Which pollutant is primarily regulated in relation to industrial processes?

The primary pollutant regulated in relation to industrial processes is sulfur dioxide. This is largely due to its significant role in contributing to acid rain, which can have severe impacts on the environment, including harm to aquatic ecosystems, soil, and vegetation. Sulfur dioxide is primarily generated from the burning of fossil fuels such as coal and oil, especially in power plants and industrial facilities that process materials like metal and petroleum.

Regulations target sulfur dioxide emissions because controlling them helps mitigate its environmental and health impacts, such as respiratory problems and hazardous effects on ecosystems. The Clean Air Act and various state regulations specifically aim to reduce these emissions from industrial sources, thereby improving air quality and protecting public health.

While other pollutants listed are also regulated, they tend to stem from a broader range of sources or have different regulatory focuses that aren't as closely tied to industrial processes as sulfur dioxide is.