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Executive summary
Background
Controlled landfill is the most common system of disposal in the UK for both domestic and industrial waste, with
about 85% of national waste deposited in this way. Two recent studies found a significant association between
congenital malformations and residence near to a landfill site, the Nant-Y-Gwyddon study (Fielder et al 1997) and the Eurohazcon Study (Dolk et al 1998). A workshop was held at the Institute
for Environment and Health on January 26 1999, on behalf of the Department of Health and the Department of Environment,
Transport and the Regions, to discuss potential health effects of landfill sites, focusing in particular on reproductive
toxicity and congenital malformations.
The three main objectives of the workshop were :
- to discuss findings from recently completed research and to identify gaps in
the knowledge-base
- to agree further research requirements to fill these gaps
- to prioritise future research activities
Presentations
To provide a background for the workshop, four short presentations described
- the design and operations of a typical UK landfill site
- the Eurohazcon Study which investigated the risk of congenital anomalies associated
with residence near hazardous waste landfill sites in Europe
- the Environment Agency Waste Research Programme which includes development of
the methodology for assessing risks to human health from landfill and other waste management sites
- the Small Area Health Statistics Unit study investigating the association between
residence near landfill sites in the UK and a range of health endpoints, including congenital malformations and
certain cancers
Identifying the knowledge gaps
Health effects
The workshop participants decided that the main knowledge gaps were in the following areas:
- the geographical distributions of congenital malformations including whether
there is heterogeneity on the distributions and whether they differ for the different types of malformation
- the known causes for the congenital malformations of concern, in particular those
relating to the environment
- identification of specific potential pollutants from landfill sites which may
be of most concern in relation to congenital malformations and other adverse health effects
- the workshop decided that, of the other potential health endpoints in relation
to potential exposures from landfill sites, none were necessarily of higher priority than reproductive endpoints,
although carcinogenicity should also be kept under review
Exposure
Potential gaps in the knowledge on exposure included
- whether there was variation between landfill sites in the likely pollutants present
- clarification of the main routes of exposure for residents near landsites, including
pathway identification, and the role of atmospheric conditions and topography.
- the typical personal exposures and doses experienced by both those who work on
landfill sites and the resident population around them
- the relative importance of landfill sites as sources as compared with other potential
sources
- the use of distance from a site as a marker of true exposure, and the role of
exposure modelling
Priorities for future work in filling the knowledge gaps
A number of recommendations for future work were made. A study of congenital malformations and other health endpoints
such as low birth weight and the incidence of certain cancers in people living near landfill sites in England,
Scotland and Wales is already planned (the SAHSU study). The other recommendations are given below, together with
the priorities thought to be appropriate by the workshop participants.
High Priority
- Review of (i) potential teratogenicity of substances emanating from landfill
sites (ii) known causes of congenital malformations from both animal and human studies
- A programme of monitoring (fixed and/or personal) exposures
- A study of the geographical variation in the overall rates of congenital malformations
and the rates of specific malformations
- Investigation of the feasibility of inhalation studies of the toxicology of landfill
gases
Medium Priority
- Case-control studies of congenital malformations occurring in the vicinity of
landfill sites (dependant on the outcome of the SAHSU study
- Further study of workers at landfill sites to investigate whether infections
are related to pathogens emanating from landfill sites
Low Priority
- Investigation of the association of the geographic characteristics of soil contaminants
with the distribution of congenital malformations
May 1999
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