Pure smoke in the chimney
About half of the world’s coal burning takes place in China, but the huge country also has one of the most ambitious schemes for converting its energy generation into clean and green energy.
unfiltered into the blood stream, which will carry them to all body tissue.
In 1991, American scientists, who had observed 8,111 individuals for 17 years, showed that early deaths were not evenly distributed among the populations of eight cities. There were more deaths in areas with considerable air particle pollution. In 1999, scientists were able to make another groundbreaking conclusion: cities which had done a lot to combat pollution in the previous eight years had reduced the number of early deaths considerably.
The positive message: it is worthwhile doing something – even in the short term.
In recent decades, scientists have also realised that the tinier the smog particles, the more hazardous they are. Tiny particles are more likely to produce reactive and highly oxidising peroxides. Oxidation is a harmful process for body cells, speeding up ageing and possibly converting healthy cells into cancer cells. In the cells, peroxides could harm other chemical compounds by oxidising them, so they can no longer function as intended, such as DNA and other cellular structures.
So, today efforts are focused on measuring and minimizing the number of harmful particles sized “PM2.5”. PM is short for particulate matter such as fine dust particles, and 2.5 refers to the diameter of the particles, which average 2.5 micrometres
( m). A 2.5 m particle is about 30 times smaller than the thickness of a human hair.
The particles form in several ways such as by combustion, oxidation of nitrogen and sulphur compounds, and other chemical reactions in the atmosphere. If you are surrounded by air with a high content of PM2.5 particles, you suffer a markedly greater risk of developing lung diseases such as asthma, bronchitis, and lung cancer. So, the WHO has established a threshold value of 10 microgrammes of the particles per cubic metre of air. Sadly, this threshold is often crossed by many cities of the world, including European ones, but the situation is the worst in China. Even when authorities have been forced to establish a higher threshold - 35 microgrammes per cubic metre - the cities are simply unable to comply.
Particles also exist which are tinier than PM2.5, whose sizes are measured on a nanoscale. Doctors are not yet sure, but the particles might cause other problem. Mouse studies show that particles of less than 200 nanometres or 0.2 m can enter directly from the respiratory system to the body, where they travel along nerve cells, ending up in the brain, where they cause infection and