Every year, children around the world lose millions of healthy life years because of secondhand smoke.
New research presented at the European Respiratory Society Congress in Amsterdam shows that in 2021 alone, exposure to other people’s smoke was linked to the loss of 8.45 million healthy life years among children under 14.
The study was led by Dr. Siyu Dai, Assistant Professor at Hangzhou Normal University in China and Honorary Research Associate at The Chinese University of Hong Kong.
She stressed that there is no safe level of exposure to secondhand smoke, which is a major cause of preventable illness and death.
“It is linked to chest infections, cardiovascular disease, and neurodevelopmental problems and makes asthma symptoms worse,” she explained.
Young children are especially at risk because their lungs are still developing and they cannot control the environments they live in.
Secondhand smoke, also called passive smoking, continues to pose a global health problem. According to the World Health Organization, it causes about 1.2 million premature deaths each year, including around 65,000 children under the age of 15.
Dr. Dai and her colleague Ruiying Jin wanted to go further and measure how many years of healthy life children lose to illnesses caused by secondhand smoke.
To do this, they turned to the Global Burden of Disease Study, which collects health data from more than 200 countries and territories.
A key measure used in the study is the disability-adjusted life year (DALY). One DALY represents a year of healthy life lost, whether through early death or living with illness and disability.
Dr. Dai and her team analyzed data from 1990 to 2021 to estimate DALYs in children caused by secondhand smoke.
They found that in 2021, exposure was responsible for 3.79 million DALYs from lower respiratory infections such as pneumonia and bronchitis, 0.80 million from ear infections, and 3.86 million from other chest infections including tuberculosis.
The impact was far from evenly spread. Children in poorer regions suffered disproportionately. In wealthier areas, the rate of DALYs per 100,000 children was relatively low, but in low-income regions the numbers were dramatically higher. For example, in high-Socio-demographic Index (SDI) regions, rates of lower respiratory infection DALYs were about 7.64 per 100,000 children, while in low-SDI regions they were more than 300 per 100,000.
Dr. Dai pointed to several reasons for this imbalance, including less awareness of the dangers of secondhand smoke, more crowded and poorly ventilated homes, and weaker tobacco control policies. “Children in lower-SDI regions bear a disproportionate share of this preventable health burden,” she said.
The study shows that in 2021 alone, millions of children lost healthy years of life because of exposure to secondhand smoke. Most of these losses were preventable. Dr. Filippos Filippidis, Chair of the European Respiratory Society’s tobacco control committee, said the findings should serve as a wake-up call.
“Children often suffer the most as their lungs are still developing and they cannot avoid smoke in the home,” he said. “We need to do much more to protect children.”
He called for stronger laws to restrict smoking in homes, schools, and public places where children are present, but also emphasized that the most effective solution is reducing smoking overall.
As tobacco companies promote new products like e-cigarettes and heated tobacco, researchers say it is also important to study how secondhand vapors may affect children’s health.
The message is clear: secondhand smoke continues to cause immense harm to children around the world, and urgent action is needed to protect them from avoidable illness and lost years of life.
