UK soil becoming cleaner
Toxins and contaminant levels have fallen by about 70% in UK soil and grass, according to a new study conducted by the Environment Agency.
The reduction in the last twenty years can probably be most attributed to restrictions on emissions from major industries, the study indicates.
Geosystems Science Manager at the Environment Agency Dr Barraclough said the survey results would help inform future Government policy on contaminant sources and how they are controlled and regulated.
“Soil is often taken for granted – out of sight, out of mind. It is all too easy to forget that it grows our food, stores and filters much of our water and air, and provides a platform for buildings and roads. But globally, soils are under increasing pressure from rising populations, the intensification of agriculture and contamination,” Dr Barraclough said.
“Managing the risks to humans and the wider environment posed by soil contamination involves first deciding what level of contamination poses an unacceptable risk, and second, monitoring soil to make sure that such levels are not reached.
“[This survey] is a significant contribution to the second of these requirements, providing a snapshot of current contaminant levels on a national scale.”
Soil and vegetation from 122 rural, 28 urban and 50 industrial sites were tested for concentrations of dioxins, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and a range of metals across the UK, and determined the concentrations of 12 metals and arsenic, 22 PAHs, 26 PCBs and 17 dioxins.
The survey also found urban and industrial areas are still sources of PCBs, with concentrations about double those in rural areas. Although PCB production was banned in many countries in the 1970s and their use closely regulated, PCBs are still a major environmental problem worldwide.
They can cause serious environmental damage because they are toxic, don’t easily break down and can accumulate in the tissues of fish, birds and mammals.
“Dioxin concentrations in soils from urban and industrial locations are still two to three times those in rural areas. This is because dioxins are persistent in soil and act as a historical marker, reflecting emissions from industrial sites over the last 10-30 years.”