The air quality and pollution city tracking service from IQAir, a Switzerland-based climate group that is also a technology partner of the United Nations Environmental Program, has shown that there are as many as three cities from India on the list of ten cities with the worst air quality indices.

The ten cities with the worst air quality indicators and pollution rankings, according to IQAir:

1. Delhi, India (AQI: 556)
2. Lahore, Pakistan (AQI: 354)
3. Sofia, Bulgaria (AQI: 178)
4. Kolkata, India (AQI: 177)
5. Zagreb, Croatia (AQI: 173)
6. Mumbai, India (AQI: 169)
7. Belgrade, Serbia (AQI: 165)
8. Chengdu, China (AQI: 165)
9. Skopje, North Macedonia (AQI: 164)
10. Krakow, Poland (AQI: 160)

National Clean Air Programme (NCAP)

It  is a  time bound national level strategy for pan India implementation to tackle the increasing air pollution problem across the country in a comprehensive manner .

• It is a five-year action plan to tackle pollution across the country.
• Collaborative and participatory approach involving relevant Central Ministries, State Governments, local bodies and other Stakeholders with focus on all sources of pollution forms the crux of the Programme.
• Overall objective of the NCAP is comprehensive mitigation actions for prevention, control and abatement of air pollution besides augmenting the air quality monitoring network across the country and strengthening the awareness and capacity building activities.
• The tentative national level target of 20%–30% reduction of PM2.5 and PM10 concentration by 2024 is proposed under the NCAP taking 2017 as the base year for the comparison of concentration.
• Other features of NCAP include, increasing number of monitoring stations in the country including rural monitoring stations, technology support, emphasis on awareness and capacity building initiatives, setting up of certification agencies for monitoring equipment, source apportionment studies, emphasis on enforcement, specific sectoral interventions etc.

                      LEARNING FROM HOME/ WITHOUT CLASSES/ BASICS

PM2.5 means particulate matter in the air – caused by motor exhaust or anything combustible – that is less than 2.5 micrometers. Fine particulate matter (PM_2.5) is an air pollutant that is a concern for people’s health when levels in air are high

           WHO’s air quality guidelines state that by reducing particulate matter (PM10) from 70 to 20 micrograms per cubic metre, air pollution-related deaths could be reduced by roughly 15 per cent. WHO safe limits for annual mean of PM 2.5 and PM 10 levels are 10 and 20 micrograms per cubic meter.

            Airborne particles are sometimes referred to as ‘particulate matter’ or ‘PM’. They include dust, dirt, soot, smoke, and liquid droplets. Some particles are emitted directly into the air from a variety of sources that are either natural or related to human activity. Natural sources include bushfires, dust storms, pollens and sea spray.

          Those related to human activity include motor vehicle emissions, industrial processes (eg electricity generation, incinerators and stone crushing), unpaved roads and woodheaters.

                Particles can be classified on the basis of their size, referred to as their ‘aerodynamic diameter’. ‘Coarse particles’ are those between 10 and 2.5micrometres (µm) in diameter; ‘fine particles’ are smaller than 2.5 µm;and ‘ultrafine particles’ are smaller than 0.1 µm. Studies have linked exposure to particle pollution to a number of health problems including respiratory illnesses (such as asthma and bronchitis) and cardiovascular disease.

                              INDIA’S STANDARD FOR LEVEL OF POLLUTION

India has set standards for what it thinks are appropriate warnings for a particular level of pollutant. AQI help in comparing pollution levels at a glance with a colour code and a numerical value. In India, AQIs are determined based on the concentrations of seven pollutants, including PM2.5 (fine, respirable particles), sulphur dioxide (SO2), nitrogen dioxide (NO2) and carbon monoxide (CO).There are six AQI categories, namely: Good, Satisfactory, Moderately polluted, Poor, Very poor and Severe.

                   India has also introduced BS-VI emission standards.