Vietnam is among the top 10 countries with the worst air pollution, according to a study released during this year's World Economic Forum in Davos.
Vietnam's Air (Effects on Human Health) ranking was 123rd among the 132 countries surveyed.
India has the world's worst air pollution, beating out China, Pakistan, Nepal and Bangladesh, according to the study.
Vietnam's water supply (Effects on Human Health) was ranked 80th of the 132 surveyed.
In terms of overall environment, Vietnam, the study ranked Vietnam 79th.
The Environmental Performance Index is conducted by the environmental research centers of Yale and Columbia universities with assistance from dozens of independent scientists. The study uses satellite data to measure the concentration levels of air pollution.
The EPI ranks countries according to 22 performance indicators spanning ten policy categories designed to reflect facets of both environmental public health and ecosystem vitality.
The categories are environmental burden of disease, water (effects on human health), air pollution (effects on human health and ecosystems), water resources (ecosystem effects), biodiversity and habitat, forestry, fisheries, agriculture and climate change.
According to the 2012 EPI, Switzerland leads the world in terms of addressing issues of pollution and the challenge of managing natural resources.
Meanwhile, Malaysia was ranked the best performer among Southeast Asian nations, at 25th.
In 2010, Malaysia was ranked 54th among 261 countries, whereas Singapore was 28th; however, the city-state dropped to 52nd on the latest index.