Cost–benefit analysis of using sewage sludge as alternative fuel in a cement plant: a case study

  • Martí Nadal
  • Marta Schuhmacher
  • José L. DomingoEmail author


Background, aim, and scope

To enforce the implementation of the Kyoto Protocol targets, a number of governmental/international institutions have launched emission trade schemes as an approach to specify CO2 caps and to regulate the emission trade in recent years. These schemes have been basically applied for large industrial sectors, including energy producers and energy-intensive users. Among them, cement plants are included among the big greenhouse gas (GHG) emitters. The use of waste as secondary fuel in clinker kilns is currently an intensive practice worldwide. However, people living in the vicinity of cement plants, where alternative fuels are being used, are frequently concerned about the potential increase in health risks. In the present study, a cost–benefit analysis was applied after substituting classical fuel for sewage sludge as an alternative fuel in a clinker kiln in Catalonia, Spain.

Materials and methods

The economical benefits resulting in the reduction of CO2 emissions were compared with the changes in human health risks due to exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and carcinogenic metals (As, Cd, Co, and Cr) before and after using sewage sludge to generate 20% of the thermal energy needed for pyro-processing. The exposure to PCDD/Fs and metals through air inhalation, soil ingestion and dermal absorption was calculated according to the environmental levels in soil. The carcinogenic risks were assessed, and the associated cost for the population was estimated by considering the DG Environment’s recommended value for preventing a statistical fatality (VPF). In turn, the amount of CO2 emitted was calculated, and the economical saving, according to the market prices, was evaluated.


The use of sewage sludge as a substitute of conventional energy meant a probability cancer decrease of 4.60 for metals and a cancer risk increase of 0.04 for PCDD/Fs. Overall, a net reduction of 4.56 cancers for one million people can be estimated. The associated economical evaluation due to the decreasing cancer for 60,000 people, the current population living near the cement plant, would be of 0.56 million euros (US$ 0.83 million). In turn, a reduction of 144,000 tons of CO2 emitted between 2003 and 2006 was estimated. Considering a cost of 20 euros per ton of CO2, the global saving would be 2.88 million euros (US$ 4.26 million).


After the partial substitution of the fuel, the current environmental exposure to metals and PCDD/Fs would even mean a potential decrease of health risks for the individuals living in the vicinity of the cement plant. The total benefit of using sewage sludge as an alternative fuel was calculated in 3.44 million euros (US$ 5.09 million). Environmental economics is becoming an interesting research field to convert environmental benefits (i.e., reduction of health risks, emission of pollutants, etc.) into economical value.


The results show, that while the use of sewage sludge as secondary fuel is beneficial for the reduction in GHG emissions, no additional health risks for the population derived from PCDD/F and metal emissions are estimated.

Recommendations and perspectives

Cost–benefit analysis seems to be a suitable tool to estimate the environmental damage and benefit associated to industrial processes. Therefore, this should become a generalized practice, mainly for those more impacting sectors such as power industries. On the other hand, the extension of the study could vastly be enlarged by taking into account other potentially emitted GHGs, such as CH4 and N2O, as well as other carcinogenic and non-carcinogenic micropollutants.


Cancer effects Cement plant CO2 emissions Cost–benefit analysis Sewage sludge 



This study was financially supported by Uniland Cementera SA, Barcelona, Spain.


  1. Al-Khashman OA, Shawabkeh RA (2006) Metals distribution in soils around the cement factory in southern Jordan. Environ Pollut 140:387–394CrossRefGoogle Scholar
  2. Al-Neaimi Y, Gomes J, Lloyd OL (2001) Respiratory illnesses and ventilatory function among workers at a cement factory in a rapidly developing country. Occup Med 51:367–373CrossRefGoogle Scholar
  3. Begg KG (2002) Implementing the Kyoto protocol on climate change: environmental integrity, sinks and mechanisms. Glob Environ Change 12:331–336CrossRefGoogle Scholar
  4. Conesa JA, Gálvez A, Mateos F, Martín-Gullón I, Font R (2008) Organic and inorganic pollutants from cement kiln stack feeding alternative fuels. J Hazard Mat 158:585–592CrossRefGoogle Scholar
  5. Davidovits J (1994) Global warming impact on the cement and aggregates industries. World Resour Rev 6:263–278Google Scholar
  6. DEFRA (2004) Valuation of the external costs and benefits to health and environment of waste management options. Final report for Defra by Enviros Consulting Limited in association with EFTEC. Department for Environment, Food and Rural Affairs, London, UKGoogle Scholar
  7. Dolan P, Metcalfe R, Munro V, Christensen MC (2008) Valuing lives and life years: anomalies, implications, and an alternative. Health Econ Pol Law 3:277–300Google Scholar
  8. EC (2001) Recommended interim values for the value of preventing a fatality in DG Environment cost benefit analysis. European Commission. Available at: [accessed August 12 2008]
  9. EC (2003) Directive 2003/87/EC of the European Parliament and of the Council of 13 October 2003 establishing a scheme for greenhouse gas emission allowance trading within the Community and amending Council Directive 96/61/EC. Official Journal of the European Union, L 275/32Google Scholar
  10. Ferré-Huguet N, Nadal M, Mari M, Schuhmacher M, Borrajo MA, Domingo JL (2007) Monitoring metals near a hazardous waste incinerator. Temporal trend in soils and herbage. Bull Environ Contam Toxicol 79:130–134CrossRefGoogle Scholar
  11. Fuster G, Schuhmacher M, Domingo JL (2004) Cost–benefit analysis as a tool for decision making in environmental projects. Application to a reduction of dioxin emissions in Tarragona Province, Spain. Environ Sci Pollut Res 11:307–312CrossRefGoogle Scholar
  12. Galvez A, Conesa JA, Martin-Gullon I, Font R (2007) Interaction between pollutants produced in sewage sludge combustion and cement raw material. Chemosphere 69:387–394CrossRefGoogle Scholar
  13. Generalitat de Catalunya (2006) Proposta d’informe de valoració dels resultats de les proves mediambientals d’utilització de combustibles alternatius derivats de llots secs de depuradores d’aigües urbanes a forns de fabricació de clínquer. Direcció General de Qualitat Ambiental, Departament de Medi Ambient i Habitatge, Generalitat de Catalunya, Barcelona, Catalonia, Spain (in Catalan)Google Scholar
  14. Genon G, Brizio E (2008) Perspectives and limits for cement kilns as a destination for RDF. Waste Manage 28:2375–2385CrossRefGoogle Scholar
  15. Hof AF, den Elzen MGJ, van Vuuren DP (2008) Analysing the costs and benefits of climate policy: value judgements and scientific uncertainties. Glob Environ Change 18:412–424CrossRefGoogle Scholar
  16. Isikli B, Demir TA, Urer SM, Berber A, Akar T, Kalyoncu C (2003) Effects of chromium exposure from a cement factory. Environ Res 91:113–118CrossRefGoogle Scholar
  17. Isikli B, Demir TA, Akar T, Berber A, Urer SM, Kalyoncu C, Canbek M (2006) Cadmium exposure from the cement dust emissions: a field study in a rural residence. Chemosphere 63:1546–1552CrossRefGoogle Scholar
  18. Marengo E, Bobba M, Robotti E, Liparota MC (2006) Modeling of the polluting emissions from a cement production plant by partial least-squares, principal component regression, and artificial neural networks. Environ Sci Technol 40:272–280CrossRefGoogle Scholar
  19. Martí-Cid R, Bocio A, Llobet JM, Domingo JL (2008) Balancing health benefits and chemical risks associated to dietary habits: RIBEFOOD, a new Internet resource. Toxicology 244:242–248CrossRefGoogle Scholar
  20. Nas TF (1996) Cost–benefit analysis. Theory and application. SAGE, Thousand Oaks, CaliforniaGoogle Scholar
  21. Nouwen J, Cornelis C, De Fre R, Wevers M, Viaene P, Mensink C, Patyn J, Verschaeve L, Hooghe R, Maes A, Collier M, Schoeters G, Van Cleuvenbergen R, Geuzens P (2001) Health risk assessment of dioxin emissions from municipal waste incinerators: the Neerlandquarter (Wilrijk, Belgium). Chemosphere 43:909–923CrossRefGoogle Scholar
  22. Palmer K, Burtraw D, Shih JS (2007) The benefits and costs of reducing emissions from the electricity sector. J Environ Manage 83:115–130CrossRefGoogle Scholar
  23. Petersdorff C, Boermans T, Harnisch J (2006) Mitigation of CO2 emissions from the EU-15 building stock: beyond the EU Directive on the energy performance of buildings. Environ Sci Pollut Res 13:350–358CrossRefGoogle Scholar
  24. Reijnders L (2007) The cement industry as a scavenger in industrial ecology and the management of hazardous substances. J Ind Ecol 11:15–25CrossRefGoogle Scholar
  25. Schuhmacher M, Domingo JL, Garreta J (2004) Pollutants emitted by a cement plant: health risks for the population living in the neighborhood. Environ Res 95:198–206CrossRefGoogle Scholar
  26. Schuhmacher M, Nadal M, Domingo JL (submitted) Environmental monitoring of PCDD/Fs and metals in the vicinity of a cement plant after using sewage sludge as a secondary fuel. Chemosphere (unpublished data)Google Scholar
  27. Turner RK, Burgess D, Hadley D, Coombes E, Jackson N (2007) A cost–benefit appraisal of coastal managed realignment policy. Glob Environ Change 17:397–407CrossRefGoogle Scholar
  28. US EPA (2000) Draft exposure and human health reassessment of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. EPA/600/P-00/001. US Environmental Protection Agency, Washington, DCGoogle Scholar
  29. Viscusi WK, Aldy JE (2003) The value of a statistical life: a critical review of market estimates throughout the world. J Risk Uncertainty 27:5–76CrossRefGoogle Scholar
  30. Yang CY, Chang CC, Tsai SS, Chuang HY, Ho CK, Wu TN, Sung FC (2003) Preterm delivery among people living around Portland cement plants. Environ Res 92:64–68CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Martí Nadal
    • 1
  • Marta Schuhmacher
    • 2
  • José L. Domingo
    • 3
    Email author
  1. 1.Laboratory of Toxicology and Environmental Health‘Rovira i Virgili’ UniversityReusSpain
  2. 2.Environmental Engineering Laboratory, ETSEQ‘Rovira i Virgili’ UniversityTarragonaSpain
  3. 3.Laboratory of Toxicology and Environmental Health‘Rovira i Virgili’ UniversityReusSpain

Personalised recommendations