What is the ruling on participating in the study and follow-up of a project that relies on an interest-based loan, if the work involved specializes in environmental protection and reducing the project's negative impacts on it?

It is permissible to participate in an existing project financed by a usurious loan, because the impermissibility is not related to the money itself. However, if the project does not exist and requires study by the inquirer, then it is not permissible, because it involves assisting in borrowing with usury, which is forbidden due to Allah's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression."