Health outcomes in populations living close to landfill sites

1
Health outcomes in populations living close to
landfill sites
The Small Area Health Statistics Unit (SAHSU),
Department of Epidemiology and Public Health,
Imperial College

• Lars Jarup, David Briggs,
• Cornelis de Hoogh, Christopher Hurt,
• Tina Kold Jensen, Sara Morris,
• Jon Wakefield and Paul Elliott

2
Modelling exposures from landfill sites Methods
and issues
The Small Area Health Statistics Unit (SAHSU),
Department of Epidemiology and Public Health,
Imperial College

• Cornelis de Hoogh, David Briggs, Christopher
  Hurt,
• Lars Jarup and Paul Elliott

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
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
10
(No Transcript)
11
Click for larger picture
12
(No Transcript)
13
Click for larger picture
14
(No Transcript)
15
19,196 landfill sites x 1.6 million postcodes x
16 years x 2 lag periods 1011 buffering
operations!
16
(No Transcript)
17
Click for larger picture
18
Exposure by socio-economic status
19
Results - congenital anomalies
20
Results - congenital anomalies
21
Results - stillbirth and birth weights
22
Results - stillbirth and birth weights
23
Results cancers
24
Click for larger picture
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
Conclusion

• 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

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
  2001323363-8.
• http//www.bmj.com/
• http//www.doh.gov.uk/whatsnew/index.html