Radiometric dating of environmental records in natural archives

Abstract

Environmental records recovered from natural archives including lake sediments, salt marshes and inland waters and dated by natural (210Pb) and artificial (137Cs) fallout radionuclides were used to support management decisions on a range of different environmental issues. These included determining the level and source of pollution by airborne contaminants (persistent organic compounds and heavy metals such as lead or mercury) in Western USA, restoration of salt marshes along the USA Atlantic coast, and the use of antifoulant paints in UK inland waters. Outcomes from this research included evidence of the long term and widespread occurrence of the pesticide Endosulfan, used in hearings that lead to it being added in 2011 to the United Nations’ list of persistent organic pollutants to be eliminated worldwide. Natural inundation was shown to be the most cost-effective way of eliminating mosquito ditches in the Fire Island National Seashore and restoring the hydrology and ecological functions of the salt marshes. Evidence of the long-term damaging effect of TBT based antifouling paints in the Norfolk Broads contributed to the decision by the Broads Authority to initiate an ongoing campaign to promote the use of environmentally friendly antifoulants on all boats in the Broads system and minimise their use where possible.