Organotin compounds in the marine environment-current monitoring techniques and their regulatory and environmental management requirements in England and Wales

Organotin compounds are the world's most widely used organometallic chemicals with annual production at approximately 50,000 tons. Pollution by organotins in the marine environment is generally associated with the historical use of tributyltin (TBT) and triphenyltin (TPhT) as antifoulants. Organotin compounds are ubiquitous within the coastal marine environment, with the highest concentration found within benthic sediments in regions of high boating activity and industry (ng g-1 to μg g-1 range). TBT and TPhT have strong affinities to particulate organic matter and demonstrate long-term persistence within the marine environment. Sediments are the major sink for TBT and TPhT, with rapid removal to the particulate matter phase from the water column generally preceding its degradation. Adsorption mechanisms are a dualistic function of hydrophobic interaction and electrostatic interaction. Despite the strong affinity to the solid-phase, adsorption is a reversible reaction, where desorption to the water column can readily occur. Due to its high toxicity, modern analytical techniques are required to be sensitive and selective enough to meet higher monitoring demands set by regulators, with gas chromatography and high performance liquid chromatography as the most commonly used techniques. UK management strategies for organotin compounds are incorporated within dredged material waste management. Work within this chapter aims to provide an overview of organotins within the marine environment, the monitoring and analytical methods used and the legislation governing dredging and the disposal of dredged material waste.