Hexachlorobenzene levels in multimedia environmental samples from selected chemical production plants.

A sampling and analysis program was conducted to determine hexachlorobenzene (HCB) levels in air, water, soil and sediment. Nine industrial plants were selected, representing six major industries: perchloroethylene, trichloroethylene, carbon tetrachloride, chlorine, triazine herbicides and pentachloronitrobenzene. Of the six industries sampled, higher concentrations of HCB were associated with the production of perchloroethylene, trichloroethylene and carbon tetrachloride. In the one plant that produced only carbon tetrachloride, HCB levels were quite low. HCB concentrations were relatively high in samples from the pentachloronitrobenzene plant, i.e., low microgram/m3 range in air and generally over 100 micrograms/g along roads within the plant. Very low levels of HCB were associated with plants producing chlorine and triazine herbicides. Several different waste-disposal methods were used at the perchloro- and trichloroethylene plants that were sampled. The highest level of HCB was detected in air and soil at the plant using on-site landfill and open-pit storage. High HCB levels were detected in loading and transfer areas at plants using off-site disposal methods. Lower HCB levels were found at plants using on-site incineration, but downwind air concentrations were elevated above background at these plants. Production of perchloro- and trichloroethylene by low-temperature oxychlorination and incineration of liquid bottom wastes resulted in high levels (micrograms/m3) of HCB in the air but relatively low levels in the effluent water.(ABSTRACT TRUNCATED AT 250 WORDS)