Annual Report 2020

Four Decades of Trusted Science

HEI was founded in 1980 on the heels of a tumultuous period, with great upheaval in the way Americans viewed science and the environment. In 2020, the country found itself in another time of uncertainty. While much has changed since HEI’s launch 40 years ago, the need for impartial, trusted science — the need for a common ground on which to base decisions — endures.

In this year’s annual report, we look to HEI’s past, present, and future to examine how investing in rigorous science can shed light on decisions with lasting impacts for our health, economy, and the world.

A Model That Endures – Because It Works

Rigor and independence are the central tenets of the HEI model. Read more

Thank You to Our Peer Reviewers in 2020

HEI thanks all the experts who offered their time and expertise, and provided thoughtful and high-quality comments and feedback on research applications as well as final reports. Read more

Section Overview

Vision for the Future

See our 5-year guiding vision and detailed plan for targeted air quality and health research and learn how we are working toward a more inclusive future. Read more

Science for Policy

Our funded researchers and network of leading air-quality experts offer a valued source of impartial science to inform often controversial policy decisions. Read more

Our Financials

Get details on our annual expenditures and funding support from government, industry, and foundation sponsors. Read more

Investing in Next-Generation Science

HEI’s research programs build upon the latest technological innovations in monitoring, modeling, and data analysis to advance insights on air pollution and health. Read more

Global Impact

HEI is advancing science on the burden, and sources, of air pollution around the world, especially in China, India, and other developing nations facing significant pollution challenges. Read more

Vision for the Future

Every five years, HEI’s staff and Board of Directors take stock of the organization’s activities and chart a path for the future. The HEI Strategic Plan for Understanding the Health Effects of Air Pollution 2020–2025 captures a point in time — reflecting the insights gained and impacts achieved over the past five years — and offers a guiding vision for air quality research moving forward. In keeping with HEI’s driving focus on advancing science that’s useful to stakeholders, the Strategic Plan was informed by consultations with HEI sponsors in EPA and industry, as well as individuals and organizations in the scientific community, the environmental community, state and international agencies, and others. Taking into consideration this diversity of perspectives ensures that HEI’s work responds to the needs and priorities of those who rely on the Institute for high-quality, impartial science.

While a five-year strategic plan necessarily focuses on the near-term future, it is clear that issues around air quality and climate will continue to evolve well past that time frame. This long-term context is reflected in the plan’s overarching theme: informing air quality and health decisions for 2020–2025... and beyond.

The vision is built on four major research opportunities:

Accountability: This area focuses on elucidating the links between air quality actions and health by improving methods for assessing these links, understanding causality, and analyzing costs and benefits.

Mixtures: In this area of research, HEI seeks to improve methods for examining how air pollutants affect health in the context of complex pollutant mixtures, low versus high pollutant concentrations, climate change, and variability over time and space.

Transport and urban health: In anticipation of diverse and potentially disruptive changes in transport, this area focuses on both traditional and emerging concerns related to vehicles and transport in the broader setting of urban health, including reviewing the worldwide literature on traffic-related air pollution exposure and health effects.

Global health: HEI will continue to shed light on the health effects of air pollution in developing countries and to analyze air pollution’s burden of disease around the world.

Cutting across all of these research areas is a continued focus on transparency in policy-relevant science, which requires attention to data access, systematic literature reviews, and rigorous evaluation of statistical methods.

HEI investigator Nga Lee (Sally) Ng wearing a white lab coat and goggles and looking off to her left while standing in front of an environmental chamber at Georgia Tech.

Sally Ng, one of HEI’s many Walter A. Rosenblith New Investigator Award recipients over the years. Her work focuses on secondary organic aerosols. (Photo by Nick Burchell)

This time line highlights key research areas selected for implementation during HEI’s 2020–2025 Strategic Plan. Horizontal bars show projected time ranges for HEI work in the areas of accountability, mixtures, transport & urban health, and global health, and how they dovetail with upcoming decisions on major rules (US, EU, China, India, WHO) related to ambient air quality, fuels, and emissions.

Implementing the HEI Strategic Plan 2020-2025: This time line highlights HEI’s key research area selected for the 2025 Strategic Plan period.

Envisioning — and Creating — a More Inclusive Future

Heartened by the renewed attention to the persistent racism that excludes certain people and groups from the full opportunity to engage in endeavors of American society, including scientific education and research, HEI recently outlined a commitment to promote inclusion in its work by

  • taking every step to engage and provide a welcoming environment for underrepresented scientists in the scientific work of HEI,
  • providing a safe and welcoming environment for all at HEI, free from discrimination of all types, including race, gender, LGBTQ+, ethnicity, national origin, and disability, and
  • supporting these goals with both immediate and sustained action.

HEI will hold itself accountable to these commitments by analyzing its track record for engaging underrepresented scientists in its work. It will set goals for improving performance, monitor progress, and report publicly and regularly on that progress.

Investing in Next-Generation Science

Diagram showing several viewing angles of NASA’s Multi-Angle Imager for Aerosols satellite as it travels above the southwestern United States. HEI investigators use space-based air quality monitoring data collected by instruments on the satellite.

HEI investigators use space-based air quality monitoring data produced by NASA’s Multi-Angle Imager for Aerosols (MAIA) satellite. (Courtesy NASA/JPL-Caltech)


Air Pollution and COVID-19

As the COVID-19 pandemic emerged, HEI responded with a call for applications for research on the intersection of air pollution exposure and COVID-19 outcomes. The appeal generated 45 letters of intent; 5 studies were funded out of 10 invited full proposals.

Science, like air pollution, doesn’t sit still. Air quality is in a constant state of change; as technologies, policies, and behaviors shift, so do the pollutants in our environment and the ways in which they impact our health. Fortunately, the opportunities to understand pollution and its health effects have continued to evolve apace. HEI’s research programs build on and help advance the latest technological innovations in air quality monitoring, such as sensors and satellites, as well as techniques to model and interpret what the data can tell us about human exposures and health.

A New Generation of Accountability Research

Tracking the real-world impacts of policy decisions is a complex undertaking. HEI’s accountability research program has made significant progress in uncovering the outcomes of air quality actions and improving methodology to ensure these studies stand up to scrutiny.

School Bus Retrofits

Sara Adar of the University of Michigan is studying the National Clean Diesel Rebate Program, which allocates funding to school districts across the United States to replace or retrofit old-technology diesel-powered school buses. Her team is comparing student health and educational performance in approximately 400 districts that received funding with about 2,700 districts that did not.

Curbing Coal in China

Two ongoing studies are looking at air quality actions in China. Patrick Kinney of Boston University leads a team to evaluate major national regulations, in particular those that target coal and other specific sources, to assess their impacts on mortality rates. In a separate study, Sam Harper and Jill Baumgartner at McGill University are assessing a coal ban and heat pump subsidy program in the Beijing region, with an eye toward understanding the chemical composition of fine particles from different pollution sources (focusing on household coal use) and their contribution to health outcomes.

Traffic and Children’s Health

Perry Hystad of Oregon State University is assessing the effects of emission-control measures — including national emissions regulations as well as local congestion reduction programs — on birth outcomes associated with traffic-related air pollution in Texas. Texas provides an interesting test case, because about 1.7 million pregnant mothers have lived within 500 meters of a Texas highway or expressway during the past 25 years, a period in which nitrogen dioxide concentrations (a marker of traffic-related air pollution) dropped by more than 50%.

Getting a Handle on Exposure

Pollution can vary widely over time and space. Five HEI-funded studies seek to improve scientists’ ability to accurately track people’s exposure to pollution and reduce uncertainty in efforts to determine what these exposures might mean for health.

Enhancing Exposure Assessment

Scott Weichenthal of McGill University is studying approaches to assessing the health impacts of long-term exposures to traffic-related air pollution in Canadian cities by comparing results from fixed-site and mobile measurements with the outputs of deep learning models. Gerard Hoek of Utrecht University leads an effort to map air pollution across the Netherlands, assess different types of sensors and monitoring platforms, and evaluate the performance of several exposure models. Kees de Hoogh of the Swiss Tropical and Public Health Institute is using cell phone tracking data and air quality data to assess opportunities to improve exposure and health effects estimates by taking people’s daily movements into account.

Understanding Uncertainty

Lianne Sheppard of the University of Washington is studying different approaches to air pollution exposure assessment including low-cost sensors, mobile monitoring, and passive samplers, with a focus on determining associations with cognitive decline and dementia incidence.

A team led by Klea Katsouyanni of King’s College London is investigating the consequences of measurement error on estimates of health effects of long-term exposure to outdoor air pollution in London with sophisticated exposure models that account for mobility and include outputs from several types of air pollution models.

Science for Policy

Policy decisions related to air quality can have significant and lasting impacts on businesses and economies, public and environmental health, and our everyday lives. While it is impossible to fully predict the outcomes of each policy, a solid scientific foundation helps policy makers and the public determine when action is warranted, and what form it should take. A robust body of reliable, impartial research is crucial to policy makers’ ability to anticipate the benefits and costs of the air quality interventions being pursued at local, national, and regional levels.

Weighing in on EPA Rules

In 2018, the U.S. Environmental Protection Agency (EPA) proposed a rule, “Strengthening Transparency in Regulatory Science,” that could prevent EPA decisions based on studies for which the data are not made publicly available. Under the proposed rule, EPA could potentially omit some study findings from consideration that have informed decisions on air and water quality for many years.

In a formal response to this proposed rule submitted in May 2020, HEI staff and Committee members noted the organization’s longstanding commitment to enhancing transparency and data access but also identified key challenges of the proposed EPA rule. The best scientific reviews take advantage of the full range of studies available, rather than excluding otherwise very strong studies because of data access concerns alone. In addition, the rule would likely impose significant additional costs on scientists and research institutions, with no plan for covering these costs. The comments outlined a more comprehensive mechanism EPA could use to determine which studies to consider in its policy decisions.

Sharing the State of the Science

The Clean Air Scientific Advisory Committee acts as an independent advisor to the EPA to help inform its air quality standards. To support the committee’s technical assessments, in October 2019 HEI submitted a series of comments on the state of the science for key topics in air quality research. The comments drew on HEI-funded studies and the broader research context to offer a view of the current understanding in five main areas: particulate matter, ozone pollution, low-level exposures, accountability research, and the determination of causality in assessing linkages between air pollution and health.

Considering a European Green Deal

As the European Union considers updating its air quality policies, HEI joined forces with the World Health Organization and other international scientific organizations to explore the evidence and inform a European Green Deal, an ambitious plan to make the European economy sustainable while addressing climate and environmental challenges. In a meeting in Brussels, Belgium, held in January 2020, 150 participants from HEI, partner organizations, public agencies, industries, and environmentalists addressed the latest science on low-level exposures, the effectiveness of current air quality standards, and the need for a systematic, multilevel, and multisector approach to tackling air pollution and its health effects. A key conclusion from the meeting was that the estimated health benefits of air quality actions by far outweigh the implementation costs.

View inside the European Parliament Hemicycle during a meeting. Scientific knowledge supplied to the Parliament informs environmental and health decisions for the EU’s 27 member states.

Scientific knowledge supplied to the European Parliament informs environmental and health decisions for the EU’s 27 member states.

Reliable, impartial research is crucial to policy makers’ ability to anticipate the benefits and costs of the air quality interventions being pursued at local, national, and regional levels.

Evidence of Effects at Low Exposure Levels?

In setting standards for permissible pollutant concentrations, EPA considers what pollutant levels are likely to cause harm. Studies conducted over the past decade have brought increasing attention to the possibility that pollutants may adversely affect health at levels previously thought to be safe, with some calling for EPA to address these potentially harmful low-level exposures in its pollution standards.

Initial results from two HEI-funded studies on this topic, led by Francesca Dominici at the Harvard T.H. Chan School of Public Health and Michael Brauer of The University of British Columbia, were made available to EPA during the agency’s process to review the National Ambient Air Quality Standards for particulate matter. While EPA staff recommended tightening the standards, the agency ultimately ruled to retain the current standard. The full results of Dominici’s and Brauer’s studies, as well as a third study led by Bert Brunekreef at the University of Utrecht, are now complete and are undergoing a detailed examination by a special panel of the HEI Review Committee.

Global Impact

Air pollution doesn’t stop at the border, and neither does HEI’s work. Engaging with air quality research on the global stage is critical to understanding key pollution sources, the effects of standards and policies, and air pollution’s impacts on public health everywhere. HEI has a long track record of world-leading research on air pollution and its health effects conducted in North America and Europe. With additional funding, many recent projects and programs have focused on China, India, and other low- and middle-income countries where high levels of pollutants are generated, threatening human health regionally and drifting across continents and oceans.

Expanding Knowledge on Air Pollution’s Burden

The Global Burden of Disease (GBD) project of the Institute for Health Metrics and Evaluation (IHME) is a leading resource for understanding health around the world, placing risks from air pollution in the context of the full range of health risks such as diet and tobacco. HEI supports and builds on the GBD project in two main ways. First, HEI-funded researchers rigorously examine linkages between air quality and health using IHME data, strengthening the evidence base that GBD scientists use to quantify the contributions of air pollution sources and other factors to illnesses and deaths. Second, HEI collaborates with IHME to develop the State of Global Air, a report and interactive website that offer a comprehensive analysis of air quality trends and health burdens in every country in the world.

A Valued Resource

The reach of the State of Global Air has grown significantly in recent years, reflecting its role as a go-to resource for vetted, trustworthy information on pollution levels and key health indicators. In addition to its value for researchers, public health practitioners, and policy makers, the State of Global Air generates substantial media coverage, helping to bring broader public awareness to air quality issues around the world.

Incorporating the Latest Science

Every year, GBD scientists refine estimates of the burden of disease that can be attributed to exposure to air pollution, based on the latest scientific evidence and methods. In 2020, for the first time the State of Global Air included in its estimates air pollution’s effects on adverse birth outcomes. A growing body of evidence links mothers’ exposure to air pollution during pregnancy with the increased risk of their infants being born too small (low birth weight) or too early (preterm birth). Scientists estimate that in 2019 air pollution contributed to nearly 500,000 deaths among infants in their first month of life. Babies born in sub-Saharan Africa and South Asia face the highest risk. New HEI-funded research may lead to additional insights on air pollution’s health burden among children. A study launched in 2020 and led by Susan Anenberg of The George Washington University is focusing on associations between concentrations of nitrogen oxides and asthma in children. The team aims to determine the portion of pediatric asthma in each country that may be attributed to nitrogen dioxide exposure for integration into future GBD analyses.

Advancing Science in India

HEI staff and scientists traveled to India on several occasions shortly before the COVID-19 pandemic shut down in-person conferences. In December 2019, three Indian research institutes and HEI co-hosted a workshop aimed at developing a broad strategy for advancing the science on air pollution and health effects in India. Participants outlined potential near- and long-term opportunities for policy-relevant research. They also mapped out a plan to support this work by establishing a national network among research institutions called Collaborative for Air Pollution and Health Effects Research (CAPHER-India).

CAPHER-India was formally launched at a follow-up session in early March during the Indian Public Health Association Conference 2020, where HEI staff and partners also organized a plenary session. The network is preparing to set research priorities and plan for training and capacity building.

Photo by Jennifer Fish/Social Documentary Network

Heat map” showing countries in darker and lighter hues to illustrate the different levels of news media coverage of HEI’s State of Global Air 2020 report in each country.

Launch of HEI’s State of Global Air 2020 drew significant media interest. Coverage in India and South America has been growing. (Source: Meltwater)

State of Global Air 2020: A Special Report on Global Exposure to Air Pollution and its Health Impacts

State of Global Air 2020: A Special Report on Global Exposure to Air Pollution and its Health Impacts

Financial Summary 2019-2020

Statements of Financial Position

Assets June 30, 2020 June 30, 2019
Cash and cash equivalents $6,984,309 $3,883,423
Restricted cash 147,838 147,705
Contributions receivable 1,125,904 659,388
Unbilled incurred costs on grants 1,369,180 5,985,317
Prepaid expenses 126,131 62,438
Office equipment, office furniture and fixtures, and leasehold improvements, net 73,097 98,647
Total Assets $9,826,459 $10,836,918
Liabilities and Net Assets    
Contracted research payables $322,063 $565,658
Accrued contracted research 1,493,603 1,883,581
Deferred revenue - 592,611
Deferred rent payable 59,084 58,768
Other accounts payable and accruals 637,240 640,920
Total liabilities 2,511,990 3,741,538
Net Assets:    
Without donor restrictions 616,506 616,265
With donor restrictions 6,697,963 6,479,115
Total net assets 7,314,469 7,095,380
Total Liabilities and Net Assets $9,826,459 $10,836,918

Statements of Activities

  June 30, 2020 June 30, 2019
Revenues and support:    
EPA grants for the Health Effects of Air Pollution Program $2,953,933 $5,812,109
EPA contracts for Energy Research 537,944 462,552
Other industry contributions 5,327,001 5,087,321
Other non-federal grant and contract revenue 740,126 1,125,080
Other revenues 241 56,114
Total revenues and support $9,559,245 $12,543,176
Research programs:    
Research studies 3,504,941 4,522,170
Research planning and study selection 497,873 516,682
Scientific study management 198,562 197,249
Scientific study review 261,988 244,278
Scientific publication and communication 983,426 776,581
  $5,446,790 $6,256,960
Special Scientific projects:    
Energy research 777,527 1,090,916
Traffic studies review 427,040 113,994
Global health science 941,744 1,254,839
  2,146,311 2,459,749
Total research and scientific expense 7,593,101 8,716,709
Administration 1,747,055 1,426,414
Total expenses 9,340,156 10,143,123
Net increase in net assets 219,089 2,400,053
Net assets at beginning of year 7,095,380 4,695,327
Net assets at end of year $7,314,469 $7,095,380

The HEI Financial Statement and the Mayer Hoffman McCann P.C. Auditors’ Report may be obtained by contacting Jacqueline C. Rutledge.

HEI made significant progress in fiscal year 2020 toward the objectives of the Health Effects of Air Pollution program with ongoing research on possible health effects from low levels of exposure and examining the potential effects of traffic exposure in its broader context. We have also made progress in expanding our efforts in Global Health Science. These activities were made possible by funding from our core government and industry partners with additional funding from government, industry, and foundation sponsors. Separate funding has also allowed us to move forward with our Energy Research Program. The significant balance in Temporarily Restricted Net Assets ensures we will have funds to continue and expand our current targeted research initiatives in future years.

A Model That Endures – Because It Works

HEI earns the trust of stakeholders because of two central tenets: rigor and independence. Its unique model ensures that research follows the highest standards of quality and that the results are presented without hype or bias. The impacts of HEI’s work are testament to the fact that scientific research — conducted with transparency and integrity — remains more relevant than ever. The HEI model requires these important steps:

  • HEI’s Board of Directors appoints widely respected experts to the Institute’s scientific committees and consults with a wide range of stakeholders to guide research priorities.
  • The Research Committee creates targeted research programs and oversees competitively funded scientific studies.
  • The Review Committee assesses study results to ensure the scientific integrity of the methods and findings.
Black and white photo of Archibald Cox.

In 1980, founding Chair Archibald Cox outlined a model in which HEI would convene top experts to oversee and assess research on the health effects of air pollution, without weighing in on the policy implications. Critically, the Institute would be independent, with balanced funding from industry and government. HEI would never lose sight of its founder's vision for generating science that everyone can trust.

Simple graphic showing numbers of HEI reports published and other achievements over past 40 years.


Thank You to Our Peer Reviewers

We would like to thank all the experts who offer their time and expertise to HEI and provide thoughtful and high-quality comments and feedback on research applications as well as final reports. We also thank our quality assurance audit teams, our Research Committee and Review Committee and the Traffic Literature Review Panel. We would not succeed without the help of all these individuals.

Anna Nolan, New York University, USA

Amanda Simanek, University of Wisconsin Milwaukee, USA

Christina J. Fuller, Georgia State University, USA

Francesco Forastiere, Imperial College London, UK

Kofi Amegah, University of Cape Coast, Ghana

James Wagner, Michigan State University, USA

Loretta Mickley, Harvard University, USA

Megan Horton, Icahn School of Medicine at Mount Sinai, USA

Markey Johnson, Health Canada, Canada

Marianthi-Anna Kioumourtzoglou, Columbia University, USA

Patricia Fabian, Boston University, USA

Ulrike Gehring, Utrecht University, Netherlands

Tor Oiamo, Ryerson University, Canada

Maciek Strak, National Institute for Public Health and the Environment, Netherlands

John Gulliver, Imperial College London, UK

Marianne Hatzopoulou, University of Toronto, Canada

Howard Chang, Emory University, USA

Paul Villeneuve, Carleton University, Canada

Hwashin Shin, Queen’s University, Canada

Dave Stieb, Health Canada, Canada

Homero Harari, Mount Sinai Health System, USA

Eric Lavigne, University of Ottawa, Canada

Randall Martin, Washington University, USA

Ander Wilson, Colorado State University, USA

Peter Adams, Carnegie Mellon University, USA

Sverre Vedal, University of Washington, USA

Benjamin Barratt, Imperial College London, USA

Gavin Shaddick, University of Exeter, UK

Sara Adar, University of Michigan, USA

Chris Paciorek, University of California, Berkeley, USA

Kristen Burwell-Naney, University of Maryland, USA

Lucy D’Agostino McGowan, Wake Forest University, USA

Li Bai, ICES, Canada

Veronica Berrocal, University of California–Irvine, USA

Joshua Keller, Colorado State University, USA

Eleanor Setton, University of Victoria, Canada

Bradley Peterson, Children's Hospital Los Angeles, USA

Fred Lurmann, Sonoma Technologies, USA

Michael McCarthy, Sonoma Technologies, USA

Adam Szpiro, University of Washington, USA

Prakash Doraiswamy, RTI International, USA

Linda Brown, RTI International, USA

Jon Samet, University of Colorado, USA

Jay Lubin, National Cancer Institute, USA (retired)