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)
    Health effects:
      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
    Health effects:
    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; 
    Health effects: 
      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. 
    Health effects:
    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


  • Get your home/office/school checked for air pollutants
  • Check AQI values regularly and follow the recommendations
  • On days with heavy pollution, wear a well-fitting face mask. Choose a mask which filters particles smaller than PM 2.5. 'Standard N95' for example means that the mask filters 95% of all dust particles larger than 0.3 micrometers. The form of the mask has to seal well around the nose and mouth so that as little air as possible is breathed in through the gaps between the mask and the user. Vogmasks show the best performance in tests and there are also special models for children
  • Get the right air purification system for your home / office / school. We recommend a combination of air conditioning and purification as the most effective way to provide clean indoor air, especially in spacious interiors
  • For standalone air purifiers, three filters are important, namely a pre-filter, a HEPA filter and an activated coal filter. Additional filters are not necessary; however an air quality light sensor and an alarm for filter change are very useful features
  • Place plants around the home
  • Avoid ionization methods and oxidative sprays as they destroy some toxic substances, but release others instead! If it´s not possible to remove the source of bad smells, odor absorbents for small rooms and air purification systems with integrated activated coal filters for larger rooms are healthier and more effective!