Incinerators Study

Project Background:

The use of incineration for waste disposal in the UK is increasing due to EU restrictions on the use of landfill. A number of new Municipal Waste Incinerators (MWIs) have been built and between 2003 and 2010 there were 22 operating in England, Scotland and Wales. The incineration process and emissions of modern MWIs are regulated by the Waste Incineration (England and Wales) Regulations 2002 which sets operational conditions, technical requirements, and emission limit values. However there is public concern over any possible health risks associated with modern incineration and this study has been commissioned to extend the evidence base and provide more information to the public on this subject.  

This study investigating potential associations between reproductive and infant health and emissions from municipal waste incinerators (MWIs) in England, Scotland and Wales was announced in January 2012 by the Health Protection Agency, whose functions have since been transferred to Public Health England.

 

Aims of the study:

The study has been commissioned to extend the evidence base and to provide further information to the public about any potential reproductive and infant health risks from MWIs.

The study proposes to investigate the following questions:

  1. Are the emissions from incinerators required to operate under the standards set by the EU Waste Incineration Directive (WID) (2000/76/EC) linked with adverse reproductive and infant health outcomes?
  2. Is living near a municipal waste incinerator linked with adverse reproductive and infant health outcomes?

Both of these questions will be considered with respect to implementation of the EU Waste Incineration Directive (WID) (2000/76/EC), which came into force in 28 December 2002 for new incinerators and 28 December 2005 for existing incinerators.

Associations will be investigated between adverse reproductive and infant health outcomes and daily modelled ground level concentrations of incinerator emissions from all 22 MWIs in England, Wales and Scotland, modelled using regulatory monitoring information from the English and Scottish Environment Agencies.  Linkage between HES maternity and ONS/NN4B birth records has been requested to provide birth records with gestation weeks for interpretation of some outcomes (e.g. birthweight) and to assign trimester-specific exposure estimates.  Statistical analyses will look at associations with modelled exposure estimates during pregnancy and distance from an incinerator, as well as rates of outcomes before and after an incinerator opened, adjusting for relevant confounders such as deprivation.  Regulatory monitoring information on incinerator emissions provided by the Environment Agency, Natural Resources Wales and Scottish Environment Protection Agency for each incinerator will be used to estimate ambient exposures to emissions from MWIs.  The atmospheric dispersion model ADMS-Urban will be used. 

Health Data:

This study will use health data from the Office for National Statistics, Hospital Episode Statistics database, National Community Child Health Database (NCCHD - Wales), Scottish Information Services Division and British Isles Network of Congenital Anomaly Registers.  The following health outcomes will be considered:

  • Preterm delivery
  • Birth weight
  • Small for gestational age
  • Sex-ratio at birth
  • Multiple births
  • Congenital anomalies
  • Stillbirths
  • Infant deaths

The analyses will provide information on the population exposures from UK incinerator emissions and explore whether there is any epidemiological evidence of an association between living near an incinerator and adverse reproductive and infant health outcomes. Daily particulate emissions from incinerators will be used to provide a modelled estimate of exposure during the entire pregnancy and for important periods during pregnancy, such as the first three months, which is when many body organs start to develop.  The modelled exposure estimates for the mothers babies with these outcomes will be compared to those of mothers whose babies did not have these outcomes from the national births register held by SAHSU. 

In an additional analysis, distance from an incinerator will be investigated for evidence of an association with these outcomes.  A third analysis will look at rates of outcomes before and after an incinerator opened or was modified to comply with the EU Waste Incineration Directive, in comparison with rates in similar areas.  Analyses will take into account the level of deprivation in the area where the mother lives, their ethnicity and other potential factors that may influence any observed association (or lack of association) between MWIs and the outcomes.

In addition to daily particulate emissions, incinerators are required to take periodic sampling (two to four times a year) of heavy metals and dioxin emissions. The potential to model these emissions will be investigated in conjunction with a separate validation study using national air pollution monitoring data to investigate whether the contribution of MWIs to air pollution exposures can be distinguished from other sources.  Also, a separately funded biomonitoring study will look at exposures of mothers living near incinerators and will analyse data from questionnaire and biological samples.  The validation and biomonitoring studies will help to inform interpretation of the main study findings. 

Methods have been informed by discussion with an independent scientific advisory group with epidemiological and statistical expertise in this area of work and, for incinerator emissions, by discussion Defra and input from the UK regulators.

Benefits to Public:

The study was commissioned to extend the evidence base and to provide further information to the public about any potential reproductive and infant health risks from MWIs and to extend the evidence base with respect to exposures and any potential reproductive and infant health risks from MWIs. Study information will be provided on the SAHSU website for the public. 

Publications:

Ghosh RE, Freni Sterrantino A, Douglas P, Parkes B, Fecht D, de Hoogh K, Fuller G, Gulliver J, Font A, Smith RB, Blangiardo M, Elliott P, Toledano MB, Hansell AL. Fetal growth, stillbirth, infant mortality and other birth outcomes near UK municipal waste incinerators; retrospective population based cohort and case-control study. Environment International. 2018. https://doi.org/10.1016/j.envint.2018.10.060

Douglas P, Freni-Sterrantino A, Leal Sanchez M, Ashworth DC, Ghosh RE, Fecht D, Font A, Blangiardo M, Gulliver J, Toledano MB, Elliott P, de Hoogh K, Fuller GW, Hansell AL .Estimating Particulate Exposure from Modern Municipal Waste Incinerators in Great Britain. Environ Sci Technol. 2017 Jul 5;51(13):7511-7519. http://pubs.acs.org/doi/abs/10.1021/acs.est.6b06478

Ghosh RE, Ashworth DC, Hansell AL, Garwood K, Elliott P, Toledano MB. Routinely collected English birth data sets: comparisons and recommendations for reproductive epidemiology. Arch Dis Child Fetal Neonatal Ed. 2016 Sep;101(5): F451-7. http://fn.bmj.com/content/101/5/F451.long

Font A, de Hoogh K, Leal-Sanchez M, Ashworth DC, Brown RJC,  Hansell AL, Fuller GW. Using Metal Ratios to Detect Emissions from Municipal Waste Incinerators in Ambient Air Pollution Data. Atmospheric Environment. July 2015. http://www.sciencedirect.com/science/article/pii/S1352231015300753

Ashworth DC, Fuller GW, Toledano MB, Font A, Elliott P, Hansell AL, de Hoogh K. Comparative assessment of particulate air pollution exposure from municipal solid waste incinerator emissions. Journal of Environmental and Public Health. 2013 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3725787/

Ashworth DC, Elliott P, Toledano MB. Waste incineration and adverse birth and neonatal outcomes: a systematic review. Environ Int. 2014 Aug;69:120-32 http://www.sciencedirect.com/science/article/pii/S0160412014001147

Funding:

The study is funded by Public Health England (PHE), the Scottish government, the MRC-PHE Centre for Environment and Health and the National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Health Impact of Environmental Hazards at King's College London and Imperial College London (HPRU-2012-10141) in partnership with Public Health England (PHE). The work of the UK Small Area Health Statistics Unit is funded by Public Health England as part of the MRC-PHE Centre for Environment and Health, funded also by the UK Medical Research Council (MR/L01341X/1). Danielle C Ashworth was funded by a MRC PhD studentship. PE is director of the MRC-PHE Centre for Environment and Health and acknowledges support from the NIHR Imperial Biomedical Research Centre. PE is associate director of Health Data Research UK-London. The funders had no role in study design, analyses, interpretation of the data, or decision to submit results.