This post originally appeared on State of the Planet, the Earth Institute's blog.

Air quality matters for human health, and many of the world’s urban areas suffer from high levels of contamination. One of the worst pollutants is PM_2.5., which are microscopic particles less than 2.5 microns in diameter that lodge deep in the lungs, potentially leading to respiratory and cardiovascular disease in exposed populations. According to World Health Organization research on the environmental burden of disease, outdoor air pollution causes close to one million premature deaths worldwide each year, with particulate matter as one of the leading contributors. Fine particulates originate in large part from fossil fuels combustion and from agricultural and forest fires. MORE 

This post originally appeared on State of the Planet, the Earth Institute's blog.

In January, 132 countries received their environmental report cards. The Environmental Performance Index, released at the World Economic Forum in Davos, ranked countries on aspects of environmental impacts on human health and on ecosystems. The rankings were based on scores each country earned on 22 indicators dealing with environmental health, air pollution, water, biodiversity and habitat, agriculture, forests, fisheries, and climate change and energy. Coming in at first place on the 2012 EPI is Switzerland, with Latvia, Norway, Luxembourg, and Costa Rica rounding out the top five. The U.S is ranked 49th and Iraq is in last place. MORE 

My colleagues and I recently released the 2012 Environmental Performance Index (EPI) at the annual World Economic Forum meeting in Davos, Switzerland. Countries that ranked high rejoiced; those low on the list sought explanation.

Nobody wants to look bad.

The EPI is a biennial report produced jointly by Yale and Columbia Universities that ranks countries on their environmental performance across a variety of measures, from pesticide regulation and forest loss to child mortality. There were 22 measures this year, each categorized under one of two overarching categories: environmental health or ecosystem vitality. After long hours of number crunching, the EPI produces a single number that ranks countries against each other. (You can find your country's rank here.) MORE 

Keep your eyes peeled this February for the release of the world's first Ocean Health Index, put together by Conservation International, the National Geographic Society, and the New England Aquarium.

The Index's goals are much the same as our land-based Environmental Performance Index - to develop an analytically rigorous and data-driven approach to assessing the health and well-being of the world's oceans, to track and measure ecosystem vitality and public health, and to better inform policymakers. Check out more about the Index at http://bit.ly/crmTyl and check out our Q&A session with Steve Katona, Managing Director of the project. MORE