Air pollution is a major environmental hazard to human health. It is well known that both short-term and long-term exposure to particulate matter in the air is a risk factor for different health outcomes.

Hundreds of scientific papers published around the world have confirmed the effects on morbidity (incidence, hospitalizations, emergency room visits, among others) and on mortality from various causes. Over the years, the causality between the exposure to ambient particulate matter and several health outcomes has been confirmed (e.g., respiratory and cardiovascular diseases). Several hypotheses about effects on other organs and systems have been tested (e.g., metabolic and neurological diseases).

In this context, WHO regularly estimates the global burden of disease attributed to particulate matter for 5 causes of death whose epidemiological causality is confirmed: acute lower respiratory Infections (ALRI), chronic obstructive pulmonary disease (COPD), stroke, ischaemic heart disease (IHD) and lung cancer (LC). These data are also reported as Sustainable Development Goal (SDG) Indicator 3.9.1, "Mortality rate attributed to ambient and household air pollution", for which WHO is the custodial agency.

To assess the burden of disease or health impacts attributed to a given exposure, the knowledge of the health risks magnitude associated with the exposure of interest is a vital input, commonly referred to as the concentration-response functions (CRF) or exposure-response functions (ERF). These functions are derived from scientific epidemiological evidence and are generally reported as various measures of effect estimates in studies (i.e., hazard ratios, relative risks, odds ratios, etc., according to the epidemiological design). Unfortunately, access to and use of this information is rather limited to a specialized scientific audience.

Easier access to this information is important to showcase the amount of scientific knowledge already available and call for research in regions and countries which are underrepresented. It also enables the dissemination of critical information to conduct health impact assessments and burden of disease estimates attributed to air pollution around the world, especially in low and middle-income countries (LMIC). In this way, decision making could be supported by scientific evidence on the need to decrease the high environmental pollutants concentrations that are putting populations’ health at risk; even more so in a context where 99% of the world's population lives in places where air pollution levels exceed the air quality guidelines established by WHO.

This epidemiological repository is a compilation of quantitative information on the magnitude of mortality risks related to long-term exposure to ambient particulate matter, identified through a two-stage search strategy of epidemiological studies.

Therefore, the aims of this repository are:

• to provide decision-makers, policymakers, researchers and all interested parties in countries around the world an easily accessible database with exposure-risk relationships between ambient particulate matter and mortality;
• to serve as a complementary tool for health impact and/or burden of disease assessments from air pollution, together with software such as AirQ+; and
• to provide an easily accessible and transparent input data used for the most recent update of the burden of disease estimation due to air pollution carried out by WHO (2022).

If you have any questions or comments, please send an email to [email protected]

Please contact us to provide additional studies that fill the inclusion criteria and that you would like to be included in the repository.