Ideal lawn mower for an asthmatic?

Hi all, I was wondering if anyone had recommendations for lawn mowers that would be good for an asthmatic. I feel a little out of place on this forum as up until now I have barely ever had to mow lawns - Dad always did when I was living at home and since moving out I've mainly lived in flats.

The past year and a half I have been living in a share house on a 1/4 acre block (a standard house block here inMelbourne, Australia). However one of my housemates loves mowing the lawn so I have only had to mow it a couple of times. Today was one of those days and it triggered a fairly bad asthma attack. I think this was due to petrol/gas fumes rather than grass as I don't usually have allergic reactions to grass clippings.

My lawn mowing loving housemate and her husband will be moving out towards the end of the year or beginning of next year so I'm going to have to start mowing the lawn a lot more often. Plus I feel lazy not being able to help out more now. She insists she loves mowing the lawn but I feel guilty letting her do all the mowing.

The current lawn mower will go with them. It's pretty old so that may be contributing to the fumes it's releasing. I did some research on electric mowers and they sound great from an allergy point of view, but I'm not sure if they would be suitable for the amount of lawn I have. Are there petrol/gas mowers that are more suitable than others for those with asthma or other lung problems? I'm also prone to chest infections since a bad case of pneumonia a few years ago.