Death rate is the measure of the frequency of death within a specific population and specific time interval. The formula is defined as follows:
$$ \frac{\text{Deaths occurring during a given time period}}{\text{Size of the population among which the deaths occurred}} $$
Global Burden of Disease (GBD) is a regional classification system that places countries into a regional classification. GBD super regions are designated based on their geographical closeness and epidemiological similarity. There are seven GBD super regions: South-East Asia, East Asia & Oceania; South Asia; North Africa & Middle East; Sub-Saharan Africa; Latin America & Caribbean; Central Europe, Eastern Europe & Central Asia; and High Income.
"Death Burden" or the burden of disease is an estimate that tries to calculate the number of deaths that can be attributed to air pollution. An estimate of deaths attributed to PM25 and household air pollution done by the GBD includes ischemic heart disease, lung cancer, chronic obstructive pulmonary disease (COPD), lower-respiratory infections (such as pneumonia), stroke, type 2 diabetes, and adverse birth outcomes.