Focus

Highlights

1. 1.

   Particulate matter 2.5 micrometres or smaller is one of six common pollutants monitored by environmental agencies worldwide. Components of PM2.5 include sulphates, black carbon, nitrates and ammonium. Combustion engines, industrial activities, coal and wood burning, agricultural activities are some human sources of PM2.5 while dust or sand storms and wildfires are some natural sources.

2. 2.

   In 2023, Bangladesh recorded the highest average concentration of PM2.5 at 79.9 micrograms per cubic metre (μg/m3). It was followed by Pakistan (73.7 μg/m3), India (54.4 μg/m3), Tajikistan (49 μg/m3) and Burkina Faso.

3. 3.

   Of the 134 countries and territories included in this report, French Polynesia had the lowest average concentrations of PM2.5 in 2023 – 3.2 μg/m3. Mauritius recorded slightly higher levels (3.5 μg/m3) followed by Iceland (4 μg/m3), Grenada (4.1 μg/m3) and Bermuda (4.1 μg/m3).

4. 4.

   The report also ranks capital cities based on population weighted average concentrations of PM2.5 recorded in 2023. New Delhi tops the list with the highest concentration – 102.1 μg/m3. It is followed by Dhaka, Bangladesh (80.2 μg/m3); Ouagadougou, Burkina Faso (46.6 μg/m3); Dushanbe, Tajikistan (46 μg/m3) and Baghdad, Iraq (45.8 μg/m3).

5. 5.

   On the opposite end, San Juan, Puerto Rico recorded the lowest average PM2.5 levels at 2.7 μg/m3. Other capital cities with similarly low levels were: Wellington, New Zealand (3.1 μg/m3); Canberra, Australia (3.8 μg/m3); Reykjavik, Iceland (3.9 μg/m3) and Hamilton, Bermuda (4.1 μg/m3).

6. 6.

   India’s annual average PM2.5 concentrations rose slightly between 2022 and 2023 from 53.3 μg/m3 to 54.4 μg/m3. Levels in National Capital Territory, Delhi rose by 10 per cent in 2023 compared to the previous year and saw a peak in November reaching 255 μg/m3. The report notes that emissions from vehicles contribute to 40 per cent of the pollution in the capital territory. The region is also known to burn around 1.87 million tons of coal annually.

7. 7.

   In India, the most polluted city in 2023 was New Delhi with an average PM2.5 concentration of 102.1 μg/m3. Other cities included Kolkata (47.8 μg/m3), Mumbai (43.8 μg/m3), Hyderabad (39.9 μg/m3), Bengaluru (28.6 μg/m3) and Chennai (28 μg/m3).

8. 8.

   According to the report, as many as 1.3 billion people in the country (96 per cent of the population) experience PM2.5 levels more than seven times of the 5 μg/m3 outlined in the WHO guidelines.

9. 9.

   The report notes that regions which are most affected by pollution, at times, have less access to resources such as air quality monitoring stations. Thus, data accumulation in such places is often an uncertain endeavour.

   
   

   Focus and Factoids by Swadesha Sharma.