Vietnamese main mode of transportation - motorcycles are the main cause of urban air pollution in one of the factors. According to Vietnam's environmental experts estimate that the emission of air pollutants from transportation accounts for about urban air pollution emissions by 70%. Vietnamese capital Hanoi have been to people who, without exception, its impressive large motorcycle traffic. The number of motorcycles in Vietnam and the per capita number of highest in the world. According to friends in Vietnam, Hanoi's population was about 3.1 million, while per capita motorcycle ownership is 70%, about 2.17 million; Ho Chi Minh City to maintain capacity of 3.7 million motorcycles, also to the daily average rate of increase in 1000 . As the bus lines, trips are small, so the main motorcycle transport as the Vietnamese people. Vietnam traffic regulations: Other vehicles avoid motorcycles, road and 2 / 3 or 3 / 4 plan to motorcycle traffic; allow motorcycles on the highway.

In Hanoi, people of all ages must wear a mask to go out. Many women also use the triangle surrounded the entire head, both to protect the skin, on the other hand, the air is very dirty, very quickly if you do not feel chest tightness, wear a mask. These motorcycles do not exhaust purification equipment, produce lots of dust. When a traffic jam, air PM10 levels increased by 4 ~ 5 times than usual. In addition, the motorcycle's fuel quality is very poor, leading to excessive lead content in air.

Unfortunately, the Vietnamese national oil produced very good quality, but costs are higher, in order to reap huge profits, some companies in Vietnam are imported from poor quality fuel. Switzerland - Vietnamese Clean Air Programme of technical staff Hoang Viet Cuong said: "Vietnam has a very good quality sweet crude oil resources, but we are still importing low-quality fuel." Hoang Viet Cuong national oil companies have been working in Vietnam, he said Some stations deliberately add certain additives to the fuel, this "water down" the practice of fuel to increase profits is exacerbated by the quality of motorcycle fuel deterioration.