The Supreme Administrative Court has accepted an appeal filed by the National Environment Board (NEB) against a ruling made by the Chiang Mai Administrative Court ordering the NEB to complete an air pollution management plan.

Lawyers responsible for a class action lawsuit filed by academics, activists, medical professionals, and residents in Chiang Mai against the Prime Minister and other government agencies for lack of action on air pollution said they have been informed of the appeal in a letter dated 3 April and ordered to submit a defence statement within 30 days. 

The lawsuit was filed in April 2023 against then-Prime Minister Gen Prayut Chan-o-cha, the NEB, the Securities and Exchange Commission (SEC), and the Capital Market Supervisory Board (CMSB) for not taking action to solve air pollution in the north of Thailand.

In January 2024, the Chiang Mai Administrative Court ruled that the Prime Minister and the NEB were either negligent or did not act in a timely manner to address air pollution in the northern provinces. It ordered the Prime Minister and the NEB to prevent or relieve the damages caused by air pollution and complete an emergency plan within 90 days of the ruling.

However, it dismissed the lawsuits against the SEC and the CMSB on the grounds that the two agencies were not responsible for air pollution, directly or through administrative negligence.

Since the lawsuit is filed against the Prime Minister and not Gen Prayut as an individual, anyone who becomes Prime Minister while the lawsuit is ongoing will be responsible for taking any action ordered by the Court. 

Chiang Mai and other northern provinces routinely experience severe air pollution levels between December – April each year, with Chiang Mai often ranking as one of the most polluted cities in the world.