SEGH Articles

Health in Impact Assessment: primer published

02 July 2017
The changes to the EIA directive as recast in April this year (2017) brings human health very firmly into consideration. Any project which is subject to EIA (Environmental Impact assessment) is required to evaluate the impact from the project on human and population health.

The changes to the EIA directive (  as recast in April this year (2017) brings  human health very firmly into consideration. Any project which is subject to EIA (Environmental Impact assessment) is required to evaluate the impact  from the project on human and population health.  Projects may range from major infrastructure projects, such as new railways and airport runways, waste incinerators, industrial scale agricultural activities, to applications for fracking, open cast mines, amongst others.


In order to move the consideration of human and population health central stage within the process of impact assessment, the Institute of Environmental Management and Assessment (IEMA) has worked with Ben Cave Associates, and the Faculty of Public Health, to produce a primer which is intended to spark discussion across all professionals. Impact assessment requires the input of many different specialists; it is hoped that all of them will become engaged in this debate.

Although Health Impact Assessment  (HIA) has been carried out successfully for many projects, evaluation of human and population health has sadly been missing from many projects. It is worth remembering that the impacts can be both positive and negative. Getting the balance right is imperative. Impacts may derive from release of contaminants during the construction phase, through to contamination of water, release of proposed use of chemicals of concern, or equally may be the health benefits of the construction of a new health care facility, with release of dust and noise during the construction phase, but with a longer term overall benefit. Likewise, the disruption and impact from construction of a railway may be negative, but a shift in mode of transport away from the car in developed nations brings about improved air quality, and in developing nations provides transport which may previously have been absent, improving quality of life, not least of which may be access to healthcare facilities, or the ability to transport perishable goods to market in a timely manner. It should not be assumed that a HIA will try to get in the way of development, but rather that it will look at appropriate outcomes.


Balancing the various impacts is context sensitive. The geology and geography of the land to be developed will vary.  For example, water availability, permeability of rocks, or fragility of habitats, will vary, depending upon the location of a project, as will a wide number of other considerations. Identifying these issues correctly and evaluating health impacts is imperative.

The directive also requires adherence to the principle of resource efficiency. A move away from mining for new materials for production, to a requirement for re-use of materials, helps to decrease the impact on many communities, as well as the land itself. The directive requires a move towards sustainability.

Health Impact Assessment takes into account not only the ‘hard’ environmental impacts, but also the less visible ones, such as social cohesion, engagement with hard to reach communities, loss of amenity as well as impact on employment.

The EIA directive does not explicitly ask for a full  HIA to be carried out. However, in order for meaningful evaluation of human and population health to be taken into account, engagement needs to be early, and cross sectoral, as well as competent. HIA can do this. The primer does not argue for full HIAs to be undertaken, simply that human and population health is evaluated in a timely and competent manner.

As an organisation which promotes consideration of health from many directions, the research which SEGH members undertake can often be influential in the decision –making which Impact Assessment needs to undertake. Personally, I have often quoted pieces of research which have been presented at SEGH conferences. Although HIA professionals work with a good evidence base, sometimes it is necessary to err on the side of caution. Extending our evidence base is imperative. One of the stated aims of SEGH is the sharing of knowledge. Using that knowledge wisely for the good of others is the outcome we should seek.

Although the  IEMA primer is intended to be used initially in the UK, the questions which we pose are legitimate in other countries too. (Like SEGH, IEMA is an international organisation.)  Early intervention and engagement can ensure best outcomes for all concerned, driving best practice, and improving the health outcomes of   wider communities.

 The pdf is free to download from IEMA.  ( Hard copies are available from IEMA, but the cost of these is £25.00.

Please feel free to use this within your various communities.

By Gillian Gibson, Gibson Consulting and Training

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  • Effects of steel slag and biochar amendments on CO 2 , CH 4 , and N 2 O flux, and rice productivity in a subtropical Chinese paddy field 2018-12-07


    Steel slag, a by-product of the steel industry, contains high amounts of active iron oxide and silica which can act as an oxidizing agent in agricultural soils. Biochar is a rich source of carbon, and the combined application of biochar and steel slag is assumed to have positive impacts on soil properties as well as plant growth, which are yet to be validated scientifically. We conducted a field experiment for two rice paddies (early and late paddy) to determine the individual and combined effects of steel slag and biochar amendments on CO2, CH4, and N2O emission, and rice productivity in a subtropical paddy field of China. The amendments did not significantly affect rice yield. It was observed that CO2 was the main greenhouse gas emitted from all treatments of both paddies. Steel slag decreased the cumulative CO2 flux in the late paddy. Biochar as well as steel slag + biochar treatment decreased the cumulative CO2 flux in the late paddy and for the complete year (early and late paddy), while steel slag + biochar treatment also decreased the cumulative CH4 flux in the early paddy. The biochar, and steel slag + biochar amendments decreased the global warming potential (GWP). Interestingly, the cumulative annual GWP was lower for the biochar (55,422 kg CO2-eq ha−1), and steel slag + biochar (53,965 kg CO2-eq ha−1) treatments than the control (68,962 kg CO2-eq ha−1). Total GWP per unit yield was lower for the combined application of steel slag + biochar (8951 kg CO2-eq Mg−1 yield) compared to the control (12,805 kg CO2-eq Mg−1 yield). This study suggested that the combined application of steel slag and biochar could be an effective long-term strategy to reduce greenhouse gases emission from paddies without any detrimental effect on the yield.