International Journal of Health Sciences and Research www.ijhsr.org ISSN: 2249-9571

Review Article

Health Effects of among Residents of : A Systematic Review

Palak Balyan1, Chirashree Ghosh2, Arun Kumar Sharma3, B.D. Banerjee4

1Research Scholar, 2Associate Professor, Environmental Pollution Laboratory, Department of Environmental Studies, University of Delhi-110007, 3Professor, Department of Community Medicine, 4Professor, Department of Biochemistry, University College of Medical Sciences & GTB Hospital, University of Delhi-110095, India

Corresponding Author: Palak Balyan

ABSTRACT

Background: Air pollution is increasingly documented as a threat to public health and recognized as an important and modifiable determinate of respiratory diseases in urban environment. Differences in vulnerability and susceptibility due to different population characteristic, may affect the risk of developing a health effect and its severity. The present study evaluates scientific literature on air pollution, and its health effects on population of Delhi to identify the risk of exposure. This comprehensive review summarizes the limitations and gaps in recent studies and recommends some suggestions for future research. Methodology: PubMed and Google Scholar were rigorously searched for finding out research studies pertaining to air pollution and health effects in Delhi, India. All together, 13 studies from 1998 to 2017 were reviewed to understand the status of air quality and its adverse effect on human health. Findings: Air quality of Delhi was detrimental to human health and kept on deteriorating with time. Suspended Particulate Matter (SPM), Nitrogen oxides (NOX) and various other pollutants were above the recommended standard. Adverse health effects (coughing, wheezing, Hypertension etc.) has shown positive association with air pollutants, specifically with particulate matter. A more comprehensive research construing long term effect of air pollution on human health is thus, warranted for advocating policy or guidelines for measuring and understanding the harmful effects and also for the control of air pollution.

Keywords: Air Pollution; Public Health; Health Effects; Delhi; India

INTRODUCTION Central pollution Control Board had noted Delhi, the capital city of India, is many of the establishment had idle pollution inhabitants of approximately 16.7 million control devices and short chimney. [3] people. [1] It is also the third largest urban Transport sectors contributes around three agglomeration in the world. Delhi is ranked fourth of pollutants in air of Delhi. [5] among the most polluted cities in the world. Vehicular sources alone generate more than [2] The primary contributors to air pollution 3000 metric tons of pollutants per day. [6] in Delhi are both natural and anthropogenic Delhi, with a little over 1% of India’s like industrial units, vehicular emission, population, is home to a 10% of the road dust, tire pads, construction activities vehicular load of the country. [7] The motor etc. [3] vehicle fleet was 9.6 million in the year Delhi has approximately nine lakh 2015. [8] The number of vehicles per registered industrial establishments. [4] kilometer of road in Delhi has gone up from

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128 to 191 between 2003 and 2009. [20] estimated that globally 1.1 billion people Moreover, ongoing large scale construction breathe unhealthy air. [13] In the past, several activities contribute dust in the air. The ever studies have highlighted the significant increasing sources and lack of sink potential contribution of ambient air pollution in due to deforestation have also led to high human morbidity and mortality. [14-21] In the ambient air pollutant concentration within year 2012, World Health Organization the city. [6] (WHO) reported that around seven million Climate plays an important role in people died and one in eight of total global determining level of pollutants at Delhi. deaths were attributable to air pollution. Air Delhi has cool dry air and inversion in air pollution has contributed to about two-thirds stratification with low wind velocity during of cardiac mortalities and one-third of winter. Such condition prevents dispersion deaths due to Chronic Obstructive of air pollutants. [9] A crop residue burning Pulmonary Diseases (COPD). [14] of 500 million tons during winter in There is substantial and definitive surroundings of Delhi causes evidence suggesting acute aggravation of formation because of inversion. [10] In symptoms and deterioration of pulmonary summer, air quality gets deteriorated due to function in patients suffering from dust storms originating from Thar desert and and COPD on acute exposure to air middle-east Asia. [11] Dust in polluted pollutants. [22-24] However, the long-term environment become harmful because of effects of several air pollutants, especially coating of pollutants. Moreover, Delhi being biogenic ones, on human health is till now a land locked city, is not able to dilute its not investigated with certainty. Various pollutants by moderating effect of sea. [3] health effects that have been suggested to Air pollution is a major occur due to diverse air pollutants such as environmental problem affecting the health , bioaerosols, ozone, carbon of people in both developed and developing monoxides, VOCs, nitrogen dioxide and countries. [12] The United Nations sulfur dioxide are summarized in the Environment Programme (UNEP) had Table1.

Table 1: List of important air pollutants, their sources and health effects. Pollutants Sources Health effects Particulate Biomass combustion, transportation, incinerators and Acute change in pulmonary functions, COPD, matter manufacturing industries. asthma, cardiovascular diseases Biological Pollens, dust, mites, animals droppings and urine, pet hair, Most often responsible for triggering pollutants or insects, fungi/mold spores, parasites, some airborne bacteria and respiratory illness (asthma, COPD, allergies), Bioaerosols viruses, dairy products and food processing activities infectious diseases & skin diseases Sulphur dioxide Coal and oil combustion or automobile and industrial emission Causes chest constriction, headache, vomiting and respiratory illness Nitrogen dioxide Gas stoves and kerosene heater cooking or automobile and Respiratory and cardiovascular illness industrial exhaust Carbon Burning of coal and gasoline or motor exhausts Reduction in oxygen carrying capacity of monoxide blood, headaches and fatigue VOCs Solvents and chemicals, perfumes, sprays, polishes, air Respiratory illness, headaches, eyes/nose/throat fresheners, repellents, preservatives & smoke irritation & Ammonia Tobacco smoke, cleaning supplies, litter boxes or dustbins. Eye / skin irritation, headache, nose bleeds and sinus problems Ozone Formed from reaction of NOx and VOC’s Respiratory illness, eye and skin irritation (secondary pollutant)

Epidemiological studies have Population characteristics that can modify indicated that health effects of air pollution the health effects related to pollution and on differ for different populations. confer susceptibility are predominantly age, Differences in vulnerability and underlying disease, and potentially genetics susceptibility may affect the risk of and gender. [25-27] Thus, it is pertinent to developing a health effect and its severity. monitor the local levels of air pollutants and

International Journal of Health Sciences & Research (www.ijhsr.org) 274 Vol.8; Issue: 1; January 2018 Palak Balyan et al. Health Effects of Air Pollution among Residents of Delhi: A Systematic Review determine the magnitude of its impact on (from pre identified 11 studies) were also the local population regarding the additional included in this review, so in total 13 studies burden of morbidity and premature were reviewed [Fig. 1]. mortality that it inflicts on that population. The present study intends to systematically review the studies concerned with air pollution level in Delhi and corresponding health effects. The Objective of the review are as follows: 1. To describe briefly the air pollution status in Delhi. 2. To explore risk of health outcomes with exposure to air pollution.

METHODOLOGY A systematic review of electronic and published literature was undertaken. Electronic literature search was restricted to

PubMed & Google Search and printed Figure 1. Algorithm for study selection in review manuscript. publications were scanned from the libraries of participating institutions on the theme of : air pollution and its health effects. The study Air quality monitoring in Delhi is was restricted to publications from 1995 carried out through a number of air quality onwards. monitoring stations across the territory, The following terms were used for operated and maintained by various searching the PubMed and Google Scholar: organizations viz. Central Pollution Control Air pollution, Health impact, Delhi (mesh Board (CPCB), Delhi Pollution Control term) in PubMed yielded 16 studies. Committee (DPCC), and System of Air and Air pollution, Health, Delhi in abstract Quality and Weather Forecasting and and title for Google Scholar yielded 22 Research (SAFAR) of Indian Institute of studies. Tropical Meteorology (IITM), Pune. NAAQ Study Selection: standard has been released by Central A total of 38 articles were found in Pollution Control Board (CPCB) search on PubMed (16 studies) and Google government of India in 2009. [28] NAAQ Scholar (22 studies) and a total of 11 articles standard provides upper limit of various were included for review. Only one study pollutants in air. CPCB report on air quality appeared in both searches. The remaining in Delhi provides an insight into trend of 27 articles did not have any substantial three air pollutants viz. SO2, NO2, and [3] information about association between air PM10, level from 2009 to 2015. The pollution and health in Delhi concentration of NO2 and PM10 were above Original studies showing health recommended level. The concentration of effects of ambient air pollution in Delhi SO2 was within the standard limits. (India), irrespective of the study design, However, as far as NO2 is concerned, were selected for our analysis. Studies that continuous rise in concentration was tried to measure effect of indoor air observed in past 7 years. Table 2 provides a pollution only, were excluded from the list of air pollutants and remark on their review as our aim was to study “effect of level by various studies conducted in Delhi outdoor air pollution”. Further, two related in last 20 years. articles selected from cross referencing

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Globally urbanization has made a remained within recommended limit from significant change in composition of air in 1986 to 2007 in Delhi but a sudden steady the metropolitan cities, likely a similar trend rise was noted from the year 2001 to 2015 was observed in air composition of Capital [33] and in year 2008 NOx surpassed NAAQ City of India. In all the studies SO2 level recommended level. The most abundant was found under recommended level where metals were Fe and Zn and least abundant as PM levels were far exceeding the was Cd found in Delhi air. [32] The benzene prescribed standard limits. It may be due to and benzo-pyrene was also reported to be the substantial rise in gasoline and diesel above NAAQ standard as per the CPCB powered private vehicles. [35] NOx level report. [24]

Table 2: Reviewed pollution status of Delhi.

Study SO2 NO2 PM CO Benzene Remarks Pollution data year Chabbra etal. [23] 2001 BPL BPL APL NS NS No clear trend observed in Air Quality 1989-1998 (AQ). Airpollutant level remained constant with some fluctuation [29] Nidhi et al. 2007 BPL BPL APL NS NS A decrease in SO2 concentration and an 1998-2004 increase in NO2 concentration was observed Aggarwal et al. [30] 2006 BPL BPL APL NS NS Maximum concentration of PMwas noted 2000-2003 in winter month [24] CPCB 2008 BPL BPL APL NS APL NO2 was APL at most of monitoring Stations 2002-2005 Pande et al. [31] 2005 BPL NS APL NS NS 2003-2004 [32] Jayraman et al 2007 NS APL APL APL NS NO2 & CO found to be above the recommended level approx. 2004-2005 half of the time of study duration Khillare et al. [33] 2012 NS NS APL NS NS 2008-2009 [34] Guttikunda et al. 2013 NS APL APL NS NS 2.5 times increase in PM10 and little less 2001-2011 than 2 timesincrease in NO2 was observe 21 3 3 3 (Permissible limits of various pollutants as per NAAQ standard are: NO2 24hr avg80 µg/m ; SO2 24hr avg80 µg/m ; PM10 24hr avg100 µg/m ; 3 3 3 3 RSPM24hr avg60 µg/m ;CO8hr avg02 mg/m ; Benzene average 05 µg/m ; Benzo-pyrene average 01 ng/m ) BPL= below permissible limit, APL= Above permissible limit & NS=Not studied

Air quality index (AQI) adopted in of exposure to pollutant is a big hurdle to India in 2014, is a six colour code understand the multipronged pathway from developed for easy understanding of air exposure to development of a disease. pollution by laymen and hence, to make them aware of air quality and to involve Health effect of air pollution: them in strategies for control and mitigation. Respiratory tract dysfunctions were [36] AQI is computed by concentration of most commonly investigated and reported in eight pollutants ((PM10, PM2.5, NO2, SO2, reviewed studies. They range from acute CO, O3, NH3, and Pb). However, three out infections (such as pneumonia and of these eight pollutants (O3, NH3, and Pb) bronchitis) to chronic conditions (such as were not included in any of the studies asthma and COPD). In the reviewed studies, conducted in Delhi. CO levels were the adverse health outcomes were found to recorded in one study only. O3 is one of the have a significant association with the air most consistent pollutants linked with health pollution like cough with or without effects. Phlegm, Chest tightness, Allergic Rhinitis, All reviewed studies have used air Sinusitis, Bronchial Asthma, COPD, pollutant data from fixed monitoring station, Hypertension, increased risk for which does not represent the real and exact cardiovascular events, Headache, Dizziness measure of air pollution exposure at and Eye irritation [Table 3]. personallevel. Thus, an exact measurement

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Table 3. Health effect of air pollutants on population of Delhi. Parameter Output Type of Findings Study variable study Respiratory symptoms Wheeze ever Prevalence Cross- OR = 1.61 for commercial complex relative to OR of symptoms for sectional residential colony. commercial complex, industrial survey area relative to residential area. Mathew et al. [37] 2015 Wheeze Prevalence Cross- OR = 2.87 for commercial complex and 1.97 for during sectional industrial area -do- activity survey Cold and Prevalence Cross- OR = 2.58 for commercial complex and 1.34 for -do- cough sectional industrial area frequency survey URS Prevalence Case control OR = 1.24 for more polluted Delhi than rural West Powered with large sample size study Bengal (CPCB) [24] LRS Prevalence Case control OR = 1.66 for more polluted Delhi than rural West -do- study Bengal. Distribution highly correlated with PM Diagnosis Asthma Emergency visit Ecological 21.30 % of events were attributed to CO and TSP Pande et al. [38] 2002 study Prevalence Cross- No difference of prevalence in mid-high pollution The zone division is relative sectional zone and low pollution zone and demarcation level of 400 survey microgram per meter cube is 4 times higher than recommended level Chhabra et al.[23] 2001 COAD Emergency visit Ecological 24.90 % of events were attributed to CO and TSP Pande et al. [38] 2002 study prevalence Cross- No difference of prevalence in mid-high pollution Chhabra et al. [23] 2001 sectional zone and low pollution zone survey Emergency visit Ecological 1/3rd variability of COAD exacerbation was due to Aggarwal et al. [30] 2006 study variability in the level of SPM. Acute Emergency visit Ecological 24.30 % of events were attributed to CO and TSP Pande et al. [38] 2002 coronary study event Respiratory Hospitalisation Ecological Relative risk for hospitalization due to air pollution Nidhi et al. [29] 2007 disease study is 1.07-2.82 Respiratory Hospitalisation Ecological Ozone, NO and RSPM increased respiratory Jairaman et al. [32] 2007 disease study diseases related hospital visits by 24, 13 and 3% respectively. Respiratory OPD Ecological r = 0.766; P< 0.01; r = 0.631, P< 0.05, between Maji et al. [39] 2015 disease attendance study OPD patients and AQI at two tertiary care hospitals Hypertension Prevalence Case control Four times more pre-valence of Hypertension in Up regulated p-selectin positive study Delhi compared to control population. platelets, altered lymphocytes subtype Banerjee et al. [40] 2012 Physiological status PFT PFT Cross- Severe obstruction in industrial area Mathew et al. [37] 2015 sectional PFT FVC, FEV1, Deterioration in PFT were more in medium-high Chhabra et al. [23] 2001 MMEF, PEFR Cross- polluted areas than low pollution areas. sectional A proportion of asymptomatic with isolated reduction in MEFR in medium-high polluted zone PFT FVC, FEV1, Case control PFT was deteriorated in 40% people in Delhi PFT more deteriorated in low study (case) than 20% in West Bengal (control) SEZ than high SEZ CPCB [24] 2008 Health risk assessment Cancer risk Incremental Cross 2908 excess case of carcinoma due to presence of Khillare et al. [33] 2012 lifetime cancer sectional heavy metal in air. Cr is responsible for 80 percent risk assessment study of cases.

Health risk Health risk Cross- HR is 22.11 times higher for NO2 and 16.13 times Health risk = dose exposure / sectional for SPM than due to SO2 LOAEL Study Pande et al. [31] 2005

Health risk All natural Time-series Every 10µg/m3 rise in particulate is associated with Rajarathnam et. al. [19] 2011 cause of study 0.15% rise in all natural cause of mortality. mortality Health risk morbidity due Cross- No significant difference were noted between Joshi et al. [41] 1998 to asthma, heart sectional highly polluted urban area and low polluted rural disease or Study area allergy LOAEL =lowest observed adverse effect levels.

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Very few studies were conducted in December 2000. Emergency room visits for Delhi concerning air pollution and its asthma, COAD, and acute coronary events association with health. During 1997, Joshi increased by 21.30%, 24.90%, and 24.30% et al. [41] surveyed and determined the respectively on account of higher pollutant morbidities due to vehicular pollution in level which was more than the permissible Delhi. Based on area sampling, highly value. polluted urban areas (SPM concentration, > Pande et al. [31] (2005) assessed 500 μg/m3) and less polluted rural areas location and age specific exposure to (assumed to be < 400 μg/m3) were identified pollution and their health risk. They and numbered serially. The results of these observed SO2 as a pollutant to which two studies showed that exposure to exposure of subject was least, and its vehicular pollution in the urban area was concentration was well within standards three-fold (staying in highly polluted areas) prescribed by NAAQ. They computed than the rural area, but interestingly, there average relative “adverse health risk” for was no significant difference between the SPM and NOx taking SO2 as the reference two groups concerning morbidity due to as 16.132 and, 22.111 respectively. asthma, heart disease or allergy. Aggarwal et al. [30] 2006 attempted to Chabbra et al. [23] 2001 conducted a find association of respiratory ailments cross sectional study on a randomly (COPD, Asthma, and Emphysema) with stratified sample of 4171 permanent pollutants (SO2, NO, SPM and RSPM) and residents, living near each one of the nine meteorological factors in the year 2000- pollution monitoring stations in Delhi. They 2003. They found that in winter months, the demarcated Delhi into high, medium and risk of exposure to pollutants increase low polluted zones by the level of pollution compared to other seasons due to stability in in these areas from 1989 to 1998. the air stratification as pollutants get trapped Respiratory symptoms were more prevalent in to the lower layers of the atmosphere in zones corresponding to low socio- resulting in high concentrations. A positive economic zone, the reason might be statistical correlation with the number of prolonged outdoor pollution exposure. COPD cases viz., SPM (r = 0.474; p < 0.01) However, the prevalence of Bronchial and RSPM (r = 0.353; p < 0.05) was Asthma, COPD, and Chronic Bronchitis observed. The two factors (SPM and was not significantly different in two zones. Relative Humidity) had explained one-third A proportion of asymptomatic showed an of variability in COPD admission. isolated reduction in Maximal Mid Jayaraman et al. [32] 2005 tried to Expiratory Flow Rate (MEFR) suggesting determine the association between the air early small airway disease. Subjects with pollutants and daily variations in respiratory such isolated reduction in maximal MEFR morbidity in Delhi during the years 2004– were more in medium- high zones. 2005 by conducting data analysis based on Pande et al. [38] 2002 studied the the Generalized Additive Poisson regression relationship between the rate of model including a Lowess smoothing hospitalization due to acute respiratory function for the entire patient population events (asthma and COPD exacerbations), and subgroups defined by season. Single acute coronary events and ambient air pollutant model showed that a 10 µg/m3rise quality. Daily counts of patients visiting the in pollutant level led to statistically emergency room of the All India Institute of significant relative risks (RR): 1.033 for O3, Medical Sciences (AIIMS, ) for 1.004 for NO2, and 1.006 for RSPM. acute asthma, acute exacerbation of chronic Nidhi et al. [29] 2007 determined the obstructive airway disease (COAD) and association between environmental acute coronary event was obtained pollution and respiratory morbidity in Delhi prospectively from January 1997 to for the period 1998–2004 by calculating

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Relative Risk (RR) of hospitalization due to matter, hence, signifying effect of the local respiratory ailments caused by air pollutants factor on air pollution attributed mortalities. in seven hospitals from different parts of Banerjee et al. [40] 2012 conducted a Delhi. They found RR for hospitalization case control study comparing cardiovascular due to air pollution varied from 1.07 to 2.82. morbidity and risk factors in the population A comprehensive epidemiological of Delhi with subjects residing in study to examine health risk due to air Uttarakhand as a control. Systolic and pollution in Delhi was conducted by the diastolic hypertensions were 2.5 and 4 times CPCB in 2008. [24] They identified a more prevalent in Delhi, respectively. significant association between air pollution Hypertension showed a positive correlation and all relevant adverse health outcomes. with RSPM specifically diastolic The findings were compared with a rural hypertension (rho = 0.350). A statistically control population in West Bengal. It was significant abundance of target cell was found that Delhi had 1.7-times higher observed in the population of Delhi prevalence of respiratory symptoms signifying the liver problem in a substantial compared with rural controls (P < 0.001); number of non- smoker and non-alcoholic the odds ratio of upper respiratory population. Citizens of Delhi have 1.5 times symptoms in the consecutive 3 months in more platelets than the control with an up Delhi was 1.59 (95% CI 1.32-1.91) and for regulated expression of platelets suggesting lower respiratory symptoms (dry cough, a hypercoagulable state, a risk factor for the wheeze, breathlessness, chest discomfort) it cardiovascular event. The relative was 1.67 (95% CI 1.32-1.93). Prevalence of proportion of different subtype of asthma (in the last 12 months) and lymphocytes was observed. An increase in physician-diagnosed asthma among the CD8+ and the natural killer cell was residents of Delhi was significantly higher observed where as CD4+ and CD19+ than in controls. Lung function was reduced showed a decrease in abundance, which in 40.3% individuals of Delhi compared to showed a significant correlation with 20.1% in the control group. particulate matter. Khillare et al. [33] 2012 studied the A cross sectional survey was composition of heavy metal in suspended conducted by Mathew et al. [37] 2015 to particulate matter and calculated compare the prevalence of respiratory Incremental lifetime cancer risk (ILCR) symptoms (wheeze, cough, phlegm) with assessment. They estimated that up to 2908 pollution status. A statistically significant excess cancer cases (102 for Cd, 2559 for positive relationship of PM10 was observed Cr (VI) and 247 for Ni) were likely in Delhi with wheezing in participants. Majhi et al. due to lifetime inhalation exposure to these [39] 2015 observed a positive correlation species at their current concentrations. between AQI and OPD attendance due to Rajaratnam et al. [19] 2011 studied respiratory morbidities. the effect of particulate matter with the rise Majority of studies were restricted to in all-cause mortality in Delhi. Mortality effect of air pollution on respiratory system. data from local municipality were taken as Studies conducted by Chhabra et al. [23] and the output. A 0.15% rise in all natural all- CPCB [24] had studied comparatively large cause mortality (with every 10µg/m3 sample size and tried to search for increase in the particulate matter) after comprehensive outcomes in study subjects. adjusting for meteorological parameters was An underlying respiratory pathology even in reported. The rise they observed was less asymptomatic and also its effect on other than what was expected from previous body systems was also observed. Banerjee literature. They attributed the excess rise in et al. [40] had attributed high prevalence of mortalities to demographic characteristics, hypertension, increased risk for an acute composition and toxicity of particulate cardiac event and altered immune cell

International Journal of Health Sciences & Research (www.ijhsr.org) 279 Vol.8; Issue: 1; January 2018 Palak Balyan et al. Health Effects of Air Pollution among Residents of Delhi: A Systematic Review subtypes in Delhi to air pollution. Almost all health problem affecting health of people in of the studies conducted in Delhi were an adverse manner. The air quality remained associative in nature. There is a paucity of poor and kept on deteriorating in last two cohort studies in Delhi. Cohort studies will decades. The effect of poor air quality help to understand the exact role of air manifested as various health effects in the pollution in the causation of various form of respiratory dysfunctions, cardiac diseases. Thus, large cohort studies for long disorders and their increased risk. The duration investigating comprehensive adverse health effects showed most effects on the human body will provide us consistent relationship with suspended an insight into long-term effects of chronic particulate matter (SPM). Many of the pollution exposure. Such studies are existing epidemiologic investigations especially important because changes in conducted in Delhi regions suffer from physiological functions are usually insidious inaccurate exposure assessment, insufficient and might take a long time to appear data and long term follow up of cohort depending upon quantity and duration of studies. Therefore, cohort studies with exposure to pollutants. There are larger sample size are needed to investigate capacitation and physiological adaptation in the influence of air pollution on morbidity exposure over time, which may not result in and mortality, for advocating policies and overt symptoms of the disease, although guidelines for, monitoring and control of there is a concomitant reduction in the harmful effects of air pollution. physiological capacity. Interestingly, the studies reviewed ACKNOWLEDGEMENTS and present review is based on assumption Authors are thankful to Department of Science of homogeneity of Delhi’s population. and Technology (DST) purse grant and Ministry Physiological and pathological response to of Environment, Forest and Climate change (MoEF), Govt. of India for supporting the work. pollutant exposure is very heterogeneous among people of the same study area also, REFERENCES so studies are required to understand the 1. Commissioner C, Road M. Census of India genetic and physiological determinants of 2011 Provisional Population Totals - India - pathogenesis to open up windows for Data Sheet Child Sex Ratio in Census of preventing and managing disorders due to India 2011 Provisional Population Totals - pollution exposure. Further, models India - Data Sheet. Minist Home Aff India. showing the quantitative association of 2011;1–60. pollutant exposure and its impact on health 2. WHO. WHO Global Urban Ambient Air are developed using data from developed Pollution Database [internet]. 2016 [cited countries like North America and Europe 2017 Oct 15] Available from: http://www.who.int/phe/health_topics/outdo where the pollutant concentrations are only orair/databases/AAP_database_summary_re one tenth to one fifth of the levels in India, sults_2016_v02.pdf and it is doubtful whether the effects at such 3. Central Pollution Control Board. Air high concentration follow the same pollution in Delhi- An analysis. Delhi; quantitative relationship. ENVIS Centre on Control of Pollution (Water, Air, & Noise); 2016. 26 p. CONCLUSIONS 4. Economic survey of Delhi 2014-2015 Exposure assessment and [internet]. Delhi: Planning Department, epidemiologic studies in the developing Government of National Capital Territory of world are most important as informative Delhi; 2015 [cited 2017 Oct 15].Available database for the recent global health from: http://delhi.gov.in/wps/wcm/connect/DoIT_ understanding. Despite inconsistencies, Planning/planning/economic+survey+of+de findings from Delhi based studies strongly hli/economic+survey+of+delhi+2014+- indicate that air pollution is a major public +2015

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5. Goyal SK, Ghatge SV, Nema P et al. 16. Le ND, Sun L, Zidek JV. Air pollution. Understanding urban vehicular pollution Chronic Dis Can. 2010; 29 (Suppl 2): 144- problem vis-a-vis ambient air quality–case 63. study of a megacity (Delhi, India). 17. Kumar R, Sharma SK, Thakur JS et al. Environmental monitoring and assessment. Association of air pollution and mortality in 2006 Aug 1;119(1-3):557-69. the Ludhiana city of India: a time-series 6. Central Pollution Control Board. Status of study. Indian journal of public health. The Vehicular Pollution Control Programme 2010;54(2):98. in India. Central Pollution Control Board; 18. Balakrishnan K, Ganguli B, Ghosh S et al. 2010. 131 p. Programme Objective Series Short-term effects of air pollution on 2010;PROBES/136/2010. mortality: results from a time-series analysis 7. Delhi Traffic Police [internet]. [cited 2017 in Chennai, India. Research report (Health Oct 15] Available from: Effects Institute). 2011; 7-44. https://delhitrafficpolice.nic.in/about- 19. Rajarathnam U, Sehgal M, Nairy S et al. us/statistics Time-series study on air pollution and 8. Goyal P, Dhirendra M, Kumar A. Emissions mortality in Delhi. Research Report (Health of criteria pollutants from vehicular traffic Effects Institute). 201; (157):47-74. in Delhi, India. Journal of Environmental 20. Samet JM. Air pollution and Research and Development. 2013 Apr epidemiology:“déjà vu all over again?”. 1;7(4A):1693. Epidemiology. 2002 Mar 1;13(2):118-9. 9. Agarwal S. Seasonal variability in size- 21. Dockery DW. Health effects of particulate segregated airborne bacterial particles and air pollution. Annals of epidemiology. their characterization at different source- 2009;19(4):257-63. sites. Environ SciPollut Res. 22. Thambavani DS, Maheswari J. A combined 2017;24(15):13519–27. analysis of airborne particulate pollutants 10. Sharma AR, Kharol SK, Badarinath KVS et exposure and its potential risk.ChemSci al. Impact of agriculture crop residue Trans. 2013; 2(2): 598-604. burning on atmospheric aerosol loading - A 23. Chhabra SK, Chhabra P, Rajpal S et al. study over Punjab State, India. Ann Ambient air pollution and chronic Geophys. 2010;28(2):367–79. respiratory morbidity in Delhi. Archives of 11. Kumar S, Aggarwal SG, Malherbe J, Barre Environmental Health: An International JP, Berail S, Gupta PK, Donard OF. Tracing Journal. 2001;56(1):58-64. dust transport from Middle-East over Delhi 24. Central Pollution Control Board. in March 2012 using metal and lead isotope Epidemiological Study on Effect of Air composition. Atmospheric Environment. Pollution on Human Health (Adults) Delhi. 2016;132:179-87. Delhi: Central Pollution Control Board; 12. Nandasena YL, Wickremasinghe AR, 2008, August. 339 p. Environmental Health Sathiakumar N. Air pollution and health in Series 2008; EHS/1/2008. Sri Lanka: a review of epidemiologic 25. Levy JI, Greco SL, Spengler JD. The studies. BMC public health. 2010;10(1):1. importance of population susceptibility for 13. Selvaraj, K, Haribhai, V.P. Comparative air pollution risk assessment: a case study of Study of Different Sorbents to Adsorb power plants near Washington, DC. Various Components from Flue Gases Environmental Health Perspectives. 2002; and/or Exhaust Gases. International Journal 110(12):1253. of Advanced Research. 2016;4(2): 44-56. 26. Mead MN. Who’s at risk? Gauging 14. World Health Organization. Household air susceptibility to air pollutants. pollution and health [internet]. [updated Environmental health perspectives. 2011; 2016 Feb; cited 2017 Oct 15]. Available 119(4):176. from: 27. Nikolaos I. Stilianakis. Susceptibility and http://www.who.int/mediacentre/factsheets/f vulnerability to health effects of air s292/en/ pollution: The case of nitrogen dioxide. 15. Schwartz J. Air pollution and blood markers Joint research centre, European of cardiovascular risk. Environmental health commission; 2015. 33 p. perspectives. 2001;109(Suppl 3):405. 28. Central Pollution Control Board. National Ambient Air Quality Standards [internet].

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Delhi: Central Pollution Control Board; 35. Narain U, Bell RG. Who Changed Delhi's 2009[cited 2017 Oct 15]. Available from: Air? Economic and Political Weekly. http://cpcb.nic.in/National_Ambient_Air_Q 2006:1584-8. uality_Standards.php 36. Central Pollution Control Board. Air 29. Nidhi, Jayaraman G. Air quality and Quality Index [internet]. Delhi: Central respiratory health in Delhi. Environ Monit Pollution Control Board; 2009[cited 2017 Assess 2007;135:313-25. Oct 15]. Available from: 30. Agarwal R, Jayaraman G, Anand S et al. cpcb.nic.in/FINAL-REPORT_AQI_.pdf Assessing respiratory morbidity through 37. Mathew J, Goyal R, Taneja K K et al. Air pollution status and meteorological pollution and respiratory health of school conditions for Delhi. Environmental children in industrial, commercial and monitoring and assessment. 2006;114(1- residential areas of Delhi. Air Quality, 3):489-504. Atmosphere & Health. 2015;8(4):421-7. 31. Pandey JS, Kumar R, Devotta S. Health 38. Pande JN, Bhatta N, Biswas D et al. risks of NO 2, SPM and SO 2 in Delhi Outdoor air pollution and emergency room (India). Atmospheric Environment. visits at a hospital in Delhi. Indian J Chest 2005;39(36):6868-74. Dis Allied Sci. 2002;44(1):13-19. 32. Jayaraman G. Air quality and respiratory 39. Maji S, Ahmed S, Siddiqui WA. Air quality health in Delhi. Environmental monitoring assessment and its relation to potential and assessment. 2007;135(1-3):313-25. health impacts in Delhi, India. Current 33. Khillare PS, Sarkar S. Airborne inhalable Science. 2015;109(5):902-9. metals in residential areas of Delhi, India: 40. Banerjee M, Siddique S, Mukherjee S et al. distribution, source apportionment and Hematological, immunological, and health risks. Atmospheric pollution cardiovascular changes in individuals research. 2012;3(1):46-54. residing in a polluted city of India: a study 34. Guttikunda SK, Calori G. A GIS based in Delhi. International journal of hygiene emissions inventory at 1 km× 1 km spatial and environmental health. 2012;215(3):306- resolution for air pollution analysis in Delhi, 11. India. Atmospheric Environment. 2013; 41. Joshi TK. A health survey to determine the 67:101-11. adverse health impact of pollution in Delhi. Centre for occupational and environmental medicine. MAMC, 1998.

How to cite this article: Balyan P, Ghosh C, Sharma AK et al. Health effects of air pollution among residents of Delhi: a systematic review. Int J Health Sci Res. 2018; 8(1):273-282.

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International Journal of Health Sciences & Research (www.ijhsr.org) 282 Vol.8; Issue: 1; January 2018