Experts say many of Delhi’s air quality monitoring stations may give inaccurate readings, because they are not placed properly — for example, too close to trees or buildings, or near roads.

These faults make it hard to trust whether the reported pollution levels reflect real “clean air” conditions.

The Supreme Court’s order to allow green crackers on a “test basis” just days before Diwali has reopened debate over balancing tradition and health.

Experts say there is no clear way to check whether a cracker is truly green, and past attempts at enforcement have been weak.