Yayyyyyy ! !! Happy thorkey day to Frank and his family ! 😽 <| sep |> Ok yes , you ' re not going to get it without pollen . But we ' ve had pollen and thunderstorms forever . Why was this phenomenon not observed and recognised prior to the last 30 years ? Regulations on diesel in Australia are not very stringent compared to other countries . The UK has a lot of diesel cars . The city of Ahvaz in Iran , where another outbreak occurred , has been rated as having some of the worst air pollution in the world . So I think it ' s a combination of air quality , pollen loads and thunderstorm conditions . Other people have obviously thought similarly and these particular scientists looked at diesel and found , yes , under laboratory conditions , it looks like it could be a factor . Obviously more research is necessary . And probably will now take place now that we ' ve unfortunately had such an extreme event with fatalities .