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Public Health Implications of Contaminated Land. GUIDELINES. Dr Josep Vidal-Alaball Specialist Registrar in Public Health Medicine Swansea. NPHS Staff Conference, October 2006. OVERVIEW. Guideline Objectives Target users covered by the Guideline Basic concepts Most common contaminants
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Public Health Implications of Contaminated Land GUIDELINES Dr Josep Vidal-Alaball Specialist Registrar in Public Health Medicine Swansea NPHS Staff Conference, October 2006
OVERVIEW • Guideline Objectives • Target users covered by the Guideline • Basic concepts • Most common contaminants • Precautions • Communication (risk communication) • How to manage a case of land contamination • Appendixes • Glossary and acronyms • References
Guideline Objectives • Describe natural levels, soil guideline values, toxicity, health effects and public health implications of the most current land contaminants found in Wales. • Provide guidance on how to communicate risk to the population affected by land contamination. • Inform population about basic precautions that can be taken to minimise risk posed by contamination. • Establish best practice for managing land contamination in Wales through direct collaboration between agencies involved in land contamination issues in Wales • To strength channels of communication between the agencies involved in land contamination in Wales.
Target users • Local Authorities • National Public Health Service for Wales • Local Health Boards • Chemical Hazards and Poisons Division (Health Protection Agency)
Basic concepts • Contaminated land defined as “Any land which appears to the local authority in whose authority it is situated to be in such a condition, by reason of substances in, or under land that significant harm is being caused or there is significant possibility of such harm being caused” (Part IIA of the Environment Protection Act (1990, Section 78(A)) • The EA estimates between 5,000 and 20,000 contaminated land sites in England and Wales (Wales, has a significant number of such sites)
Land contamination may impact on health or the environment • Contamination may effect people’s perceptions of their local environment and it may affect the use of land • Contamination may also affect people’s personal finances
Risks to humans posed by contaminants on land: • Increased levels of illness have not been observed in people living on contaminated land • However ill effects, which may be undetectable using current epidemiological and analytical methods, may occur • Impact from contaminated soil can be difficult to separate from other types of pollution • Possible health effects of the contaminants are difficult to establish because there are many confounding factors
Basic concepts Source-pathway-receptor model: • A contaminated parcel of land will only pose a risk to human health if there is a route of exposure between the site and a given population, in accordance with the source–pathway-receptor model
source (contaminated land) receptor (humans) Pathway: route needed by the chemical substances to enter the human body: inhalation of volatile compounds, ingestion of soil (particularly in children), consumption of contaminated food or water or direct dermal contact with polluted sources.
Basic concepts Soil Guideline Values (SGVs): • Published by the DEFRA and the EA • SGVs aimed to help deciding when land poses a “significant possibility of significant harm” (SPOSH) • Values above the SGV do not imply necessarily that the risk to human health is significant • The SGVs have been derived for long term exposure to contaminants in the soil. No guidelines for acute exposure
Most common contaminants • Uses and sources of pollution • Natural levels • Soil guideline values • Toxicity • Health effects • Biological sampling • Public Health Implications
CADMIUM • Cadmium can be found in cigarettes, fertilisers used in agriculture and in low levels in all foods (highest in shellfish, liver, and kidney meats) • Mean cadmium content in soil 1.2 mg/Kg. Median 0.9 mg/Kg (England and Wales)
TDSI: Tolerable daily soil intake • Breathing or eating air or food contaminated with cadmium over a long period of time can cause health effects including: • Renal dysfunction (characterised by proteinuria) • Growth disturbances • Lung disturbances (bronchitis, obstructive lung disease) • Skeletal damage (osteomalacia and osteoporosis – Itai-itai disease) • Reproductive disturbances • Anaemia
Tests are available to measure cadmium in blood, urine, hair, or nails
Precautions Contaminated gardens • E.g. Vegetables can be grown in raised beds with clean soil Special precautions with children • Children are especially vulnerable to contaminants, because of increased exposure when playing in the garden
Risk communication • Is an interactive process of exchange of information • People’s fears should be taken seriously • Contaminated land management requires more than technical expertise. Social issues such as house prices, house ownership or stigma of the neighbourhood are also important
Uncertainty is an important factor that complicates risk communication in contaminated land issues • Risk Comparisons. Often, an involuntary risk is compared with a voluntary one (e.g. the risk from nearby incinerator is compared with smoking or dietary habits). If such a comparison is done in the spirit of minimising the importance of the involuntary risk, it will generate anger.
Risks are generally more worrying if perceived: • To be involuntary • As inequitably distributed, some benefit while others suffer • As inescapable by taking personal precautions • To arise from an unfamiliar or novel source • To result from man-made, rather than natural sources • To cause hidden and irreversible damage with onset many years later • To pose particular danger to small children or pregnant women or more generally future generations • To threaten a form of death (or illness/injury) arousing particular dread • To damage identifiable rather than anonymous victims • To be poorly understood by science • As subject to contradictory statements from responsible sources (or even worse, from the same source), or from untrustworthy source. • Invisible or undetectable, catastrophic, memorable, uncertain, uncontrollable or unethical risk.
All apply to contaminated Land ! • Involuntary • Inequitably distributed • Inescapable • Arise from an unfamiliar or novel source • Result from man-made, rather than natural sources • Cause hidden and irreversible damage with onset many years later • To pose particular danger to small children or pregnant women • Threaten a form of death arousing particular dread: CANCER • Damage identifiable rather than anonymous • Poorly understood by science • As subject to contradictory statements from responsible sources • Invisible or undetectable, catastrophic, memorable, uncertain
Some problems…. • LHBs, HPA, NPHS: Very late engagement with unrealistic expectation to respond • Lack of consultation can result in • inaccurate health messages • raised expectation • unnecessary community concern
Some solutions …. Openness and transparency • Trust should be based on mutual respect • Communication should be open and honest • The language used should be understandable for the general public Engage early with LHBs, LAs, HPA!
How to manage a case Protocol under review (end November) Will cover: • Initial response • Key individuals and organisations • Communication strategy • Public Health implications/actions
Appendixes • Example of Press release: allotments contaminated with arsenic • Example of letter of information to residents (NEED TO BE ADAPTED TO LOCAL CIRCUMSTANCES) • Do’s & Don’ts for Residents • Questions & Answers at Notification of Results • Contact details for key individuals • Health Information leaflet for residents (separate document)
Glossary and acronyms References
Acknowledgements • Dr David Russell Chemical Hazards and Poisons Division, Cardiff • Mr Andrew Jones National Public Health Service for Wales, Bangor • Dr Sandra Payne National Public Health Service for Wales, Mold • Mr Peter Davies Chemical Hazards and Poisons Division, Cardiff
Dr Josep Vidal-Alaball Specialist Registrar in Public Health Medicine National Public Health Service Wales Mid and West Wales Region 36 Orchard Street Swansea SA1 5AQ Wales, U.K. Tel. + 44 (0) 1792 607411 Fax. + 44 (0) 1792 470743 Josep.Vidal-Alaball@nphs.wales.nhs.uk