I read that satellite analysis of nitrogen dioxide emissions during recent lockdowns and movement restrictions showed drops in the pollutant produced from burning fossil fuels (Some cities in S-E Asia see bluer skies during movement restrictions, May 8).

For Singapore, last year's satellite analysis of nitrogen dioxide emissions showed the greatest concentration of pollution over Jurong Island, which houses petrochemical complexes, as well as the Jurong industrial area.

The pollution radiates out in decreasing intensity to engulf the greater part of the country, with the exception of the northern sector of Kranji, Woodlands and Sembawang.

It appears that the main source of the pollution is Jurong Island, where the Economic Development Board has been encouraging investments in speciality chemicals.

The industry's need for land is insatiable. Over the years, reclamation works in the area have affected the marine environment.

Sadly, Singapore gets to enjoy clean air only during the November to February period when the strong north-east wind drives the pollutants southwards.

As citizens' health is at risk, the developments on Jurong Island should be contained. Better pollution control measures would also help to reduce our carbon footprint.

Denny Sim