埃文河和弗罗姆河中的多氯联苯（PCBs）。

Bull Environ Contam Toxicol. 1975 Dec;14(6):687-91. doi: 10.1007/BF01685243.

On June 19, 1973 very high levels of Aroclor 1254 were determined in the River Avon and Frome. The source might have been cleaning of systems in factories which use them. The levels decreased with time. In fish from the River Avon three types of Aroclors were determined.

1973年6月19日，在埃文河和弗罗姆河中检测到了极高含量的多氯联苯混合物1254。其来源可能是使用这些物质的工厂对系统进行的清理。含量随时间下降。在埃文河的鱼类中检测到了三种多氯联苯混合物。