He says it "boils his blood" that he was made to play his first-round qualifying match on Tuesday.

The 26-year-old was "gasping for air" as he lost to Belarusian Ilya Ivashka.

Play had earlier been suspended for an hour as Melbourne was blanketed in smoke from the bushfires.

The email was sent to male players by the ATP Tour and Tennis Australia, and has been seen by BBC Sport.

It concludes the "conditions are challenging, but the medical experts say they are acceptable for play".

In a post on social media earlier on Thursday, Broady outlined his concerns.

"The more I think about the conditions we played in a few days ago, the more it boils my blood. We can't let this slide.

"The email we received yesterday from the ATP and AO was a slap in the face. Conditions were 'playable'. Were they 'healthy'?

"Citizens of Melbourne were warned to keep their animals indoors the day I played qualifying, and yet we were expected to go outside for high-intensity physical competition?

"What do we have to do to create a players' union? Where is the protection for players, both male and female? On tour we let so many things go that aren't right but at some point we have to make a stand. ALL players need protection not just a select few."

Slovenia's Dalila Jakupovic was forced to retire from her qualifying match after a coughing fit and says other players she spoke to reported breathing difficulties and headaches.

The email to ATP members said "player welfare is utmost in our considerations", and details the hitherto undisclosed protocols that Tennis Australia has put into place.

A 'PM2.5' air quality reading is being taken every four minutes at Melbourne Park. Whenever the reading exceeds 200, Tennis Australia says play is suspended.

Readings elsewhere in the city on Tuesday suggested the air quality index was over 200, but the email says "no play has taken place at any time above the 200 threshold on the PM2.5 scale".

It also claims some sporting organisations have a threshold of 300 before they take any decision to suspend play.

There were no problems with air quality as qualifying continued on Thursday. Wednesday's heavy rain has brought in cooler conditions, with Melbourne's air officially rated as "good".

'A lot are saying they can't wait to get out of Australia right now'

American player Noah Rubin, who lost in the first round of qualifying on Wednesday, said a lot of players felt "disrespected" by the email, which he described as being sent "too late".

Former Wimbledon junior champion Rubin, 23, says he had "blood and black stuff" coming out of his nose after his match, also complaining of irritated eyes and shortness of breath.

"A lot of players have been feeling it in the throat and eyes," Rubin, who was not the source of the leaked email, told BBC Sport. "It can't be healthy breathing it in.

"The talk between players is about disappointment. A lot are saying they can't wait to get out of Australia right now and we love playing in Australia.

"It's left a bad taste in a lot of people's mouths - almost literally.

"We feel awful about what is happening with the fires - it is terrible and obviously there are way worse things - but we're talking about how are we having a tournament going on, and how do we not know how to go about it? Why can't we play inside; why are there not emergency things taking place?"

Rubin added he had approached Tennis Australia and the ATP for clarity, accusing them of being defensive when he asked for more communication to be given to the players about why decisions had been made.