"However, as a video of the project shows, Iglesias is using aerosol spray paint cans for the Thunberg mural, which environmentalists say emit volatile organic compounds that contribute to global warming.
While it is unclear how many spray cans Iglesias has used, the mural spans four stories and at least one smaller project utilized 500 cans of the paint scientists say can generate asthma-inducing smog."
https://www.theblaze.com/news/greta_thungberg_mural_toxic_spray