Secondhand smoke is dangerous, and about a fifth of Americans are exposed to the carcinogenic byproduct of cigarettes in the workplace, according to a Centers for Disease Control and Prevention report released last week.

Nonsmoking workers living in states without comprehensive smoke-free laws, and those who work in industries such as construction, mining and transportation, have a higher prevalence of secondhand exposure, according to the report.

The American Lung Association ranks Kentucky poorly for inadequate tobacco prevention and cessation funding, smoke-free air laws and a failure to raise the minimum smoking age to 21.

Smoke-free laws, in particular, help reduce secondhand smoke exposure. That can range from smoke-free businesses, schools and parks to smoke-free sidewalks, community events or even public places.

In Bowling Green, city officials banned smoking in city parks, workplaces and enclosed public spaces in 2011. Enforcement of that ban has been limited, with only 25 violations cited since its implementation, according to Bowling Green Police Department spokesman Officer Ronnie Ward.

But those basic protections aren’t present in many adjacent counties, and nearly 28 percent of adults smoke cigarettes in the 10-county Barren River Area Development District, according to the BRIGHT Coalition’s most recent Community Health Assessment.

This has major repercussions for the community.

“Secondhand smoking is almost the same as smoking yourself,” said Dr. Diego Cabrera, a hematologist and oncologist who specializes in lung cancer at The Medical Center at Bowling Green. “You inhale a little less particles, or carcinogens, but you do inhale them.”

Secondhand smoke exposure can lead to heart disease, lung cancer and stroke – and more than 40,000 deaths each year, according to the CDC.

Lung cancer, which is the leading cause of cancer death nationwide, is the most recognized threat from cigarette smoking and secondhand smoke.

“The majority of patients I see with lung cancer are smokers,” Cabrera said, but “about 10 percent of my (lung cancer) patients have never been smokers.”

Lung cancer is but one of a long list of cancers caused by exposure to cigarette smoke. Secondhand smoke harms all areas of the body, and poses threats to everyone exposed.

For children, it can cause sudden infant death syndrome, ear infections, colds, pneumonia, bronchitis and severe asthma, and harms lung development. For pregnant women, it can cause pregnancy complications, poor birth outcomes, preterm deliveries and low birth weights. For adults, it can cause premature death, heart disease, stroke, lung cancer, lung disease, chronic obstructive pulmonary disease, emphysema, asthma and chronic bronchitis, according to the National Cancer Institute.

There’s also thirdhand smoke, which occurs when chemicals from cigarette smoke cling to indoor surfaces like clothes and furniture. Research is still early, but some studies have suggested that thirdhand smoke can damage people’s DNA and potentially cause cancer.

“It’s not as well established as secondhand smoking, but we know it can cause health issues,” Cabrera said.