"Millions of children are returning to school. While we have been concerned of their safety with regard to COVID, there is another invisible killer which has been affecting children severely that also needs urgent attention."Dr Arvind Kumar, Chairman, Institute of Chest Surgery, at Medanta - The Medicity, Gurugram
From chronic cough, lung damage, and cancer risk, to cardiovascular issues, PCOS, and mental disorders, the list of health issues that can be directly traced back to air pollution keeps growing.
Studies have shown this damage begins even before a child is born.
And yet there are very few studies, particularly in India—home to one of the most populated cities in the world—that comprehensively establishes the impact of air pollution on kids' health.
This changes with a new landmark study which has found strong evidence linking air pollution to a distinctly higher risk of asthma and obesity in kids.
The extensive study published in the journal Lung India compares the health status of adolescent children in Delhi to those of Mysuru and Kottayam to see how the toxic air in Delhi impacts the kids' health in comparison to those in the other cities.
"In Delhi, almost 1 in 3 kids have a prevalence of asthma, nearly three times that of kids in Mysuru/Kottayam. But what we really weren't expecting was the correlation between air pollution and childhood obesity."Dr Sundeep Salvi, Director, Chest Research Foundation (CRF), Pune
Before we dive into what the study found, let's looks at how the study was conducted.
The study was carried out jointly by Lung Care Foundation and Pulmocare Research and Education (PURE) Foundation
For the study adolescent kids between the ages of 13-14 (grade 8) and 16-17 (grade 11) were chosen randomly from private schools in Delhi (3), Mysuru (3), and Kottayam (6).
Participants from Kottayam and Mysuru were chosen to be the control group as these cities are among the least polluted in India.
The test involved questionnaires and spirometry tests
3157 kids were included in the study. Of these 928 belonged to Delhi.
45 percent of the participants from schools in Delhi were girls
61 and 42 percent participants from Kottayam and Mysuru respectively were girls.
What the Study Found
Students in the Delhi schools were found to have a consistently higher prevalence of Asthma and allergy symptoms as compared to school children in Kottayam and Mysuru.
More than half the kids from Delhi had sneezing and nearly half experienced watery eyes. Prevalence of cough, rashes and shortness of breath were nearly 3 times higher in kids from Delhi as compared to Mysuru and Kottayam.
29.3 percent children from Delhi were found to have airflow obstruction or asthma on spirometry as compared to 22.6 precent children in Kottayam and Mysuru.
This was despite the fact that the two other significant variables associated with childhood asthma—family history of asthma, and smokers in the family—were more prevalent in Mysuru and Kotayam.
Diagnosis of asthma was lower in the kids in Delhi, and even less got treatment.
Among the 29.3 percent children observed to have asthma on spirometry in Delhi, only 12 percent reported to have been diagnosed with asthma and only 3 percent used some form of inhalers.
The study also found a huge difference in the prevalence of asthma among boys and girls. But this was recorded in all three cities.
Dr Salvi hypothesises that it might have something to do with hormones, and not so much with pollution.
The study also found that 39.8 percent children from Delhi were obese/overweight as compared to 16.4 percent children from Kottayam and Mysuru.
"We also found that children who were obese had much higher odds of developing asthma," said Dr Sundeep Salvi, Director, Chest Research Foundation (CRF), and one of the co-authors of the study, at the press conference.
Obese and overweight children, the study found, had a 79 percent greater chance of having asthma on spirometry across all three sites combined.
Air pollution seems to perpetuate this link between obesity and asthma as the association was found to be 38 percent higher in kids from Delhi as compared to those in Mysuru and Kottayam.
This is the first time that any study in India has established this link between obesity in children and higher prevalence of asthma.
According to the study authors, particulate matter pollutants like PM2.5 and PM10 are the prime suspects for this connection.
Why the Kids & Why This Study?
According to Dr Kumar, the reason why children are more at risk of health complications from air pollution because "they breathe more than adults, and their lungs have growing tissues. There are many more variables that could impact the health of an adult."
The study authors also point out that it is easier to conduct such an extensive study on children through schools.
The study underscores the urgent need for action.
"This is probably the largest spirometry study conducted in India, and it was logisitcally very difficult as well. It sets the stage for other similar studies in the future which is very important."Prof Parvaiz Koul, Professor and Head, Internal and Pulmonary Medicine, Sher-i- Kashmir Institute of Medical Sciences & Editor, Lung India
Prof Koul also talks about how all parents in Delhi (and cities with similar pollution levels) must b sensitised to the gravity of the situation and just how hazardous the air they're breathing is to their kids' health.
"The observation is of children in Delhi but many cities, particularly in north India have very high levels of air pollution, comparable to that of Delhi. So, although this study was conducted in Delhi, the observations may also be relevant to these other cities."Dr Sundeep Salvi, Director, Chest Research Foundation (CRF), Pune