A significant drop in Air Pollution levels across India after about a month COVID-19 lockdown

A significant drop in Air Pollution levels across India after about a month COVID-19 lockdown.

Dr K K Aggarwal and Dr Anil Kumar, President and Director HCFI

The levels of NO2 and Ozone across India are within the National Ambient Air Quality Standards.

No clear relationship observed between current Air quality vs Confirmed COVID-19 cases in India.

During COVID-19 pandemic and lockdown enforced, countries across world have reported a significant drop in air pollution and witnessed improvement in air quality. 

In India, the most significant improvement in air quality during lockdown was observed in cities across Indo-Gangetic plain as in most of the normal days, particularly in winter months, particulate matter (PM10 and PM2.5 levels) and NO2 values are high in Indo-Gangetic plain due to geographical location and other factors including very high population density and spread of industrial clusters.

As per an earlier analysis done by Team of HCFI, after 11 days COVID-19 lockdown, the level of  particulate pollution (particulate matter,  PM10 and PM2.5) dropped by nearly 60% in  Delhi.  PM10 (particulate matter 10 micrometres or less in diameter) and PM2.5 (particulate matter 2.5 micrometres or less in diameter) are particles present in the air that are classified as pollutants and can harm human health.  The deadliest particle in Delhi's foul air is PM 2.5 (primarily come from combustion - fires, automobiles and power plants), which increases the likelihood of respiratory and cardiovascular diseases.   

Across the Globe, studies have been conducted to get a clear relationship between air pollution exposure and COVID-19 confirmed cases as high levels of air pollution can cause damage to the lungs and thus makes one, more susceptible to either getting the infection or to getting complications from  COVID-19. The World Economic Forum also said that people living with poor air quality may be more susceptible to COVID-19 disease.

A recent study w.r.t. Exposure to air pollution and COVID-19 mortality in the United States  by Xiao Wu et.al of  Dept. of Biostatistics, Harvard T.H. Chan School of Public Health, USA, indicates that Coronavirus patients in areas that had high levels of air pollution before the pandemic, are more likely to die from the infection than patients in cleaner parts of the country. This study offers the first clear link between long-term exposure to pollution & Covid-19 death rates.

The authors in above study found that an increase of only 1 μg/m3 in PM2.5 is associated with a 15% increase in the COVID-19 death rate. Results are statistically significant and robust to secondary and sensitivity analyses. They have concluded that a small increase in long-term exposure to PM2.5 leads to a large increase in COVID-19 death rate. The study results underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis.  

In this regard, Team of Experts of HCFI have done detailed analysis of air quality data ( Air Quality Index- AQI, PM10, PM2.5, NO2 and Ozone) from about 180 Continuous Ambient Air Quality Monitoring Stations (CAAQMS) across India and correlated with Confirmed COVID-19 cases . Status of Confirmed COVID-19 cases of various States/UTs as on 21-04-2020 and corresponding State/UT wise Air Quality status ( as per average CPCB/SPCB data w.r.t. National Air Quality Index as on 21-04-2020 at 4:00 PM) is given below in the Table:

State/ UT	Confirmed COVID-19 cases	AIR Quality status ( PM10, PM2.5, NO2 and Ozone values in microgram per meter cube)
Andhra Pradesh	722	AQI range	City	CAAQMS Location	AQI	PM10	PM2.5	NO2	Ozone
		38-52	Amrawati	Scretariat	52	52	18	30	13
			Raja Mahend-ravaram	Aanad Kala kshetram	38	16	9	5	38
			Tirupati	Tirumala	39	13	10	8	39
			Visakha-patnam	GVM Corporati-on	52	52	18	30	13
Bihar	113	49-139	Gaya	Collecto-rate	96	-	48	21	96
			Muzaffar-pur	Collecto-rate	61	-	34	30	61
			Patna	Govt. High School	108	108	26	11	4
				Muradpur	64	64	40	17	9
				Rajbansi Nagar	49	49	30	-	21
				Saman-pura	139	49	47	30	53
Chandi-garh	26	30	Chandi-garh	Sector-25	30	30	22	15	29
Delhi	2081	55-163	Delhi	Alipur	94	94	54	26	67
				Anand vihar	84	84	77	21	56
				Aya nagar	62	62	56	18	26
				Bawana	118	118	100	22	89
				CRRI	77	77	56	18	14
				DTU	97	86	61	22	97
				Dwarka Sector-8	89	84	50	20	89
				IGI Airport	64	64	45	-	34
				IHBAS	68	-	20	-	-
				JLN stadium	89	70	43	18	89
				Lodi Road	64	64	-	-	64
				National stadium	66	66	59	19	31
				Mandir marg	72	72	51	34	20
				Nehru nagar	163	79	68	22	163
				Okhla phase-2	89	-	42	19	6
				Patparganj	55	55	41	12	35
				Punjabi Bagh	77	77	65	34	31
				R.K.Puram	63	63	43	25	46
				Rohini	98	98	89	11	19
				Shadipur	81	-	26	27	81
				Sirifort	64	64	45	19	60
				Sri Auro-bind marg	121	48	37	6	121
				Vivek vihar	87	87	62	30	52
				Wazirpur	75	75	67	33	45

State/ UT	Confirmed COVID-19 cases	AIR Quality status ( PM10, PM2.5, NO2 and Ozone values in microgram per meter cube)
Gujrat	1939	AQI range	City	CAAQMS Location	AQI	PM10	PM2.5	NO2	Ozone
		51-75	Ahmeda-bad	Maninagar	72	72	47	17	60
			Ankleshwar	GIDC	75	75	51	6	47
			Gandhi Nagar	Sector-10	56	56	34	4	31
			Nandesari	GIDC	51	49	28	51	-
			Vatva	Phase-4 GIDC	69	69	53	31	24
Haryana	254	25-165	Ambala	Patti Mehar	42	-	39	21	42
			Bahadurgarh	Arya Nagar	77	77	74	23	58
			Ballabh garh	Nathu colony	74	64	74	11	14
			Bhiwani	H.B.Colony	62	58	24	18	62
			Daruhera	Municipal corporation office	63	50	61	13	63
			Farida-bad	Sector-30	98	98	19	14	41
				Sector-16 A	165	-	48	-	165
			Fatehabad	Huda sector	64	59	45	10	64
			Gurugram	NISE Gwal Pahari	67	67	50	12	35
				Sector-51	118	85	58	19	118
				TERI gram	85	59	56	-	85
				Vikas Sadan	121	-	51	27	121
			Hisar	Urban Estate-II	70	70	46	24	28
			JInd	Police line	64	51	50	19	64
			Kaithal	Rishi nagar	50	50	35	29	22
			Karnal	Sector-12	54	-	54	10	34
			Kurshetra	Sector-7	56	40	33	14	56
			Mandikhera	General Hospital	64	64	33	-	40
			Maneshar	Sector-2 IMT	73	73	25	2	-
			Narnaul	Shastri nagar	53	53	34	-	14
			Palwal	Shyam nagar	115	115	94	8	14
			Panchkula	Sector-6	25	-	25	22	24
			Panipat	Sector-18	91	91	41	70	46
			Rohtak	M D Univ.	49	-	49	-	27
			Sirsa	F Block	69	69	37	6	24
			Sonepat	Murthal	83	83	32	35	15
			Yamuna nagar	Govindpura	81	58	44	20	81
Karnataka	408	31-60	Bengaluru	BTM layout	50	32	-	17	36
				Bapuji nagar	51	31	18	9	51
				Hebbal	31	31	18	3	-
				Jaya Nagar	34	29	24	26	34

State/ UT	Confirmed COVID-19 cases	AIR Quality status ( PM10, PM2.5, NO2 and Ozone values in microgram per meter cube)
Karnataka (continued)	408	AQI range	City	CAAQMS Location	AQI	PM10	PM2.5	NO2	Ozone
		31-60	Bengaluru	Peenya	60	-	60	8	-
				Sanegurva Hill	38	38	-	24	-
				Silk board	35	32	23	6	35
			Bagalkot	Vidayagiri	53	38	-	5	53
			Chikkballapur	Chikkaballapur rural	45	33	18	16	45
			Chickamangaluru	Kalyana nagar	52	52	35	25	28
			Mysuru	Hebbal Ist stage	52	35	24	13	52
			Rama nagara	Vijay nagar	39	39	30	15	9
Kerala	408	33-60	Ernakulam	Kacherypady	60	23	16	-	-
			Kannur	Thavakkara	59	53	59	18	14
			Kochi	Vyttila	52	27	28	6	2
			Kolam	Polayathode	47	37	47	13	5
			Kozhikode	Palayam	42	41	42	10	9
			Thiruvanthapuram	Kanavattorm	55	39	37	14	55
				Plammoodu	33	27	12	8	28
Madhya Pradesh	1485	45-169	Bhopal	T.T. Nagar	109	109	68	12	104
			Damoh	Shrivastav colony	45	-	45	19	-
			Dewas	Bhopal chauraha	110	101	110	22	74
			Gwalior	City Centre	95	44	24	11	95
				Phool bagh	72	-	72	-	-
			Indore	Chhoti Gwaltoli	100	100	78	61	37
			Jabalpur	Marhatal	104	104	55	27	64
			Katni	Gole Bazar	123	123	62	20	94
			Maihar	Sahilara	64	64	30	43	-
			Mandideep	Sector- D Ind. Area	59	59	58	16	25
			Pithampur	Sector-2 Ind. Area	116	116	78	14	16
			Singrauli	Vindhyachal	169	151	99	33	169
			Ujjain	Mahakaleshwar	159	114	159	16	150
Mizoram	1	24	Aizawaa	Sikulpuikawn	24	24	-	1	12
Jharkhand	46	93	Jorapokhar	Tata stadium	93	93	39	14	-
Assam	35	35	Guwahati	Railway colony	35	35	33	8	32
Odisha	74	99	Brajraj Nagar	GM office	99	99	95	-	-

State/ UT	Confirmed COVID-19 cases	AIR Quality status ( PM10, PM2.5, NO2 and Ozone values in microgram per meter cube)
Maharasthra	4666	AQI range	City	CAAQMS Location	AQI	PM10	PM2.5	NO2	Ozone
		44-89	Aurangabad	More chowk Waluj	52	38	33	17	52
			Chandrapur	Chandrapur	65	65	49	16	24
				Khutala	85	34	36	19	85
			Mumbai	Bandra	55	55	27	5	-
				Chhatrapati Shivaji Int. Airport	60	60	-	7	-
				Colaba	44	-	26	3	44
				Kurla	76	76	-	20	18
				Powai	78	62	29	3	26
				Sion	89	89	50	18	34
				Worli	52	52	30	5	28
			Nasik	Gangapur road	56	41	39	26	56
			Navi Mumbai	Mahape	87	87	42	30	42
				Nerul	70	69	44	13	28
			Pune	Karve road	50	35	37	11	20
			Solapur	solapur	44	44	42	-	36
Punjab	245	30-96	Amritsar	Golden temple	43	40	17	17	43
			Bathinda	Hardev nagar	96	32	11	23	-
			Jalandhar	Civil line	36	36	35	11	18
			Khanna	Kalal majra	33	33	25	8	20
			Ludhiana	Punjab Agri. Univ.	35	25	22	20	35
			Mandi Govindgarh	RIMT univ	96	32	11	23	96
			Patiala	Model town	37	37	24	8	17
			Rup nagar	Ratanpura	30	30	24	16	-
Rajasthan	1576	57-82	Alwar	Moti Doongri	66	39	35	43	66
			Ajmer	Civil line	77	51	31	11	77
			Bhiwadi	RIICO Ind. Area-III	74	74	55	15	55
			Jaipur	Adarsh nagar	82	30	22	15	82
				Police Commissionerate	68	58	43	22	68
				Shatri nagar	70	28	22	19	70
			Jodhpur	Collectorate	79	79	52	27	53
			Kota	Shrinathpuram	57	38	34	17	57
			Pali	Indra colony vistar	76	76	51	15	75
			Udaipur	Ashok nagar	81	55	44	15	81

State/ UT	Confirmed COVID-19 cases	AIR Quality status ( PM10, PM2.5, NO2 and Ozone values in microgram per meter cube)
Tamilnadu	1520	AQI range	City	CAAQMS Location	AQI	PM10	PM2.5	NO2	Ozone
		26-68	Chennai	Alandur bus depot	26	-	16	2	26
				Manali village	68	-	16	8	68
				Manali	40	-	37	9	-
				Velachri res area	40	-	5	2	30
Telangana	873	41-60	Hyderabad	Bollaram Ind. area	53	53	42	39	28
				Central Univ.	45	35	22	45	5
				ICRISAT	41	41	30	22	20
				IDA Pasahamylaram	50	46	35	50	24
				Sanathnagar	49	-	48	12	49
				Zoo park	60	-	60	54	19
Uttar Pradesh	1184	55-161	Agra	Sanjay palace	114	-	114	64	11
			Bulandshahr	Yamunapuram	161	161	137	29	117
			Ghaziabad	Indirapuram	89	89	57	25	82
				Loni	123	123	90	16	82
				Sanjay nagar	109	109	95	44	60
				Vasundhara	89	89	67	51	22
			Greater Noida	Knowledge park III	113	113	82	-	92
				Knowledge Park V	102	102	-	26	90
			Hapur	Anand vihar	159	159	83	74	2
			Kanpur	Nehru nagar	62	-	50	13	62
			Lucknow	Central School	114	-	114	9	11
				Gomti nagar	74	-	74	24	59
				Lal bagh	55	-	43	22	18
				Talkatora distric centre	67	-	67	9	-
			Meerut	Ganga nagar	92	92	48	24	28
				Pallavpuram phase II	113	113	60	16	18
			Mujaffar nagar	New mandi	103	103	67	7	19
			Noida	Sector 62	89	72	89	17	65
				Sector 1	104	104	55	19	83
				Sector116	77	-	77	23	46

State/ UT	Confirmed COVID-19 cases	AIR Quality status ( PM10, PM2.5, NO2 and Ozone values in microgram per meter cube)
West Bengal	392	AQI range	City	CAAQMS Location	AQI	PM10	PM2.5	NO2	Ozone
		21-69	Howrah	Belur Math	21	21	14	20	-
				Ghusuri	58	42	27	18	56
				Padmapukar	28	27	28	13	13
			Kolkatta	Bollygunge	52	27	13	6	52
				Bidhan nagar	48	25	20	7	48
				Fort Villiam	55	26	23	14	55
				Jadavpur	27	27	16	11	20
				Ravindra Bharti Univ.	69	25	20	25	69
				Rabindra sarobar	48	21	-	8	48
				Victoria	41	31	18	16	41
			Sliguri	Ward 32 Bapupura	38	32	38	38	22

The above data of current Air Quality vs Confirmed COVID-19 cases in India do not show any clear relationship. However, long term exposure of higher levels of air pollutants, particularly higher PM2.5 levels, may weakens the immunity and thus raises the risk of COVID-19 infection. Detailed study in this regard is needed.

However, as per present study, the levels of NO2 and Ozone throughout  the India are found within the National Ambient Air Quality Standards, notified as per the Central Pollution Control Board Notification in the Gazette of India,  dated 18th November, 2009 ( PM10 std. 24 hourly = 100 microgram per meter cube, PM2.5 std. 24 hourly = 60 microgram per meter cube, NO2 std. 24 hourly = 80 microgram per meter cube and Ozone std. 1 hourly = 180 microgram per meter cube).

Though, levels of PM10 and PM2.5 have significantly declined during Lockdown period as compared to Normal days. However, levels of PM10 and PM2.5 in some States/ UTs at few locations are found above the Standards.

Though, presently, we have observed clean air due to the lockdown in India but this respite is for short term period.  After the restrictions are lifted and human activities start, there will be a sudden rise in air pollution.   But, the lockdown  during  COVID-19 has shown ways to tackle air pollution issues, only what’s needed is political will, societal interventions and strict enforcement.