Alkyl lead pollution and bird mortalities on the Mersey Estuary, UK, 1979–1981

Abstract

In autumn 1979 about 2400 birds of many species were found dead and sick on the Mersey Estuary, UK, which is an important wader and wildfowl wintering area. Smaller mortalities occurred in 1980 and 1981. Affected birds contained elevated lead levels, much of the lead being in the form of alkyl lead. Apparently healthy birds contained lower amounts of alkyl lead but still enough to cause some ill-effects. It was concluded that the birds had died of alkyl lead poisoning after eating prey contaminated with industrial effluent from petrochemical works. Further, it was likely that several thousand apparently healthy birds were also at risk.