Heavy Industry is the most heavy polluting business in the game. It consists of such things as refineries, cement factories, etc. It is considered a low-tier business, because it requires (buys) relatively easy to find resources (fuel and offices), and it employs mainly Unskilled and Skilled workers (only High density HI employs some Executives). Special buildings: A great way to increase production without the air pollution resulting from actually placing more buildings. - Materials Storage (special warehouse, +30% Heavy Industry Production, 10000/mo) File:MaterialsStorage 001.jpg