First of all, you can talk to people downstairs and ask them to reduce the use time of the range hood or adjust the use mode so that the lampblack will not disturb the people too much. You can express your troubles and worries, remind them that this behavior may violate community regulations and cause problems such as neighborhood discord, so that they can find solutions together.
Secondly, you can complain to the property or relevant departments to reflect the situation that the range hood downstairs disturbs the people. The property or relevant departments will send people to investigate the situation and make corresponding treatment, such as reminding the downstairs residents to pay attention to the use of range hoods and urging the improvement of oil fume emission.
Finally, if the above methods can't effectively solve the problem, you can also defend your rights through legal channels. You can consult local neighborhood committees or related lawyers to find out what measures should be taken to safeguard your rights and interests.
In short, in the face of the situation that the range hood disturbs the people, we should deal with it calmly and try to solve the problem through consultation. If the situation cannot be improved, you can consider appealing for rights protection.