1 / 2 / 3-TRIMBENZENE M-DIETHYLBENZENE P-DIETHYLBENZENE UNDECANE DODECANE TOTAL HC PAMSHC Department of the Environment Isoprene Concentration Patterns / Summary and Conclusion Department of the Environment Background MDE TOXICS LAB Serving EPA Region / Department of the Environment Anthropogenic and Biogenic Isoprene Concentrations / /