum safe level for humans over a 24-hour period is 25. AQI levels were over 400 in Beijing during two days in November.