<prompt> Translate the following text to EnglishIngawa Sheria ya sasa ya Hewa Safi imechangia sana kuboresha baadhi ya masuala haya, kupunguzwa kwa ziada kwa uzalishaji wa SO2, NOx na zebaki ni muhimu ili kukabiliana na matatizo ya afya ya umma na mazingira.  <response>: While the current Clean Air Act has played a role in significantly improving some of these issues, additional reductions in the emissions of SO2, NOx, and mercury are necessary to address persistent public health and environmental problems. 