Makes me wonder if cooks, who (in many countries) stand in front of a gas stove for long hours every day have a statistically higher chance of asthma?

Even worse than asthma

https://preventcancer.org/article/lung-cancer-asian-american...

> Environmental exposures, such as cooking oil fumes and secondhand smoke, have long been identified as risk factors for lung cancer among women in Asia who do not smoke

Those exposures are completely unrelated to the burner used in the kitchen.