Sri Lanka witnessed its worst marine environmental disaster due to the XPress Pearl container ship’s fires, explosions and partial sinking near the coast of Colombo between the 20th of May and 2nd of June 2021. The XPress Pearl containership with more than 25000 MT cargo on board, caught fire and later exploded emitting toxic gases and particulate matter into the atmosphere and ocean.

Air pollution due to the emitted gases, volatile compounds, metals, particulate matter and aerosol would be harmful to humans, flora and fauna as unhealthy levels of polluted air cause short-and long-term respiratory diseases. In addition, excess particulates can impair the cloud micro-physics and lead to diminished and/or toxic rainfall in the western hill slopes. 

We examined whether the Air Quality Indices (AQI) in Colombo were affected by the fires by examining the abundance of fine particulates. The chart below shows the fine particulate (PM2.5) concentrations as measured by the US Embassy in Colombo since September 2017.

                               PM2.5 Content in Colombo

A clear-cut relationship cannot be observed as to the impact of the massive effusions from the XPress Pearl ship on the air quality of the Colombo district.

Although a large amount of toxic gases and particles were emitted in a short period of time by Xpress Pearl burning, a sharp contrast in air pollution is not detected during May and June 2021 compared to the air pollution that existed in the months of May and July of previous years. Analysis of daily data for May and June too shows that there was no escalation. Work with hourly and minute by minute data in the Colombo district also supports this theory.

Note, our subsequent modeling shows that the pollution would have tracked towards the North-East due to the prevailing strong winds arriving from the South-West during the period of the fires. However, our instruments in Puttalam and Nawalapitiya too did not reveal an abrupt escalation.