Relative Risks of Cardiopulmonary and Lung Cancer Mortality by PM_2.5 Exposure in Ambient Air of Delhi Particularly During Smog Episode

ABSTRACT

Background

Delhi, the capital city of India has experienced the problem of the great smog during November since a long time. Adverse meteorological conditions, stubble burning, and the celebration of Diwali were considered as the major responsible factors for the smog episodes. This study was designed to identify the concentration and relative risks associated with the exposure of PM_2.5 in ambient air of Delhi during the episodic events.

Methods

24-h average ambient levels of PM_2.5 were procured for the year 2015–2020. Relative risks of cardiopulmonary and lung cancer diseases associated with PM_2.5 exposure have been estimated using a probabilistic approach of risk assessment.

Findings

The average relative risks (2015–2020) for lung cancer mortality (RR 2.15; 95% CI 2.13, 2.17., p < 0.001) were observed higher than cardiopulmonary mortality (RR 1.66; 95% CI 1.65, 1.67., p < 0.001). An attempt has been done to identify the effect of high exposure concentration on relative risks particularly during smog period. The estimated relative risks during November (2016–2018) for lung cancer mortality were ranged as 2.51–2.68 and cardiopulmonary mortality were ranged as 1.85–1.93.

Conclusion

Such high levels of associated relative risks during such episodes could be considered as an important additive hazard factor for overall mortality burden.

Graphical Abstract

Highlights

• PM_2.5 produced during smog event has a serious impact on the respiratory and cardiopulmonary health, resulted in increment of relative risks;

• Relative risks of lung cancer mortality were higher in compare of cardiopulmonary mortality, suggesting more carcinogenic effects of fine particles on human health;

• The results of the study suggest that there is a strong effect of location, days and burning practices, when estimating air quality.

Acknowledgments

One of the authors A. Garg gratefully acknowledges the scholarship provided by GGSIP University, New Delhi vide letter [No: GGSIPU/DRC/Ph.D/Adm./IPRF/2017/178] dated 08/03/17. The authors would also like to thank Director (Research and Consultancy) for providing financial assistance in the form of Faculty Research Grant Scheme to carry out the research study.

Conflict of interest

The authors declare no potential conflict of interest regarding the publication of this work. In addition, the ethical issues including plagiarism, informed consent, misconduct, data fabrication and, or falsification, double publication and, or submission, and redundancy have been completely witnessed by the authors.

Additional information

Notes on contributors

Anchal Garg

Anchal Garg completed her M.Sc. (Gold Medalist) and Ph.D. in Environment Management from GGS IP University. Currently, she is working as a Post-Doctoral Research Fellow in Earth System Science Department, Stanford University.

N. C. Gupta

Dr. Arvind Kumar did M.Tech and Ph.D in Soil and Water Conservation Engineering. He is having 9 years experience in professional areas like Water Resource Management, Agricultural Drainage Engineering, Soil salinity, hydrology, irrigation Engineering, Agricultural water management. He is currently Scientist F in Department of Science and Technology, Ministry of Science and Technology, India.

Arvind Kumar

Prof. NC Gupta is Post-graduate in Physics. He obtained his M. Phil. and Ph. D in Energy and Environment Systems from Jawaharlal Nehru University (JNU), New Delhi. He has more than 25 years of research experience. He has instructed vide variety of courses which includes Energy, Environment and Technology, EIA, Air pollution, Climate Change and disaster management and risk analysis.