A recent report from the World Meteorological Organization (WMO) states that, China and Europe have recorded below-average PM2.5 levels in 2023, thanks to decreased anthropogenic emissions.   According to WMO report, PM2.5 emissions from wildfires in North America are unusually high. Meanwhile, India is experiencing above-average PM2.5 levels due to increased pollution from human and industrial activities. In contrast, China and Europe are reporting lower-than-average PM2.5 measurements.   “The 2023 data shows a negative anomaly, which means a drop in PM2.5 compared to the reference period of 2003-2023 over China and Europe,” said Lorenzo Labrador, a scientist at the WMO.   PM2.5 nanoparticles, measuring less than 2.5 micrometers in diameter, pose significant health risks when inhaled over extended periods, as they can enter the bloodstream. These particles originate from human activities such as fossil fuel combustion, transportation, and industrial processes, as well as natural sources like wildfires and wind-blown desert dust.   The report says that a vicious cycle of climate change, wildfires and air pollution is having a spiraling negative impact on human health, ecosystems and agriculture. Evidence shows that in severely polluted areas, particles can decrease crop yields by as much as 15%. This occurs because particles reduce the amount of sunlight reaching leaf surfaces and physically blocks leaf stomata, which are essential for the exchange of water vapor and carbon dioxide with the atmosphere.