Hazard potential ranking of hazardous waste landfill sites and risk of congenital anomalies
- M Vrijheid1,
- H Dolk1,
- B Armstrong1,
- G Boschi2,
- A Busby1,
- T Jorgensen3,
- P Pointer4,
- and the EUROHAZCON Collaborative Group
- 1Environmental Epidemiology Unit, Department of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
- 2APS, Azienda Padova Sevizi, Spa, Padova, Italy
- 3COWI Consulting Engineers and Planners, Odense, Denmark
- 4Shanks & McEwan (Southern) Ltd, Milton Keynes, UK
- Correspondence to: Dr M Vrijheid, Unit of Radiation and Cancer, International Agency for Research on Cancer, 150 Cours Albert Thomas, 69372 Lyon Cedex 08, France;
- Accepted 10 April 2002
Background: A 33% increase in the risk of congenital anomalies has been found among residents near hazardous waste landfill sites in a European collaborative study (EUROHAZCON).
Aims: To develop and evaluate an expert panel scoring method of the hazard potential of EUROHAZCON landfill sites, and to investigate whether sites classified as posing a greater potential hazard are those with a greater risk of congenital anomaly among nearby residents relative to more distant residents.
Methods: A total of 1270 cases of congenital anomaly and 2308 non-malformed control births were selected in 14 study areas around 20 landfill sites. An expert panel of four landfill specialists scored each site in three categories—overall, water, and air hazard—based on readily available, documented data on site characteristics. Tertiles of the average ranking scores defined low, medium, and high hazard sites. Calculation of odds ratios was based on distance of residence from the sites, comparing a 0–3 km “proximate” with a 3–7 km “distant” zone.
Results: Agreement between experts measured by intraclass correlation coefficients was 0.50, 0.44, and 0.20 for overall, water, and air hazard before a consensus meeting and 0.60, 0.56, and 0.53 respectively after this meeting. There was no evidence for a trend of increasing odds ratios with increasing overall hazard or air hazard. For non-chromosomal anomalies, odds ratios by water hazard category showed an increasing trend of borderline statistical significance (p = 0.06) from 0.79 in the low hazard category, 1.43 in the medium, to 1.60 in the high water hazard category.
Conclusions: There is little evidence for a relation between risk of congenital anomaly in proximate relative to distant zones and hazard potential of landfill sites as classified by the expert panel, but without external validation of the hazard potential scoring method interpretation is difficult. Potential misclassification of sites may have reduced our ability to detect any true dose–response effect.
EUROHAZCON Collaborative Group: Lenore Abramsky, North Thames (West) Congenital Malformation Register; Fabrizio Bianchi, Tuscany EUROCAT Register; Ester Garne, Funen County EUROCAT Register; Vera Nelen, Antwerp EUROCAT Register; Elisabeth Robert, France Central East Congenital Malformation Register; John ES Scott, Northern Region Fetal Abnormality Survey; David Stone, Glasgow EUROCAT Register; Romano Tenconi, North-East Italy EUROCAT Register