§ Lord Colwynasked Her Majesty's Government:
Whether they can estimate the average mercury pollution levels in city and rural areas in the United Kingdom; and what are the likely sources of this contamination. [HL668]
§ Lord WhittyThe following table shows estimated UK emissions of mercury between 1990–99. Data since 1970 on emissions of air pollutants, including mercury, are published annually in theNational Atmospheric Emissions Inventory (NAEI), a copy of which can be found at the NAEI website at www.aeat.co.uk/netcen/airqual/index.html.
concentrations of gaseous mercury over the six-month monitoring period were in the region of 2–3 ng/m3. Significantly higher concentrations, around 24 ng/m3, were measured at the ICI Chemical and Polymers plc plant. However human inhalation of atmospheric mercury is considered to be insignificant compared to exposure from the ingestion of fish products. This is because mercury in its toxic methylated form, which is thought not to be present in air in significant quantities, tends to bioaccumulate in predatory fish and shellfish. The Food Standards Agency regularly monitors dietary exposures of UK consumers to mercury and has found exposures to be well within World Health Organisation limits. Further information may be found on the Food Standards Agency website at www.foodstandards.gov.uk.
Although measurements of atmospheric mercury have been limited by measurement technology, techniques have improved, and the Department for Environment, Food and Rural Affairs is reviewing its 67WA monitoring programmes with a view to increasing their scope in future. As part of this review, DEFRA recently commissioned a report into what is known about mercury, including the best estimates of UK air concentrations. This report, Sources, Sinks and Levels of Atmospheric Mercury in the UK (Lee et al, 2000), can be found on the National Air Quality Archive website at www.aeat.co.uk/netcen/airqual/reports/dera_hg/dera_hgl.pdf.
A monitoring programme to measure mercury levels in urban and rural areas is scheduled to begin in 2002 and will include sites in London (two sites), Glasgow, Leeds and Eskdalemuir.