Light winds and the heavy use of fireworks led to some of the worst air quality levels on O'ahu and Maui on New Year's Day, according to the Department of Health.

The air quality was worse than New Year's 2009 and exceeded the federal 24-hour standard for fine particulates at several locations, the Health Department reported. Monitors at these locations showed that the air pollution increased at about midnight when revelers burned fireworks to ring in the new year and began to subside at about 3 a.m., the department said.

The Clean Air Branch monitored air quality at stations at Honolulu, Sand Island, Pearl City, Kapolei and Kīhei on Maui. Over a 24-hour period, particulate matter in the air exceeded federal standards at the Honolulu, Pearl City and Sand Island locations, the department said.

On a typical day, the particulate matter at the Honolulu station ranges from 4 to 15 micrograms per cubic meter. But on Jan. 1, the Honolulu monitor averaged 62 micrograms per cubic meter, with a high of 632 recorded at 2 a.m., the department said.

Fireworks smoke consists primarily of particulate matter, which can penetrate the lungs and aggravate respiratory conditions. With the Islands already experiencing hazy conditions because of light southerly winds, the heavy use of fireworks worsened the air quality, the department said.