The World Health Organization (WHO) has established safe levels for the concentration of fine particulate matter, known as PM2.5. These are tiny particles in the air that can penetrate deep into the lungs and cause respiratory and cardiovascular problems. The WHO guidelines state that the safe level for PM2.5 is an annual average of 10 micrograms per cubic meter (μg/m3), and a 24-hour average of 25 μg/m3. However, many people around the world are still exposed to levels above these limits, with significant health consequences.
PM2.5 is produced by a range of human activities, including burning fossil fuels, industrial processes, and transportation. Natural sources such as wildfires and dust storms can also contribute to PM2.5 levels. The particles are so small that they are invisible to the naked eye, but they can have a significant impact on human health. When inhaled, PM2.5 particles can travel deep into the lungs and enter the bloodstream, causing inflammation, damage to lung tissue, and increased risk of heart disease and stroke.
According to the WHO, around 7 million people die each year as a result of exposure to air pollution, with PM2.5 being a significant contributor to these deaths. Many more people suffer from respiratory and cardiovascular diseases that are linked to air pollution, leading to a significant burden on healthcare systems worldwide.
Despite the serious health consequences of exposure to PM2.5, many people around the world are still exposed to levels above the WHO safe limits. In fact, according to a 2020 report by the State of Global Air project, 91% of the world's population lives in areas where PM2.5 levels exceed the WHO guidelines. This includes both urban and rural areas, with the highest concentrations of PM2.5 found in low- and middle-income countries.
The report found that in 2019, the global average concentration of PM2.5 was 24 μg/m3, well above the WHO safe level. The highest levels of PM2.5 were found in South Asia and sub-Saharan Africa, with annual average concentrations of 69 μg/m3 and 40 μg/m3, respectively. In comparison, North America had an annual average concentration of 8.3 μg/m3, while Europe had an average of 14 μg/m3.
While many countries have made progress in reducing PM2.5 levels in recent years, there is still much work to be done to ensure that everyone has access to clean air. The WHO recommends a range of interventions to reduce air pollution, including improving public transportation, increasing access to clean energy sources, and promoting active transport such as cycling and walking. In addition, policies and regulations are needed to limit emissions from industry and transportation.
In conclusion, the WHO safe levels for PM2.5 are an annual average of 10 μg/m3 and a 24-hour average of 25 μg/m3. However, many people around the world are still exposed to levels above these limits, with significant health consequences. It is essential that governments and individuals take action to reduce air pollution and ensure that everyone has access to clean air. By doing so, we can reduce the burden of respiratory and cardiovascular disease and improve the overall health and wellbeing of people worldwide.