1. Health outcomes in populations living close to landfill sites Lars Jarup, David Briggs, Cornelis de Hoogh, Christopher Hurt, Tina Kold Jensen, Sara Morris, Jon Wakefield and Paul Elliott The Small Area Health Statistics Unit (SAHSU), Department of Epidemiology and Public Health, Imperial College

2. Modelling exposures from landfill sites: Methods and issues Cornelis de Hoogh, David Briggs, Christopher Hurt, Lars Jarup and Paul Elliott The Small Area Health Statistics Unit (SAHSU), Department of Epidemiology and Public Health, Imperial College

3. Background Excess risk of adverse birth outcomes and certain cancers have been reported, primarily in the USA ( hazardous waste sites ) Low birthweight (Goldberg et al, 1995; Kharazzi et al, 1997; Berry and Bove, 1998) Stillbirth (Kharazzi et al, 1997) Congenital anomalies (Geschwind et al, 1992, Croen et al, 1997) Mallin, 1980 (bladder cancer) Goldberg et al, 1995 (several cancers including liver) Willams et al, 1998 (brain cancer)

4. Background Two recent European and UK studies EUROHAZCON (1998) neural tube, cardiac and vascular defects decrease in risk by distance, BUT several landfills in “reference area” not accounted for Nant-y-Gwyddon (2000) increased risk of malformations also before site opening

5. Aims Primary objectives: to test the hypotheses that living near a landfill site is associated with excess risk of congenital anomalies, stillbirth, low birthweight or very low birthweight Secondary objective: to test the hypothesis that living near a landfill site is associated with an excess risk of certain cancers

6. Industrial emissions Vehicle emissions Mineral dusts Solid waste Waste handling Atmospheric dispersion Animal/bird dispersion Drainage/ Leaching Runoff Gaseous emissions Aqueous emissions Soil contamination Dermal contact Ingestion Water pollution Inhalation Prior land use Excavation Waste disposal Capping/ restoratio n After- use Plant uptake Click for larger picture

7. Analyses Effects of socio-economic status and other explanatory variables urban-rural differences maternal age (for abdominal wall defects) Landfill sites classified as receiving ‘special’ (hazardous) or ‘non-special’ waste Periods before and after opening of landfill sites Poisson regression 99% confidence intervals

8. Study area “Exposed” population defined as living within 2 km from a landfill site 80% of the national population Likely limit of dispersion (WHO 2000) 1 - 2 km depending on pathway

9. Study period

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15. 19,196 landfill sites x 1.6 million postcodes x 16 years x 2 lag periods = 10 11 buffering operations!

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18. 31.533.235.2Excluded 24.432.443.1Unexposed 35.334.230.4Exposed Most deprived Intermediate Most affluent Exposure by socio-economic status

19. Results - congenital anomalies

21. Results - stillbirth and birth weights

23. Results – cancers

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25. Discussion The largest study to report on the possible association between residence near landfill and health outcomes Deprivation adjustment may incompletely account for individual-level characteristics associated with risk of congenital anomalies and cancers Need to take account of the complexity of the system, and data limitations, in using GIS for exposure assessment

26. 80% of population live within 2km of a landfill site No causal mechanisms currently available to explain our findings Alternative explanations possible data artefacts residual confounding Further understanding of the potential toxicity of landfill emissions and possible exposure pathways is needed in order to help interpret the epidemiological findings Conclusion

27. References Elliott P, Briggs D, Morris S, de Hoogh C, Kold Jensen T, Maitland I, Richardson S, Wakefield J, Jarup L. Risk of adverse birth outcomes in populations living near landfill sites. BMJ 2001;323:363-8. http://www.bmj.com/ http://www.doh.gov.uk/whatsnew/index.html