In a handwritten letter, Shaydon Teh said while the scourge of the haze from the Indonesian forests had disappeared, local factories were spewing noxious smoke into the air.

“On Tuesday, I saw a factory here burning recycled plastics. I felt really sad because my football training was cancelled for three straight weeks because of the haze.

“To make our country better, we must put a stop to the haze,” wrote the boy, who is in Year Seven of a private school.

Shaydon’s father, Reno Teh, said he found the letter in his son’s school bag and had no hand in writing it.

“He loves his football practices and he has been ranting over the matter for the past month or so,” he told FMT, saying he would post the letter, on his son’s behalf, to Health Minister Dzulkefly Ahmad.

Illegal plastic factories have been alleged to be polluting the air.

A Canadian TV channel had gone undercover to visit the plastic recycling factories and found them to be flouting the law.

Environmental group Persatuan Tindakan Alam Sekitar SP (PTAS), had also claimed that the factories were polluting the air for the past year, using the haze to cover up their operations.

The Kedah government had responded by shutting down more than 20 illegally-operating factories and sealing their equipment.