By Kathleen Doheny
MONDAY, April 19 (HealthDay News) -- Exposure to secondhand smoke appears to substantially raise the risk for chronic sinusitis, a new Canadian study has found.
In fact, it might explain 40 percent of the cases of the condition, said study author Dr. C. Martin Tammemagi, a researcher at Brock University in Ontario.
"The numbers surprised me somewhat," Tammemagi said. "My general impression was that public health agencies were strongly discouraging smoking and controlling secondhand smoke, and that governments in parallel were passing protective legislation to reduce peoples' exposure to secondhand smoke."
But his team found that more than 90 percent of those in the study who had chronic sinusitis and more than 84 percent of the comparison group, which did not have the condition, were exposed to secondhand smoke in public places.
"To see that exposure to secondhand smoke was still common did surprise and alarm me," he said.
The ill effects of secondhand smoke have been well-documented, and experts know it contains more than 4,000 substances, including 50 or more known or suspected carcinogens and many strong irritants, according to Tammemagi.
The link between secondhand smoke and sinusitis, however, has been little studied, he noted. "To date, there have not been any high-quality studies that have looked at this carefully" and then estimated the role that smoke plays in the sinus problem, he said.
In their study, the researchers evaluated reports of secondhand smoke exposure in 306 nonsmokers who had chronic rhinosinusitis, defined as inflammation of the nose or sinuses lasting 12 weeks or longer. The sinuses are cavities within the cheek bones, around the eyes and behind the nose that moisten and filter air within the nasal cavity.
The researchers asked the participants about their exposure to secondhand smoke for the five years before their diagnosis and then compared the responses with those of 306 people of similar age, sex and race who did not have the sinus problem.
Those with sinusitis were more likely than the comparison group to have been exposed to secondhand smoke not only in public places but at home, work and private social functions, such as weddings, the researchers found. For instance, 13 percent of those with sinus problems were exposed to secondhand smoke at home, compared with 9 percent of those without sinus problems. The association held, the study said, even after the researchers adjusted for such potential contributing factors as exposure to air pollution.
About 40 percent of the sinus problems in the sinusitis group appeared to be due to the secondhand smoke, Tammemagi estimated.
And, the more places someone was exposed to smoke, the higher their risk for sinus problems, the study found.
Exactly why isn't known, but it's possible that exposure to secondhand smoke can cause direct irritation to the cells lining the nasal passages, Tammemagi said. The irritation, in turn, "can lead to changes in the permeability [leakiness] of the lining so that bacteria or allergens can pass into the tissues and cause irritation and can suppress the immune system locally in several ways, leading to poor defenses," he explained.
The findings, reported in the April issue of Archives of Otolaryngology--Head & Neck Surgery, are not surprising, said Dr. Jordan S. Josephson, a sinus specialist at Lenox Hill Hospital in New York City and director of the New York Nasal and Sinus Center, who wrote Sinus Relief Now.
"Secondhand cigarette smoke definitely impacts those who are exposed," Josephson said. "Clinically, I see that secondhand cigarette smoke affects patients' lungs and their sinuses the same way that primary smoke affects these vital organs."
The bottom line, he said, is clear but often ignored.
"The take-home message is that smoking cigarettes is not just bad for your health but bad for those people around you, including your loved ones."