China currently suffers from the world's heaviest PM 2.5 pollution. In recent years outdoor air pollution in numerous Chinese cities has exceeded levels set by the EU by over 30
times and does not appear to be declining.
Unfortunately this is not confined to our external environment as outdoor pollution inevitably leads to higher levels of indoor pollution. Compounding the problem is the fact that China lacks the
level of regulatory protection that is present in developed countries leading to high levels of unsuspected indoor pollutants. These may include mold, lead and toxic chemicals evaporating
from new furniture and household objects, and toxins leaching from building materials due to poor-quality construction.
Which pollutants are present in Shanghai`s air?
Nitric oxide (NO) - major sources are combustion processes (heating, power generation and engines in vehicles and ships)
Long-term exposure increases symptoms of bronchitis in asthmatic children and causes reduced lung function and lung development (note this effect is already being seen at
concentrations currently found in European and U.S. cities)
Sulfur dioxide (SO2) - main source is burning of sulfur-containing fossil fuels for domestic heating, power generation and motor vehicles
Coughing, excess mucus secretion, aggravation of asthma and chronic bronchitis, increased susceptibility to respiratory infections, eye irritation
Ozone (O3) - is mainly formed from NO and VOCs with sunlight;
Irritation of eyes, nose, respiratory system and lungs
Carbon monoxide (CO) - a toxic gas formed in combustion processes; main sources are gas stoves, burning of wood and coal, vehicle gases from closed garages and combustion
motor-powered ventilation and generators. CO binds to red blood cells and interferes with oxygen transport
Heavy metals - emitted from industrial processes and traffic, heavy metals can stick to fine dust particles and enter the lungs and blood stream. Organic heavy metal
compounds are of special concern since they can pass the blood-brain-barrier and cause damage to the brain.
Particulate matter- PM affects more people than any other pollutant. It is a complex mixture of mineral dusts (silicates, sulfates, nitrates,
asbestos etc), black carbon and organic matter (pollen, bacteria). The most health-damaging particles measure less than 10 μm (≤ PM10) and can
penetrate deep into the lungs. Particles smaller than 2.5 μm are able to penetrate into the gas exchange regions of the lungs and enter the blood stream. Air quality measurements
typically report PM10 and PM2.5 concentrations in micrograms per cubic meter (μg/m3). The AQI (air quality index) is a
useful tool to visualize the results on a scale from 0 - 500. The AQI is related to the actual PM concentrations, but it is not proportional to them over the whole scale (see diagram
below). Because not all measuring stations use the same formula to calculate the AQI, the μg/m3 value is more reliable.
Higher risk of cardiovascular and respiratory diseases, arteriosclerosis, heart attack, lung cancer and brain damage possibly including Alzheimer’s disease. Even low concentrations
may have health consequences, therefore the WHO 2005 guidelines recommend the lowest possible concentrations of PM. There is a close, quantitative relationship between exposure to high
concentrations of PM10 and PM2.5 and increased mortality.
AQI calculation according to the formula used by the American embassy