Plant chromium toxicity on Summerford Bing, Falkirk, central Scotland

Summary Summerford Bing is an old industrial site near Falkirk which was contaminated from about1860–1970 by chemical and other works. The industrial wastes were redistributed in a spoil heap about 300 m × 300 m in area. Drainage water from the heap was known to have high concentrations of chromium. An attempt to establish birch on the spoil heap's slopes has been partially successful but many of the trees were very stunted. Soil analyses showed that hexavalent chromium toxicity was the most likely cause of the poor birch growth and this was confirmed by an experiment on birch seedlings. Acute plant chromium toxicity is a rare phenomenon in Britain where it is always associated with anthropogenic soils. The possibility of the site's toxicity to humans is discussed and it is concluded that the site is potentially hazardous to health.