Hexachlorobenzene. Prior to 1960, hexachlorobenzene (HCB) was used to treat seed grain. This prevented fungal infestation in seeds before they were planted. In the late 1950s, about 4,000 Turkish citizens became seriously ill when they mistakenly ingested HCB-treated seed grain for food grain. Toxic responses include skin blisters, hepatomegaly (enlarged liver), and thyroidomegaly (enlarged thyroid), as well as arthritis, osteomyelitis (inflammation within bones), and osteoporosis (loss of bone density) in the hands. Oral ingestion is the obvious route of absorption. Little is known about the toxicokinetics of HCB; however, like organochlorines (e.g., DDT), HCB persists in the environment, is biomagnified, and has a comparatively long biological T1/2 due to its slow rate of biotransformation.