HEI supports research across the globe, often with supplemental financial support from foundations and international organizations. Although the majority of HEI's studies have been in North America, important additional scientific insights have been provided by a growing number of new studies in Europe, Latin America, and Asia.
HEI has attracted significant additional support for its international work from foundations, international organizations, the European Union and industry. In Europe, for example, HEI worked in partnership with WHO on Air Quality Guidelines, and with the European Union on multi-investigator studies of air pollution and health in North America and Europe (APHENA). In Asia, with added support from domestic and international foundations, HEI implemented the Public Health and Air Pollution In Asia (PAPA) program (see several research reports and a comprehensive review comprehensive review of the Asian literature on air pollution and health). We have also conducted the first major multi-country, multi-investigator studies in Latin America (ESCALA). Additional studies in countries outside the US are funded through our competitive research selection process.