A new report, titled “PM2.5 in ecologically different districts in India: characteristics and health effects,” has revealed that around 75% of adolescents aged between 14 and 17 years in east Delhi complained of breathlessness.
The health survey was conducted among 2,427 participants based in six different districts: Ludhiana (industrial), east Delhi (megacity), Vishakhapatnam (coastal), Patiala (agricultural biomass burning), Panchkula (PM2.5 attained- city), and Jaisalmer (desert).
According to the study, prepared by The Energy and Resources Institute (TERI) and supported by the Shakti Sustainable Energy Foundation, PM2.5 mass concentration had crossed the regulatory daily limit of 60 micrograms per cubic meters for the five districts, except Panchkula.
In the study, heavy metals were identified as major components of PM2.5 characteristics that may result in potential health effects under prolonged exposure.
A health survey on a study group of adolescents from Kendriya Vidyalayas in the age category of 14-17 years (mainly from Classes IX-XII) in the six districts was conducted between June 2019 and March 2020.
“During the analysis, it was noted that the highest number of complaints about breathlessness was from Delhi and Patiala, while the highest sneezing and running nose complaints were from Ludhiana. Thus, the effect of bad air (elevated PM2.5 level in highly polluted districts of this study) on respiratory health was evident,” said the study. It stated that in the east Delhi district, the maximum number of self-reported respiratory complaints were for breathlessness (75%), itchiness of eyes (24%), sneezing (22%), and cough in the morning (21%).
The study revealed that the lockdown restrictions in 2020 resulted in a 39% reduction in PM2.5 concentration in the Delhi region. The mean levels of heavy metals detected in PM2.5 samples were chromium (76.1 ng/m3), copper (147.2 ng/m3), zinc (615.4 ng/m3), molybdenum (278.4 ng/m3), and lead (406.1 ng/m3) in Delhi during October 2019. The study reported toxic metallic elements, such as nickel (4.8 ng/m3), arsenic (11 ng/m3), and cadmium (21 ng/m3), in noticeable quantities.
The study also estimated the Heavy Metal Exposure Index (HEI) on the basis of the substance priority list given by the Agency for Toxic Substances and Disease Registry (ATSDR). HEI shows the most significant potential threat of heavy metals to human health due to their known or suspected toxicity. “HEI estimated in Delhi before lockdown (21.5) was more compared with after lockdown (13.2). In the surveyed six districts, the HEI value was highest in Ludhiana, followed by Delhi,” said the report.
Meena Sehgal, the project investigator, said, “Prioritising areas for mitigation actions based on toxic pollutants is critical for reducing harmful exposure. Heavy Metal Exposure Index shows some cities have higher exposures and a timeline should be set to control these.”
The other team members of the study were Kanhaiya Lal, Mahima Uttereja, Vidhu Gupta, Kiran Shivpuri, and Gaurav.
