July 1, 2011

Case study: Cities with Best and Worst air quality

Top 10 cities with world's best air

In June of 2008, There was a rank graded by Mercer Consulting for cities with the best quality in the world. Mercer Consulting established the scale on a point-by-point scoring indicator. This point by point scoring had Zurich 108.0 points while Baghdad merely scored 13.5 points. The cities were all based on with a comparison with New York with an index score of 100 points. This quality of live scale rates 215 cities around the world. The scale is used by different companies to position employees in cities for international assignments.

1. Zurich, Switzerland
2. Vienna, Austria &  Geneva, Switzerland
4. Vancouver, Canada
5. Auckland, New Zealand
6. Dusseldorf, Germany
7. Munich, Germany
8. Frankfurt, Germany
28. Honolulu, USA
38. Birmingham, UK.
49. New York, USA
56. Glasgow, UK
72. San Juan, Puerto Rico
80.  Cape Town , South Africa
202. Port au Prince, Haiti
215. Baghdad, Iraq

Top 10 cities with world's worst air

In 2010, there are several charts about world's cities with poor air quality. The ranks are different based on different criteria. I choose  24/7 Wall St.'s rank because it reviewed several dozen studies on air quality conducted over the past few years, along with data from government websites and private sources. Our review examined data about the following pollutants: 
  • Sulfur dioxide: Produced when fossil fuels are burned and is the primary cause of acid rain. Exposure causes eye irritation, coughing, worsening of asthma and respiratory-tract infections.
  • Nitrogen dioxide: Produced by generators, power plants and motor vehicles. It has been shown to cause bronchitis and other pulmonary diseases.
  • Particulates: Refers to a variety of small pollutants, including lead, dust, ammonia, soot and pulverized minerals. They're a leading cause of lung cancer. According to the World Health Organization (WHO), mortality in cities with high levels of particulates "exceeds that observed in relatively cleaner cities by 15% to 20%."
With that background, here are 24/7's 10 cities with the worst air quality:
1. Beijing, China
1. New Delhi, India
3. Santiago, Chile
4. Mexico City, Mexico
5. Ulaanbaatar, Mongolia
6. Cairo, Egypt
7. Chongqing, China
8. Guangzhou, China
9. Hong Kong
10. Kabul, Afghanistan


Zurich Population Density. 4049/km² (10251.3 /sq mi)
Mexico City Population Density, 5960.3/km2 (15437.2/sq mi)  

In 2008, Zurich was ranked no.1 with best air quality city and in 2010,  it was ranked no.2 in best quality of living by Mercer. I choose Zurich as my role model to see what has been done in transportation policy related to good air quality. While Beijing may be the most air polluted city, but the cause is industrial emission instead of cars. So I choose Mexico City, which has the highest level of ground-level ozone in the world, as my role model to examine what can be done to improve air quality.

No comments:

Post a Comment