According to the BBC, the recent blockade of the Suez Canal was caused by the huge container ship Ever Ever, which was trapped inside and caused serious sulfur dioxide pollution.
That is, due to the Suez blockade, hundreds of ships were trapped on both sides of the Suez Canal and were forced to stand in the same place for several days.
As a result, the concentration of sulfur dioxide (SO2) in the air has reached five times the usual level on the Mediterranean side of the canal. Sulfur dioxide is a by-product of fuel combustion in marine engines.
According to the BBC, the International Maritime Organization (IMO) has been working hard in recent years to reduce sulfur dioxide emissions because it may have a negative impact on the environment and human health.
As the Suez blockade lasted for six full days, as many as 350 ships were trapped in the same place. Most are anchored at the northern end of the canal in the Mediterranean. Although its main engine has been shut down, the auxiliary power supply and water heater are still on board.
This resulted in a high concentration of sulfur dioxide in the atmosphere, and the European satellite Sentinel-5P also detected sulfur dioxide. The satellite is operated by the European Space Agency and has a sensitive spectrometer called Tropomi, which can detect traces of a variety of harmful gases including sulfur dioxide.