Demonstration of Near-Referencemonitoring of air pollution using low cost compact air quality monitoring

stations in Delhi, India

Paul R PickeringCAA Better Air Quality Conference

Busan, South Korea29 August 2016

Acknowledgements

Paul R Pickering Nevco Engineers Pvt Ltd

Nick Reid Akansh Gupta

Dr Geoff Henshaw

TUV India Pvt Ltd Central Pollution Control Board

L N Bharti Dr D Saha

Asia’s air monitoring challenge

• Survey of 69 Asian cities in 17 countries found

70% have insufficient stations, not ideally located

and monitor few pollutants (ADB 2014)

• Air Quality Index representative of a city should

consider air quality data from different

microenvironments (IITM 2016)

• Sustainability of air quality monitoring networks is

a major challenge with budget constraints

More monitoring needed for India’s air pollution control policies

Study shows poor air quality reduces life expectancy

of Indians by 3.4 years and Delhi residents 6.3 years

(Ghude SD et al 2016)

Near-Reference instruments offer a realistic solution

• Strong statistical correlation to reference methods

• Calibration traceable to Standard Reference

Materials for high data quality objectives

• Reliably measure criteria air pollutants to

international standards e.g. EPA, EU, WHO

• Complement existing air pollution networks for

higher density, real-time data

• Easy to deploy for localised monitoring events

• Less expensive to own and operate

AQM 65 CAQMS PC, phone, tablet

Cloud serverModem

Low cost compact air quality monitoring station (CAQMS)

Secure real-time air data• ISO 27001 data centres

• Data access via secure website

• 256-bit SSL encryption

• User defined passwords

Central Pollution Control Board trials AQM 65 CAQMS in Delhi

Aeroqual AQM 65 CAQMS installed at the CPCB site

by Nevco Engineers and calibrated by TUV India

Purpose of the CPCB trial

• AQM 65 configured to deliver

Near-Reference data for O3,

NO2, CO, SO2 and PM2.5

• August 2015 to January 2016

• Demonstrate accuracy and reliability of CAQMS

• Evaluate fitness for purpose under challenging

environmental conditions

• Correlate with local reference air quality data

High data validity recorded for criteria pollutants

CO NO2 O3 SO2 PM2.5

Hourly

Number of

values3406 3686 3133 3684 3678

% Valid data 96.56 96.92 96.38 96.87 96.71

Daily

Number of

values152 159 155 159 159

% Valid data 95.0 99.4 96.9 99.4 99.4

The instrument recorded over 90% data validity for

hourly data and over 95% for daily data

Accurate and reliable in ambient conditions

CO NO2 O3 SO2 PM2.5

Hourly

Maximum 10.212 0.188 0.222 0.849 1233

Minimum 0.000 0.000 0.000 0.000 0.643

Average 1.572 0.023 0.037 0.022 191

SD 1.343 0.021 0.025 0.040 186

Daily

Maximum 6.240 0.050 0.100 0.140 713

Minimum 0.060 0.000 0.000 0.000 15

Average 1.560 0.020 0.040 0.020 190

SD 1.120 0.010 0.020 0.020 159

The instrument demonstrated excellent response

to ambient conditions and high data recovery

Local events captured in hourly average data

Good ability to measure high PM2.5 (>1000 µg m-3)

Seasonal variations captured in daily average data

Summer to winter transition shows higher PM, CO,

NO2 and SO2 while ozone levels declined

Hourly concentrations captured during Diwali period

Elevated PM2.5 and SO2 levels were approx. four

times higher than either side of Diwali

Diurnal and hourly pollutant patterns collected

Site pollutant behaviour was dominated by morning

and evening traffic and urban emissions

PM2.5 comparison to DPCC Reference Data

Good correlation with DPCC site 5 km to East

DPCC trials monitoring during the odd-even vehicle campaign

Delhi Pollution Control Committee uses AQM 65

for supplementary monitoring in January 2016

Hourly average concentrations during odd-even vehicle trial

Data from the AQM 65 at the CPCB site for first

week of the Delhi odd-even trial

Key conclusions

• The CAQMS demonstrated excellent response to

ambient conditions and high data recovery

• High pollutant concentrations during Diwali were

captured and documented

• Diurnal pollutant variations collected and analysed

• PM2.5 channel correlated well with DPCC station

5km E indicating high regional PM contributions

• CPCB concludes AQM 65 ‘works consistently

including data generation up to 90% and to our

satisfaction’

Letter from CBCB India

“The instrument

(AQM 65) was

found to work

consistently

including data

generation up to

90% and to our

satisfaction.”

D Saha, Scientist ‘E’,

In-charge Air Lab,

CPCB

Thank you for your attention