Human health risks from petroleum contamination in soils are currently evaluated using a wide variety of approaches. This gives rise to inconsistencies and difficulties in determining whether or not a risk assessment is sufficiently protective of human health.

To address these issues, ensure compliance with new legislation (Part IIA of the 1990 Environmental Protection Act) and to target the cleaning-up of contaminated land at areas where it is most needed, a significant change to current practice is needed. A consultation paper from the Environment Agency introduces the need for change, summarises the approaches used internationally and proposes a way forward, outlining the key issues requiring input from consultees.

The Agency publication underlines that petroleum hydrocarbon contamination is complex. The type of crude oil, its distillation, processing and blending, and the subsequent processes that act on the material once it is released into the environment all result in the development of petroleum residues of extreme chemical complexity.

The Agency adds: “Yet sound, defensible and practical decisions are required on how to manage the risks to human health from exposure to petroleum hydrocarbons in soil.”

The Paper also says: “Other industrialised countries have been faced with the same problem. The modern, risk-based approaches that have been developed, largely as a result of exhaustive reviews and consultations, offer some direction as to the approach that should be adopted in the UK.

“Decisions need to be made about the handling of compounds that exhibit threshold and non-threshold toxicological effects, about the degree of sophistication that should be adopted in a UK approach and about issues of implementation, including the practical aspects of analysis and the costs for site and risk assessments.”

The Environment Agency will take into account consultation responses to finalise the framework setting out the approach to be followed.

Once the framework is published, detailed toxicological and “fate and behaviour” reviews will be prepared. The framework and review information will then be combined to derive Soil Guideline Values (contaminant concentrations in soil designed to protect human health) for petroleum hydrocarbons, exceedance of which will require further investigation or remediation.

The consultation document – Principles for Evaluating the Human Health Risks from Petroleum Hydrocarbons in Soils: A Consultation Paper – is available via the Agency – or from the MRC Institute for Environment and Health.

The consultation will remain open until 3 October 2003.

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