Air pollution occurs when gases, dust particles, fumes (or smoke) or odor are introduced into the atmosphere in a way that makes it harmful to humans, animals and plant. This is because the air becomes dirty (contaminated or unclean). During our work in the field, we have often encountered statements like “our clothes become dirty when left out in the open”, “there is a thin layer of dust on everything after some time” etc. However such statements although true lack any basis and proof and we cannot have a comparison regarding how bad is the air in the area compared to let’s say air near our office in Delhi. How safe is the sir I breathe in my room? Is my health being impacted due to the air I breathe while commuting to office or while in office? These questions have no easy answers.

However, a start can be made by monitoring the amount of dust particles which are in the air along with comfort factors like Temperature and humidity. Measuring the amount of dust particles and comparing these results with the Air Quality Index for India can give a measure of how polluted the air is while comfort factors like Temperature and humidity can help in gauging the impact of climate change, construction, vehicle density and other factors in the area.

Environics Trust has procured some devices which can do exactly this task – measure different sizes of dust particles (PM 1, 2.5, 10), temperature and humidity. There are sensors available to measure other polluting and harmful factors like CO, SO2, NOx etc, and these sensors may be incorporated in future devices which will be procured.

The Sensors inside the device sense the physical quantity and convert it in to electrical quantity by which we can get the accurate data of the pollutants. It is important to note that dust sizes below 2.5 micron is especially hazardous to the humans and these particles can by-pass the safety mechanisms of our body and get lodged into our lungs. As we may be aware, cases of asthma and respiratory disorders are on the rise in almost all cities and dust particles of these sizes are the cause. Also, we are unable to distinguish what these dust particles actually are, they may be silica, asbestos or anything else. This classification can only be done after taking a sample and testing in a lab.

The Device – In our monitoring device there are following components:-

  1. ESP 8266-NODE MCU 12E:-This is the main part or the controller of the device. All the data of the sensors, sim card and battery are controlled by this component. A program has been developed which instructs the control to perform necessary actions. The chip is Wi-Fi enabled and this feature may be used in future.
  2. SPM MONITOR PMS 5003:- sensor to measure or monitor the dust particles present in the air.
  3. AM 2320:- Sensor to measure and record temperature and humidity.
  4. SIM MODULE: – In this module we insert the sim card which is used to transmit the data to the server where the data is store and presented as graph.
  5. VOLTAGE MODULE: – With the help of this module we can charge the battery of the device.
  6. VMOS BATTERY:-We use a battery of 3000 mAH (miliAmpere-hour)

Objective: As we all know that in Nov 2016 the air pollution of Delhi reached critical levels. The government officials blamed this on the farmers in Punjab and Haryana who burn their crop stubbles and have been doing the same for many years. No one bothered to question that if this activity caused so much pollution in Delhi, what would be the impact in Punjab and Haryana itself.

Another major concern is that in the mining areas / other hazardous work places as per monitoring’s done by the government agencies and the business owners, the air quality is normal and within legal parameters. However, communities in the vicinities have regularly cited health and other problems related to air pollution caused due to such industrial activities. So far they did not have a way to put forward this issue in a scientific way with DATA.

Another very important issue is the dust levels in the workplace itself. Although if the dust is high in the environment outside the factory, it can be assumed that it will be high inside the factory also. A worker spends about 10-12 hours inside the factory breathing this hazardous completely ignorant about the impact on his heath. Even his family members are at risk as the dust may be present on the clothes he wears back from work.

Moreover the government agencies which are involved in monitoring’s have only a few devices which are placed in so called monitoring stations which are established in only a few locations and may not capture the accurate pictures. Also these agencies usually put in public domain only average figures which may not be real time and many a times manipulated figures. In Delhi there are only 10 such stations while Haryana has 4 stations which give an hourly data based on AQI standards

These monitors procured by Environics trust will help us in measuring dust, temperature and humidity accurately in real time in places close to mines, thermal power plants, cities and other places and put forward the argument scientifically and with data which was so far stated only in statements and thus ignored by concerned people. This data will also force the officials to look at real causes of climate change and impact on air quality rather than make tall claims and accusations.

AIR QUALITY INDEX in India: –   The Minister for Environment, Forests & Climate Change, Shri Prakash Javadekar launched The National Air Quality Index (AQI) in New Delhi on 17 September 2014 under the Swachh Bharat Abhiyan. There are six AQI categories, namely Good, Satisfactory, Moderately polluted, Poor, Very Poor, and Severe. The proposed AQI will consider eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb) for which short-term (up to 24-hourly averaging period) standards are prescribed. Based on the measured ambient concentrations, corresponding standards and likely health impact, a sub-index is calculated for each of these pollutants.

AQI Category, Pollutants and Health Breakpoints
AQI Category (Range) PM10 (24hr) PM2.5 (24hr) NO2 (24hr) O3 (8hr) CO(8hr) SO2 (24hr) NH3 (24hr) Pb(24hr)
Good (0-50) 0-50 0-30 0-40 0-50 0-1.0 0-40 0-200 0-0.5
Satisfactory (51-100) 51-100 31-60 41-80 51-100 1.1-2.0 41-80 201-400 0.5-1.0
Moderately polluted (101-200) 101-250 61-90 81-180 101-168 2.1-10 81-380 401-800 1.1-2.0
Poor (201-300) 251-350 91-120 181-280 169-208 10-17 381-800 801-1200 2.1-3.0
Very poor (301-400) 351-430 121-250 281-400 209-748 17-34 801-1600 1200-1800 3.1-3.5
Severe 430+ 250+ 400+ 748+ 34+ 1600+ 1800+ 3.5+

Brief Analysis of usage of devices so far

At 2 locations near our office

Location – Z More                  GPS location   – N 28 30 46.7 E 77 12 13.0

Time: May 23- 12:30 to 12:40 PM and 5:40 to 5:55 PM / May 24 –11:20 to 11:30 AM and 5:16 to 5:30 PM

  23 May Morning 24 May 23 May Evening 24 May
  Avg Max Min Avg Max Min Avg Max Min Avg Max Min
Temperature 40.74 41.80 38.60 48.76 54.00 40.80 38.35 38.90 37.50 39.67 41.00 38.10
Humidity 24.96 27.90 23.20 21.00 27.30 16.80 27.30 29.40 26.30 26.93 28.10 25.40
PM1 51.68 74.40 38.80 59.77 67.70 54.40 62.39 82.20 47.70 47.45 64.40 39.90
PM 2.5 71.77 101.10 49.90 79.79 94.40 72.20 89.95 130.00 63.30 66.81 94.40 51.10
PM 10 83.53 121.10 56.60 90.82 114.40 78.80 111.32 176.60 68.80 79.68 125.50 53.30

Table 1 – Values of different Pollutants at Location Z More

Location – Near Shani Bazaar                     GPS Location – N 28 30 55.0 E 77 12 20.0

Time: May 23- 12:30 to 12:40 PM and 5:40 to 5:55 PM / May 24 –11:20 to 11:30 AM and 5:16 to 5:30 PM

  23 May Morning 24 May 23 May Evening 24 May
  Avg Max Min Avg Max Min Avg Max Min Avg Max Min
Temperature 41.28 42.20 40.40 49.57 52.40 46.70 38.11 38.20 37.80 43.52 52.40 40.90
Humidity 22.61 23.60 21.50 18.79 20.40 17.20 27.29 27.90 26.90 25.42 26.00 25.00
PM1 49.59 156.60 26.60 59.28 73.30 51.10 71.95 157.70 40.00 53.45 89.90 39.90
PM 2.5 67.17 216.60 34.40 75.82 91.10 66.60 117.95 360.00 50.00 68.85 111.10 49.90
PM 10 75.56 232.20 38.80 82.55 103.30 72.20 165.21 620.00 56.60 77.38 128.80 55.50

Table 2 – Values of different Pollutants at Location Shani bazaar

Devices were handed over to ET Colleagues on 23 May to take home and measure these values at their respective houses. Below are the results of measurements.

Location 1 Location 2 Location 3 Location 4
Avg Max Min Avg Max Min Avg Max Min Avg Max Min
Temperature 33.68 35.00 30.30 33.18 35.40 26.80 35.60 39.00 30.80 33.87 35.90 30
Humidity 60.35 92.90 41.60 40.04 46.50 31.50 27.37 36.50 19.60 31.97 39.30 28
PM1 210.48 906.60 8.80 49.77 104.40 18.80 119.96 656.60 10.00 116.31 262.20 4
PM 2.5 299.36 1768.00 10.00 68.79 140.00 29.90 175.04 1870 12.20 155.90 358.80 10
PM 10 347.83 2318.00 10.00 80.21 166.60 32.20 207.27 3122 12.20 175.10 424.40 18

Table 3

Office Location 5 Location 6 Location 7
Avg Max Min Avg Max Min Avg Max Min Avg Max Min
Temperature 33.00 33.70 30.50 33.36 36.60 29.60 33.83 37.20 31.10 35.14 37.1 31.5
Humidity 41.04 42.60 37.20 37.52 47.60 24.90 36.09 45.00 23.70 31.76 52.10 27.4
PM1 132.44 268.80 40.00 82.67 266.60 4.40 92.86 596.60 8.80 88.52 210.00 18.8
PM 2.5 168.17 350.00 48.80 113.86 334.40 4.40 132.93 1082.00 10.00 117.66 276.60 28.8
PM 10 182.24 398.80 48.80 125.18 388.80 4.40 149.45 1366 10.00 133.53 344.40 28.8

Table 3/4 – Values of Pollutants at houses of ET Staff

Brief Analysis

  • Monitoring’s near the office at Z More on IGNOU Road saw temperatures reaching about 52.4 Deg on 24 May. PM levels were the highest during 23 May evening. The dust levels were even higher on 23 evening at Shani Bazaar and went up to 620 (PM 10)
  • Average Dust levels were higher on 24 morning as compared to 23 Morning. This could be because there was rainfall the day before. However, in the evening average dust levels were higher on 23 as compared to 24 May. This trend was noticed at both locations.
  • Location 3 saw a spike in Dust starting at 6:47 PM on 23 May and went up to 1936 (PM 10). The values went down to 256 (PM10) at 7:11 PM. Again on 24 May between 7:35 PM and 7:55 the values are above 1000 going up to a maximum of 2736(PM10). The levels were even higher on 25 May and went upto 3122 at 9:56 AM. As intimated the device was kept in the temple
  • At Location 7, the value of PM 10 suddenly increased to 334 at 4:50 PM. The values remained more than 100 till 1 PM the next day. The avg dust level for this time period was 186.
  • At Location 2 temp at 10:25 PM was 31.6 which reduced to 26.8 at 11:33 PM and started increasing thereafter. This suggests that some Air conditioning device was switched on during this time. Humidity showed a decrease as well in the same period.
  • At location 4, when not at home (during office hours) dust levels were noticed to be less than 70 (average of 59). When at home the average dust levels went to 227 with a high of 358. Urgent need to decipher this trend.
  • Location 1 – PM (1, 2.5 and 10) increased suddenly from 92,110 and 110 respectively to 346.6, 442.4 and 500 at 6:53 AM on 25 May and for an hour the readings were high. The levels again increased at 9:21 AM for about 30 minutes and at 1:30 PM for 30 minutes, and at 8:10 PM for 30 minutes again. Moreover the humidity levels at the place are high. The location has a cooler which explains the high level of humidity at his place.

Challenges / Issues

  • Calibration of sensors – the sensors being low cost, there can be some issues with regards to calibration of the sensors. This was evident when two machines were used at the same place and gave very different results. Work is continuing to ensure comparability of all the sensor devices.
  • Mobile Network and data issues – the device uses a sim card and data connection to report the measurements to a web site. However, due to mobile network congestion or weak network signal, many times, the sim card is unable to send the values to the website leading to data gaps. Also, to fix the issue, the device needs to be switched on/off repeatedly when the problem occurs. Work is in progress to fix this issue urgently.
  • Temperature – when kept in direct Sunlight or on a hot surface, the temperature recorded is especially high going above 55 deg. Redesign of the box will help in fixing this issue.

Note –

  • Although the calibration issue is prevalent, this should not disregard the extremely high values which were noticed and steps should be undertaken to reduce the high dust levels
  • There are no legal limits for temperature and humidity in the ambient air or in the environment. However as per Factories Act and Mines Act, there are legal limits for temperature and humidity in workplaces. For eg as per Gujarat Factories Rules 1963, the temperature in a workroom at a height of 1.5 (meter) above the floor level shall not exceed 30°C measured using wet bulb thermometer (about 34°C using dry bulb).

Authors – Mohit Gupta and Shalini Singh