ECSENOMICS Trends in Pollution in the United States. 1990-1997 T-131 Figure 18-2 Pollution per Unit Output Sulfur -e Volatile organic ead Carbon dioxid r Particulates ⊥A 1900190519101915192019251930351940194519501955196019651970197519801985199019952000 Year McGraw-Hilllrwin Source: Environmental Protection Agency, Department of Energy, and Department of Commerce. For each pollutant, the quantity is divided by real gross domes tie product in 1996 pricesMcGraw-Hill/Irwin Copyright © 2001 The McGraw-Hill Companies, Inc. All rights reserved. Trends in Pollution in the United States. 1990-1997 T-131 Figure 18-2 Source: Environmental Protection Agency, Department of Energy, and Department of Commerce. For each pollutant, the quantity is divided by real gross domestic product in 1996 prices