PM2.5 levels around the world
PM2.5 refers to fine particles (2.5 microns in size or less) that are released into the atmosphere when carbons are burned, such as farm waste, transportation fuels, or fossil fuels for electric generation. For reference, a human hair is about 50 to 70 microns in diameter. PM2.5 is of particular (no pun intended) concern, as pollution of this size can get deep into one's lungs unless one wears an appropriate respirator (N95 or N99 mask) when exerting oneself when a lot of the pollution is present.
Japan on its own does not produce enough of these particles to often pose a serious health risk, but our neighbor, China, relies on burning coal for some 70% of its electricity. As a result, their air is often unsafe to breathe. Greenpeace studied the matter and estimates that an astonishing 257,000 deaths per year in China are due to pollution from coal burning power plants!
This problem now affects South Korea and Japan because the prevailing winds bring this dirty air from China to our shores. Depending on the weather, the air in Japan can become unsafe due to Chinese pollution requiring people to wear masks outdoors or school children to remain indoors, as happened recently in Niigata Prefecture.
I have added a widget to the right column of this blog which gives the air quality for Kashima City. It comes from an interesting website which tracks air quality around the world: Air Pollution: Real-time Air Quality Index.
Here's a guide to the meaning of the widget's colors:
|0-50 = Good|
Air pollution poses little or no risk
|51-100 = Moderate|
Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.
|101-150 = Unhealthy for Sensitive Groups|
Members of sensitive groups may experience health effects. For example, people with lung disease are at greater risk from exposure to ozone, while people with either lung disease or heart disease are at greater risk from exposure to particle pollution. Active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy exertion outdoors. The general public is not likely to be affected when the AQI is in this range.
|151-200 = Unhealthy|
Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects. Active children and adults, older adults, and people with lung disease, such as asthma, should avoid prolonged or heavy exertion outdoors. Everyone else, especially children, should reduce prolonged or heavy exertion outdoors.
|201-300 = Very Unhealthy|
Health alert: everyone may experience more serious health effects. Active children and adults, older adults, and people with heart or lung disease, such as asthma, should avoid all outdoor exertion. Everyone else, especially children, should avoid prolonged or heavy exertion outdoors.
This takes me back to my teen years in the San Fernando Valley near Los Angeles in the 1960s. The chemical pollution from automobiles was so bad that the air was unsafe and could make one's throat and lungs ache with a burning sensation. At times the air had a brownish tinge that limited visibility to under five miles. I vividly remember taking a trip to Washington State with my parents in my father's small airplane. When we returned a few days later, we could see the smog as a brown bubble in the valley and when we descended into it, it smelled with an odor like chlorine, as when you walk into the building housing an indoor swimming pool! Yuck.
The Chinese government is trying to grapple with this issue, but a solution is a long way off. Until then, we will monitor our air quality and take steps on those days when we get this unwelcome "gift" from our big neighbor to the west.