Bathurst Paceway was set to host a race meeting on Monday until the call was made at 11.30am the air quality was too hazardous to allow horses to run.

Stewards had been monitoring the air quality at the track over the proceeding four hours and watched the Air Quality Index (AQI) steadily climb from an already 'unhealthy' 200 to a 'very unhealthy' 280 at the venue.

The race meeting is one of several sporting events across the region to be cancelled in recent weeks, as dust and smoke pose a risk to people's health.

Other harness racing events have been affected as well. Friday's Sydney Cup meeting at Bankstown was cut while Saturday's Menangle program saw 21 late scratching due to the weather.

"It's rare out here to lose a meeting. The air pollution levels were on the rise for most of the morning so we made the decision, after consultation with trainers, to call the meeting off," Bathurst Harness Racing Club CEO Danny Dwyer said.

"We conferred with vets and we also looked at horses who had done trackwork earlier in the day. Their heart rate was normal though their breathing was a lot more increased after the workout."

Monday's meeting would have been a rare restricted grade meeting, allowing horses who don't normally get their time in the spotlight to get some competitive racing.

"These are the sorts of meetings Bathurst trainers have been crying out for, to cater for horses whose form hasn't been fantastic over the last four to five starts," he said.

"The fields were fairly even and it gave those trainers a chance to pick up some prize money without travelling too far.

"We only had six of these meetings last year and it's the same again this year."

Bathurst's next meeting will take place on Friday.