Heavy smog, worsened by weather, raises alarm across Asia

BANGKOK (AP) — Unusually high levels of smog worsened by weather patterns are raising alarm across Asia.

In Bangkok, a combination of construction dust, auto exhaust and other pollutants has taken air quality to unhealthy levels in recent days.

The Thai Pollution Control Department said Monday that a low pressure system was partly to blame, leaving the smog concentrated over the country's biggest city. A department official said about half of the high levels of PM 2.5, tiny particulate matter that can dangerously clog lungs, was due to diesel engine emissions.

In South Korea, the ultrafine dust levels prompted emergency measures to reduce the health hazard.

Pollution often is out of control by the time countries take action. India's cities are among the smoggiest and it is just starting to tackle the problem.