Ammonium nitrate explosion at the main port in Beirut (Lebanon) and air pollution: an analysis of the spatiotemporal distribution of nitrogen dioxide.

Abstract

An explosion of the ammonium nitrate (AN) stored at Beirut Port devastated the city on Tuesday 4 August 2020. Such an explosion produces pollutants such as nitrogen oxides (NOx). The most common NOx is nitrogen dioxide (NO2), which is present in the atmosphere due to natural and anthropogenic processes. The presence of NO2 is used as indicator of air pollution. However, the specific contribution of NO2 to air quality is uncertain due to the presence of other constituents, especially particulate matter (PM10). Research has shown that extended exposure to NO2 may result in serious health effects. This study investigated the impact of the explosion on NO2 levels in the atmosphere above Beirut and the surrounding area. NO2 data from the Sentinel-5P program were used to map the levels of NO2. Furthermore, ground-monitoring data were used to assess the levels of PM10 and ozone (O3) due to the evident association between these constituents and NO2. Results showed that NO2 levels were higher than before the blast. However, 7 days after the explosion, NO2 levels had returned to normal, while the levels of PM10 and O3 remained normal following the explosion. However, a slight increase in the daily average atmospheric pressure was noticed after the explosion, which was attributed to the decomposition of ammonium nitrate.