Passive smoking equally harmful in increasing lung cancer risk, heart ailments: Study

10 April 2017:

People often think that only addiction and indulgence in smoking makes a person vulnerable to the hazards of tobacco, but, it is not true. The ill-effects of second-hand smoke can be equally detrimental to the health of a person who happens to be present near the smoker, particularly in young children, adolescents and women.

Passive smoking involves inhaling toxic components and various carcinogens, which are present in secondhand smoke. These carcinogens include benzene, benzo[a]pyrene, 1, 3-butadiene and 4-(methyinitrosamino)-1-(pyridyl)-1-butanone with various other harmful components.

A study published in a journal called Carcinogenesis said that passive smokers are at a greater risk of heart ailments and lung cancer. The study was conducted by the Icahn School of Medicine at Mount Sinai in New York City.The research mainly focused on finding a precise way to calculate the exposure of second-hand smoking instead of making patients fill in questionnaires.

“A crucial finding of this study is that nonsmokers are exposed to secondhand smoke without even realising it,” said Dr. Raja Flores, the lead researcher and chairperson of thoracic surgery at the Icahn School of Medicine.

Over 20,000 non-smokers were a part of this study. The researchers calculated the blood levels of cotinine as an indicator of exposure to second-hand smoking. Cotinine is a byproduct of nicotine.

The researchers observed a noteworthy rise in the years of life lost. The highest levels of cotinine were associated with 7.5 years of life lost, while the lowest levels were associated with 6.5 years of life lost. According to the researchers, the spiked cotinine levels also make one prone to all types of cancers, including lung cancer and cardiovascular diseases (CVD). The researchers couldn’t establish any cause and effect relationship with the findings.

“Questionnaires show that responders do not know they were exposed to smoke, but cotinine blood levels are more accurate in determining their exposure and subsequent risk of lung cancer and other smoking-related disease,” Flores stated in a school news release.

Apart from revealing about the reduction in life expectancy, the study emphasised on stricter smoking restrictions and preventive measures to people who have been exposed to second-hand smoke.

“Using cotinine level to measure exposure to secondhand smoke has important public health implications, because increasing the scope of smoke-free environments would likely decrease cotinine levels in the general population, and ultimately death,” Dr. Emanuela Taioli, the director of the Institute for Translation Epidemiology at Mount Sinai said.

“Exposure to secondhand smoke is unequally distributed in the population. Children, non-Hispanic blacks, people living in poverty and those who rent their housing are disproportionally affected and most vulnerable,” Taioli added.