London, Amid the spike in air pollution in Delhi-NCR, a new study has found that early-life events, such as the exposure to air pollutants, increase the risk of chronic lung disease in young adulthood.

The findings, published in the European Respiratory Journal, add to the growing evidence that chronic lung disease in adulthood can be traced back to childhood.

Chronic bronchitis and chronic obstructive pulmonary disease (COPD), with the hallmark features phlegm and irreversible airflow limitation, respectively, are lung diseases known to affect adults with a history of long-term smoking.

"We found the prevalence of chronic bronchitis and irreversible airflow limitation to be rather high considering the young age of the study participants." said study senior author Erik Melen from Karolinska Institutet in Sweden.

"Those diseases are usually diagnosed in patients older than 50 years of age," the researchers wrote.

In the present studies, the researchers used data from birth up to age 24 years from the follow-up of the Swedish population-based birth cohort 'BAMSE', which includes 4,089 participants from the Stockholm area recruited 1994-96.

Analyses performed by the research team showed that smoking, as well as early-life air pollution exposures and childhood asthma, are risk factors for chronic bronchitis, whereas breastfeeding was identified as a protective factor.

In addition, the early-life risk factors for the development of irreversible airflow limitation were recurrent lung infections, asthma, and exposure to air pollution.

"The levels of air pollutants in the current study mainly reflect local emissions from road traffic, which implies that this preventable risk factor may play an important role in the development of chronic lung disease in young adults," the authors wrote.

Given that air pollution levels in Stockholm are comparatively low by international standards, this makes the current findings very important in a global context.

And despite the young participants' age, active smoking was linked to chronic bronchitis, which underlines the negative health effects from even a limited period of exposure to tobacco smoke.

"In conclusion, our two novel studies demonstrate that chronic bronchitis and irreversible airflow limitation do exist in young adults and emphasize the importance of early-life events for maintaining lung health during adulthood," the study authors noted.