Tonight is shaping up to be a particularly challenging New Year's Eve celebration for the 13 percent of the state population who suffer from breathing difficulties.

The National Weather Service is predicting widespread haze, partly cloudy skies and northwesterly winds of just 6 mph tonight — the sort of perfect lull dreaded by people with asthma and other breathing problems as legal and illegal fireworks release lung-troubling particulates into the air.

"When you combine that with air quality that has already been compromised with voggy conditions and the brushfires on the Big Island, it only adds to the degradation," said Jean Evans, executive director of the American Lung Association in Hawai'i. "It's going to be a very difficult night for a lot of people."

The Lung Association estimates that some 175,000 people in Hawai'i suffer from breathing difficulties. In the most serious cases, breathing problems triggered or exacerbated by fireworks smoke can lead to respiratory arrest and even death.

While the organization does not track the number of emergency room visits on New Year's Eve or the Fourth of July, Evans said there is ample anecdotal evidence of Hawai'i residents seeking emergency help for breathing problems whenever fireworks are widely used.

"We understand fireworks sales have been pretty good this year and there are always a lot of illegal aerials and other fireworks that are hard to regulate," Evans said. "It's a hard night to avoid, especially on O'ahu. Hopefully, families and neighbors will be kind to each other and keep in mind those who have breathing difficulties, especially the elderly and the very young."

The state Department of Health will once again be monitoring air quality during New Year's and comparing it to national ambient air quality standards.

Breathing hazards aren't just confined to the limited hours during which fireworks are allowed to be used. In Pearl City, Salt Lake, Pālolo Valley and many other areas of the island, fireworks have been illegally set off weeks, even months, in advance of tonight's celebrations. And, as Evans noted, elevated levels of particulates in the air can continue to bother those with respiratory problems for several days after New Year's, depending on weather conditions.