An earlier version of this story stated that Wareham ranks No. 1 among Massachusetts towns in incidences of lung cancer. The source of that information subsequently corrected herself to say that the No. 1 ranking was based on 1999-2003 data. As of 2007, Wareham ranks No. 3.

Massachusetts is often touted as one of the healthiest states in the union. Last year, the United Health Foundation ranked the Bay State as the second healthiest in the nation behind Vermont. Its residents are among the least likely to smoke, and as a state, Massachusetts boasts the third lowest smoking rate in the nation. However, those numbers are not reflected in Wareham.

Wareham ranks third in the state for incidence of lung cancer in towns with more than 20,000 residents, according to Mark Paskowsky, a Research Analyst from Seven Hills Behavioral Health Tobacco-Free Community Partnership. Revere rates the highest, followed by Billerica.

Of the estimated 20,000 people who live in Wareham, about 4,000 of them are smokers. That is 37 percent higher than the rest of the state.  Almost a quarter of all adults in Wareham regularly light up, according to the Massachusetts Department of Public Health Tobacco Cessation and Prevention Program.

Men are the most likely to be affected. Mortality from lung cancer is 25 percent higher among males in Wareham compared to the rest of the Bay State. The number of hospitalizations due to lung cancer is more than 20 percent higher for men in Wareham.

“The numbers are alarming,” said Judith Coykendall, program manager at Seven Hills Behavioral Health Tobacco-Free Community Partnership.

Perhaps the most shocking statistic is the rate of smoking during pregnancy. Wareham ranks a whopping 174 percent higher than the overall state average, with 20.3 percent of expectant mothers lighting up.

Studies have shown there is a direct link between a person’s level of education and socioeconomic background to their likelihood of picking up the habit.

“Higher smoking rates are linked to environment indications,” Coykendall explained, noting that people who do not attend college and face economic struggles are more likely to begin smoking. Stress, she added, is the biggest contributing factor to why people continue to light up.

The link between a demographic's socioeconomic status and the likelihood of them picking up the habit is evident in the numbers. In the blue-collar city of Revere, the adult smoking rate is 50 percent higher than the statewide average, compared to upscale Wellesley, which has among the lowest incidence of lung cancer and is 67 percent lower than the state average.

Nearly 85 percent of lung cancer cases are a result of smoking, according to the state Department of Health.

“We treat lung cancer in non-smokers as a different disease,” said Dr. Elizabeth Blanchard, an oncologist who specializes in lung cancer at Southcoast Hospitals. The prognosis for stage four lung cancer in smokers is about nine months with medication, versus a-year-and-a-half for non-smokers with the same diagnosis, she explained.

While most people associate smoking as the cause of lung cancer, there are other factors that account the disease. Tumors caused by genetic mutations over time are the most likely cause for the remaining 15 percent of cases, according to Blanchard.

Worldwide, lung cancer is the most common cancer in terms of both frequency and mortality. “Lung cancer is the number one cause of cancer related deaths,” Blanchard noted. “More women died from lung cancer than breast cancer.”

Quitting sooner rather than later makes a difference, Blanchard said. After a few weeks of being cigarette-free, former smokers will notice they have an easier time breathing and lower blood pressure. Studies show that if a smoker quits by the age of 30, they are 90 percent less likely to die from a smoking-related death. Even at age 50, quitting will reduce those chances by 50 percent.

It appears that Wareham smokers are trying to quit. Since MassHealth coverage of Quit Works, a tobacco cessation program, began in July 2006, 521 Wareham smokers have used the benefit. Additionally, the Massachusetts Smokers’ Helpline indicated that 271 people from Wareham called between 2004 and 2009 for cessation help.

Top 10 highest  lung cancer rates in Massachusetts towns and cities:

1. Revere

2. Billerica

3. Wareham

4.Taunton

5. Wilmington

6. Marshfield

7. Dracut

8. Randolph

9. Tewksbury

10. Salem