NEW YORK — Smoke from Canadian wildfires spreading to the United States has caused an increase in the number of people with asthma going to emergency rooms, particularly in the New York area.

The U.S. Centers for Disease Control and Prevention on Thursday released two studies on the health effects of smoke, which blanketed city skylines in an orange haze in late spring. A medical journal also published a study this week.

When air quality deteriorates, “an asthmatic feels it before anyone else,” said Dr. Adrian Pristas, a pulmonologist in Hazlet, New Jersey, who recalls a string of patient calls in June during the smokiest days.

People with asthma often experience wheezing, shortness of breath, chest tightness, and coughing at night or early in the morning.

“I have no doubt that all asthmatics had an increase in their symptoms,” Pristas said. “Some were able to get by on their own, but others had to ask for help.”

Each of the studies focused on different geographic areas: one was national, another specific to New York State, and the last focused on New York City.

Nationally, asthma-related ER visits were 17% higher than normal during the 19 smoky days of wildfires between late April and early August, according to a CDC study which pulled data from some 4,000 US hospitals.

Hospital traffic increased more dramatically in some parts of the country during wildfire smoke: 46% more in New York and New Jersey.

A second study published by the CDC it focused only on New York State, not New York City, because the state and city have separate hospital databases, one of the authors said.

She revealed that asthma-related ER visits increased 82% statewide in the day with the worst air quality, June 7. The study also indicates that central New York State had the largest increase in emergency room visits, more than doubling.

the third study, published by the American Journal of Respiratory and Critical Medicine, focuses solely on New York City. A more than 50% increase in asthma-related emergency room visits was seen on June 7, said study lead author George Thurston of New York University.

None of the studies looked at other measures of health, such as increased heart attacks or deaths.

Smoke from wildfires contains tiny particles, called PM2.5, which can lodge deep in the lungs and cause serious problems for asthmatics. But as problematic as wildfire smoke is, an analysis showed it contained lower amounts of some toxic elements found in urban air pollution, Thurston said.

The third study also tried to compare the increase in ER visits during wildfire smoke with what happens at the height of a poor pollen season, with wildfires driving about 10% more ER visits. .

“It’s reassuring. It may not have been as bad as it looks,” Thurston said.

Jeffrey Acquaviva, a 52-year-old asthmatic from Holmdel, New Jersey, found this conclusion difficult to accept.

“Yes, of course,” said Acquaviva, who works in a family construction business.

As the smoke intensified in June and the air in her garden turned thick and “golden,” Acquaviva changed the filters on her air conditioners and stayed indoors for two and a half days.

His symptoms worsened further (his breathing was dangerously labored) and he was eventually taken by ambulance to a hospital where he remained for three days.

Pristas, Acquaviva’s doctor, recalled how overwhelming the smoke was: “There was nowhere to hide.”