4. This Act neither affects nor limits the application of the Environment Quality Act (chapter Q-2) in respect of pesticides. Notwithstanding the foregoing, the emission, deposit, issuance or discharge of a pesticide into the environment is not prohibited within the meaning of the second paragraph of section 20 of the Environment Quality Act if it results from an activity carried out in accordance with this Act or the regulations or orders of the Minister made under this Act, unless the risk of harmful effects, damage or impairment referred to in that section is unreasonable.